Electronics V41 N09 19680429 ·
ec ron1cs
Eliminating ground-loop errors: page 58 Fast, precise a-d converters: page 69 Air isolation for IC diode arrays: page 75
April 29 , 1968 $1.00 A McGraw-Hill Publication
Below: In-flight checkout is made automatic, page 81
NEW "MS" LINE OF
TOROIDAL INDUCTORS
ACTUAL SIZE
· ULTRAMINIATURE (Less than 114" high)
·HIGH Q
· PRECISION ADJUSTED WITH EXCELLENT TEMPERATURE CHARACTERISTICS
DESIGNED & SUCCESSFULLY TESTED TO COMPLETE MIL-T-278 ENVIRONMENTAL REQUIREMENTS
UTC MS UNITS
50.---..~~r--..~-r-~-r~~
401---+----l--bofl=-~~-+---I 30t---+~~r-...L-t-~-+---·
Q 20 t---t--..,.~--+----if----'11
10-----~~+---+~-+-~-+~~
01 2 5 10 20 50 100
FREQUENCY KHZ
Stack lnd.Mhy ma DC DCRO Type Na. (0 DC) Max.· Max.
MS-1
1 60
1.4
MS-5
5 28
7
MS-10 10 20 11
MS-25 25 13 38
MS-50 50
9 75
MS-100 100 6 132
* The maDC shown is for approximately 5% drop in inductan ce.
The new "MS" toroidal high Q coils provide
unique packaging flexibility: only .23" high x .35" diameter (conforms to T0-5 base and terminal di-
mensions) with solderable and weldable leads which make them ideal for hybrid Flat Pack and IC appli-
cations. These units have excellent Q in the 10 kHz to 50 kHz range and are designed for usage from 1 kHz to 100 kHz (see curve).
They are precision adjusted ± 2% at O.lV RMS
at 1 kHz. Inductance variation is less than 2%
+ from - 55° to 105° C. MIL type TF5RX20ZZ.
Stock items shown are avai Iable for immediate delivery. Special values will be designed to your requ irem ents.
Write for brochure for complete data
Circle 900 on reader service card
Our project engineer calls it a "microwave multimeter." Our marketing people call it a "universal microwave test set:' Our catalog calls it the HP 8410A Network Analyzer. You'll call it the answer to your measurement problems. Here's why-
First, "it" measures all these microwave parameters: gain / attenuation and phase shift, i.e., complete transmission coefficients; magnitude and angle of reflection coefficient with polar or Smith Chart plots of impedance / admittance. With "it," you can characterize active and passive components or systems at single or swept frequencies.
Second, "it" features all these advantages: broad frequency coverage from 110 MHz to 12.4 GHz; more than 60 dB dynamic range with less than ten milliwatts drive signal ; swept frequency operation over octave bands with automatic tuning ; high accuracy and resolution; unparalleled ease of operation.
"It" is actually a modular system: a signal-processing mainframe with choice of two readout plug-ins; a wideband RF
converter unit; a full-range transmission test unit; and two reflection test units for 0.11 to 12.4 GHz coverage.
Whatever you measure with " it," you can do the job more accurately, more completely, in less time , with less work and fewer pieces of equipment at lower cost than ever before. "It" is a designer's dream.
Th e modules for transmission measurements, 0.11 to 12.4 GHz, cost $6450. Add the capability for polar and Smith Chart displays of reflection characteristics, 0.11 to 12.4 GHz, for $3985.
Ask your HP field engineer how the 8410A "microwave multimeter, universal test set, network analyzer" can answer your problems. Or write Hewlett-Packard, Palo Alto, Calif. 94304; Europe: 54 Route des Acacias, Geneva.
i:I HEWLETT PACKARD
MICROWAVE NETWORK ANALYZERS
04804
Circle 1 on reader service card
Walco Electric bought downtime insurance by switching to Westinghouse semiconductors.
With service expert attached.
Walco Electric, Providence, R. I., made a startling improvement in the downtime savings they could promise customers. They switched to Westinghouse rectifiers and thyristors for increased reliability.
The application service expert who recommended this improvement was a Westinghouse Area Manager. As an applications specialist, his job is to help solve your toughest circuit problems find ways to upgrade your product's performance, get around cost corners.
For instance, the Area Manager working with Walco's Chief Engineer helped eliminate costly downtime problems- by selecting the most reliable solid state components for Walco's line of wire preheaters, continuous annealers, constant tension winders, rolling mill devices, extruder drives and custom power supplies.
Switch to Westinghouse for this brand of service and semiconductor dependability. Big user or not, you 'll get the same intensive action from a Westinghouse Area Manager. Call your local Westinghouse Sales Office or write Westinghouse, Semiconductor Division, Youngwood,Pa.15697.
SC -2112
Electronics Volume 41, Number 9
April 29, 1968
News Features
Probing the News
93 Signal gains for electronic music 101 Second-source IC's on firm footing
Electronics Review
37 Industrial electronics: lmpatt diodes in police radars
38 Computers: New GE computer man; Competition from MOS
39 Consumer electronics: Mini-microwave ovens
39 Advanced technology: New vidicon; Long-distance holography
40 Medical electronics: Preventing "crib death"
41 Government: FAA buying policy 44 Avionics: CAT detector 46 Space electronics: Luneberg lens 48 For the Record
Electronics Abroad
145 Japan: Sony's color tv tube has three cathodes; Nippon Electric readies high-gain IC i-f amplifier
147 West Germany: More automation for Germany's railroads; Everything's fine at the Hanover Fair
148 Great Britain: Instrument spots defects in steel tubing
New Products
109 IC's poaching on op amp preserves 115 Components review 115 Semiflexible cable turns the corner 119 Instruments review 119 Oscillator serves many functions 120 Place on panels sought for meters 123 Microwave review 123 Tiny tee in attenuator increases
range 127 Subassemblies review 127 Three-wire design speeds up memory 131 Semiconductors review 131 FET reaches into gigahertz range 132 Optics aid pulse amplifier
Title R registered U.S. Patent Office; © copyright l968 by McGraw-Hill Inc. All rights reserved, including the right to reproduce the contents of this publication, in whole or in part.
-+-Circle 2 on reader service card
Technical Articles
I. Design
Design theory 58 Protecting data from the ground up Differential data amplifiers eliminate error voltages created by circulating ground currents Robert I. Demrow, Analog Devices Inc.
Circuit design 64
Designer's casebook · FET's resistance change trips heater
control · SCR helps video signal gate a-c
power line · P-i-n diodes turn on microwave bands
faster
Industrial 69 electronics
Triple play speeds a-d conversion Three-ramp integration scheme makes conversions 85 times faster than dualramp circuits
H. Bent Aasnaes and Thomas J. Harrison
International Business Machines Corp.
Integrated 75 electronics
II. Application
Isolation problems get an airing New air-isolation technique for integrated circuits is set for largescale production Hal Clausen and Roger B. Rusert Fairchild Semiconductor Corp.
Avionics 81
Testing on the wing Automatic airborne checkout systems are needed to monitor performance of new aircraft in flight Alfred Rosenblatt Avionics and space editor
Departments
4 Readers Comment 8 People 14 Meetings 23 Editorial Comment 25 Electronics Newsletter
51 Washington Newsletter 134 New Books 136 Technical Abstracts 138 New Literature 143 Newsletter from Abroad
3
Electronics
Editor-in-Chief: Donald Christiansen
Associate managing editors
Technical: Stephen E. Scrupski News: Robert Henkel Copy: Sally Powell
Senior associate editors Joseph Mittleman, Harry R. Karp
Department editors
Avionics & Space: Alfred Rosenblatt Computers: Wallace B. Riley Communications: William Bucci Consumer electronics: John D. Drummond Design theory: Joseph Mittleman Industrial electronics: Harry R. Karp Instrumentation: Carl Moskowitz Military electronics: Richard Gundlach Solid state: Mark B. Leeds
Section editors Electronics abroad: Arthur Erikson Electronics review: Stanley Zarowin New Products: H. Thomas Maguire,
William P. O'Brien Probing the news: Eric Aiken
Assistant editors Stephen Wm . Fields, Peter Schuyten, James Kirby, Owen Doyle
Rjlgional bureaus
Domestic
Boston: James Brinton, manager Los Angeles: Lawrence Curran, manager; Burton Bell New York: Howard Wolff, manager San Francisco: Walter Barney, manager; Peter Vogel Washington: Robert Skole, man age r; Paul Dickson
Foreign Bonn: John Gosch London: Michael Payne Tokyo: Charles Cohen
Copy editors James Chang, Frederick Corey, Larry Miller
Graphic design Art director: Saul Sussman Assistant art directors: Ann Mella, Valerie Betz Production editor: Arthur C. Miller
Editorial secretaries: Claire Benell , Lynn Em ery, Kay Fontana, Patricia Gardner, Lorraine l.ongo, Barbara Razulis, Frances Vacca
McGraw-Hill News Service Director: Arthur L. Moore; Atlanta: Fran Ridgway; Chicago: Bruce Cross; Cleveland: Arthur Zimmerman; Dallas: Marvin Reid; Detroit: James Wargo; Houston: Robert E. Lee; Los Angeles: Michael Murphy Pittsburgh: Louis Gomolak San Francisco: William F. Arnold Seattle: Ray Bloomberg; Washington: Charles Gardner, Daniel B. Moskowitz, Herbert W. Chesh ire, Seth Payne, Warren Burkett, William Small, William D. Hickman
McGraw-Hill World News Service Bonn: Robert Dorang; Brussels: George Williamson; Hong Kong: Wes Perry; London: John Shinn; Mexico City: Gerald Parkinson; Milan: Ronald Taggiasco, Jack Star; Moscow: Howard Rausch; Paris: Robert E. Farrell, Peter Kilborn; Rio de Janeiro: Leslie Warren; Tokyo: Marvin Petal
Reprints: Susan Nugent
Circulation: Milton Drake
Publisher: Gordon Jones
Electronics: April 29, 1968, Vol. 41, No. 9
Publi shed every other Monday by McGraw-Hill, Inc. Founder: James H. McGraw 1860-1948. Printed at 99 North Broadway. Albany. N.Y. 12207: second class postage paid at Albany, N.Y .
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Title ® re gistered in U.S. Patent Office; © Copyright 1968 by McGraw-Hill, Inc. All r ights reserved. Th e contents of this publication may not be reproduced either in whole or in part without the consent of copyright owner.
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4
Readers Comment
Hardening isn't easy
To the Editor: In our article "Skipping the hard
part of radiation" [March 4, p. 122] it was intended that the information we presented be restricted initially to the task of selecting the most likely candidates for electronic components that would eventually be used in designing a hardened circuit. Although the technique described can be applied to predictions of circuit behavior, such predictions should by no means be considered as other than preliminary.
We make this point because we do not wish engineers to be misled into believing that we have set dm'lll the only requisite for hardening electronics in nuclear radiations.
Joseph T. Finnell Fred W. Karpowich Avco Corp. Wilmington, Mass.
Receiver reinvented
To the Editor: It looks as though my f-m re-
ceiver, using the wide band principle and a counter discriminator ["Mobile f-m broadcast receiver design," May, 1954, p. 130], is being reinvented. However, I hold U.S. Patent 3,018,371 on it.
During the 14 years since the article, my f-m receiver has reappeared, both here and abroad, in a number of guises and in papers that add nothing to my original work. For example, an article by Richard Sanguini [Electronics, May 16, 1966] corresponds to figure 5 of my article.
The most recent reinvention was described in February of this year in a paper delivered by L.L. Kossakowski of ITT Europe at the International Solid State Circuits Conference in Philadelphia. It is no more than what I indicated in figure 6 of my article.
The title I suggested, over a decade ago, was "A new f-m receiver free from multipath distortion." I still believe that title describes my work more accurately
Electronics J April 29, 1968
New Bridge Design For Safe, Accurate, Easy Measurement of 'Lytic Capacitors
10) ·
·
-1, - I
"
ff
The Sprague Model 1W7 Capacitance Bridge introduces new, improved technical refinements as well as restyling for added attractiveness and ease of operation. Built by capacitor engineers for capacitor users, it incorporates the best features of bridges used for many years in Sprague laboratories and production facilities.
Precision Measurements over Entire Range from 0 to 120,000 µf The capacitance range of the 1W7 Bridge can be extended to l.2F with an external standard capacitor. The internal generator is a line-driven frequency converter, and detection is obtained from an internal tuned transistor amplifier/null detector, whose sensitivity increases as the balance point is approached. It has provision for 2-terminal, 3-terminal, and 4terminal capacitance measurements, which are essential for accurate meas-
urement ... ±([l +DJ% + IOpF)
... of medium, low, and high capacitance values, respectively.
No Damage to Capacitors The model 1W7 Capacitance Bridge will not cause degradation or failure in electrolytic or low-voltage ceramic capacitors during test, as is the case in many conventional bridges and test circuits. The 120 Hz a-c voltage, applied to capacitors under test from a built-in source, never exceeds 0.5 volt! It is usually unnecessary to apply d-c polarizing voltage to electrolytic capacitors because of this safe, low voltage.
Complete Specifications Available For complete technical data on this precision instrument, write for Engineering Bulletin 90,011 to Technical Literature Service, Sprague Electric
Co., 35 Marshall St., North Adams, Mass. 01247.
4IO·IUI
r.ircle 510 on reader service card
New from S uel
S Times the Resistance of a Conventional Metal-film Resistor
of Equal Size!
Wattage
Maximum
Type Rating Size Resistance
Extended-Range
Filmistor Resistor
1/10
.09S" D. .2SO" L.
1.S MO
Conventional
Metal-Film 1/10 Resistor
.09S" D. .2SO" L.
EXTENDED-RANGE FILMISTOR®
METAL-FILM RESISTORS
Substantial saving of space in all watta.ge ratings -
1/20, 1/10, 1/8, 1/4 1/2, and 1 watt-with
absolutely NO SACRIFICE IN STABILITY!
Extended-Range Filmistor Resistors now offer, in addition to accuracy ... stability ... reliability ... resistance values in size reductions which were previously unobtainable. Size and weight advantages of Filmistor Resistors now make them ideal for applications in high-impedance circuits, field-effect transistor circuits, etc. Many designs which previously had to settle for the higher temperature coefficients of carbon-film resistors in order to obtain required resistance values can now utilize the low and controlled temperature coefficients of Filmistor Metal-Film Resistors.
Other key features are ± 1% standard resistance tolerance, low inherent noise level, negligible voltage coefficient of resistance, and tough molded case for protection against mechanical damage and humidity.
For complete technical data, write for Engineering Bulletin 7025D to Technical Literature Service, Sprague Electric Co., 35 Marshall Street, North Adams, Massachusetts 01247.
SPRAGUE COMPONENTS
RESISTORS CAPACITORS TRANSISTORS INTEGRATED CIRCUITS THIN·FILM MICROCIRCUITS INTERFERENCE FILTERS
41Jll· UH
PACKAGED COMPONENT ASSEMBLIES FUNCTIONAL DIGITAL CIRCUITS MAGNETIC COMPONENTS PULSE TRANSFORMERS CERAMIC· BASE PRINTED NETWORKS PULSE·FORMING NETWORKS
SPRAGUE "
THE MARK OF RELIABILITY
'Spr11u1' 1nd ·@·'" realstered tr1dem1rk1 of the Spr11u1 Eltctr\c Co .
Circle 511 on reader service card 5
First counters to operate automatically across the VHF gap.
Until now you couldn't make simple, automatic frequency measurements from 100 to 300 MHz without a special VHF plug-in. The extra plug-in was clumsy in the lab. And when switching plug-ins was impossible-as in automatic console systems-the VHF gap was unavoidable. Now two self-contained Systron-Donner counters span the VHF gap, operating automatically from DC to the microwave region.
Non-stop DC to 12.4 GHz. The VHF
gap is filled by a built-in prescaler in this new Thin Line counter. The instrument operates just like a simple frequency counter across the board from DC to 12.4 GHz.You merely connect the signal and read the final answer on the display. Built with IC's to take only J-3/ 4"of rack space and operable by remote control. it is the ideal instrument for automatic systems.
...two more reasons to check with
Systron-Donner before you buy.
Non-stop DC to 3 GHz. New ACTO®
plug-in with built-in prescaler carries this counter across theVHF gap to3 GHz with fully -automatic operation. The new broadband plug-in can be replaced by others to raise the frequency range to 40 GHz, to measure very noisy signals, to measure
FM and pulsed RF. to read time interval. etc. This is the best available wide-range laboratory counter
-the root of a system that can accomplish nearly everything possible with counter instrumentation.
..... ~---··
Send for Catalog.
Circle 6 on reader service card
SVSTRDN
DONNER
888 Galindo Street, Concord, California 94520.
than the title under which the article appeared.
Kerim Onder, M.A. Fellow, IEE Senior member, IEEE New York City
The price isn't right
To the Editor: The news item [March 4, p. 26]
concerning a Post Office Department bid invitation for a new facer-canceler to replace PitneyBowes units now in use incorrectly quoted the unit price as $24,000.
The last order for 107 machines was negotiated at $16,500 each, delivered and installed.
F.S. Wardwell Pitney-Bowes Inc. Stamford Conn.
· Electronics erred.
Revving up
To the Editor: In the article, "Motor gives re-
verse twist to the Intelsat 3 antenna," [April 1, p. 71] the authors say that they have conducted a survey of different motors for this task and have concluded "brushless d-c motors have a higher reliability, but they would need a complex, low-efficiency analog driving circuit to achieve the required beam pointing accuracy."
This seems to indicate that their survey was not complete. This quote would apply to an electronically commutated motor, but not to a scheme which uses inductive elements for the commutation. At Philco-Ford SRS division a despin drive has been developed which uses a brushless d-c motor. This unit is lighter, consumes less power, and the electronic control
unit is much less complex than the digital drive described in the article. Furthermore, the brushless d-c motor does not have the starting anomalies associated with a synchronous motor driven in a stepping mode.
Stephen H. Marx Supervisor, Equipment Design Philco-Ford Corp. Palo Alto Calif.
The authors reply:
We were aware, in our survey, of Philco's work on its d-c motor. However, we felt the stepper motor we selected satisfied our requirements better.
The d-c motor always operates at the peak point on the torquespeed curve. Any load change is then reflected as a speed change which the motor loop must correct for. In Sylvania's digital system, speed remains constant with load change but the antenna steps in phase to correct for the load disturbance.
Power consumption could be less for the d-c motor than for the stepper. But circuit drift with the d-c design becomes more of a problem. And while the Philco motor does not have the same starting anomalies as the stepper, it has another set of design considerations. It must operate first in a speed conh·ol mode, then switch over to a position mode. The complexity of the controlling circuitry could be comparable to Sylvania's starting circuitry.
Francis E. Donnelly Jr. Reynold P. Graunas John D. Killian
Sylvania Electric Systems Waltham Mass.
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~ _ _ _ _ s~e- _ _ z!_c~ __J
I Electronics April 29, 1968
r - - - - - - - , I Application For
I
lfET
I
t----------1 ;sw1TCBES ~
I I PROBLEM: Use one flat pack to switch
I two ± 10 V signals ... and drive with
s v logic.
I
110UT
I e,OUT I
I
REQUIRED: Two switching channels completely contained in one package ... Delay less than 1 µS , .. Inverting logic (logic low - switch OFF) ... -55°C to + 125°C operation.
GIVEN l.e;n±lOV. 2. DTL logic - output swing is 5 V. 3. Available power supplies:
+5 v, +10 v, -20 v.
I
I
I
I
DCilllf
I
I
I SOLUTION: Siliconix DG 11 lF - Both I channels complete in one package, I ...MOS FET switch and bipolar driver
no other parts needed. Connect
II DTL output to driver input, ground "R", Vee to+ 10, P and VEE to -20,
apply e;n to source and drain is output.
1Tight packaging your hang up? Contact us for applications assistance or
I write for our free FET Switch and Driver Data Packet.
III H Siliconix incorporated
.... _______ .... I I 7140 W. Evelyn Ave. · Sunnyvale, CA 94086 Phono 1408) 245-1000 · TWX: 910 -339 -9216
Circle 7 on reader service card 7
People
Heinemann time-delay
relays lead a double life.
Most time-delay relays give you a pause for your money. And that's it. Our hydraulic-magnetic time-delay relays go a good bit further. They can double as their own load relays.
This is possible because the relays have continuous-duty coils. They can remain energized indefinitely after actuation. If you can get by with a contact capacity of. up to 5 amps (125vac, resistive) you can have a simpler, less expensive product to put on the market.
There are some other advantages worth noting. Non-thermal actuation, for one. It avoids the problem of heat-loading effect
when you have frequent recycling. It also minimizes ambient temperature complications. Recycling time is shorter, too; it can be as brief as 15% of the specified delay period.
We offer a diversity of models, ranging from open frame to hermetically sealed, for AC or DC operation. Switching can be either SPOT or DPDT. Delays: 0.25 to 120 seconds.
Our Bulletin 5006 will give you full data. Drop us a line and we'll put a copy in the mail. Heinemann Electric Company, 2600 Brunswick Pike, Trenton, N.J. 08602.
<4018 <$> HEiNEMANN
8
Circle 8 on reader service card
Until a few years ago, ships were
designed piecemeal; space for the
electronics equipment was near the
bottom of a long
list of priorities.
The Navy is
changing that;
projects under
consideration
now undergo
the same kind of
systems ap-
proach as space
Roderick
projects.
It's hardly surprising, then, that
Litton Industries Inc. turned to a
man with spacecraft experience
when it needed a new president for
its Advanced Marine Technology
division. It chose Robert L. Rod-
erick, 43, who has been manager of
Hughes Aircraft Co.'s Surveyor
project.
The division that Roderick heads
works closely with another Litton
division, Ingalls Shipbuilding,
which is constructing a new yard in
Mississippi. "Our function," ex-
plains Roderick, "is to get marine
contracts, perform the systems en-
gineering, and then turn the design
over to Ingalls."
Whole package. Roderick has his
hands full with new business. Lit-
ton won the contract-definition
phase for the Navy's fast-deploy-
ment logistics ship, only to see the
program cut from the fiscal 1968
defense budget. The fiscal 1969 re-
quest, however, contains $186 mil-
lion for four of the ships.
Litton was also one of three win-
ners in the contract-definition phase
for the Navy's landing helicopter
assault ship, and it's competing for
a development and production con-
tract. And the Advanced Marine
Technology division will submit by
April 30 its bid for the contract-
definition phase for the Navy's new
destroyer, designated nx.
Roderick, noting the broad trans-
fer of his systems management ex-
perience from Surveyor to his new
job, says, "This is valuable, especi-
ally in the DX competition, because
of it high electronics content. There
are 250 tons of electronic hardware
in the DX."
The list includes sonars, air-de-
fense missiles, tracking and search
Electronics I April 29, 1968
ML· 8785
<GD> MAOf llf U. S.A.
New Machlett tetrode ... for single tub.e design at high power levels
Vapor-cooled ML-8785 (or ML-8786, water-cooled) is particularly suitable for these applications:
High Power Communications
Class C Telegraphy ..· to 350kW
Linear RF Power Amplification
Class AB-Suppressed Carrier Service to260 kW PEP
Pulse Modulation or Amplification
40 kV
DC Plate Voltage
50 kv
Peak Plate Voltage
500 a
Pulse Cathode Current
1000 µ.S
Pulse Duration
.01
Duty
Pulse Power to 15 Mw
Write today for details on these versatile "single-tube-design" tetrodes. The Machlett Laboratories, Inc., 1063 Hope Street, Stamford, Co.nn. 06907.
Electronics I April 29, 1968
THE MACHLETT LABORATORIES, INC.
A SUBSIDIARY OF RAYTHEON COMPANY
Circle 9 on reader service card 9
Your custom
pulse transformer
is a standard
DST* transformer
Some of the case styles in which Sprague DST Pulse Transformers are available. Note the in-line leads.
You can select the transformer design you need from the new Sprague DST Family, a fully-characterized series of Designer Specified Transformers which Sprague Electric has pioneered. It's easy. Start with the two basic parameters dictated by your circuit requirements: primary (magnetizing) inductance and volt-second capacity.
New Sprague engineering data gives basic information from which all nominal sine wave parameters are derived. This data allows you to specify the one transformer from thousands of possibilities which will optimize performance in your application.
Design Style A minimizes magnetizing inductance change as a
function of temperature. Typically it's < ± 10% change from 0 to 60 C; < -+- 30% from -55 to +85 c.
Design Style 8 anJ C give you broad bandpass characteristics, and
still keep magnetizing inductance change < ± 15% from 0 to 60 C.
Design Style D is fast. Associated leakage inductance and coupling capacitance are kept at a minimum. This style is just what you need for interstage and coupling devices in computer drive circuits.
The Sprague DST Series packs a lot of transformer into minimum volume packages - epoxy dipped for minimum cost, or pre-molded. The JOO mil in-line lead spacing is compatible with integrated circuit mounting dimensions on printed wiring boards.
To solve your pulse transfonner design, start now. Write for Engi· neering Bulletin 40,350 to the Technical Literature Service, Sprague Electric Company, 35 Marshall St., North Adams, Mass. 01247.
·Trademark
SPRAGUE COMPONENTS
PULSE TRANSFORMERS CAPACITORS TRANSISTORS RESISTORS THIN·FILM MICROCIRCUITS INTEGRATED CIRCUITS
INTERFERENCE FILTERS PACKAGED COMPONENT ASSEMBLIES FUNCTIONAL DIGITAL CIRCUITS MAGNETIC COMPONENTS CERAMIC-BASE PRINTED NETWORKS
PULSE·FORMIN~ N~TWORKS
SPRAGUE®
THE MARK OF RELIABILITY
Spr11ut' ·nd ·@· lrt re1lsttttd tr1d1m1rks of th1 Spr11u1 Electric Co.
10 Circle 10 on reader service card
People
radars, and antisubmarine missiles. "These are all developed items,"
Roderick explains, "and our job is to pull them all together in the most effective way. We will design the command-and-control system."
Roderick says the Navy is sold on the systems approach, "and I think someone from the aerospace industry is likely to come up with a more imaginative approach than a marine designer, because the idea of going about it as a whole package-engineering and economicsis so new to the marine business."
Motorola thinks its European semi-
conductor operations have grown
up enough to get along without
dire ct super-
v is i o n by the
parent company.
"We're ready to
cut the cord,"
says C. Lester
Hogan, vice
president an d
general manager of the Semicon-
Scalise
ductor Products division.
Hogan is turning over direction
of all European production and
marketing to George M. Scalise, 33,
who'll work out of Geneva at first.
Backing this move to give Euro-
pean operations mo.re autonomy
will be a 60,000-square-foot plant in
Toulouse, France, to be dedicated
May I.
Start-up in June. Scalise says the
plant will start assembling silicon
transistors and integrated circuits
in June. He expects full production
- from diffusion to final testing-in
12 to 18 months.
"Our customers will be mainly
in the computer and consumer busi-
ness, and we'll be making the same
kind of packages made in Phoenix,
including plastics," he says.
Toulouse was chosen as the pro-
duction site because the University
of Toulouse is there and the city
is the third largest in France, so it
offers a good labor pool.
Scalise, who'll report to Hogan, 0
has held several posts as sociated
with IC production since joining
Motorola in 1962. He was manager
of manufacturing support opera-
tions in Phoenix.
Circle 11 on reader service card +
For the short haul, why tie up capital in test instruments?
It Makes More Sense to Rent What You Need from Electro Rents.
Say you've got a "one shot" test or a peak load problem. We can supply whatever test equipment you need - in calibration, ready to plug in - and deliver inside of 24 hours. No red tape, no maintenance problems, no project holdups, no capital expense. No wonder engineers all over the country cite Electro Rents as their one reliable source for the electronic test equipment
they need now but not for keeps.
Make sense to you? Make a note to call, write or wire for our brochure.
LOS ANGELES (Main Office and Laboratories) 4131 Vanowen Place, Burbank, Calif. 91504 ·Phone: (213) 843-3131
Other locations in San Francisco, San Diego, Phoenix and Dallas.
EJi~tro Rents
One naine keeps cropping up
as a source for integrated circ~its
regardless of the type you are ordering.
12
Electronics I April 29, 1968
Your purchasing agent can tell you who.
MOTOROLA SEMICONDUCTOR PRODUCTS INC.
Electronics \ April 29, 1968
13
Meetings
We'll ship them immediatelytoroids and oscillators* right out of stock-at far below competitive prices.
At Allen Electronics Division, we manufacture these, and other components, in quantity for the world's finest electronic organs. So we constantly maintain a complete stock of high quality frequency sources, and over 150 sizes of toroids. We'll send you the few you need to start your idea; the many you'll need to produce it.
All Allen components are made under the most rigid quality controls, including thorough inspection and testing, at one of the most modern and efficient plants in the country.
Send for complete information on the "Prontotypes". Then, when you have an application that requires quality components immediately, at no-penalty prices, you'll know where to get them. Pronto.
Quantum talks will focus on theory
There'll be a shift in emphasis at this year's International Quantum Electronics Conference in Miami, May 14 to 17. Attention will focus more on the theoretical areas, such as nonlinear optics, although there
will still be a number of papers on lasers. The change stems from the establishment, last year, of a Conference on Laser Applications and Engineering.
In one session, two research teams working independently will report on methods for calculating with reasonable accuracy nonlinearities in crystals. Their work should aid in the search for materials that interact better with
light. One of the papers, by Sudhanshu S. Jha and Nicolaas Bloembergen, both of Harvard Univer-
sity's engineering and applied physics deparhnent, will discuss quantitative results from the standpoint of Miller's indexes of crystallog-
raphy. The other paper, by J. Ducuing and C. Flytzanis of the Institute d'Optique in Orsay, France,
will deal with the magnitude of different nonlinearities, presenting experimental data for both har-
monic generation and frequency mixing.
Light tuning. Five engineers from the Bell Telephone Laboratories, R. G. Smith, Joseph E. Geusic, Hyman J. Levinstein, Shobha Singh, and Le Grand Van Uitert, will contribute a paper on their work with continuously .pumped optical parametric oscillators, work that makes it possible to tune coherent light through the visible spectrum down through the infrared [Electronics, April 15, p. 52].
Another paper on lasers covers work by F. E. Goodwin and T. A. Nussmeier, engineers from Hughes Aircraft Co. Their report will describe the development of a carbon dioxide laser system that beams a tv signal 18 miles [Elech·onics, April 15, p. 54].
Ali Javan, a physics professor at the Massachusetts Institute of Technology, will discuss phaselocking lasers to lower frequency sources to stabilize absolute frequency measurements in the far infrared.
For more information write R.W. Terhune, Ford Motor Co. Research Laboratories, Dear· born, Mich. 48121
L.; ' "(.
.. ~. ,(',.;.;:~:~·-..
.tlltMtYPEt OSL H~t""""'" <'
- ..... 9.
ma.L~l
·1 \U '"IJ ...._,
l.
Type C Oscillator Range: 15 Hz to 10 kHz
Use: Designed for applications having
moderate requirements for stability
in respect to temperature and frequency drift.
Toroids Over 150 sizes available from stock include Permalloy, Ferrite and Powdered iron types. Some no-center-tap. Inductance tolerance ±2%.
"Allow several extra days for packaging.
ALLEN electronics division
,,AUtUcg~~~~v ~:~~·n~~~ia. 18062
14 Circle 14 on reader service card
Calendar
Symposium and Equipment Show, American Vacuum Society; Grand Hotel, Anaheim, Calif., May 1-3.
Human Factors in Electronics Symposium, IEEE; Marriott Twin Bridges Motor Hotel, Washington, May 6-7.
Aerospace Electronics Conference, IEEE; Sheraton-Dayton Hotel, Dayton, Ohio, May 6-8.
National Conference on Aerospace Meteorology, American Institute of Aeronautics and Astronautics; New Orleans, May 6-9.
Technical Conference and Exhibit, American Society for Quality Control; Sheraton Hotel, Philadelphia, May 6-8.
Appliance Technical Conference, IEEE; Columbus-Plaza Sheraton Hotel, Columbus, Ohio, May 7-8.
International Technical Communications Conference, Society of Technical Writers and Publishers; International Hotel, International Airport, Los Angeles, May 8-11.
Electronic Components Conference, IEEE and Electronic Industries Association; Marriott Twin Bridges Motor Hotel, Washington, May 8-10.
Electronic Components Technical Conference, IEEE; Everglades Hotel, Marriott Twin Bridges Motor Hotel, Washington, May 8·10.
International Quantum Electronics Conference, IEEE and American Institute of Physics; Everglades .Hotel, Miami, Fla., May 14-17.
Industry and Communications Power System and Air Conditioning Joint Technical Conference, IEEE; St. Louis Gateway Hotel, St. Louis, Mo., May 7-10.
Pattern Recognition: the Retina and the Machine; University of Manitoba, Winnipeg, Canada, May 15-17.
(Continued on p. 16)
Electronics I April 29, 1968
A periodical periodical designed, quite frankly, to further the sales of Microdot connectors and cables. Published entirely in the interests of profit.
A~Jk~o/M
J.hr{lolfitutt (',()flf.lltf/l.dd Jott M fJJf)t
Un/JfYll.altiM, OM.
Our cage door was rattled last week by a ~arassed engineer type who was sproutmg cables and connectors and holding a la~ge sampler that was sloppily stitched with
LOVE FOR SALE
We quoted him section 404.5 of the penal
TAKE TWO - LOVE FOR SALE - SIDE ONE
"Where was I. Oh, I was saying
MICRODOT IS IN
paper work alone would drive your comptroller grayish. With us it's one P.O. One big savings. We've cut costs on cable assemblies not the performance just the cost. How's that?"
THE CABLE ASSEMBLY BUSINESS
AND AT CUT RATE PRICES. code just to be on the safe side, and
invited him in.
END OF TAPE
He said he was from the cable assembly department. And we said whose? And he said Microdot's. And we said Hmmm. And he said there's a Jot of people that don't think of Microdot as a cable assembly house and he'd like to do something about it like write an ad.
So we said fine, what would it be about and he brought out a fat stack of papers and said here, and we said forget it, but if you could tell it to us like it is in about twenty seconds we'd tape it. So he did. And we were so impressed, we thought we'd play it back to you. It's darned interesting. Ready? (And remember, he's not a professional and he talks fast but we think the points came across.) '
The idea is we can assemble cables for a lot less than people who try to do it themselves because we know what we're doing.
There are no set-up charges. And we'll even make up one assembly. And .we can really save people a lot of money if they use Ollr connectors.
"A nother thing, people not only save money, b!lt they can be sure their assemblies will be right. We figure why should they take a chance on their learning curve and bllild, say thirty assemblies, and have ten maybe turn out not so hot? Our way you order thirty, you get thirty that work'.'
"You're running out of time'.' "Okay. Real quick. Hey out th ere. Why
"Okay;' we said, "but you didn't explain the Love !or Sale bi!. It was a sneaky way to get us mterested m your pitch'.'
"Oh, it truly is love for sale. We love our work'.'
A guy with dedicated humor that crumby can't be all bad. We told him ~e'd see what we could do about spreadmg the word. So, to test if anyone is interested in low cost cable assemblies we're running this microminiaturizetl RFQ. The whole idea seems to be worthy. If you agree, write in. We'll respond immediately.
TAKE ONE - LOVE FOR SALE - SIDE ONE
buy connectors one place, cable another,
and assembly in a third? The cost in MICRODOT INC.
"Not enough people have thought of
I Mbuiscirnoedso.~.t
as being in the cable But we are, because
assembly we make
I cables and connectors. We're also very
-------------
MICROMIN RFQ FOR FAST FAST ACTION. To Microdot Inc., 220 Pasadena Ave., So. Pasadena, Calif. 91030
experienced in cable assemblies. "And we'll assemble all sorts of funny
I I
Dear Pricecutters:
combinations. Our cables, somebody I Please accept this abbreviated
I el~e's connectors. ~ome of our connectors
form as a gauntlet flang at you as a challenge, challenging your
I with someone else s. Mix and match'.'
low. low assembly price claim.
I We turned off the recorder. "You mean
I we'll assemble competitive stuff?"
D Job to quote on, attached.
Company_ _ _ _ _ _ _ __ _ _ _ __ _ _ __ Title_ _ _ _ _ _ _ _ _ _ _ Phon e_ _ _ _ _ __ Address _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ __
"Sure:' "Does the Pres know?"
I D We have something in mind. I You should get in tou ch.
City·-------------------
·"Smur~e'.·'
L----------~~---------~~-------
Electronics I April 29, 1968
Circle 15 on reader service card
15
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16 Circle 16 on reader service card
Meetings
(Continued from p. 14)
Meeting of the Society of Automotive Engineers Committee on Electro· magnetic Compatibility; Stardust Hotel, Las Vegas, May 15-17.
Pulp and Paper Industry Technical Conference, IEEE; Pfister Hotel, Milwaukee, May 15·17.
Symposium of the Association for Computing Machinery, National Bureau of Standards; Gaithersburg, Md. May 16.
Pollution Control Symposium, Analysis Instrumentation Division of t he Instrument Society of America; Marriott Motor Hotel, Philadelphia, May 19·22.
Region 6 Conference, IEEE; Sheraton Motor Inn, Portland, Ore., May 20·22.
International Microwave Symposium, IEEE; Howard Johnson Motor Lodge, Detroit, May 20·22.
Short Courses
Selected applications of computers in engineering, University of Michigan, Ann Arbor, May 20·31; $350 fee.
Medical engineering, George Washington University's School of Engineering and Applied Science, Washington, June 3·7; $250 fee .
Structure of programing languages, Cornell University, Ithaca, N.Y., June 4·8; $150 fee.
Call for papers
International Antennas and Propaga· tion Symposium, IEEE; Northeastern University, Boston, Sept. 9-11. June 21 is deadline for submission of abstracts to Leon J. Ricardi, MIT, Lincoln Laboratory, P.O. Box 73, Lexington, Mass. 02173
U.S. National Committee Fall Meeting, International Scientific Radio Union; Northeastern University, Boston, Sept. 10-12. June 1 is deadline for submission of abstracts to Leon J. Ricardi, MIT, Lincoln Laboratory, P.O. Box 73, Lexington, Mass. 02173
Applied Superconductivity Conference and Exhibition, Oak Ridge National Laboratory; IEEE and the Ameri<;an Physical Society; Gatlinburg, Tenn., Oct. 28-30. Aug. 5 is deadline for submission of abstracts to W.F. Gauster, Oak Ridge National Laboratory, Building 9201-2, P.O. Box Y, Oak Ridge, Tenn. 37830
Electronics I April 29, 1968
We have impedance measuring down to a SYSTEM
Automatic impedance-measuring systems are here I Start
with a GR automatic capacitance bridge or an automatic
Impedance comparator and you're on your way to making
measurements in half a second or less at 0.1 %accuracy or
better.
Add a scanner to connect components automatically. Add a printer to give you a permanent record of output data. Add a recorder to plot curves for you. Add a component handler to feed and to sort components automatically.
Add an on-line computer to perform calculations, to direct the measurement process, or even to type a report.
Scan, measure, compare, sort, compute, record - systems perform these functions faster, more accurately, and more economically. Choose from standard system components, or let us custom-design a system for you .
GENERAL RADIO
For complete information, write General Radio Company, W. Concord, Massachusetts 01781; telephone (617) 369-4400. In Europe, write Postfach 124, CH8034 Zurich 34, Switzerland .
Circle 17 on reader service card
Thanks to our Delco distributors. They stand ready to deliver power fast. From 32 offices all over
the country, with one near you. Each distributor is hand-picked for his organization, experience and ability to provide quality service. So he can give you what you need in power semiconductors: silicon or germanium power transistors; silicon power rectifiers and diodes. Anything in the Delco line. If you're still in the design stage, he's got up-to-date specs, prices and applications information. And sample quantities * when you need them. Just give him a call. He'll show you why the Kokomoans are in power.
* From 1 to 4,999 pieces.
fr.Ml fl~~~2Rf!!!f!10
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MARK OF [XCELLEN CE
Kokomoans' Regional Headquarters
Union, New Jersey* 07083 Syracuse, New York 13203
Box 1018 Chestnut Station 1054 J ames Street
(201) 687-3770
(315) 472-2668
Chic ago , Illinois* 60656
5151 N. Harlem Avenue (312) 775-5411
Sa nta Monica, Calif.* 90401 726 Santa Monica Blvd. (213) 870-8807
Detroit, Michigan 48202 57 Harper Avenue (313) 873-6560
Kokomo, In d. 46901 700 E. Firmin (317) 459-2175 Home Office
·omcc includes field lab and resident engineer for application assistan ce.
18
Electronics I April 29, 1968
IN THE EAST
BALTIMORE, MD. 21201 Radio Electric Service Co. 5 North Howard Street (301 )-539-3835
BINGHAMTON, N.Y. 13902 Federal Electronics, Inc. P. 0. Box 1208 (607) -748-8211
CLIFTON, N.J. 07015 Eastern Radio Corporation 312 Clifton Avenue (201)-471-6600
NEWTON, MASS. 02195 The Greene Shaw Co., Inc. 341-347 Watertown St. (617 )- 969-8900
NEW YORK, NEW YORK 10036 Harvey Radio Co., Inc. 2 West 45th St. (2 12)-582-2590
PHILADELPHIA, PENN. 19123 Almo Industrial Electronics, Inc. 412 North 6th Street (215)-922-5918
PITTSBURGH, PENN. 15206 Radio Parts Company, Inc. 6401 Penn Ave. (412)-361 -4600
WOODBURY, L. I., N.Y. 11797 Harvey Radio Company, Inc. 60 Crossways Park West (5 16) -921-8700
IN THE SOUTH
BIRMINGHAM , ALA. 35233 Forbes Distributing Company, Inc. 1416 Fourth Ave., South (205)-251-4104
MIAM I, FLORIDA 33142 Mountain Electronics Division of Mountain National Co. 3730 Northwest 36th St. (305 )- 634-4556
RICHMOND, VA. 23220 Meridian Electronics, Inc. 1001 West Broad Street (703 )-353 -6648
WEST PALM BEACH, FLA. 33402 Mountain Electronics Divisi on of Mountain National Co. 1000 N. Dixie Highway (305) -833 -5701
IN THE MIDWEST
CINCINNATI, OHIO 45237 United Radio, Inc. 7713 Reinhold Drive (513 ) -761-4030
CLEVELAND, OHIO 44125 The W. M. Pattison Supply Co. Industria l Electronics Division 4550 Willow Parkway (216) -441-3000
INDIANAPOLIS, IND. 46225 Graham Electronics Supply, Inc. 122 South Senate Avenue (317 )- 634 -8486
KALAMAZOO, MICH. 49005 Electronic Supply Corp. P. 0. Box 831 (616)-381 -4626
KANSAS CITY, MO. 64111 Walters Radio Supply, Inc. 3635 Main Street (8 16) -531-7015
MINNEAPOLIS, MINNESOTA 55401 Stark Electronics Supply Co. 112 3rd Ave., North (612)-332-1325
SKOKIE, ILL. 60076 Merquip Electronics, Inc. 7701 N. Austin Ave. (312 )- 282 -5400
ST. LOUIS, MO. 63144 Electronic Components for Industry Co. 2605 South Hanley Road (314 ) -647-5505
IN THE WEST
ALBUQUERQUE, N. M. 87103 Sterling Electronics, Inc. 1712 Lomas Blvd., N. E. (505) -247-2486
DALLAS, TEXAS 75201 Adleta Electronics Com pany 1907 McKinney Ave. (214)-742-8257
DENVER, COLO. 80219 L. B. Walker Radio Company 300 Bryant Street (303 ) -935-2406
HOUSTON, TEXAS 77001 Harrison Eq uipment Co., Inc. 1422 San Jacinto Street (713)- 224-9131
LOS ANGELES, CAL. 90015 Radio Products Sales, Inc. 1501 South Hill Street (213 )- 748 -1271
LOS ANGELES, CAL. 90022 Kieru lff Electronics, Inc. 2585 Commerce Way (213 ) -685-5511
OKLAHOMA CITY, OKLAHOMA 73102 Radio. Inc. 903 North Hudson (405)-235-1551
PALO ALTO, CAL. 94303 Kieru lff Electronics, Inc. 3969 East Bayshore Road (415 )- 968-6292
PHOENIX, ARIZ. 85005 Sterling Electronics, Inc. 1930 North 22nd Ave. (602)- 258-4531
SAN DIEGO, CAL. 92101 Mi lo of Californi a, Inc. 2060 India Street, Box 2710 (7 14)-232-8951
SEATTLE, WASH. 98108 Kieru lff Electroni cs, Inc. 5940 6th Ave., South (206)-763-1550
TACOMA, WASH. 98402 C & GElectronics Company 2502 Jefferson Ave. (206)-272-3 181
TULSA, OKLAHOMA 74119 Radio, Inc. 1000 South Main Street (918) -587-9124
IN CANADA
SCARBOROUGH, ONTARIO Lake Engineering Co., Ltd. 123 Manvi ll e Rd. (416)-75 1- 5980
Electronics I April 29, 1968
Circle 19 on reader service card 19
Announce the Completion of an
INTERNATIONAL TECHNOLOGICAL AND COMMERCIAL SURVEY ON INTEGRATED CIRCUITS (Microelectronics)
Purpose of the Survey
This survey is intended to provide expert advice on a number of important decisions facing managements, which are more difficult to make than the judgements required about five years ago on changing from electronic tubes to transistors. The latter only involved replacing one active component by another, whereas the use of microelectronics, of whatever type, means replacing entire elementary circuits with " circuit blocks ".
Proposal
Terms and Conditions
At this critical stage of development, reliable up-to-date information and assessments are required, on a whole series of questions, for the right technical and commercial decisions to be made by the managements, chief engineers and circuit designers of the large number of industries involved, including : Computers, Calculators, Telecommunications, Electrical Power Control, Scientific and Industrial Measuring and Testing Instruments, Industrial Controls, Remote Signals and Control, Television, Radio, Dictating Machines, Signal Equipment, Nuclear Measurement and Controls, etc.
International Technical Surveys, Inc. (l.T.S.), Geneva, an independent international organization specializing in carrying out multi-client surveys on advanced techniques,hasorganized this study for their clients. Past surveys, at early stages in their development, have dealt with (a) Fuel Cells, (b) Thermoelectricity, (c) Magnetohydrodynamic Power Conversion, (d) Thermionic Power Conversion, (e) Semiconductors, etc...
As with previous surveys, the final report will be available only to subscribers. It will not be published, and obtainable only by clients agreeing to the conditions contained in the acceptance form.
Scope of the Survey
The scope of the survey, carried out by a team of international experts, will provide up-to-date information, assessments and guidance on the following questions:
1) Microelectronics or integrated electron ics?
11 e) Connectors.
2) Why integrated electronics?
11 f) Displays.
3) Linear vs digital circuits ; is there a place for both ?
12) The applications of integrated electronics.
4) Hybrids vs monolithics ; advantages and drawbacks.
12a) Counting, pulsing and memory circuits.
4a) Thick-film circuits.
12b) Logic.
4b) Thin -film circuits.
12c) Linear circuits.
4c) Components for thin- and thick-film circuits.
13) Integrated electronics in computers.
4d) Monolithics.
14) Integrated electronics and power circuits.
5) Digital integrated circuits : RTL, DTL, E2CL or TTL ?
15) Integrated electronics in communications and tele -
6) Design and manufacturing problems using inte-
metry.
grated electronics.
16) Integrated electronics and consumer products.
7) Is " make or buy " the real alternative?
17) Integrated electronics in industrial control.
8) Large -scale integration : when, what and by whom?
18) Other applications of integrated electronics.
9) The economics of integrated electronics.
19) The testing of integrated electronics.
10) The reliability of integrated electronics.
20) Price developments of integrated electronics.
11) The impact of integrated electronics on discrete components markets.
20a) Examples of integrated circuits. 20b) The price/cost confusion.
11 a) Discrete semiconductors.
20c) What quantity discounts to expect?
11 b) Resistors and capacitors.
21) Market data and forecasts.
11 c) Potentiometers, switches, selectors.
22) The top world suppliers of integrated electronics.
11 d) Relays.
23} Conclusions and recommendations.
---------------------------------------------------------------
INTERNATIONAL TECHNOLOGICAL AND COMMERCIAL
SURVEY ON INTEGRATED CIRCUITS (Microelectronics)
For acceptance or more information, please fill in coupon, clip and mail without delay.
It is understood that:
a) the final report is of a private nature for use within subscribers' own organization or associated companies,
b) the final report will not be disseminated publicly,
c) the final report will be made available by l.T.S. only to subscribers accepting the above conditions.
D We agree to subscribe to the above survey for a total fee of US $400.- (or equivalent in local currency) payable on delivery
of the final report.
D We w ish to receive more information on the survey.
(cross the D that applies) .
INTERNATIONAL TECHNICAL SURVEYS INC.
Tel. 253373 - Cables : ltsintech Telex : 22643 (Delval) 8, rue de la Madeleine Geneva (Switzerland)
NAM E: COMPANY : ADDRESS :
DATE : SIGNED: _ __
20 Circle 20 on reader service card
Circle 21 on reader service card +
Look what AMP just did to
edge connector
costs:
Newly designed contacts and housings. Plus automation. Lowest per-line cost we've ever offered on an edge connector.
We modified the proven fork design by adding large contoured contact surfaces. We molded housings of UL-approved polysulfone with eggcrating ; set cavities on .156" centers, allowing for
.100" density if desired. Provided crimp
snap-in contacts. And designed
connectors with from 3 to 33 positions.
Then we tooled up our AMPOMATOR* '
machine to give you 5,000 automatically
terminated leads each hour. And updated our AMP-0-LECTRIC* mach ine
to provide 3,000 ready-to-use fork
contacts an hour. And with either machine, you get AMP's precision controlled crimping and simplified worryfree operation. Plus cost savings.
For details on the Modified Fork edge connector, write AMP Incorporated, Harrisburg, Pa. 17105.
*Trademark of AMP Incorporated
One of a full line of printed circuit connectors available from AMP ... Worldwide.
These are i.mpulse items
Any impulse from half a microamp activates our relays. No other meter relay manufacturer offers this full scale sensitivity. And Weston can provide the type of closure best suited to your application-sensitive (non-locking), LCCA, magneticcontact, non-physical contact, or all solid-state. Photo sensing and solid-state switching are com-
bined in the Model 1075, for example, with wide scale DC ranges from 1Oµa to 500 volts. Or, you can switch a five amp AC load entirely by photoelectric means with our 1930/1940 Series relays. Model 1066, the ultimate in solid-state design, provides two independently adjustable set points, switching capacity of one amp at 117 volts AC,
selectivity to 1µa, and an optional input monitor. For the full story on industry's broadest selection of adjustable relays, write for Catalog 02-110.WESTON INSTRUMENTS DIVISION, Weston Instruments, Inc., Newark, N.J. 07114,
a Schlumberger company.
WESTON®
Electronics [ April 29, 1968
Editorial comment
McNamara's parting shot
is almost on target
War is hell but, happily, wars do come to an end. In contrast, the Defense Department's battle with its countless suppliers goes on forever.
The electronics industry opened a new front recently witl1 its criticism of the department's procurement procedures [March 4, p. 23]. Not only is that conflict continuing, it may have been exacerbated by Robert S. McNamara's parting shot-a memo to his staff in which he expressed his satisfaction with DOD procurement policies. True, he had misgivings about the way they were being applied, and urged his staff, in a number of specific recommendations, to assure that "fair and equitable practices cover the buyer-seller relationship."
But McNamara issued his memorandum almost at the moment he was leaving his post as Secretary of Defense and the electronics industry's suspicion that he waited too long may be justified.
Because of growing dissatisfaction by contractors, McNamara had assigned Thomas Morris, assistant secretary of defense, to sound out the views of executives at major defense companies on DOD practices and policies. Moreover, the defense agency had been keeping its ear to the ground for feedback from discontented suppliers. McNamara's memorandum, while defending his policies, notes the criticisms and seeks to answer them.
Morris reported nearly universal support for the procurement reforms (such as extensive use of incentive and fixed-price contracts and the use of weighted guidelines in profit negotiations), made during McNamara's administration. But he noted growing concern by contractors that the reforms, improperly applied, might cause them to assume "undue financial risk and cost penalties.'' .
Replying to the charge of improper cost sharing, McNamara said he wanted to be sure that research and development performed for DOD at its direction is not subsidized by industry.
A frequent complaint of contractors concerns the careless dissemination of proprietary technical information among comp etitive bidders during tlie contract-definition stage. On that score, McNamara insisted that the department must ensure the in-
tegrity of its procedures "to preclude the transfer of one contractor's competitive advantage to another, thus reducing the eventual competition to a price basis only.'' Otherwise, he said, it will penalize the most efficient contractors and discourage their continued interest in doing business with the Government.
Other companies complained that sometimes work will be requested but contracts aren't written to cover it. McNamara called for a halt to the practice, and recommended that when inadequate contractual arrangements result in an increase or decrease in the contractor's cost, the Defense Department must provide "equitable adjustments in a timely manner.''
Contractors have been particularly vocal when they have been required to accept firm, fixed-price contracts in areas where many development and production uncertainties exist. Calling for good judgment in the choice of contracts, McNamara said the emphasis on the higher-risk-type contracts should not be construed as a mandate for their use in inappropriate situations.
Often when contractors propose value engineering changes, they are mulled over for months at a time. Some are never acted upon, but others are made as normal engineering changes and the contractor does not benefit as he would if they were handled as value engineering changes. McNamara said those practices must cease; since they tend to deny the Government the benefit of good cost saving ideas.
The weighted guidelines are favored by many contractors, but criticism arises when the guidelines are manipulated to support a preconceived rate of profit. McNamara agrees that the guidelines are intended to "offer profit opportunity to conform with the degree of risk the contractor is called upon to assume."
The use of competitive and fixed-price contracts and the high degree of capital investment was designed by the defense agency to reduce tlie degree of contract supervision needed. But it doesn't always work that way. In some cases more government personnel are involved in administering contracts than during the era of cost-plus-fixed-fee contracting.
We applaud the ex-Secretary's admonitions that Pentagon personnel exercise careful judgment in applying existing policies. We hope that Secretary Clark Clifford will continue where McNamara left off. Without implementation, McNamara's memo will be no more tlian an admission that there is much room for improvement in the Defense Department's relationship with its suppliers.
+-Circle 22 on reader service card
23
Our Mexican string quartet.
Even in this automated world , stringing memory planes is still a hand operation. That's why Indiana General went to Mexico.
Here, at Ferromagnetica, a long tradition of handcrafted quality goes into every plane we make. The inherent skill and a pride of workmanship of our large staff assures reliability.
Mexico means another kind of reliability, too. Close to the United States, travel is unhindered.
It has a firm economy and stable government. Neither long distances or social upheavals are likely to interfere with delivery.
And backing up Ferromagnetica is our Memory Products operation in Keasbey, N.J.-the people who first developed memory cores. This combination offers you the greatest selection in cores, planes, and stacks in a full range of materials and sizes for all applications.
We 'd like to tell you more about our memory products. What they are, how they work, and why they are the best. Write G. P. Perkins, Manager of Sales, for the complete story on IGC memory products. Indiana General Corporation, Electronics Division/Memory Products, Keasbey, New Jersey.
Don't fiddle around.
INDIANA GENERAL
Making Magnetics Work
24 Circle 24 on reader service card
Electronics I April 29, 1968
Electronics Newsletter-
April 29, 1968
Autonetics tickets Phillips for LSI job
The new assistant to the president at Autonetics-and undoubtedly the man who will run the firm's large-scale integration facility when it swings into production later this year-is Alvin Phillips, often referred to as the father of Sylvania Semiconductor's SUHL line of transistor-transistorlogic IC's. Phillips joined Autonetics April 22 as S.F. Eyestone's assistant after serving as general manager of Sylvania's integrated-circuit operation.
Autonetics, a division of North American Rockwell, has often used the post of president's assistant to familiarize new executives with the company before assigning them more descriptive titles and more specific jobs. C.F. O'Donnell, Autonetics' senior vice president for research and engineering, says Phillips has a solid background in engineering, production, and marketing-the kind of experience needed to convert the firm's engineer-dominated MOS microelectronics laboratory into a profitable production operation.
Relabeling IC chips saves face abroad
A big part of the growing business in unpackaged integrated-circuit chips [Electronics, April 15, p. 47] is the sale of IC's ·to British and Continental semiconductor makers for relabeling. These .companies, lagging behind American technology in this ·field and pressed with demands for IC's from their customers, are quietly buying diced circuits and whole wafers, packaging them, and putting on their own labels. And U. S. suppliers are going along with the face-saving subterfuge.
Insiders guess that this relabeling business accounts for as much as 20% of the $15 million market for unpackaged chips. And they expect this ratio to grow as U.S. firms develop more advanced transistor-transistor-logic and linear circuits. Some smaller U.S. makers, especially those that are second sources, are also buying unpackaged chips for relabeling.
Litton computer to use wafers
In what may be a major step toward LSI computer design, Litton Industries' Guidance and Control Systems division is developing a model of a navigation computer that would employ unpackaged 1%-inch-diameter semiconductor wafers containing 70,000 MOS transistors each.
A block-oriented computer, the unit will be a parallel multiprocessor; each wafer will contain up to 36 arithmetic units and a central processor. Although the computer is still in the early design stage, Alden Stevenson, the division's vice president, says the wafers may have contact pads around their perimeters to which bonds could be attached. Epoxy may be used to encapsulate entire trays of wafers. The memory will also consist of MOS wafers.
Litton is developing the computer under a contract from the Avionics Laboratory at Wright-Patterson Air Force Base.
Beam-lead bipolars ordered for Mark 2
Autonetics is buying beam-lead integrated circuits for the Air Force F-lllA's Mark 2 avionics system. The firm has ordered $285,000 of diodetransistor and transistor-transistor IC's, plus some beam-lead discrete transistors, from Raytheon's semiconductor operation in Mountain View, Calif. This is believed to he the first major production order outside the
Electronics I April 29, 1968
25
Electronics Newsletter
Bell System for beam-lead devices. The devices will be furnished in chip form to Autonetics and will replace other bipoplar IC's Raytheon has been suppying for the program. The devices will probably go into hybrid circuits.
Fairchild won't be
TTL second source
Despite the lure of a quick buck, Fairchild Semiconductor still declines to become an alternate supplier of transistor-transistor-logic digital IC's. Fairchild apparently decided that it can make money with its TTL design and that its major production problems will be cleared up by year's end.
Economic pressure has been building up in the company-after a year of belt-tightening-to copy Texas Instruments' 54/ 74 and Sylvania's SUHL series. But Fairchild claims that becoming a second source would ruin its image as an innovator. It has made a few SUHL and 54/ 74 chips on one or two occasions, though.
A Fairchild marketing spokesman conceded the risk in refusing to follow TI and Sylvania, but said the TTL battle will be resolved not with the IC's available but with medium-scale and large-scale IC's.
LTV gets contract
to study solid state switching in planes
The Air Force and Navy are moving closer to a solid state system for handling all signal and power switching in aircraft. LTV Aerospace, · which since 1960 has been investigating the feasibility of substituting semiconductor switching systems for present electromechanical techniques, has received an Air Force contract to design, fabricate, and evaluate a complete system for the A-7 attack plane. The firm earlier worked out a systems concept and developed hardware specifications under a Navy grant.
In the solid state approach, signal-or control-switching is kept separate from power switching to minimize the number of operations at the power level. Information flows directly from source to the control logic, and power flows from its source-or electric bus-through a single device directly to the load. This setup thus requires fewer and thinner wires than does an electromechanical arrangement, and permits the design of a system from three basic types of modules: signal sources, control logic, and power controllers.
LTV believes the solid state system will be five times as reliable as conventional switching. Weight of the distribution system could be 30% less, the firm adds, and the modular packaging could ease maintenance by as much as 40%.
Honeywell will sell rival's transducers
26
Instrumentation £nns usually shy away from intercompany marketing arrangements. But on June 1, Statham Instruments and the Test Instrument division of Honeywell will break tradition with an agreement under which Honeywell will market a line of industrial transducers designed and built by Statham.
The pact will open an immediate market for Honeywell's test equipment, which can be used with Statham sensors to measure such things as pressure, load, weight, displacement, and acceleration.
More than a dozen transducers and related gear are covered by the agreement, including Statham's newest device-a transducing cell that can be made to measure a variety of parameters simply by changing sensor heads.
Circle 27 on reader service care:~
Packaging-Advanced manufacturing capability covers virtually every type and every configuration of resistive and / or capacitive networks-single or dual in-line, as well as flat-packs, with or without hermetic sealing.
Characteristics-Exclusive and patented formulations enable A-B to provide resistance values from 1 ohm to 5.0 megohm. Ratings to 20 watts/in2 at 85°C. Capacitance values from 10 pfd to 0.5 mfd with voltage ratings to 50 volts. Applications include precision tuned circuits.
Performance-Standard resistance tolerance :!: 10% . For critical circuitry, tolerances to :!: 0.1 % can be furnished-with resistances and TC's matched. Temperature coefficient less than 250 ppm in all cases. Special units to 100 ppm or less. Load life stability of 1% in 10,000 hours can be achieved.
Reliability-Allen-Bradley has precise control over all raw materials and manufactures all basic components-
glasses, organic materials, and substrates. Special machines-designed and built by A-B-assure uniform
product quality-at a competitive price.
Timing-Allen-Bradley has unique in-plant ceramic facilities. Prototype networks-with or without holes-can be prepared to meet
your specific needs. Quickly. Economically.
For more details, write Henry G. Rosenkranz, Allen-Bradley Co., 1315 S. First St., Milwaukee, Wis. 53204. In Canada: Allen-Bradley Canada Ltd. Export Office: 630 Third Ave., New York, N. Y., U.S.A. 10017.
6726
QUALITY ELECTRONIC COMPONENTS
zener
~
Wlt stan
p.s ···
. . . part of a range extending from 0·4 to 75W, 3·3 to
75V with 5%tolerance
Mullard zeners give you over I20 different
voltage/power ratings in the ranges 0·4 to 75W
and 3·3 to 75V. They exhibit sharp knee character-
istics, low dynamic resistance and low leakage currents.
Mullard range ofzeners
Voltage Range Power Rating Encapsulation
*BZY9I T5 to 75V
75W
D0-5
*BZY93 7·5 to 75V
20W
D0-4
OAZ222-3 5·6 and 6·2V rnW
D0-4
BZY96
4·7 to rnV
I·5W
DO-I
BZY95
IO to 75V
I ·5W
DO-I
BZY88
3·3 to 30V
0·4W
D0-7
BZX6I
33 to 75V
0·4W
D0-7
*Available with either normal or reverse polarities.
The BZY9I series is capable of withstanding peak surges of
4·4kWfor rnoµs.
28 Circle 28 on reader service card
Every designer should have a copy of the Mullard Quick Reference Guide giving information on Silicon Voltage Regulator (zener) and Reference Diodes. Also ask to be put on the mailing list of the Mullard Bulletin-a regular publication which gives details of new components and applications ... the result of extensive research and development programs in the Mullard laboratories in England.
Write today for information on Mullard zeners and for the name of your local Distributor.
Mullard Limited, Mullard House, Torrington Place, London WCI England.
U .S.A. enquiries to Mullard Inc., IOO Finn Court, Farmingdale, Long Island, New York. 11735 U.S.A. Telephone: (5I6) 694-8989 Telex: 96I455.
Mu11ara Circle 29 on reader service card-+-
The advanced capabi · developed from years of facturing Allen-Bradley Meta resistors-are now applied to line of resistor networks. This techri eua,bles the production of complex res networks on a single substrate.
Allen-Bradley's exclusive simultaneous deposition Ihe~..is. used to obtain the best resistance tolerance anti temperature coefficient matching. The reliability of
interconnections on the common resistance plane is incom-
Rarable. Uniformity and quality are inherent in A-B networks. Th illustrate, 2 PPM temperature tracking is normal.
A-B Metal-Grid networks offer a wide range of values->Vith
hidividual resistances as low as 25 ohms and as high as 2.0
megohms. Both the inductance and capacitance are low, per- l'I
mitting efficient operation at high frequencies.
~
A-B engineers will be pleased to cooperate in developin(. ne works for your specific need. For additional details, please wite t
Henry G. Rosenkranz, Allen-Bradley Co., 1315 S. First Street, Mi
waukee, Wisconsin 53204. In Canada: Allen-Bradley Canada Ltd. E'U'drt Office: 630 Third Avenue, New York, N. Y., U.S.A. 10\H7.
BRIEF SPECIFICATIONS
Resistor Networks
Tolerances: ± 1.0% to ±0.01%
R~istance Matching: to 0.005%
Temperature Range: -65°C to +175·c
Temp. Coef.: to ± 5 ppm/°C
Ladder Networks Full Scale Accuracy: 10 bits or less,
better than ± % least significant bit. More than 10 bits, better than ± V2 least
significant bit.
Frequency Response: Less than 100 nanosecond rise time or settling ti
Load Life (Full load for 1000 hr @ 125°C): 0.2% maximum change
Temp. Coef.: Less than 10 ppm/°C Temperature Range: -65°C to +175
QUALITY ELECTRONIC COMPONENTS
EC 682
You be the judge:
The 4700 challenges any other IRIG laboratory system to offer
1A, lf2, 1, and 2-inch tape widths as
a standard feature. Provides tape movements with low static and dynamic skew, under low tension, low flutter, low mass drive, with exclusive vacuum guiding and cleaning-all at eight speeds from 120 to 15/16 ips. Eliminates an entire tape transport for those reel -to-reel/loop dubbing applications by employing a set of dual IRIG heads-another tapeability feature of the 4700.
DATA ACQUISITION ADVANTAGES
Analog and digital data formats are easily accepted by off-shelf IRIG channel electronics with improved stability, drift, and linearity characteristics. Choose any combination of Direct, FM, PDM, constant bandwidth FM, serial PCM and parallel PCM solid state electronics for all eight transport speeds. For data requiring isolation from long lines, choose FM modulators with differential inputs for both bi-polar or unipolar operation to 80 KHz.
small spare parts kit and no extra charge for Sangamo's one-year warranty on parts and service. The long life expectancy of the 4700 offers the user the best price/useage ratio.
TO BE MORE PRECISE, SPECIFY THE 4700
Can we arrange a demonstration? Contact one of our application engineers, Information Systems Division , Department E-4. TWX: 910-242 -0533. Phone: 217 -544-6411.
SUPERB RELIABILITY
Excellent MTBF and MTR figures have resulted in an exceedingly
The innovators
instru=in tape i . . m~
ESl ..J
30
Circle 30 on reader service card
SANGAMO Information Systems
Springfield, Illinois
Electronics I April 29, 1968
THIS IS THE WIDEST SELECTION of
MINIATURIZED CERAMIC CAPACITORS
f IN THE INDUSTRY
·
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· Red Caps meet or exceed all applicable requirements of Mll-C-20 and Mll-C-11015 per Mll-ST0-202
RED CAPS feature
ERIE'S EXCLUSIVE NEW
~ J~SEAQ !_, ENCAPSULANT
ERIE
· Erie's new Jet-Seal excels in mechanical and electrical ruggedness · Provides excellent moisture protection · Maintains electrical and mechanical stability at temperatures from - 55°C through 150°C · Jet Seal's bright color and gloss finish will be outstanding in even the most sophisticated equipment.
TECHNOLOGICAL PRODUCTS, INC.
WRITE FOR SAMPLES on your company letterhead
ERIE TECHNOLOGICAL PRODUCTS, INC.
State College, Pennsylvania Attention: Applications Engineering
Electronics I April 29, 1968
Erie, Pennsylvania
Circle 31 on reader service card 31
B
DIG ITAL COM PUT ER
FEATURING: FOURTH GENERATION MSI CONSTRUCTION OVER 80 COMMANDS 16 BIT WORD LENGTH TWO GENERAL PURPOSE ACCUMULATORS 4K BYTE ORIENTED EXPANDABLE MEMORY DIRECTLY ADDRESSABLE TO 64K
2.5 µS MEMORY CYCLE TIME
PRIORITY INTERRUPT EXTENSIVE INTERFACE CAPABILITIES OCCLJPIES ONLY 8- % INCHES RACK SPACE $13,900, COMPLETE WITH TELETYPE
See us at booth X3, SJCC
32 Circle 32 on reader service card
CONTACT: DATAMATE DIVISION GAMCO INDUSTRIES, INC. P.O. BOX 310 BIG SPRING, TEXAS 79720 (915} 267-8766
Circle 33 on reader service card --->--
U1rsatil1 1:uru1 tra1:1r. FET/SIR 1:apability:
11575.
Fairchild's Model 62008 can test a greater variety of devices than any curve tracer in its price range. It operates FETs, MOS-FETs, bipolars, unijunctions, diodes, tunnel diodes and SCRs. It provides 1000V for high voltage measurement and 5 amps for high current tests. Base drive can be as low as 100nA for high-gain devices and ·up to 35V for FETs. The 62008 is compact, lightweight and rack-mountable. We also have a programmable version for high-volume production applications: the 62008/P. It does a lot more. And costs a little more. We'll gladly tell you about one or both. Ask for our data sheets.
FAIRCHILD INSTRUMENTATION A Division of F81rchlld Cemer1 llld ll'lltrument Corpor1tion 974 Eat Arques Avenue. Sunnyv1le, Cllifomi1 94086 (408) 735-5011 TWX: 910-379-61144.
NEW EG&G PICDAMMETERS
A full line of low-level current measurement instruments
All EG&G Picoammeters include features others only talk' about. Like the unique combination of precise accuracy and rapid, accurate calibration capability without resorting to calibration charts or resistor measurement. And, the all solid-state design, including a low level MOS FET input stage. What's more . . . you'll find an
EG&G Picoammeter to meet your needs and your budget. That's because EG&G offers the most complete line of low level current measurement instruments available. From high precision units or automatic ranging units, both complete with digital readout, to general purpose, manually-operated bench top models.
HERE ARE THE SPECIFICS ON FOUR OF THE MOST POPULAR EG&G PICOAMMETERS.
Model ME-1035, Precision Picoammeter - for Standards or Calibration labs. Current measuring range of 10-5 amps to 10-12 amps with 10-15 amps resolution. All solid state design with MOS FET input, temperature controlled feedback resistors for added stability, pushbutton range control, adjustable summing point voltage and current offset monitor, pushbutton controls for rapid internal calibration requiring no external standards or sources. Digital readout. Price: $3,945.00
Model ME-930, Digital Picoammeter - for general lab work and automatic digital systems. Current measuring range of 10-11 amps through 10-2 amps full scale in 10 decade steps. A full digital picoammeter with automatic range changing capability and automatic polarity selection. All solid-state design with MOS FET input, remote function control and optional printer drive, digital readout of level and range. Price: $3 ,575.00
Model ME-920, Automatic Range Changing Picoammeter- for general laboratory use and production line testing. Current measuring range of 10- 11 amps through 10-2 amps in 10 decade steps. An automatic ranging picoammeter with remote function capabilities. All solid-state design, with MOS FET input and automatic polarity indication. Price: $2,435.00
Model ME-705, General Purpose Picoammeter - for general laboratory use. Current measuring range of 3x10- 13 amps through 10-2 amps in 22 steps (11 decades with X3 meter multiplier). A general purpose, manually operated bench-top picoammeter. All solidstate design, with MOS FET input stage. Price: $560.00
For more complete detai ls on the more complete line of EG&G Picoammeters, contact your local EG&G Products Divi sion representative. Or, write EG&G Inc., Laboratory Products Division, P.O. Box 755, Goleta, California 93017.
34 Circle 34 on reader service card
n
~
LABORATORY PRODUCTS DIVISION
Electronics I April 29, 1968
Prototype
: ..
0
vour19&9
t1ol,tf ~<AV( SClll IRIGQ(R '"'II~ 1111 '"'' 11 !l1r.Q
--·--_-'_-"-.... -.;,.. .~..:.....~... -
960 W Half-Wave Kit
fULl ~1AVE flll!AC IRIGG(R P"IR JUT Tl'.1 t KO
4A MOTOROLA
960 W Full-Wave Kit
power control designs
Wilh a 'T1T' Kill
If you're looking ahead to getting higher performance and more economy out of next year's power control designs than you realized from this year's circuits (and what designer isn't! ) ... you'll want one or both of these "T & T" - Thyristor and Trigger - prototype kits designed to introduce you to both application advantages - now!
Each kit is priced at the regular, 1-99 price for the thyristor alone - you get the 28 V, plastic trigger free together with performance data and circuits, ready for use right on your "new design" workbench!
ElF SCR's, long a popular, industry-standard for medium-powered, 50 to 600 V, commercial/industrial designs, furnish minimum power loss - low, 1.3-volt VF @ 5 A, 25 · C; immunity from false triggering due to noise with a realistic, 10 mA (typ) gate firing level;
100 A current surge protection and mounting versatility with 6 different hermetic cases.
Motorola's 960 W TRIAC takes the place of two conventional, back-to-back SCR's and has symmetrical gating and holding characteristics in all modes. In addition, 100 A peak surge capability, 50 to 400-volt Vn0 ~1 and built-in transient overvoltage protection make it a natural choice for a variety of cost-lowering, circuit-simplifying applications.
Both kits include one of the new, silicon Annulart plastic bilateral triggers offering symmetrical switching, low switching current, and higher-energy pulsesto-gate.
Prototype extra workpower into your continuous control circuits ... fill in and mail the coupon today!
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Ideal for prototyping universal motor speed control circuits with feedback control, crowbar, voltage regulators, battery charging, etc. , circuits, the T & T H -960
kit consists of: · 2N4170, 8 A, 200 V stud Elf SCR
0 T & T H-960 Kits@ $2.10 each for the SCR and Free Trigger 0 T & T F-960 Kits@ $3.45 each for the TRIAC and Free Trigger
· MPT28, 28 V, Bilateral Trigger
· Complete Technical Specifications · 11 New Design" Circuits and
Name ______________Title________
"SCR Power Control Fundamentals"
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Send to Box 955, Phoenix , Arizona 85001. Offer expires June 1, 1968.)
I
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MOTOROLA
Semiconductors
Electronics I April 29, 1968
35
Noisy Signal1
Extract it with a PAR Waveform EductorTM
The PAR Waveform Eductor is a signal averager used to extract repetitive signals from noise. For complete information or to arrange a demonstration of this instrument, which is priced at only $4,200, write Princeton Applied Research Corporation, P.O. Box 565, Princeton, New Jersey 08540, or call (609) 924-6835.
73
~RINCETON APPLIED RESEARCH CORPORATION
April 29, 1968
Electronics Review Volume41 Number 9
Industrial electronics
lmpatt impact
Impatt diodes, until now used exclusively in military hardware, may soon make themselves felt in the civilian market, and the price of this progress may turn out to be a traffic fine for speeding. The Bomac division of Varian Associates has developed a microwave radar "trap" using impatt diodes in place of an oscillator tube.
The first model of the system has just been delivered to the Muni Quip Corp., a subsidiary of the Duncan Parking Meter Corp., Elkridge Grove Village, Ind.
According to Muni Quip's chief engineer, Floyd Harwood, the new radar works at least as well as systems with klystrons. The Bomac system also promises to produce less spurious output, making the radar more accurate.
More expensive. The Bomac modifications were simple. Beginning with one of Muni Quip's standard radars, the engineers cut the power supply voltage by about two-thirds to get the 83 volts d-c required by the impatt. They also changed the power-supply regulation slightly and added a current control.
The modified unit has an output of 67 milliwatts at 10.5 gigahertz. In Bomac's p arking lot, the engineers found that the system worked like a charm up to the maximum speeds tested, about 45 miles per hour.
However, other factors, such as life exp ectancy of the impatts, are still under sh1dy; tes ts will continue through this year at Muni Quip.
Also, the typical impatt costs more than $100 unmounted but the klysh·on tube is only about $90. The mount needed for the diode may easily raise the price of the
combination to more than $200. Muni Quip's executive vice pres-
ident, William R. Shiry, estimates that adding an impatt would also mean adding a grand total of about $400 to the list price of the firm's standard unit, which costs $1,440. And thus he feels he'll have to wait for the price of impatts to fall b efore the device can get out of the lab-or the parking lot.
However, Shiry may not have long to wait. John Reiber, Bomac's director of microwave marketing, thinks that the impatt could soon be competitive with tubes. "Prices are high now because orders are for only a few units at a time. If we received an order for 1,000 oscillators, (diodes and oscillators), our price would drop below $100." H e also points out that a power supply designed for the impattnot a readjusted one as used in the experimental unit-could be cheaper than those now needed for klystrons.
Pull over. Varian's Bomac division has developed an impatt diode as the microwave power source for police radar traps. Solid state device shrinks system into two packages- meter and controls, on the left, and antenna, right. But its price-still a few hundred dollars more than conventional gear-is keeping it out of the market. One design is being tested by the Mini Quip Corp.
~Circle 36 on reader service card
37
Electronics Review
Computers
Deficit mending
It's no secret that the General Electric Co. hasn't exactly been piling up profits from its computer business. In fact, industry rumors have it that GE's losses on its computer operation have run into the many millions of dollars, despite cutbacks in activities both here and abroad. A change may be at hand. The company this month named John W. Haanstra general manager of its Information Systems Equipment division, Phoenix, Ariz., the
Big job. John W. Haanstra takes over GE's computer operations in Phoenix in a move evidently aimed at stemming the company's losses there.
unit that produces commercial computers.
Haanstra, known in the computer industry as an executive more interested in profits than technical breakthroughs, joined GE last summer after spending most of his professional career at International Business Machines Corp.
Great debate. Haanstra made a name for himself at IBM, where he is remembered as the man who almost single-handedly blocked the development of the System 360 series. He believed, at the time, that tl1e advent of the 360 line would threaten the position of the General Products division, the operation he headed and the source then of some two-thirds of IBM's revenue.
Haanstra's first post at GE was
as a consultant to J. Stanford
Smith, who himself had only recently been brought in to revamp the faltering computer division. Last January, Haanstra was promoted to general manager of the Advanced Development and Resources Planning division, another unit of the company in Smith's charge. This appointment, quite interesting in its own right, becomes even more significant if changes are to be made in the computer division.
Now Haanstra is taking over the manufacturing and marketing side of the computer business from Louis E. Wengert, who becomes manager of GE's Constant Speed Drives division, the motors and motor-controls section of the company.
Remembering the MOS
A maxim in the electronics industry is, "You have to run hard to stand still." Memory Technology Inc., of Waltham, Mass., which has been doing well with its braided read-only memories [Electronics, Jan. 8, p. 52,] is beginning to learn first-hand how true this is. In planning a new product based on the technology, a universal bidirectional code converter, MTI has suddenly encountered competition from an unexpected quarter-semiconductor memories.
"When we first went into business a couple of years ago," says John J. Marino, president of MTI, "we had to sell prospective customers on the idea of using readonly memories. Now that these are a generally accepted idea, we can concentrate more on the advantages of braided memories over otl1er kinds of read-only memories, such as speed and flexibility." But manufachirers of metal oxide semiconductor (i\rns) memories have recently been making some rather broad claims about Mos, so that MTI has had to delay introducing its new converter until it can be sure what the MOS people are up to. No MOS memories have yet been delivered, says Marino.
Whirling disks. The only off-the-
shelf converter now available, other than specially designed units, is a mechanical contrivance made by the Invac Corp., another Walt11am company. Invac's device uses light bulbs, photo-sensors, and whirling disks driven by a motor. Marino says Mn's braid assembly could be sold for half the cost of Invac's device. He concedes that a 2,000-bit MOS read-only memory equivalent in performance to his braided memory could sell for a
competitive price; and MOS has a definite size and weight advantage. However, tl1e MOS memories are subject to a large masking cost that makes them quite expensive in small quantities.
The converter tl1at MTI is working on is basically two braid memories connected end to end, so that one drives the other. The two braids encompass sets of core pairs instead of single cores.
The present breadboard model can convert between two eight-bit codes-any two, in either direction. It contains 32 U-shaped cores in two sets of eight pairs, and a single braid of 256 wires. Each wire in the braid threads a particular com-
bination of eight core pairs, and a different combination of the other eight pairs, passing through one of a pair for a binary 1 and the otl1er for a 0. The two combinations represent the two coded forms of a single character.
Bit position. A flip-flop register holds an eight-bit character that comes in on eight lines in parallel. The complementary outputs of each flip-flop drive selection coils on the two cores corresponding to that bit position. Because of the pattern of wires in the braid, these coils generate voltage pulses on every wire but one. The pulses re-
verse-bias the diodes connected to the braids; the one diode left unbiased admits a current pulse to its wire. This wire also threads a unique combination of core pairs in tl1e other set; sense windings in that set pick up the corresponding code, which is amplified and precented to eight parallel output lines.
Changing braid. The converter is called universal because it can
38
Electronics \ April 29, 1968
Electronics Review
work between any two codes, siinply by changing the braid. It can also work with three or more codes at once,·with a longer braid and a set of core pairs for each codeas in a communications system that uses binary-coded deciinal, Hollerith (punched card), and Baudot (teletypewriter) codes. The converter is also bidirectional, because the selection windings on the input side and the sense windings on the output side are identical. Current drivers and sense amplifiers are both connected to each winding, and biased on or off depending on the direction of conversion.
Consumer electronics
Microwave mini-oven
The American housewife is apparently happy cooking with electric heat or gas. The handful of companies that produce microwave ovens have been most successful in
selling to restaurants and institutional kitchens. And all the major airlines use microwave ovens in their airborne kitchens.
But the Raytheon Co.'s Amana Refrigeration subsidiary is trying to change all that. It's introduced a small (23-by-17-by-15 inch) counter-top oven, called the Radarange, that operates from a standard 115volt, 60-hertz power line and sells for $475.
The only other consumer microwave ovens available in the U.S. are part of large stoves and sell for more than $800.
Amana says the Radarange can bake a potato in four minutes, a hamburger in one minute, and a five-pound roast-well done-in 371/2 minutes. Although the microwave mini-oven is new to the U.S., foreign electronics firms have been in the market for some time [Electronics, Sept. 4, 1967, p. 207] with such low-cost appliances for the consumer market.
Raytheon isn't alone in believing that microwaves will soon catch on in the U.S. Last month RCA said it set up a division to sell microwave tubes to oven makers.
What's cooking. Table-top microwave oven developed by Raytheon's Amana division will sell for $475. It plugs into ordinary house current. Most other U.S. designed microwave ovens are large or were designed for institutional kitchens.
Advanced technology
Bright idea
Television cameramen covering news and sports events have to guard against suddenly ain1ing their cameras at high-intensity lights without first "peaking" the h1bes to accommodate the brightness. If they don't, the tubes are sah1rated and permanently damaged.
However, developmental work initiated at Bell Telephone Laboratories before 1967, and now in progress at both Bell Labs and Texas Instruments Inc., promises aid for the cameramen.
Bell developed a technique that replaces photo-conductive coatings (usually antimony trisulfide) in standard tv camera vidicon tubes with a silicon diode array. The array can handle sudden brightness without suffering fatigue. What's more, the array is said to provide higher sensitivity than the conventional coatings, without any loss of resolution.
Bell began the work for its Picturephone system, which is now being tested and involves the visible part of the light spectrum (0.4 to 0.7 microns). Last June, TI got permission from Bell to do similar work in the near-infrared region (0.9 to 1.1 microns) for classified military applications.
Standard tubes. A 540-by-540 array of 291,600 photo diodes on a thin silicon slice was made by Bell in its early work. Texas Instruments has since made similar sizes and, more recently, has developed a 600-by-780 format that measures 0.48 by 0.64 inch.
TI switched from the visible to the near i-r range by tailoring the diode spacing and thickness. Its present format has a center section 0.001 inch thick. A standard vidicon tube equipped with the TI array can be tuned across the spech11m from 0.3 to 1.2 microns.
To modify a standard vidicon h1be, the silicon diode array is mechanically fitted into the front end just behind the front glass. Light passes through the glass and
I Electronics April 29, 1968
39
Electronics Review
penetrates the silicon. The array is then scanned by an electron beam the same way the conventional tube is scanned.
"We get the sensitivity needed with silicon because it peaks at around 0.9 microns," reports Ward Paxton, manager of the advanced i-r systems components branch at TI. "The array is of low enough capacitance that it has few image smear characteristics."
Longer life. Using silicon instead of the glass plate may also extend the life of the modified tube; hydrocarbons and gases in the .glass eventually poison the cathode. Frank Skaggs, an engineer on n's project, says, "Most tv people now replace their tubes after 500 hours because the tubes begin to lag from fatigue. We think the arrayequipped tube will have at least a 5,000-hour lifetime."
Ti has used the arrays primarily in standard vidicon tubes, because these are the type used in military systems the firm is working on. Commercial-tv people often use orthicon tubes because of certain vidicon-tube limitations. Paxton believes, however, that arrayequipped vidicon tubes could satisfy many commercial needs because these tubes span a wide range of the spectrum.
Ti has produced several developmental systems for its military work, and Skaggs believes the silicon diode array technique will eventually break into the market for commercial camera tubes. For one thing, he points out, the array system has better red-light sensitivity than present tubes.
Seen from afar
Long-distance photography is only as good as the medium through which the picture is snapped. And obviously, the greater the distance the greater the distortion caused by the atmosphere. But a research team from Stanford University reported to the Air Force this month that holograms may be able to produce clear pictures despite atmospheric distortion.
Using a 1-joule ruby laser
Far-out photo. Hologram taken from eight miles away. Note outline of man smoking pipe at lower right corner.
mounted on a 48-inch telescope, the researchers were able to photograph a man standing more than eight miles away at nighttin1e. Pictures were taken on a desert range near Holloman Air Force Base, New Mexico, under conditions of significant atmospheric distortion, the researchers said.
With further increases in laser power and film sensitivity, the technique promises the transmission of clear hologram pictures between the earth and satellites orbiting 100 miles or more away. Atmospheric distortion would be less a problem in this case than it is between points on earth.
Glassy-eyed. The Holloman experin1ent was the first practical demonstration of a laboratory test performed at Stanford more than a year ago. In that test, shower glass was used as the distorting medium.
A hologram is the product of the interference pattern created by the phase dilierence between reference beam and image beam. Since the effect of the wave distortion is the same for both, any distortion is, in effect, canceled out.
Another advantage of holography over conventional photography, notes Prof. Joseph Goodman of Stanford's applied electronics laboratory, is that it detects the image first before forming it, thus allowing for fine adjustments.
Several outstanding problems remain to be solved before effective long-distance transmission can be achieved, Goodman concedes. Signal-to-noise ratio must be boosted to at least 10, preferably to 100, by
extending the dynamic range of the film.
Researchers must also find out how much more laser power it would take to ensure a strong signal at the receiver. The Stanford laser has 50 megawatts of power, producing I-joule for 30 seconds. Goodman thinks a Q switched 20joule ruby laser would be needed to produce a clear picture of a moving target at very long distances.
Different rig. Another advance might be to substih1te foil-lined parabolas and a television camera for the telescope and film. Computer processing of the images would also sharpen results.
In the Holloman experiment, the telescope received the reflected laser light and focused it through a reflecting mirror and lens to the film. The man eight miles off stood in front of a Rat, light-reflecting surface. Mounted a few centimeters above him was a retro-reflector-a triangular-shaped reflecting mirror -for the laser.
Although the picture was crude, the Stanford team considers it a significant step in an area of great promise. Further development will have to be conducted by the Air Force's Avionics Laboratory, though, Goodman comments, because "it's reached the stage where the university isn't the one to continue the research."
Medical electronics
Night watch
One of the most agonizing mysteries in medicine is the "crib death syndrome," which in the U.S. alone annually takes the lives of 10,000 to 20,000 infants in their sleep for no apparent reason. Various theories have been advanced, and while many have been ruled out, a few are now gaining attention.
One such theory, now being pursued by a research team composed of an engineer, a pathologist, and a surgeon at the Atlantic Research
40
Electronics [ April 29, 1968
28 Volts...5dB Gain...603 Efficiency!
TRW announces a major breakthrough in communication transistor technology with the introduction of this high efficiency, high gain .50 watt/500 MHz device.
In high power military aircraft transmitters, a single 2N5178 will do the job formerly requiring vacuum tubes or multiple-transistor circuits. The 2N5178 is also
Electronics I April 29, 1968
well suited for use in radar pulse circuits.
This state-of-the-art device em· ploys a patented cellular construction in a grounded emitter stripline package comparable in size to the T0-37. A 25-watt version, type 2N5177, is also available.
For evaluation quantities and complete technical details, con-
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Circle 41 on reader service card 41
Electronics Review
division of the Susquehanna Corp., will soon be tested with microelectronic equipment.
The team believes the crucial element in the phenomenon to be the vagus nerve-the nerve that triggers the heart when it begins to falter. It believes that when an infant goes to sleep, heartbeat and pulse drop sharply, and that this slowing down of the heart continues as sleep deepens. If the process isn't interrupted, the re-
Guardian. Pulse of sleeping infant is mon itored to prevent "crib death." Band fits on infa nt's arm.
searchers contend, the child can literally sleep to death.
Close calls. A hiccup or cough or other cause of arousal in sleep produces a "vagal storm" that speeds the heartbeat and pulse. Says a member of the team: "If the theory is correct, a large number of infants in their first months have 'near misses' every night they sleep."
The first step in testing the theory will be to monitor the pulse of a sleeping infant. In conjunction with the Case Institute of
Western Reserve University, the team has fashioned a breadboard "wristwatch" that uses a piezoelech·ic chip as a sensor and contains a simple transmitter made of discrete semiconductors that will transmit a wideband f-m signal. The monitoring system is now being tested on adults at Atlantic Research.
Remedy. Should the theory be correct, says Jack Spurlock, the team's engineer, the monitor could be used to trigger a remedial "control overtake," such as a vibrator, to stimulate the child's vagus.
In the early fall, the researchers hope to have a much smaller prototype monitor built with integrated circuits. Transmitter, battery, and sensor will be embedded in a thin nylon bracelet a child could wear without discomfort. The signal, at a frequency of 230 megahertz and a bandwidtl1 of 35 kilohertz, would be received by a small broadband receiver in the home. From the home, it would be forwarded over landline to a central computer for analysis. According to Spurlock, the team's hypothesis will be proven or disproven in the next two years.
The project, which has been sponsored in-house by Atlantic Research, was recently granted funds by the Northern Virginia Heart Association.
Government
Grounding the middlemen
Although many electronics contractors maintain that tlle Federal Aviation Administration isn't the easiest Government agency to work with, many still are attracted by the business. But now, as a result of investigations by the General Accounting Office, much of that allure will fade.
The FAA has sometimes purchased test equipment only as part of a basic air traffic control or navigation system-even if the equipment was standard-but this is going to stop completely.
The FAA will now buy standard test equipment directly, instead of using the prime contractor as a middleman. However, when test equipment isn't standard, the FAA will allow the prime contractor to supply it.
In the purchase of the semiautomated terminal air traffic control system Tracon-C, for example, the contractors will supply the test equipment as part of the turnkey package supplied to each airport. Bids on Tracon-C are due May 28, but the FAA still has no definite idea of how many terminals its $14.5 million will cover [Electronics, Feb. 19, p. 155].
Double fares. The GAO found that in eight of the 20 cases investigated the FAA purchased off-the-shelf, standard test equipment through prime contractors rather than directly from the manufacturers. This meant, of course, that the FAA was paying for two companies' profits and for more overhead and handling. The GAO studied two contracts closely.
In one, the purchase price of the test equipment was $178,050. The prime contractor added $57,264, which included $25,205 in profit and 20,426 in general and administrative costs. The rest was for packing, shipping, engineering aids, and "materials variance."
In the second contract, the test equipment itself cost $240,995. The prime contractor charged an additional $62,790, of which $27,617 was profit, $15,905 was for material overhead, and $19,268 was for general and administrative costs.
Round trips. The GAO study disclosed that the FAA paid to have some test equipment shipped about 6,000 miles-from a manufacturer in Oregon to the prime contractor's plant near Boston, then back to the installation site situated near Los Angeles.
The GAO found a number of other cross-country treks for test equipment. So obvious was the waste of money that the GAO reported: "We made no effort to calculate the amount of additional transportation costs incurred by the FAA."
In addition, the GAO discovered that test equipment was being inspected and calibrated twice: once
42
Electronics J April 29, 1968
4ways to view displays
with the Tektronix Type 564
s Iii·
rean s1oraue
OSCillOSCOD8
Entire screen can be used for a stored display.
Entire screen can be used for a nonstored display.
The Tektronix Type 564 is virtually two instruments in one. It offers all the advantages of a storage oscilloscope plus those of a conventional oscilloscope.
Split-Screen Displays An unique split-screen display area enables you to simultaneously use either half of the screen for storage and the other half for conventional displays, or use the entire area for stored or conventional displays.
Independent control of both halves of the screen permits you to take full advantage of the storage facilities . For example, you can use half the screen to store a reference waveform, the other half to display waveforms for comparison. You can erase or retain either half of the display area as you choose.
Bistable Storage Advantages
With bistable storage oscilloscopes, such as the Type 564 and Type 549, the contrast ratio and brightness of stored displays are constant and independent of the viewing time, writing and sweep speeds, or signal repetition rates. This also simplifies waveform photography. Once initial camera settings are made for photographs of one stored display, no further adjustments are needed for photographs of subsequent stored displays.
Storage time is up to one hour, and erase time is less than 250 milliseconds. An illuminated 8 cm by 10 cm graticule facilitates measurements and aids in taking photographs with well-defined graticule lines. Adding to the operating ease is a trace position locater that indicates, in a nonstore area, the vertical position of the next trace or traces.
Tektroni x bistable storage cathode ray tubes are not inherently susceptible to burn-damage and require only the ordinary precautions taken in operating conventional oscilloscopes.
Plug-In Unit Adaptability The Type 564 accepts Tektronix 2 and 3-series plug-in units for both vertical and horizontal deflection . Display capabilities of these units include single and multi-trace with normal and delayed sweep; single and multiple X-Y; low-level differential; dual-trace sampling; spectrum analysis, and many other general and special purpose measurements.
Type 564, without plug-in units . . . . .
$ 925
Rack-Mount RM564 . . . . . . . . . . .
Similar electrical characteristics to Typ e 564 . 7" high .
$1025
Type 3A6 Du al-Trace Amplifi er Unit . . . . . . . $ 525
DC lo 10 MHz from 10 mV/div to 10 V/div . 5 display mod es. Internal sign a l del ay lin e.
Type 3B4 Time Base Unit . . . . . . . . . . . . . . . $ 425
Sweep speeds from 0.2 µs/div to 5 s/div . Single sweep . Up
to . X50 direct-reading magnifier extends fastest sweep lo
50 ns/div.
U.S. Sales Prices roB Beaverton, Oregon
Each half of split-screen can be used independently for stored displays.
Either half of the split-screen can be used for a stored display, the other half for a nonstored display. (Shown below).
Tektronix, Inc.
Electronics \ April 29, 1968
For a demonstration, contact your nearby Tektronix field engineer or write: Tektronix, Inc. , P. 0. Box 500, Beaverton, Oregon 97005.
Circle 43 on reader service card 43
Electronics Review
"Bulldog"
Marshall spends another
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Marshall? He's the crankiest of the Twelve Cranks on Pleasant Avenue. One of the extra-picky grumps at Trygon Power Supplies who feels good all over only when he can pick something off our production line and shriek, "Hey! This is no % #&¢@# good!"
So far, he's had problems with our Super-Mercury series. Because there haven't been any problems.
The Super-Mercury is a brand new competitively priced series, the new generation of the industry-accepted, field-proven Trygon Mercury Series: fully programmable wide-range power supplies, power and value packed, offering precision Constant Voltage/ Constant Current operation. Precision performance (with up to 2000 watts output), in ranges up to 160 volts and up to 100 amps..005% regulation and 0.015% stability are standard (.005% stability optional) as is MIL Spec, RFl-free performance. Total ripple and noise less than lmv rms and IOMV P·P(to IOMHz). Master-slave tracking, auto-load share paralleling and remote sensing and programming are also standard with Trygon's patented tracking overvoltage protection available.
Marshall and his friends check the dozens of Super-Mercury features that make this series a Super-buy for you. Now it's your turn to check on them. Order a Super-Mercury as a starter.
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44 Circle 44 on reader service card
on receipt by the prime contractor operated for 157 hours and detected
and again on receipt by the FAA at 14 areas of turbulence. It missed
the installation site. Both were one and triggered five false alarms.
based on the manufacturer's man- Warning time averaged three to
ual. Of course, the prime contractor four minutes before the turbulence
was charging the Federal Aviation was encountered.
Administration for its inspection The latest version should be
and calibration services.
ready in about nine months, accord-
The GAO, an investigating arm of ing to Edward Flint, manager of
Congress, didn't identify the com- the program at Autonetics. It will
panies involved, in line with its incorporate a number of improve-
policies of soft-pedalling reports ments over earlier models, which
[Electronics, Dec. 25, 1967, p. 107]. were prone to triggering false
The FAA conceded that the charges alarms. Flint notes, however, that
were substantially correct.
the airlines are willing to live with
some false alarms if they can be
certain that no critical turbulence
goes undetected.
The i-r sensor beam is fixed to
Avionics
detect disturbances out to 50 miles ahead of the plane within a 2° verti-
cal and 10° horizontal field of view.
CAT by the tail
The fourth version of. the system, the one used in the most recent Pan
Much has been said in avionics cir- Am tests, was the first to employ a
cles about ''belling the CAT," but fixed beam.
clear-air turbulence remains the Another refinement, first used in
same menace to aircraft it was when the third version of the detector,
the pun was considered funny. Of helps minimize false alarms trig-
the many research efforts aimed at gered by the minor turbulence that
finding a means of alerting pilots results from momentary changes in
to the presence of turbulence, how- the aircraft's attitude. This prob-
ever, one has finally resulted in a lem is licked by using a vertical
marketable system.
gyro cutoff signal to turn off the
The Autonetics division of the infrared CAT sensor when the air-
North American Rockwell Corp. is craft pitches down 1° or up 3.5°
taking the "experimental" tag off or rolls 4.5°.
its air-turbulence detector and offer- Temperature change. During the
ing it to the airlines as a commer- Air Force flights, Autonetics engi-
cial product. Armed with statistics neers found that the presence of tur-
compiled in 372 hours of operation bulence was signaled by a change
during 76 flights-30 in an Air Force in carbon-dioxide temperature, a
C-135 and 46 in an Pan American change in carbon-dioxide density,
'\i\Torld Airways Boeing 707 on regu- and a change in ice-crystal concen-
lar passenger runs [Electronics, tration. The C02 absorption band
Nov. 27, 1967, p. 52]-Autonetics was selected for the system on the
representatives have been present- basis of studies conducted by Au-
ing the case for the system to offi- tonetics that were started some
cials of American, Eastern, TWA, eight years ago.
Pan Am, and United Air Lines.
The system weighs under 50
The latest version of the detector pounds and requires less than 100
-configuration number five-has watts; both levels, Flint says, are
three major parts: an infrared radi- lower than would be required by a
ometer sensor, a data processor, and radar detector. Besides CAT, inci-
an indicator panel. The system op- dentally, the detector can pick up
erates in the far infrared range at turbulence caused by thunder-
the lower edge of the carbon-diox- storms.
ide absorption band-between 14 No price tag has yet been put on
and 16 microns.
the system. It's designed for any
Time to prepare. In the most re- aircraft that cruises between 25,000
cent Pan Am tests, conducted last and 41,000 feet, and Flint says it
December and January, the system looks technically feasible, with a
Electronics I April 29, 1968
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Electronics Review
range extension to about 150 miles, for supersonic transports.
Space electronics
Fiddling with Symphonie
A paper on the use of a Luneberg lens in a mechanically despun satellite antenna drew an indulgent, and even faintly amused, response at an American Institute of Aeronautics and Astronautics conference in San Francisco this month. But Henning W. Scheel, a 26-yearold German electronic consultant, may have been aiming his ideas beyond his predominantly American audience.
Scheel and his associates are trying to influence the design of the Symphonie satellite, a threeaxis-stabilized craft being developed jointly by Germany and France to provide television and telephone relays [Electronics, Sept. 4, 1967, p. 207].
Plans are to launch two satellites -one by 1971, the other in 1972. They're being designed to weigh less than 374 pounds, to permit launching by the ELDO-PAS vehicle. The two countries are putting up about $56 million for the project; requests for proposals went out in January.
Scheel says flatly that three-axis stabilization will cost twice as much as spin stabilization and be less reliable. He and a colleague, K. Rudzinski, convinced the influential German newspaper, Frankfurter Allgemeine Zeitung, to devote nearly a full page last month to their discussion of "unnecessary risks in the Symphonie project" and to Scheel's alternative.
Rudzinski said that no satellite with three-axis stabilization that weighed less than 660 pounds had yet been built. He said the three U.S. satellites with three-axis stabilization all required nearly as much money for one satellite as the Symphonie sponsors are prepared to spend for two.
Scheel made his case for the
Luneberg lens as the antenna for a spin-stabilized satellite at the AIAA. Luneberg lenses are spheres filled with a nonuniform dielectric; the dielectric constant is 2 at the center of the sphere but only 1 at the rim, so that radio waves emitted from any source on the surface will be collimated on the other side of the sphere.
Despinning. The big advantage of this antenna is that it can spin with the satellite; only the antenna feed has to be despun. Multiple feeds can provide multiple pencil beams to illuminate specific areas of the earth.
The German Experimental Institute for Air and Space Travel Technique, near Munich, built and tested several Luneberg lenses under a program partly supported by the West German Ministry for Scientific Research.
Aperture efficiencies of better than 0.8 were obtained, Scheel says-far better than the 0.5 or 0.6 common with parabolic reflectors. Attenuation because of absorption in the dielectric was so small as to be unmeasurable; Sheel attributes this to the high frequencies used4 and 6 gigahertz-and to a new polystyrene material.
The big argument against lens antennas, and the one that led many U.S. engineers who heard Scheel's paper to discount it, is that their weight increases with the cube of their diameter.
Also, to obtain narrow beams, large apertures are required. An 18inch diameter Luneberg lens of pure polystyrene foam that produces a 10-degree beam at 4 Ghz weighs 35 pounds-"too much for certain space applications," Scheel admits. But, he says, lenses of the same diameter that weigh only 7 to 9 pounds are available-though the artificial dielectric used causes an absorption loss that cuts gain by about 1.5 decibels. "And it seems possible to fabricate lenses of only 2 to 3 pounds," Scheel predicts.
But Scheel's biggest weapon against weight is to increase the frequency, thus reducing wavelength and increasing the aperturewavelength ratio.
Whether the Luneberg lens ar-
Electronics IApril 29, 1968
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Electronics I April 29, 1968
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47
Electronics Review
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48 Circle 48 on reader service card
gument can convince the West German government-in the face of present plans and the existing technology for mechanically despun parabolic antennas-is problematical. Scheel still expects the devices to play a role in satellite communications. At least one U.S. representative at the AI.AA meeting saw some future for the lens as a cheap ground antenna in a direct broadcast television system.
For the record
Millimeter tv. A point-to-point system capable of carrying 12 or more television channels at millimeter-range frequencies could save the CATV industry a lot of money by eliminating the need for underground cables. But even such advanced research houses as Bell Labs haven't been able to find an answer to the signal attenuation caused by heavy rain.
Now, however, the Chromalloy American Corp. and the Laser Link Corp. claim they have a system that not only can transmit up to 20 tv programs at one time over a 42gigahertz carrier, but can guarantee excellent reception even in rain.
The secret of their scheme is being kept just that, a secret. Based on a proprietary modulation technique-the "quasi-laser" is what representatives of the two companies call it-the system is to be tested in the New York City area.
Happy landings. The Boeing Co. has purchased a military radar system that measures a plane's descent speed and landing velocity and plans to install it in its 737 civilian transport. The system, developed by the Ryan Aeronautical Co., is now being used in the F-4 Phantom jet fighter, the CH-46 helicopter, and the C-130 Hercules.
Scuttlebutt. In the wake of the Pueblo's seizure by North Korea, the Defense Department is studying the reliability of self-destruct mechanisms for electronic espionage gear.
Electronics \ April 29, 1968
Official weigh- I·D.
The first in a series of bouts as "the mighty mite," but as yet unheralded, M. "Tex" Aemco takes on all challengers to determine the championship relay and timer supplier of the world. Surprisingly, Las Vegas odds-makers have rated the match a tossup. Said one of them, "Little Tex packs all the punches of the big boy, so from here on the outcome looks like it will go to the man who can think fast and move quickly."
- - us vs THEM
YES 155 YES 5 and 10 Ampere 3 Pole Industrial Relay
YES 156 YES
Miniature 4 Pole 3 Ampere Industrial Relay
YES 157 YES 10 Ampere 3 Pole Industrial Relay
TEX
Thinks fast and moves quickly. Can match his opponent punch for punch. Lightninglike delivery. Scores best before tough judges. Great crowd pleaser because of his manner of charging in head first and not stopping until the battle is won. Clean fighter. Doesn't pull any punches.
YES 615 YES Adjustable and Fixed Industrial Time Delays
POTTY BUTTERFELL
Has a lot of size going for him. Has done
well in past. He's a nice guy.
M iDIEX >!A}
NCORPORATED
AEMCO DIVISION
10 STATE STREET MANKATO, MINNESOTA 56001
PROGRAMMERS/ TIME DELAY RELAYS/ MINIATURE COAXIAL RELAYS/ INDUSTRIAL RELAYS/ MERCURY-WETTED CONTACT RELAYS
I Electronics April 29, 1968
Circle 49 on reader service card 49
MICROWAVE IC PROGRESS REPDRT#1
Sperry PACT program carries avalanche transit time oscillator past 5,000 hours of life testing
Sperry's PACT (Progress in Advanced Component Technology) Program now offers more than 5000 hours of life test data on an X band Avalanche Transit Time Oscillator. With a test history dating from July 6, 1967., the device has not yet shown a measurable change in characteristics .
A direct result of PACT, Sperry's intensified effort to accelerate the development of microwave integrated circuits, the ATTO is believed to be the smallest device of this type available anywhere for the direct conversion of DC to a microwave signal. Its outl ine dimensions are identical with that of a D0-5 diode package.
In developing the device, PACT engineers attacked the following requirements :
· Relatively high power output in microwave IC size packages.
· Electronic tunability over 5 to 50% bandwidths.
· Frequency modulation capability w ithout excessive spurious amplitude modulation .
· Minimum AM and FM noise chara c t e r i s t ics.
Success of the project depended largely on Sperry's in-house capability for development and production
of avalanching diodes. This capability met the challenge, and ATTO 's are now produced entirely within Sperry's Clearwater, Fla., facility.
As soon as PACT had demonstrated its ability to deliver the diodes required, the other technical problems came under staff scrutiny. One of the first developments was an "upside-down" diode mounting technique which puts the heat dissipating region of the silicon mesa chip as close as possible to the heat sink. Resulting reduction of thermal resistance between junction and heat sink enabled
ACTUAL SIZE
PACT engineers to handle current densities as high as 850 amps/cm2. Power outputs have reached 380 mW CW.
Both frequency and phase locking techniques have been demonstrated.
Tuning requirements were met by utilizing mechanical, varactor or VIG techniques. Magnetic tuning across a 40% bandwidth is a reasonable expectation, and Sperry's experience in stalo design has permitted FM noise reduction by a factor of 30.
In summary, PACT has now demonstrated the feasibility of ATTO power output from 20 to 350 mW at specified frequencies between 5 and 10 GHz ; inputs would vary from 80 to 110 VDC at 30 - 50 mA. These forerunners of true microwave IC's will deliver conversion efficiency as high as 5%, and
SPURIOUS AMPLITUDE MODULATION
wffi:z: -90
~~~:6~
~wz -100
<tii:.:C
"6'~"'~'"
a:o~ -110
~;< ~
~g~
+---J
05 .. -120
~50
~~~
-1300
2 3 5 710
20 30 507
MODULATION FREQUENCY IN KHz
frequency stability of 4.5 ppm/ ° C be-
tween -10 and + 50/° C.
In its ATTO effort, the PACT program has already proved its ability to provide direct DC to microwave conversion for the most demanding of custom specifications. Chances are that the technology required for your application is already in existence. And, PACT's achievements in ATTO development foreshadow a quickening pace in the refinement of microwave integrated circuits.
To learn more about an ATTO for your application or the coming impact of PACT, contact your Cain & Co. representative or write Sperry Microwave Electronics Division, Sperry Rand Corporation, Clearwater, Florida.
For faster microwave progress, make a PACT with people
who know microwaves.
Si=>E l::;f!'<Y
MICROWAVE ELECTRONICS DIVISION CLEARWATER, FLORIDA
50 Circle 50 on reader service card
Electronics I April 29, 1968
Washin·gton.Newsletter
.·... ·
April 29, 1968
The Telecommunications Prospects for a Federal Department .of Communications are fading.
panel unlikely to ask
President's telecommunications task force now leans toward recorimiending that an agency similar to NASA be formed to cover the field .of com·
for new Cabinet post munications, but not at the Cabinet level.
. .
James D. O'Connell, director of t~lecommunicat~~ns man,agexnent
and vice chairman of the task force, _has been instrumental in. swaying
the panel away from the department id.ea: He's also against turnipg over
the regulatory duties of the Federal Communications Commission to any
· new agency, and is just as 6rrnly opposed to lumping communicatiom ·
with transportation und~r one Cabinet~railk deparbnent.
Boyd in ·stow burn . on fast-train delay
Transportation Secretary Boyd is ready to blow the whistle on contractors
who have failed to get the high-speed ra·ii service between New -¥<>rk and
Washington into operation. The trains .were supposed to rolf la5t fall btj.t
have been delayed at least twice. . ·
· .· ·~. ·· . :~' ._..:.<' · .
After the Budd Co. recalled 31 of the _cars because of probl~ with
control gear and stray voltages, Boyd_appointed a task force to find out
what was wrong and hc)w_to speed the project. The task force will report
by May 17 and will probably recom:tpend appointment of one .prime con-
tractor to oversee the entire project and coordinate efforts between Budd
and the two firms building the electrical and control systems, Westing-
house and General Electric. ·
·
Some Washington sources say Boyd is SCJ fed up with .the delay that
he's ready to publicly suggest hiring Japanese consultants to lead the
project. Japan has had high-speed trains op~rating for several years. . .
More R&D cash for Post Office
Don't expect Congress to start the hall rolling toward ·~hanging the Post
Office Department into a nonprofit Govemmen(:corporation-something
the President's Post Office Commission is expected .t.o r~commend· hi its
report this week. But Congress is expecte.d .to pay more ;ittentiori to .the
· commission's urging that greater emphasis be given research and develop-
ment to provide more efficient mail handling.
Likely to come out of this: anothet' increase next year in the pos~al
R&D budget, which grew from $16 million in fiscal 1968 to $23 million
in fiscal 1969.
·
New missile studies paint to a bonanza
Study contracts just awarded for an fuiproved tactical all-weather, _air-
to-ground missile system-called AGM-X3-presage hardware orders th,at
may total more than $500 million over the next few years. The $650,000
project-definition contracts have been issued to Hughes, Martin, and
Boeing.
.
.
.. .
The new missile will supplement. the Maverick, which uses ·television
guidance and is liniited to clear-weath_e~ daylight operation. The ·guid-
ance system for the .AGM~X3 hasn't yet been selected, but one prospect
is a passive millimeter-wave radar. The Air Force is also asking the study
contractors to investigate a combination optical-radar system using inel'.·
tial guidance for midcourse corrections.
· Electron!~ I April 29, 1968
Washington Newsletter
Airlines may alone fund Comsat craft
The nation's airlines are considering the 'possibility of going ahead with Comsat on the aeronautical services satellite without waiting for Federal assistance. This line of thought, expressed by officials of the Air Transport Association, reflects worries that the oft-delayed project will be further postponed by a lack of Government funds [Electronics, March 4, p. 62], and has been spurred by recent Comsat statements that the company's charges or satellite services would come to "less than $100" per flight. This is about three times what the airlines now pay for communications on transatlantic runs, but they seem to feel that such added benefits as data relay might justify the higher price. The carriers still aren't happy, however, about Comsat's long-standing proposal that they pay a lump sum in advance.
One possible hitch in the approach being mulled is legal: Comsat's charter may not cover the independent operation of such a system. .
A report on a national aeronautical satellite plan being worked out by the FAA, other Government agencies, and industry is due in two months.
Radiation roundup: Senate to hear calls for a tough bill .··
It's beginning to look as if the radiation bill the Senate will pass will be sufficiently different from the recently passed House version to force a compromise.
Some key provisions of the tough Administration measure excluded from the House bill will be strongly urged by several witnesses at the Senate Commerce Committee's hearings on radiation. At the sessions-due to start May 6-consumer champion Ralph Nader, among others, is expected to demand that the Senate bill provide for Federal inspection of plants making radiation-emitting products and for the recall of faulty equipment-items dropped by the House [Electronics, April 1, p. 46]. And union representatives will probably push for inclusion of the Administration's call for constant monitoring of workshops where radiation-emitting goods are made.
··. as workers balk at radar overhaul
All the talk about the potential dangers of radiation-emitting equipment is having its effect in other places. Concern over possible hazards may delay the FAA's plans to overhaul its radar antennas in a dozen locations.
The FAA says there's no danger, but its technicians are refusing to work on antennas at Benson, N.C., while temporary radar equipment is in full operation 88 feet away. In past overhauls, the FAA turned off the airport radar and closed down the field, but at Benson-and other fields due for renovation-it's bringing in portable radars to keep the airports open during the overhaul period. The National Association of Government Workers has asked the National Center for Radiological Health to investigate.
F-m radio bill gets little House backing
52
Washington observers say Rep. Alvin E. O'Konski (R., Wis.) won't get to first base with a bill requiring that all radios imported or sold interstate be capable of receiving both a-m and f-m broadcasts. The bill has been referred to the Interstate and Foreign Commerce Committee, but chances are good that no hearings will be held this year. The House is not enthusiastic about the measure simply because f-m radios are selling well-their share of the home-radio market rose to 37% last year from 30% in 1966. And of the car radios sold in 1967, 10% were f-m, compared with 6.8% the year before. In all, about 15 million f-m receivers were sold last year.
Electronics I April 29, 1968
New Sorensen OBS:
Sorensen's new ORS 40-.75 delivers 1V2 times the watts per dollar of most competitive
power supplies .. . with no stinting on performance.
D Voltage Regulation/Current Regulation
(with automatic crossover).
D Voltage Regulation:± 0.01% or± 1mv
for maximum line and load changes combined.
D Voltage Ripple: 400 µ.V r.m.s. (6 mV peak-
peak to 25 M Hz)!
D Output Voltage Resolution: 0.01 % of
maximum output voltage.
D Remote Programming.
D Remote Sensing.
+ D Ambient Temperature : -20 to 71 °C
Model Number
QRS 15-2 QRS 20-4 ORS 30-1 QRS 40-. 75 QRS 40-2 QRS 60-.5 QRS 60-1 .5
Output Voltage Range
0-15Vdc 0-20 0-30 0-40 0-40
0-60 0-60
Output Current Range @ Ambient
@ 4o·c
@ ss·c
@ 11 °c
0-2.20A 0-4.40 0-1.10 0-0 .83 0-2 .20
0-0.55 0-1 .65
0-2 .00A 0-4.00 0-1.00 0-0.75 0-2.00
0-0.50 0-1 .50
0-1.20A 0-2.40 0-0.60 0-0.45 0-1.20
0-0.30 0-0.90
Size (inches)
h
w
d
3V2 8 13
5V4 8 13Y4
3V2
8 13
3V2 8 13
5Y4
8 13Y4
3V2
8 13
5Y4 8 13Y4
Pr i c e
$145. $255. $145. $145. $255. $155. $265.
Contact your local Sorensen representative or: Raytheon Company, Sorensen Operation, Richards Ave., Norwalk, Conn. 06856. TWX 710-468·2940.
[RAYTHEON~
tor more data on this versatile instrument .. . Coll Sorensen: 203-838-6571
Electronics I April 29, 1968
Circle 53 on reader service card 53
54
Electronics J April 29, 1968
30% SYSTEM COST REDUCTIONS POSSIBLE!
Since we don't know your exact system requirements, we can't predict precisely how much MECL II can reduce your costs. But, our engineers figure that 303 is a conservative estimate for most systems! Why? There are three reasons: First, there's the recent reduction in piece-part prices - as much as 653 on some types. Then, we've now introduced several new complex-function types (and, more on the way) to further reduce "can-count." And, of course, there's the complementary output feature of all MECL circuits - to provide superior design flexibility as well as reduced package-count.
It's a great combination!
Further, even the new complex-function circuits are lower in price than other comparable types. For example, the cost-per-gate-element of the MC1030/MC1031 is less than 33 cents! Yet, these Quad 2-Input Exclusive OR and NOR gates will replace up to 12 standard gates and make it possible for you to build a 25 ns, 16-Bit Parity Checker, as shown
COMPLEMENTARY OUTPUTS REDUCE PACKAGE COUNT The six-input OR/NOR gates in
the MECL II series are extremely useful in generating multiple wired-OR logic functions since six independent outputs are provided, as shown. In addition to lowering system costs by reducing package count, this unique feature reduces delay time and design headaches; plus, it provides almost unlimited flexibility of logic design.
25 ns 16·BIT PARITY CHECKER (Even Parity)
MC1031 / 1231
MECL II "WIRED OR" FEATURE
.------x+Y"+:z ~r~~'_,..-.-.----t+i---X x + v + z
~-+-+-+--x
WHERE :
X = f (Six Variables)
Y = f (Six Variables)
Z 111 f (Six Variables)
tpd Average =4.0 ns
fetal Power · 200 mW
)
x y z .....--+-<~+--
.---+-+-+-+--Y
z '--+-+++-Y
~~+-++- x y
z .....-+-+-+--
Z INPUTSl
-z
NOTE : All Outputs That Are Used Require An Internal or External Pulldown Resistor.
NOW - UP TO 65% LOWER PRICES ON SOME MECL II TYPES!
TYPE NO.
FUNCTION
PRICE 1000-UP
MClOOlP MC1002P MC1003P
MC1004P MC1005P MC1006P
MC1007P MC1008P MC1009P
MClOlOP MC1011P MC1012P
MC1013P MC1014P MC1015P MC1016P
Single 6·1nput Gate Single 6-lnput Gate Single 6·1nput Gate
Dual 4·1nput Gate Dual 4-lnput Gate Dual 4-lnput Gate
Triple 3-lnput Gate Triple 3-lnput Gate Triple 3-lnput Gate
Quad 2-lnput Gate Quad 2-lnput Gate Quad 2-lnput Gate
85 MHz AC Coupled J-K Flip-Flop Dual R-S Flip-Flop (Pos. Clock) Dual R-S Flip-Flop (Neg. Clock) Dual R-S Flip-Flop (Single Rail)
$1.25 1.25 1.25
1.30 1.30 1.30
1.35 1.35 1.35
1.40 1.40 1.40
2.40 2.60 2.60 2.60
OTHER COMPLEX FUNCTIONS TO BE ANNOUNCED SOON:
TYPE NO.
MC1017P MC1018P MC1019P
FUNCTION
Translator (Sat. Logic to MECL) Translator (MECL to Sat. Logic) Full Adder
PRICE 1000-UP
$2.75 2.75 3.50
MC1020P Quad Line Receiver MC1021P Full Subtracter MC1022P Type D Flip-Flop
1.25 3.50 3.70
MC1023P Dual 4-lnput Clock Driver (-2ns tpd) MC1024P Dual 2-lnput Expandable Gate MC1025P Dual 4- and 5-lnput Expander
5.80 1.35 1.30
MC1027P MC1029P
MC1030P MC1031P MC1033P
120 MHz AC Coupled J-K Flipflop Data Distributor
Quad 2-lnput Exclusive OR Gate Quad 2-lnpu~ Exclusive NOR Gate Dual R-S Flip-Flop (Neg. Clock)
5.80
2.60 3.95
J.95 2.60
16-Bit Coincident Memory 100 MHz Decade Counter 180 MHz Type "D" Flip-Flop
Transmission Line Driver Dual Schmitt Trigger
New MECL Data Brochure provides "how-to-use" information plus complete specifications, for the World's Fastest, Most Advanced I/C Logic Line ... 80-pages of pertinent applications information, complete data for 58 MECL II devices (30 circuits) and a general information section that includes a full explanation of the emitter coupled logic design approach. It's yours for the asking! Simply write on your company letterhead to: P.O. Box 955, Phoenix, Arizona 85001.
-=--=
i'Ect
Most MECL II circuits also available in ceramic flat pack (T0-86) for -55° to +125°C operation.
~·
MOTOROLA Se1'1'1iconductor Product:s Inc.
Electronics I April 29, 1968
Circle 55 on reader service card
55
Apri l 29, 1968 IHighlights of this issue
Technical Articles
Eliminating ground-loop errors
page 58
Ground-loop current plagues both the designer and user of electronic equipment. Separate grounding of electronic gear in a common system can cause hum in hi-£ systems or, more importantly, errors in data-measuring systems . A metl1od that eliminates t11e problem uses two operational amplifiers connected as a differential circuit.
Speedier a-d converter adds integrating ramp
page 69
One way to waste the valuable time of a computer is to feed it an analog input through a slow a-d converter. Today's process-control and data-acquisition systems demand speeds up to 20,000 conversions per second with a resolution of 14 bits. A new development, tlrn triple-ramp-integrating converter, not only does the job as well as tl1e successive approximation technique, but does so at lower cost.
New isolation boosts performance
of diode arrays page 75
The advantages of discrete diode arrays (high forward conductance) along witl1 the advantages of monolithic arrays (economy and uniformity) can be achieved using a new airisolation process. The technique, an outgrowth of the "mesa" proposals of a few years ago, may be applied in the future to other types of integrated circuits.
Automatic checkout rides co-pilot page 81
Electronics Avionics companies have been tackling the
problem of getting· cumbersome checkout equipment, now housed in huge ground vans that have to be brought up to the flight line, down to a size that will let it ride aboard the plane. Their aim is to give the pilot a constant reading of the performance of the many systems tl1at today's military craft must carry, automatically detecting faults occurring while the plane is aloft. A survey of some of the approaches taken by avionics engineers indicates that on-board automatic checkout equipment may one day be as routine as a fuel gauge. The in-flight performance monitor designed by tl1e Grumman AiTcraft Engineering Corp. for the Navy's E-2A Hawkeye airborne early warning system is shown on the cover.
Coming
Testing integrated ci rcuits
\i\Tiili the rising complexity of integrated electronic devices comes an increasing challenge in testing them. Manufacturers and users alike have developed ingenious met11ods to guarantee high performance and reliability in 1c's.
Electronics IApril 29, 1968
57
Design theory
Protecting data from the ground up
Error voltages that are created by circulating currents between pieces of separately grounded electronic equipment can be eliminated by using a differential data amplifier
By Robert I. Demrow
Analog Devices Inc., Cambridge, Mass.
Common ground may be the goal of diplomatic machinery, but it's the bane of data-measuring gear. Ground-loop currents running between pieces of equipment that are grounded at separate points to a common ground introduce voltages that can throw off the measurements.
There are ways to counter ground potential errors-the most practical and inexpensive of which i.s to use two operational amplifiers connected in a differential configuration as the data amplifier-but all the answers raise some questions of their own.
The ground-loop problem, of course, isn't limited to measuring devices. In an ordinary hi-fi installation, as on page 60, where signal source and power amplifier each has its own power supply, a 60-hertz leakage current flowing between the primary and secondary of the two transformers will be converted into a 60-hz noise at the power amplifier's input.
Dust and atmospheric humidity reduce the leakage resistance between primary and secondary transformer windings to a few megohms, and poor primary-to-secondary shielding places a substantial leakage capacitance in parallel with the leakage
The author
Robert I. Demrow, a staff engineer at Analog Devices, has the job of finding new applications for operational amplifiers, evaluating the devices' performance, and checking out problems. He received his MSEE from Northeastern University in 1958, and has worked for GE, the Foxboro Co. , and Honeywell.
resistance. For example, 100 picofarads of leakage capacitance puts roughly 30 megohms reactance at 60 hz in parallel with the leakage resistance. These leakage paths set up currents that circulate between the amplifiers, developing spurious hum voltages that are applied with the signal to the output amplifier.
The leakage currents flow in parallel through the common ground and the signal lines connecting the amplifiers. Both paths have finite resistances, Hg and Rs, though they may be as low as a fraction of an ohm. In practice, plug-and-socket connections introduce appreciable resistance, especially if they're oxide-coated or loose.
The leakage resistance and reactance of the two transformers are lumped together as a leakage impedance, ZL, connected in series with the source, VL. If each transformer has a leakage resistance and reactance of 5 megohms, the two series-connected leakage impedances will total somewhat less than 10 meghoms. Since transformer leakage is by far the largest impedance in the ground-current path, the ground currents will be roughly equal to VL/ZL. With a 115-volt source and a 10-megohm load, for instance, the ground-loop current would be a nominal 11 microamperes split between the parallel paths provided by Rg and the series-connected resistances, R0 , R. , and Rrn.
Hum at the speaker
Because the amplifier's input resistance, Rrn, is very high compared with the ground-conductor's resistance, Rg, most of this 11-µa ground-loop current flows through Rg. Hum voltage developed across Rg in this case would be 11 x Rg.
58
Electronics IApril 29, 1968
If the ground path, including plug-and-socket connections, has a resis tance of 1 ohm, the hum voltage, Vnc, across Rg will be 11 microvolts. This voltage is then applied to the series network of R0 , Rs, and Rn;, but because amplifier-input resistance is usually several orders of magnitude greater than R0 and R,, almost the whole of the hum is developed across Rn;.
But if hum is a nuisance in a hi-fi system, the effects of ground-loop currents can be a disaster in a data-measuring system. The key specifications for a data amplifier include high common-mode and differential-input impedance, a high commonmode rejection ratio, good d-c stability, and in many cases, wide bandwidth, fast slewing, and fast settling time.
Data amplifiers are widely used to measure lowlcvel signals developed by strain gages, thermo-
couples, biological probes, and other sensitive transducers. The transducer is often located at a remote test site, while the amplifier is housed in an instrumentatiO!J. center. For example, signals developed by strain gages strung along a bridge structure would most probably be fed back to a data center at one end of the bridge. Similarly, thermocouple-temperature signals produced during tests on rocket engines would usually be fed to recorders and computers located in a well-protected blockhouse.
Separate sites for transducer and instrumentation mean separate grounds, and this creates a ground-loop problem.
Since the requirements for measuring millivolt signals developed by remote transducers aren't available in any one off-the-shelf op amp, the data amplifier must be designed from scratch. Key per-
Defining some op-amp properties
Parameter Signal Gain
Invert- Noning inverting Differential
Rt/R; 1 + Ri/R2 R2/R1
DifferenDifferential' tial4
l+N
-Rs/R2
Diffcrential3·4
J ~[
R,
l
+
2RR21
Differential Input Resistance
NA NA
2R1
+ Rm [l+Al
R1+R,
1
R.A +2R1 R2
Common Mode Input Resistance
R;
Rm [l+A.B] Paralled by
_2!_ [ R1
RcM - 2-
RcM
J + R2RcM
R2+RcM
R1R2 R1+R2
-Rc2M-
Voltage Due to Voltage
Drift
Drift!
Referred
to Due to Current
Input
Drift2
Cos[1 Cos
+~] R1
ibR;
ib R souroo
~: ] eo. [1+
2eo..
i<1R1
ibR.
4eo· [ 1
+4~R3 ]
ib[R1 +R2]
J eo, [ 2 + 1 +GAGIANIANB
id R, ibRs + GAIN A
CMRRDue to
NA NA
Resistance Deviations, K
1 + GcL 4K
GcL/4K
l / 4K
GA~ A (1 + GAIN B) 4K
CMRRDue to
NA
Amplifier's Gain Inequality
A/(A2-A1) A/(A2-A1) As listed in
data sheet
A 2(A2- A 1 )
NA
2(A2A__ Ai) in parallel
with
A A, -A1
(GAIN A)
Combined Error, Cctn/Vcm ( CMRR = Cctn;Vcm )
NA
(A2-A1)/A
4K 1 + GcL
+A. - A, A
. '
4K GcL
4K
+2(A2-A1 A
2(A2 - A, ) A
(A2 - A, ) +GAIN A +A
4K +GAIN A (l+GAfNB)
:~ NOTES 1. c., is the a mplifier offset voltage drift clue to temperature ie., (
) 6T.
:~) 2. ib and id is the amplifier bias current drift and the bias difference current drift clue to tempera ture ic. , (
6T.
3. Calculations shown for R1 = R, 4. 'rhese am plifier parameters arc assumed equal in magnitude but not necessarily of the same sign.
Electronics I April 29, 1968
59
Around the loop. Transformer leakage sets up ground
A
current 1., which circulates
between the two amplifiers
v+
via path ABCD (top).
Ground-loop current flows
through signal and ground
lines connecting the two amplifiers (lower left), and
creates hum voltage, v., at
115v 60hz r-------1
power amplifier's input
terminals (lower right).
formance parameters have to be built in at a cost perhaps double that of a premium op amp.
Test-bed
In the data-measuring system on page 62, signals generated by a thermocouple placed in the stream of exhaust gases from a rocket engine undergoing test are fed over shielded cables to recording and data-processing equipment sheltered some 200 feet away. The difference in potential between the system's two ground points ends up as an error voltage applied to the amplifier along with its true input signals, a difficulty analogous to the hi-fi hum.
In extreme instances, ground potential difference at this test station could be as much as 5 volts; more typically, though, differences of 1 mv upwards are almost always present.
Typical sources of ground potential here include electrochemical effects, rectifier effects caused by soil crystals contacting buried metals and ores, thermoelectric effects created by temperature gradients in buried metals and soil elements, plus capacitive, inductive, ·and resistive coupling from power lines and charged clouds.
All these voltages can be lumped together into a single ground source, Vg, in series with the sum, Zg, of all the ground impedances between rocket
and blockhouse. As in the hi-fi case, it turns out that a substantial portion of this ground voltage is developed across the data amplifier's two input terminals.
Impedance levels are different, however. Whereas it would be rare to find the earth's resistance exceeding about 1 ohm, it isn't unusual for 200 feet of connecting cable to introduce 20 ohms or more of resistance. Consequently, practically all the 10-mv ground voltage is applied across points A and B in the diagram, and in turn across the amplifier's input terminals.
The thermocouple transducer acts as a low resistance, designated 2RT, split between the two separate current paths joining A and B. The thermocouple itself is represented for simplicity by resistance RT in each ground-loop path.
Some remedies
Before discussing the use of an op-amp differential circuit to eliminate ground potential errors, it's perhaps worthwhile to outline alternative approaches sometimes adopted. Some are aimed at interrupting the continuity of the ground loop while preserving the path for transducer signals. Increasing the ground impedance value Zg would be a step in this direction.
Another tactic-an expensive one-is to reduce the
60
Electronics I April 29, 1968
v+
SIGNAL AND GROUND LINES HAVE 1/10 TO 10 OHMS RESISTANCE
1 9~ VL/ZL (ZL>> R9 )
Vee~ IgRg~ VLRg/ZL BECAUSE R1N>>(Ro+Rsl' vh~ Vec~VLRlZL
resistance of ground conductor Rg so as to shortcircuit the ground potentials, VAB·
Yet another approach would break the groundcurrent path by operating the amplifier from an isolated power supply or by insulating the thermocouple from ground.
These methods are more easily described than implemented. For one thing, the amplifier is frequently used to feed signals into recorders, analogto-digital converters, displays, and other data-handling devices, all of them likely to be separately grounded. In these cases, the ground loop is completed through the amplifier to ground via the additional piece of equipment, nullifying efforts to run the amplifier from an isolated supply.
For good thermal response, it's often necessary to weld the thermocouple to the shucture monitored. And even if this extreme measure weren't required, the ionized gas issuing from the rocket motor would certainly provide a low-resistance path from thermocouple to ground.
In any event, the instrumentation engineer is usually presented with a pair of wires carrying signal- and ground-loop noise, and has no chance to make large-scale modifications in the over-all system. He must instead find ways within the limits of his instrumentation package to reject ground currents and the resulting error voltages.
One common method of inter-
rupting ground-loop currents is
D
to interpose an open circuit be-
tween signal source and ampli-
fier, arranging for the open cir-
cuit to transmit signals while
blocking ground-loop currents.
This seemingly impossible job
is handled by a transformer be-
tween the thermocouple and final
amplifier, shown on page 63. A
modulator-demodulator arrange-
ment, the transformer responds
only to signal voltage V, and
presents an open circuit to the
ground voltage, Vg.
This circuit can handle very
wide voltage differences between
signal and amplifier grounds, or,
when used with bridge and other
differential sources, very high
common-mode voltage levels. A
further merit is that its error re-
jection is independent of any
closed-loop gain setting-which is certainly not the
case in the differential-circuit scheme.
Disadvantages include limited bandwidth, which
can only be a fraction of the modulation frequency,
and output errors created by intermodulation be-
tween the chopper and the signal. Another draw-
back is that error-reducing feedback cannot cover
both modulator and demodulator without restoring
a path for ground currents.
The switched-capacitor technique is an alterna-
tive way to break the ground-loop circuit. Similar
in principal to the modulator-demodulator method,
it tends to yield similar ach·antagcs and disadvan-
tages, along with the added problem of poor fre-
quency response.
Balancing act
The most widely applied method of minimizing ground-loop errors aims not to attenuate the current, but to apply identical fractions of ground-loop voltage to the inverting and noninverting terminals of a differential amplifier. The ground voltage is thus seen as a common-mode voltage when the transducer signal is applied differentially to the amplifier's input terminals, and if the amplifier has high common-mode rejection, it will ignore the spurious voltage and respond only to the valid input.
I Electronics April 29, 1968
61
ROCKET MOTOR
- -- - - - - - - 200 FEET-----------,~
FINITE LINE RESISTANCES
TEMPERATURE SIGNALS, V5
60 hz POWER
TEMP DATA TO RECORDER
JUNCTION EFFECTS
WJ""'\
ELECTROCHEMICAL EFFECTS
THERMOELECTRIC EFFECTS
LEAKAGE INTO SOIL FROM - - - POWER LINES
THERMOCOUPLE OUTPUT
VN IS
COMPONENT
OF GROUND
20
VOLTAGE V9
APPLIED TO
AMPLIFIER
'SUM OF GROUND
EMFs~IOmv----+----
~~'ie IF RIN»(Rs+Rrl ~~ VAS~ V9 ::::;;: IOmv Vicious cycle. Separation of signal source and data amplifier can lead to considerable voltage difference between ground connections at each location (above). Ground voltage, reaching 5 volts in extreme
v. instances, is represented as in series with ground impedance Z, (lower left). Ground -loop current set up v. v,, by develops error voltage at amplifier's input terminals (lower right) .
The ground-loop currents shown on page 64 flow through parallel paths APB and AQB, adding to voltages V1 and V 2 at the amplifier's input terminals. If the signal source were removed, these voltages would b e created solely by the groundloop currents. Accordingly, it's possible-for d-c errors at least-to adjust the balance resistor, Rn, so as to make V1 exactly equal to V2· The equal voltages become a common-mode input for the amplifier, which ideally develops no output for identical voltages applied to its inverting and noninverting input terminals..
Commercial amplifiers are available with common-mode rejection ratios of 106 or more; these can reduce every volt of common-mode input to a microvolt of equivalent common-mode error, making over-all accuracies of 100 ppm feasible.
This setup handles only d-c common-mode errors, but the principles of balancing a-c inputs are similar.
So far, the op-amp differential circuit has b een described only as an economical way to overcome ground-loop problems in high-accuracy data-measurement applications. However, it should b e noted that the differential arrangement can be used for data measurements in which the transducer's signal is differential rather than single-ended.
Strain-gage elements, for example, are usually connected in vVheatstone-bridge arrangements, and develop push-pull output signals perched on relatively high levels of common-mode voltage. Even when the strain-gage elements are isolated from ground by as much as leakage capacitance permits, the amplifier must invariably be a differential one
62
Electronics \ April 29, 1968
CHOPPER
Vo
GROUND fMPEDANCE
GROUND VOLTAGE v9
BREAK~ TRANSFORMER
DIRECT CONNECTION BETWEEN A AND B OPENS GROUND LOOP
CAPACITOR TRANSFERS SIGNAL VOLTAGE TO AMPLIFIER BUT BREAKS CONTINUITY OF GROUND LOOP BETWEEN A AND B
Blocking grounders. Magnetic coupling between transformer's primary and secondary breaks direct connection for ground-loop currents and transmits signal as equivalent a-c voltage (above) . Alternative technique breaks direct ground-loop continuity with a switched capacitor that alternately charges to signal voltage V, and then passes this voltage to the amplifier.
to extract millivolt signals from several volts of common-mode carrier. Biomedical measuring instruments, too, invaria:bly require differential amplifiers to exh·act information from high levels of 60-hz pickup.
Picking a pair
Having established that a circuit that has to measure millivolt signals in the presence of several volts of common-mode or ground-loop noise must have low drift, high CMRR, high input impedance, fast response, and variable gain, the next step is tq see how conventional operational amplifier circuits fulfill these basic requirements.
The need for impedance levels of 1,000 megohms or more rules out a differential amplifier based on an inverting circuit whose input impedance is equal
to the circuit's input resistance; a noninverting circuit can provide adequate input impedance when used as a differential amplifier.
D-c stability depends on the drift of the two op amps selected for the differential circuit. Chopperstabilized op amps are out of the running because they require special power supplies to offset their single-endedness. But some conventional operational amplifiers have the necessary d-c stability, along with good response and input impedance.
The closed-loop gain and gain linearity that an amplifier can provide depends upon the amount of open-loop gain available for use as negative feed-
back. The relationship between closed-loop gain sta-
+ bility, % ~Gci/G01 , and open-loop gain variation,
% ~A/A, is~ % Gc1/Gc1 =% ~A/A X 1/(1 A{3)
I Electronics April 29, 1968
63
TRANSDUCER SIGNAL
RESISTOR BALANCES D-C COMMON -MOOE
ERRORS
Vo=Gc;L("l-Vzl
ADJUST
R8
TO
MAKE
R
=_ _R__ =o<
R+Rs-+R11 +R8 R+Rs+RL
V.=
R
(V. +~)
I R... Rs +Rll +Re A 2
GROUND-LOOP CANCELLING RESISTORS, R, ARE USUALLY THE AMPLIFIER'S OWN INTERNAL COMMON-MODE INPUT RESISTANCE VALUES, RcM
;?- D-C COMMON-MODE ERRORS ARE ZERO WHEN ~ =
cM1
CM2
Identical twins. Ground·loop errors can be reduced by convert:ng g1ound-loop voltage into common-mode
v. input voltage. Equal parts of are applied to inverting and non '. nverting terminals and their effect is
scaled dcwn in proportion to amplifier's CMRR (above). In practical circuit, high-value balancing resistors, R, are replaced by amplifier's common-mode input resistances, Re"- Although this setup handles cnly d-c balancing, the same principles are applicable to a-c ground-loop and common-mode errors.
where f3 is the fraction of open-loop gain used as feedback. Because I/f3 is very nearly the same as
closed-loop gain G,.i, and Af3 > > 1, the equation
simplifies to
% t:..G,.1/Cc1 = % t::..A/ A x Geil A
If the data amplifier must provide 2,000 volts/ volt gain for d-c signal scaling, and specifications call for 0.5% gain linearity, the stability equation can be manipulated to give the nominal value of open-loop d-c gain A in terms of the amplifier's expec ted open-loop gain variation, % t::..A/ A.
For example, if open-loop gain varies by 25%
due to loading, aging, or the effects of temperaturethat is 100% t::..A/ A = 25%-then 0.05% = 25% X 2,000/ A. So the minimum open-loop gain under
= these conditions is 25 X 2,000 + 0.05 106, or
120 db-a bit beyond the range of op amps with the requiTed stability.
Chopper-stabilized amplifiers could handle it, but, as noted earlier, they need elaborate power-
s11pply arrangements when used in high-impedance differential circuitry. Thus, high closed-loop gain, input impedance, and .common-mode rejection with low drift make off-the-shelf op amps impraCtical for this kind of differential circuitry.
64
I Electronics April 29, 1968
Circuit design
Designer's casebook
Designer's casebook is a regular feature in Electronics. Readers are invited to submit novel circuit ideas, packaging schemes, or other unusual solutions to design problem:;. Descriptions should be short. We'll pay $50 for each item published.
FET's resistance change
trips heater control
By Emanuel Elad
University of California, Berkeley
Transconductance in a field effect transistor is a parameter that can accurately establish the hightemperature cutoff in a heat chamber. As the temperature in the chamber rises, transconductance drops, causing a bistable circuit composed of the FET and a bipolar transistor to switch. In switching, the bistable circuit opens the line between the chamber's heating elements and the supply. By adjusting a potentiometer between the FET and the bipolar, the cutoff point is determined for any temperature between 35°C and 65°C.
Closing the reset switch allows a negative voltage to appear on the other side of RG at the base
ot Q~. This strongly biases Q~ off, establishing a 1-milliampere current How through Ra, Ri, ar.d R2 . The potential drop across Ra causes an 11-volt d-c
level on Q/s collector, which is used to control the heater's supply line.
Voltage division by R 1 and R~ results in -0.6 volts at the gate of Qi. Drain-to-source resistance in the FET is low at this gate voltage, and conse-
quently high current-in the milliampere range-
flows through Qi and the drain resistor R8. Only microamperes flow through R4 and R;:;-the two resistors paralleling the FET-making for a negligible
\ oltagt: drop across H;;. The high negative voltage that is therefore present at the base of Q~ keeps it
off despite the opening of the reset switch. As the ambient temperature increases, clrain-to-
source resistance in Q 1 increases, thus deflecting current flow out of Qi into R4 and R~. The voltage drop across R,, increases until a level is reacheddependent on the setting of R4-where the base of Q~ becomes positive with respect to its emitter. Enough current Bows through the limiting resistor R 1 to bias Q~ into saturation, and the increase in Q2's beta resulting from the rising temperature makes it easier to switch that transistor on. This places the collector of Q2 close to ground potential, thus removing the heater control voltage.
Resistors R1 and R2 now divide the -12-volt sup-
- - - - -·-- ----
+12v
Rt 10k
o,
2N3823
CONTROL VOLTAGE
Rz
10k
I ~RESET
I
I
I Elect~onics April 29, 1968
65
ply. The gate voltage is therefore -6 volts-which is above the FET's pinch off-and current flow in Q~ is mere microamperes.
After the ambient temperature falls below the circuit trip point, the reset switch must again be closed.
The circuit can be made to trip at low temperatures by placing the reset switch between the gate of Qt and resistors R2. It's preferable for reasons of accuracy, hmvevcr, to use a p-channel FET and a pnp transistor in that application.
SCR helps video signal gate a-c power line
By Wayne Simister
University of Utah, Salt Lake City
Television receivers scattered throughout a closedcircuit system can be turned on by video signals from a camera. These signals-usually only 30 microampcres-are able to switch on the 117-volt line because the scR circuit they gate helps in the switching.
·when no signal is present at the gate of SCR1 re-
sistor R~ maintains the gate and cathode of the SCR at the same potential. Resistor R3 at the gate cathode of scR2 does the same thing. Consequently the a-c line between the receiver and the 117-volt sup-
ply is open.
When a detected video signal reaches R2, SCR1 is gated into conduction. When the positive part of
the a-c voltage appears it is passed through SCR1. Power is delivered to the receiver's d-c supply and capacitor C1 charges through to D1 and the currentlimiting resistor R;;, the positive cycle's peak volt-
age. After the positive cycle returns to zero, C1's
discharge through R4 and R3 gates scR2 into conduction. Although scR2's gate voltage isn't present during all of the negative cycle, it stays on until the peak voltage is reached. Anode current in the interval between the peak and zero points keeps
the scR on. As long as the detected signal is present at the
gate of SCR1, each succeeding cycle will be coupled into the receiver's supply. The values of R1 and R2 must be selected with care, since a low R1 and high R2 will make the sCR's gate sensitive to line transients. Conversely, a high R1 and low R2 weaken the gate signal so much that it doesn't work.
The 7-watt bulb connected across the line absorbs
any inductive kicks that might occur in the receiver's filter network. A spike, resonating between capacitor C1 and internal inductance, prevents SCR2's from turning off. If the circuit is used to control an electric motor instead of a tv receiver, the incan-
descent bulb must be larger to absorb the induc-
tive phase shifting.
VIDEO 51GN4l
TELEVISIO"l RECEIVER
FROM TV
CAMERA
DETECTOR
Rz
10~
-- -- --- --- - - - -- - - - - - -....
66
Electronics J April 29, 1968
EMITTER BIAS CIRCUIT
o,
HP3001
C1 ( 0.Spf
R1
1k
O.tµh
-:];
C3 f,OOOpf
TUNABLERESONANT CIRCUIT
COLLECTORREGULATION CIRCUIT
TRANSISTOR SWITCH
+ 12vd-c
(
C4 0.5 pf
TO MIXER
P-i-n diodes turn on
microwave bands faster
By August Barone
Airborne Instruments Laboratory, Deer Park, N.Y.
Discrete frequency bands-necessary in wide-spectrum communication equipment-are generated by several hmable oscillators in a receiver. These oscillators must turn on immediately so the operator won't lose time in sweeping the bands in search of a signal. If the junctions in the oscillators' transistors are kept at 50°C, full oscillations begin 50 milliseconds after the turn-on signal appears. Collector current maintains this high junction temperature, and a p-i-n diode in each oscillator is used for switching in and out of a-c operation. Conventional systems stop oscillations by removing the d-c bias from th e transistors. Unfortunately this lengthens the h1rn on time of th e oscillator because the junctions start th eir temp erahue rise from a low temperature. The obvious drawback in the conventional system is the long waiting times necessary while switching through the different bands in the receiver. These waiting tinrns are long enough to cause the operator to miss distress signals.
P-i-n diodes are nonrectifying semiconductors used extensively as switches in microwave circuits. Unbiased, the diode has naturally high resistance and low capacitance because of the intrinsic region, where carrier lifetime is long. When forward-biased
by a d-c voltage, the intrinsic region has a high conductivity.
A p-i-n diode connected across the collector-emitter junction of a transistor offers a high impedance while a band-command trigger holds the line open between it and the + 12-volt d-c supply. Consequently, regenerative feedback can be coupled through C1 from the oscillator's collector circuit into the emitter's tank circuit. Oscillations occur and are coupled out through C-t until a command signal opens the d-c line.
·when this line is opened, current through D 1 reduces its resistance to about 10 ohms. Any a-c voltage that might appear in the collector circuit won't have the type of phase relationship that causes oscillations, because the low resistance lets th e current flow back to the emitter circuit. vVhen the operator hims on an oscillator by closing the d-c line, the oscillations begin in 50 milliseconds and the frequency is within 4% of nominal value.
Short lead lengths are necessary on all the components of this circuit, especially the bypass capacitor C3. At microwave frequencies the added inductance resonates with the bypass capacitor. The p-i-n diode must also be carefully located and have a minimum lead length, since any inductance resonates with the isolating capacitor C2· Instead of using C1 as the feedback capacitor the circuit designer may wish to make use of the p-i-n diode's capacitance. Circuit operation is not changed if this method is used. The capacitance in the diode which is low when no d-c current is flowing is shorted out when the p-i-n diode is forward biased by the closed command switch.
Electronics I April 29, 1968
67
zeroed in on some grid problems so you can get higher power gain.
Want up to 20 times power gain in a cathode driven circuit? Try one of the tubes in our complete zero-bias power triode line. While you're solving problems, throw out the bias power supply. Forget some of the associated circuitry. And don't worry about destroying the tubes if you lose grid voltage. They don't need any.
These triodes are designed for use as Class B or C amplifiers in audio or radio-frequency applications. We've got zero-bias triodes ranging from 400 watts to 10,000 watts - the most complete range of zero-bias triodes available.
Contact your nearest distributor or the Varian Field Office for further information. Offices are located in 16 major cities. Ask Information for Varian Electron Tube and Device Group.
TYPICAL OPERATION CLASS B RF LINEAR POWER AMPLIFIER , GROUNDED GRID
Plate Voltage.
Vdc Max Signal
Plate Current. A Drive Power, W Output Power, W Filament Voltage, V Filament Current, A
GLASS
CERAMIC
3-400Z 3-500Z 3-1000Z 3CX1000A7 3CX3000A7 3CX10000A7
3000 3000 3500
2500
5000
7000
0.333 0.333
32
35
655 644
5.0 5.0
14.5 14.5
0.75 85 1770 5. 21.5 23 .0
0.800 60 1170 5 .0 28/ 33
1.56 215 5500 7.5 51
5.0 1540 24 ,200 7.5 94/ 104
EIMAC
Division of Varian
San Carlos, California 94070
68 Circle 68 on reader service card
Electronics I April 29, 1968
······~···11a·1,11···································
. ..
~·· ~··
~llJllJ ll
Industrial electronics
Triple play speeds a-d conversion
Designed for high-performance applications, triple-ramp converter does the job 85 times faster than dual-integrating-ramp circuits
By H. Bent Aasnaes and Thomas J. Harrison
Systems Development Division, International Business Machines Corp., San Jose, Calif.
The high performance demanded of today's processcontrol and data-acquisition systems require analogto-digital converters capable of speeds up to 20,000 conversions per second and a resolution of 14 bits. A new technique, triple-integrating-ramp conversion, not only does the job as well as the successiveapproxin1ation technique, but does so at a lower cost.
Unlike the successive-approximation converter, the triple-ramp circuit doesn't require expensive component precision. Instead, it operates on the voltage-to-time principle of the relatively inexpen-
sive dual-ramp converter. This principle involves the .conversion of an input voltage to a time interval, which is easily measured with digital methods. But the third ramp makes the big difference-putting the new converter in the same high-performance class as the successive-approximation circuit.
An experimental h·iple-ramp converter is now undergoing tests at the International Business Machines Corp.'s San Jose, Calif., facilities.
The new circuit achieves its high speed by conve1ting th e integrated measured analog voltage-the first ramp-during two subsequent ramps, one
Electronics I April 29, 1968
69
coarse and one fine. The coarse ramp rapidly converts most of the input voltage by using less-thanfull resolution. During the fin e ramp, the remaining voltage is converted for full resolulion. Total conversion time is about 1/80th that when converting the full value at full resolution.
Even though the voltage level at which the converter switches from the coarse to the fin e step may not b e precisely known, any error is included in the third, or fine, ramp, where it is resolved and added to the converted value obtained during the second, or coarse, step.
Building blocks
In single- and dual-ramp converters, the input-
signal amplitude is changed to a time interval as an
intermediate step in obtaining a digital value. And
during this interval, pulses are counted-with th e
total pulse count corresponding to the unknown
voltage.
The single-ramp circuit compares the analog in-
put signal, Vin, with a ramp voltage, Vt(t), which is
produced by a function generator. Because the slope
of the ramp is constant, the time interval b etween
= = Vr 0 and Vr Vin is proportional to Vin·
Single-ramp converters have long been used in
low-cost, low-p erformance indush·ial applications.
Accuracy in this type of converter primarily de-
pends on the linearity of the ramp generator, and
the stability of both the clock frequency and
the comparator threshold voltage. Moreover, the
circuit is sensitive to any noise on the input signal
during the ins tan t of comparison of Vr and V10,
and its conversion time is directly proportional to
the value of the input voltage.
In an n-bit binary converter with a clock fre-
quency, fc, in pulses p er second, the maximum num-
b er
of
pulses
is
2 11 ,
so
the
co n ve r s ion
rate
is
limited
to fc/211 conversions a second. Therefore, a 12-bit
converter u sing a IO-megahertz clock can only pro-
vide about 2,500 conversions a second. These fac-
tors generally limit the single-ramp converter to
applications requiring fewer than 12 bits and to
speeds from 5,000 to 10,000 conversions a second.
Th e double-integration or dual-ramp technique doesn't depend on a highly stable ramp and clock for conversion accuracy. The input signal to the dual-ramp converter is first integrated for a fixed time interval, set by counting a number of clock pulses. The integrator voltage at the end of this interval is proportional to the input signal averaged over the integration time. A reference voltage of polarity opposite to the input signal is then integrated for the time it takes to reduce the integrator voltage to its initial value. A binary number proportional to the average-signal value is obtained by counting clock pulses during this second integration p eriod.
This up-down integration makes the dual-ramp converter inherently more accurate than the singleramp converter and results in an over-all conversion linearity superior to that of the integrator. Since the digital number is independent of the integrator's time constant, precision resistors and capacitors with low temp erature coefficients aren't required. Moreover, with the same clock measuring both tl1e first and second integration intervals, a precision clock is unnecessary. Noise error is minimized because t11e input signal is integrated, and the actual analog-to-digital conversion occurs during the second integration p eriod-after the input signal has been disconnected from the converter.
However, for all the dual-ramp converter's advantages, there is a price to b e p aid in speed. A total of 211+1 clock pulses is normally required for an n-bit full-scale conversion. ·with a 10-Mhz clock and a 14-bit resolution, which is feasible using inexp ensive components, a rate of only about 300 conversions per second can be obtained.
Although this 14-bit conversion rate is adequate for some instrumentation systems, many processcontrol and data-acquisition installations require higher rates. The successive-approximation a-cl converter commonly used for such applications is capable of 14-bit resolution at 20,000 conversions a second. This typ e of converter, however, is sensitive to noise, and is exp ens ive-primarily b ecause its design doesn't lend itself to integrated circuits.
V(t)
INTEGRATION OF INPUT SIGNAL
INTEGRATION OF VOLTAGE REFERENCE
to
t
Only two. In dual-ramp converter, the unknown input signal is integrated for a fixed time, t o tot,. Then, integration of reference voltage yields a time interval, ti to t o, which is proportional to input signal.
INTEGRATION OF INPUT SIGNAL, Vx
INTEGRATION OF REFERENCE SIGNAL, VR
, , , , , , ,
t3 ,
t
Added step. Output of triple-ramp analog-to-digital converter is integrated twice. Then a third ramp, from
t2to t a. provides vernier action for high-speed,
high-resolution conversions.
70
I Electronics April 29, 1968
c
TO CONTROL R
TO CONTROL TO CONTROL
INTEGRATOR TO SWITCHES S1, Sz, S3
CLOCK
to - - - - - -
CONTROL
---- 2 13 12 11 10 9 8 7
2 2 22 22 2
6
5 2
4 2
3 2
2
2
1
2
2°
COUNTER
PART 1
PART 2
Precise split. Like a dual-ramp integrator, but with one mo re comparator and switch and a two-part counter, the triple-ramp converter provides fast 14-bit conversion.
A triple-ramp converter with the same 14-bit resolution contains a two-part binary counter, two comparators, an analog integrator, control logic and three switches, and a pulse clock. The circuit differs from th e dual type in that the dual's second ramp is broken into the two ramps-coarse and fine. The converter's three main analog signals are the input voltage, Vx, a reference voltage, -Vn, and another reference -\111 /27· The control logic determines which signal becomes the integrator's input.
Converting by parts
When the integrator output reaches a predetermined threshold, Vr, comparator 1 changes state. Although the value of Vt isn't critical, it must be at least slightly greater than the absolute value of Vn/27· In a similar manner, comparator 2 responds when the integrator output reaches ground. The counter, divided into two parts having seven bits each, is connected so that overflow pulses from part 2 (2° to 26) proceed into part 1 (27 to 213) . Sequencing th e converter's internal operations is the control circuit.
The conversion cycle consists of three time-based operations: integration of Vx for a fixed time interval, integration of - Vn until the first clock pulse after the integrator output reaches the threshold, and integration of - Vn/27 until the first clock pulse after the integrator output causes comparator 2 to change state. During the first two integrations, clock pulses accumulate in part 1 of the counter and, during the third, pulses accumulate in part 2.
A conversion cycle starts at tin1e t0 · The initial integrator output voltage is:
(1)
where -Vr is an offset voltage resulting from minor tin1e delays in th e circuits. Each part of the counter is at zero. The control logic closes S1 and opens S2 and s~, th ereby connecting analog input voltage Vx to the integrator. Then Vx is integrated for the fixed time interval
(2)
determined by the tin1e it takes for part 1 of the counter to count 27 clock pulses. The last pulse resets part 1 to zero. The integrator output voltage at this time is
Vo(t1) = V1+ R C Vx avg ( t1 - to)
(3)
where the integrator is assumed to be ideal and Vx ai·i: is the average value of the input voltage over the time of integration.
Immediately, the second-ramp operation starts. Reference -Vn is connected to the integrator by closing S2 and opening S1; S3 remains open. This reference voltage is equal in magnitude to the maximum allowable Vx but opposite in polarity. Integration proceeds until t2, the time of the first clock pulse after comparator 1, changes state. The comparator changes state when the integral of - Vn equals Vt. Then, comparator 1 changes state. During the integration of -V11, only part 1 of the counter is running. It receives clock pulses at the 27 stage. At t2, the number in the counter is
(4)
Since each clock pulses enters the counter at the
I Electronics April 29, 1968
71
seventh bit, 27 counts per pulse are added. The integrator output voltage at t~ is
Vo(t.i) = - Vr + v:REI(
Counting precisely
At this point, only SHis closed and the third-ramp operation is triggered. Integration of - Vn/ 27 takes place between t~ and t3, where tHis determined by the first clock pulse after comparator 2 fires . This
occurs when the integrated voltage reaches - Vr. During this interval, part 2 of the counter is run-
ning. At t3, the number of pulses in the counter is
N2 = fc(ta - t2)
(6)
Any counts in excess of 27 overflow into part 1. At t3, the integrator's output voltage is
+ Vo(ta) = - Vr VRCg (t1 - to)
- RVCR (t.i - t1) - 21VRRc (ta - t.i) (7)
Because of the integrator offset and the time delay through comparator 2, this voltage isn't zero. However, as long as the converter runs continuously, V0 (t3) equals the initial voltage - Vr. Equation 7 is then reduced to
which , combined with equations 2, 4, and 6, yields
(9 )
Thus, the number N in the counter at the end of conversion is th e 14-bit representation of the average input voltage over the interval t0 to t1·
Faster by far
The triple-ramp converter, like the dual-ramp type, doesn't require the resistor, the capacitor, and the clock to b e precise or highly stable. Both types minimize noise-induced errors by averaging the input signal, but th e new converter is much faster.
Since 27 pulses have to be counted in each of the three integration periods for a full-scale signal, V"' the maximum conversion time for a 14-bit tripleramp converter is (3 X 27)/£0- about 85 times faster
than a 14-bit dual ramp's 215 /£0 · With a 10-Mhz
clock, the triple-ramp unit operates at about 26,000 conversion s a second, compared with 300 for the dual-ramp device. In general, the triple-ramp converter is faster th an the dual-ramp type by a factor of 3/2(2"/2).
Conversion accuracy isn't affected by the value of Vt. Since - Vn/27 is switched into the integrator at t~, an increase in Vt may result in one less pulse being applied to part 1 of the counter. But this pulse is equal to 128 pulses applied to part 2, so
lhe final count accommodates the error. This means that Vt need not be highly stable, and that the delay and offset voltage of comparator 1 are of little consequence.
Delaying response
Although an offset is the result of a constant delay and only changes in this delay produce an error, the switching circuitry and the integrating amplifier must b e quite fast. Since the integrating amplifier has a finite bandwidth, a delay exists from the time a signal is applied at the integrator input to the time the output appears. A delay also exists between the time the control logic applies a signal to the input switch and the time the inputs actually switch.
A tolerable conversion error would b e one bit, that is, an uncertainty in the value at the 2° stage. During one clock pulse p eriod, 128 counts can enter the counter. Since th e clock p eriod is 100 nsec for a 10-Mhz clock, each count is equivalent to 100 nsec divided b y 128, or 0.7 nsec. Th erefore, each 0.7 nsec increment in the delay due to time or temperature results in a 1-bit error.
Long on options
The triple-ramp method is by no means limited to a 14-bit converter. Changes in the counter's word length and in the reference voltage-divider resistors make it possible to trade sp eed for resolution. At a given clock frequency, speed is doubled for each two-bit decrease in resolution. A 12-bit converter, for example, op erates in excess of 50,000 conversions a second with a 10-Mh z clock frequency.
An offset voltage added to the integrator input enables signals of both polarities to be converted. This shifts the sum of the inputs to the positive range. Since an extra bit is required in the counter, conversion speed is reduced. Th e mo st significant bit in the counter is the sign bit; if zero is written as 1000 . . . 0, negative si gnals are represented in a 2's complement code.
The authors
H. Bent Aasnaes, a senior associate engineer at IBM 's Systems Development division, specializes in the development of analog circuits for process-control
computers.
Thomas J. Harrison, with IBM since 1958, is manager of analog technology for process control at the systems division 's laboratory in San Jose, Calif.
72
Electronics I April 29, 1968
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Electronics J April 29, 1968
Circle 73 on reader service card 73
This little relay
can make you a
living legend.
The new RF3 vacuum relay is 2V4 inches long .. ..that's small for something which can take peak voltages up to 12,000 volts with no strain.
It carries 25 amps rms at 2.5 MHz quite easily. It interrupts 20,000 watts of power like nothing (7 Kv or 3a max). That means it can be used in any operation involving power or rf currents ... in either communications or industrial applications.
The RF3 is only one ounce heavier than our RF1 vacuum relay, which at 3/ 4 ounce controls more power for more applications than any other relay in the world. Th is makes the RF3 an extremely econom ical item for handling almost 20 t imes more power with only a limited increase in space requirement.
Details : 7.5 peak kv at 16 MHz operating voltage; 17 amps rms at 16 MHz continuous current ; contact resistance of less than .012 ohms; life of 10°; less than 10 milliseconds operate time ; and SPDT latching contact arrangement ... soon to be supplemented by nonlatch ing Form C configuration.
All of this should give you a lot of ideas as to how the RF3 vacuum relay can make you a legend in your own time.
For more detailed information write to ITT Jennings, a Division of International Telephone and Telegraph Corporat ion, 970 McLaughlin Avenue, San Jose, California 95108.
74
Circle 74 on reader service card
I T f JENNINGS
Electronics I April 29, 1968
Integrated electronics
Isolation problems get an airing
Planar air technique gives more reliability and design freedom than the solid method , and is being used for diode arrays
By Hal Clausen and Roger B. Rusert
Fairchild Semiconductor Corp. , Mountain View, Cal if.
Isolating the elements of an integrated circuit so they'll behave like discrete components has long been one of the most stubborn problems in designing and manufacturing re's. In the most widely used dielectric isolation technique, a thermal oxide layer envelops the element islands and a polycrystalline substrate provides support. Now, however, another technique-planar air isolation-has been developed to the point where it's being commercially used in diode arrays [Electronics, April 15, p. 25]. This air isolation "challenger" has several advantages over the solid method:
· Two layers of protection instead of one, giving greater reliability.
· Compatibility with standard processing techniques, which may lead to higher yields.
· Greater freedom of design, b ecause of the shorter lead paths, easier access, and fewer wirecrossover restrictions.
· Higher forward conductance in the diode array, because of shorter lead paths.
· Easier manufacture, because isolation is ac-
The authors
Hal Clausen is senior marketing engineer in specialty products at Fairchild. He has a 8 .S. in education from the University of Illinois and nearly 12 years of experience in semiconductor work.
Roger B. Rusert received a B.A. in physics from Carleton College in 1964 and an M.A. in physics from the University of California at Berkeley in 1966. He' s a research engineer at Fairchild and a specialist in isolation.
complished after element fabrication and the surface is flat, without the bumps encountered when the solid method is used.
Many other methods have been tried over the past decade, but none worked out well enough to be put in high-volume commercial production. Some of them, such as beam-lead, have b een produced for in-house use. The others have been relegated to even lesser roles, in a few custom " ulh·aperformance" re's or as laboratory curiosities or subjects of conference papers.
Planar's parents
Like the solid method, planar air isolation is making its commercial debut in the form of diode arrays. It's an offshoot of the 1964-66 proposals for mesa and handle-wafer isolation [Electronics, March 20, 1967, p. 91].
In the mesa method, transistor elements and interconnections were formed in the conventional way. A substrate was then joined to the wafer surface by a glass wafer. Excess material was removed and the elements were isolated by selective etching.
In the handle-wafer scheme, standard active elements were protected by thermal-oxide layers. Mesas containing the devices were then etched out. A glass-coated silicon h andle-wafer was then fused to the mesas, and the wafer was isolated by lapping the material. Glass was formed around exposed mesas by backfilling, and then the handle-wafer was etched away.
Both processes were basically compatible with standard production techniques but required too fine a con trol and were relatively costly. Prototype runs suffered from low yields of usable re's and inconsistencies from unit to unit. Still, both the mesa and handle-wafer techniques showed enough promise to merit additional research , and it was this furth er work tha t led to planar air isolation.
vVhat was needed at first was a marriage of the mesa and handle-wafer techniques. This yielded
Electronics I April 29, 1968
75
COMMON CATHODE
EPI OXIDE i--~~..__--.-L~--J.~---~----L~.....-L-~--1..,/
COMMON ANODE
ANODE /CATHODE Interconnections. Air isolation applied to three diode arrangements. In these simplified array segments, the only change from one interconnection scheme to another is that of the mask; the order and arrangement of each "layer" remains the same. This advantage has been put to use in the fabrication of commercial 16-diode and dual 8-diode arrays.
better contacts with the elements; contacts could be made directly to the n+ region, through the "back door." Long paths weren't necessary.
.Second, the original mesa idea called for a critical thinning step, done by etching. This was imprecise, often leaving unwanted silicon areas. The problem was solved by switching to a lapping technique-again done from the back.
Third, the glass material used left a lot to be desired. It didn't sufficiently resist acids, its thermal coefficient of expansion differed from that of silicon, and its melting point wasn't very much below the alloy temperature of the silicon and aluminum parts. Engineers finally developed a glass material that was sodium-free and had the right melting point resistance and thermal coefficient. The glass is sedimented by a centrifuge technique using a specially constructed waf~r press that maintains a constant temperature during fusion, thus preventing irregularities in the glass layer.
Designers saw that bonding directly to the pads would require removal of the unwanted oxide during the contact cut step. They previously had removed oxide after the isolation step, but this increased mask and diffusion requirements.
Finally, production became possible when IC makers became more adept at maintaining close tolerances.
Why be discrete?
The electrical performance of planar air-isolated devices is as good as that of discrete arrays. Air isolation seems to have achieved discrete characteristics that were beyond the reach of pn-junction isolated 1c's: high breakdown voltage, redu·ced parasitic effects, and uniform parameters from element to element, among others.
The new technique provides double protection for all junctions: oxide passivation and encapsulation in glass. Compared with other forms of isolation, it requires fewer assembly operations, die attachments, and bonds. It accommodates volume production methods through batch processing. And, because it requires no special masks or expensive materials, and little in the way of new production equipment, planar air-isolated IC's will be sold at regular prices.
Illustrations of the step-by-step manufacturing cycle appear on page 78; the entire technique is straight-forward and easy to visualize.
How it's made
After the elements have been diffused, a phosphorus-doped n+ region is diffused as a bordering ring around the P+ element areas. This is to prevent channel-type inversions, which cause excessive leakages and shorts. The step, commonly called the phosphorous channel cutoff diffusion, is often applied in solid-isolation processing, and occasionally in low-leakage discrete devices as well [Electronics, April 1, p. 59].
A contact cut is then made. Next, a thick alumi-
76
Electronics I April 29, 1968
Sixteen diodes. Ceramic flat-pack mounted array fabricated with air-isolation. Large moat in center is common-cathode contact; eight circular moats are anode-to-cathode junction point contacts; trapezoidal area is common-anode contact. The cement-like gray portion around the contacts is the oxide.
num layer is evaporated and etched to form interconnections. A finely divided glass, five microns thick, is then sedimented from a suspension, over the aluminum and onto the front of the wafer. A support wafer-six mils thick-is placed over the glass layer and against the device wafer. The glass is fused under heat and pressure to join the wafers permanently.
The back of the device wafer is then lapped and etched, until its thickness reaches 20 microns. Next, an aluminum film is evaporated on the back, minimizing diode resistance drop at the die's extremities. Then an isolation mask, aligp.ed with the patterns on the front of the wafer, is placed over the
aluminum. The aluminum is etched, and then the silicon parts are etched down to the thermal oxide layer. At this point, the 1c consists of mesa-like substructures, each surrounded by moats of insulating air.
Padding exposed
Because oxide cuts have been made beneath the aluminum contact pads and the silicon has already been etched, the aluminum pads are exposed. Bonds can now be made to the back of the aluminum, which itself is firmly attached to the fused glass. Thick aluminum lead conductors are then attached. Since these may be attached on both
Arrays: Hybrid vs. monolithic
:!.J--'===:t=:~coMMON
9-1--t-...,.... e-+--+-===-+--+--f-4
CA THODE
SUBSTRATE
rf;:j!j:=:!::;";;'.J=t -=J.J~::!::=-.l===~:;""]1~...-r--cATAHNOODEDE
SUBSTRATE
COMMON CATHODE CONNECTION
COMMON ANODE CONNECTION
ANODE/CATHODE ..-rt---+- CONNECTIONS
- - SECTION A-A
FIGURE 3o
Chip-and-wire
Contrasting diode arrays. Hybrid technique (above} involves many chips, more bonds, and has wire-crossover
restrictions. Planar scheme uses only one chip, has fewer bonds, and easier pin arrangement.
=~-/ .ALUMINUM
METALIZATION
OXIDE
BACKING WAFER
SECTION A- A
Air-isolated
I Electronics April 29, 1968
77
Planar air
PN JUNCTION
Starting material
Oxide cut, aluminum added GLASS SEDIMENT
EVAPORATED THICK ALUMINUM
EVAPORATED ALUMINUM
c
Glass, support wafer joined
SUPPORT WAFER !APPROXIMATELY, .006" THICK) ALUMINUM
Evaporate aluminum, then etch
Isolation. Step·by-step processing of a planar-air-isolated diode array. In final form, mesa-like active elements are surrounded by air moats.
OXIDE ALUMINUM
sides of the die, resistance drops are relatively low and complex interconnection schemes are easily accommodated.
Bumpy path
Solid isolation has a number of drawbacks. It provides only normal oxide protection; there is no supplementary glass coating. And because solid isolation is done before the circuit's elements are diffused and metalized, it requires a nonconventional processing cycle.
One must contend with the ."-bumps" on the dielectrically isolated wafer surface. The oxide layer arrangement doesn't always permit easy access for the lead paths. As a result of the occasional long lead paths-particularly evident in large matrices-forward conductances of the elements are relatively poor. The processing cycle itself is so involved (for example, the thinning step) that only one semiconductor manufacturer has mastered the method sufficiently to enjoy broad commercial success [Electronics, Jan. 22, p. 44 and April 1, p. 25].
Chipping away at hybrids
The new method also provides better isolation than the chip-and-wire technique of hybrid 1c construction, which is a popular way to make arrays in small packages.
A typical hybrid version of the 16-diode array and its air-isolated monolithic equivalent appear on page 77. In the former, two electrically isolated metalized substrates are used, each with two chips of eight diodes mounted on it. One substrate has a p-on-n common cathode die, and the other an n-on-p common anode die. These chips have been fabricated in blocks of eight junctions to facilitate
handling and to increase the net yield. Even if four of the junctions are rejects, four usable junctions remain. Note that lead-wire crossover problems might arise if the good junctions aren't on the same die plane.
In any event, four separate die attachments and 28 lead bonds are required for each array. But if planar air isolation is used for the same type of 16-diode array, only one die attachment and 20 bonds are needed. One chip, instead of two, is required. Double protection-glass encapsulation as well as the oxide passivation-is provided. There aren't any wire-crossover problems. And, of course, there are the other general advantages cited earlier.
In the typical diode array the interconnection scheme determines the arrangement, but with air isolation only two junctions are required in each case. Thus, for a common anode, all the anodes are connected to a common point, and for common cathode, all cathodes are so connected. For anodecathode arrays, anodes are connected to cathodes in a series string.
These alternative schemes are accomplished by merely changing the isolation and metalization masks. Larger arrays may be fabricated by simply building more junctions.
As for packaging, the new process is compatible with all three major practices-T0-5 can, flat-packs, and plastic dual-in-line packages. The bonding arrangement uses aluminum wire that is ultrasonically bonded to the chip, yielding greater reliability and strength than standard gold-ball bonding.
Planar air isolation has been incorporated-in prototype quantities-in linear 1c's and in ultrafast digital circuits. Volume production of these monolithics is expected later this year.
78
Electronics I April 29, 1968
Computer systems with the golden touch ... that work for pennies
First member of the Honeywell Series 32 family of 32-bit real-time l/C computer systems, the H632, is 850 nanoseconds fast. A highperformance system for real-time scientific and control applications, like: ground support/checkout, trainers/simulators, hybrid computation, message switching/data retrieval , and general purpose scientific.
It not only costs less per instruction than any other medium-scale machine, but has an advanced concept of modular system integration and design that makes it shine in multiproce,ssor/multiprogrammable configurations. Of course, its software package is extensive, and a complete line of peripherals and
subsystems is ready to meet almost any requirement.
The H632 can grow with you ... from
a minimum SK memory with one
central processor and one input/output processor to a maximum system of 131,072 words of memory, four central processors, and four input/output processors. l/C construction throughout adds to system reliability (we're l/C people from way back).
Because the H632 does so many things so well for so little, we call it "the computer with the golden touch . . . that works for pennies." Want to learn more about the H632? Write for our new summary brochure. Honeywell, Computer Control Division, Old Connecticut Path, Framingham, Massachusetts 01701.
Honeywell
~ Q
C
O
M
PUTER
DIVISION
CONTROL
Circle 79 on reader service card
Compliments of a friend a complete multimeter at less than $3000
We think you'll agree that it's pretty friendly of Cimron to put out such a flexible instrument for so little. But it's typical of the philosophy that has always guided Cimron - customer concern. You need the most sophisticated instruments to do your work under a variety of changing conditions. And the Model 6653 gives you a great sendoff for both systems applications and laboratory or production testing. You get 5-digit readout including overrange, with an accuracy of ±0.0tl f.s. +0.01%
of reading for six months or longer. You'll save on calibration costs. Sample rates up to 300 per second; automatic polarity and automatic ranging; AC, ohms, millivolts. And look! You also get auto ranging through six millivolt and DC ranges. It's especially hard to beat all those Cimron customer concern features like remote control and printout, maintainable plug-in pc boards, and accessible calibration and test points. Write Cimron®, Dept. B-109, 1152 Morena, San Diego, Calif. 92110.
~I!
LEAR SIEGLER, INC.
DIVISION
80
Circle 80 on reader service card
Electronics I April 29, 1968
Big job. Close to 1,000 points will be monitored in flight aboard the Air Force's C-5A, giant cargo and troop transport built by Lockheed-Georgia that is the world's largest airplane.
Avionics
Testing on the wing
Automatic airborne systems for monitoring avionics performance in flight are a must for today's-and tomorrow's-fast, complex military aircraft
By Alfred Rosenblatt
Avionics and space editor
A military pilot used to have a relatively easy time keeping h·ack of his plane's electronic instruments. There weren't many to worry about, first of all, and each piece of avionics equipment performed an essentially independent function. Checking his instruments, the pilot could decide whether the displayed readings for altitude, velocity, and bearing were reasonable, and he used this data to perform such operational tasks as navigation and bomb delivery.
Not so today. Present-and planned-military aircraft are so fast and complex that the pilot is out of touch with the workings of his avionics and, in a sense, with the outside world. With the speeds and altitudes at which missions are currently flown, sightings from the cockpit may be of small value. And the sophistication of modem avionics has made
for an interdependence among the instruments. For example, navigation is now performed by a doppler radar, an inertial platform, and a computer, with the operation of each piece of equipment depending on information supplied by the others. And while this gear is bringing the plane in on its target, related avionics systems are aiming and firing off weapons and keeping tabs by radar on the enemy's response.
A strike mission may involve more than 150 different modes of operation, and all functions-and combinations of functions-must be handled precisely if the sortie is to succeed. Ground maintenance can't ensure this degree of reliability, nor can pilot or crew. Hence the need for continuous, automatic in-flight checkout of avionics equipment. The
Electronics I April 29, 1968
81
aim of a considerable effort now is the development of systems that cannot only spot faulty operation, but can diagnose and isolate it, and can switch the operation to an alternate mode. Such systems would be able to predict failures, too, and would alert the pilot of the status of his avionics.
Setting the sights
All new military aircraft feature some degree of automatic, computer-controlled monitoring; the newer the plane, the more self-test and maintenance equipment it will carry, and the more previously ground-based checkout gear will be built into its avionics. But the sort of systems envisioned by engineers now won't be flying until the mid-1970's.
functioning at full capacity, and, finally, it will display the monitored data to the pilot or another crew member.
There are, of course, problems-some very basic ones. The most obvious is the question of how all this complex monitoring circuitry is to be engineered into a plane. Another difficulty is that most of the avionics systems now being developed employ subsystems already designed. Engineers must thus build new self-checking systems around existing test points and cannot apply an integrated approach to monitoring.
Completely integrated monitoring setups will certainly be possible in the future, though, and the problem of space is largely being solved by ad-
For openers. First extensive in-flight performance monitoring in an operational aircraft was developed by Grumman for the five-place E-2A Hawkeye used for early warning, command, and control.
"What we're after is dynamic monitoring of the craft's total avionics system," says Greg Foster of Autonetics' Strike Avionics division.
The features of such a monitoring system are listed in a paper to be presented at next week's National Aerospace Electronics Conference in Dayton, Ohio, by Helgi Heinzmann, a senior design engineer at the General Dynamics Corp.'s Convair division. First, says Heinzmann, it will be able to perform all preflight, in-flight, and postflight testing, producing a no-go signal when it discovers a faulty subsystem. Second, it will trace the fault down to the level of line-replaceable units (LRu's). It will further record all this data to aid in maintenance ancl to provide a basis for failure predictions, and will be able itself to recognize gradual performance degradation. It will, as noted earlier, be capable of switching operations from a degraded mode to one
vances in electronics miniaturization. A more fundamental question concerns the over-all approach to in-flight checkout.
There are currently two schools of thought about the role of the central computer in a monitoring system. Paul Tracy, a program engineer at the General Electric Co.'s airborne early-warning radar department, puts it this way: "Should each piece of equipment evaluate itself, or should the evaluation be made at a central computer site?" In the first case, the go/no-go decision would be made on the spot and the computer would receive only a status report.
"In-flight monitoring at this point is not a wellshaped program," concedes L.M. Puckett, an associate technical director for avionics systems at the Naval Air Systems Command. "However, we're quite conscious of its necessity and are incorporat-
82
I Electronics April 29, 1968
ing various degrees of performance monitoring and failure warning into all Naval avionics projects. Quite a bit more development in philosophy is needed before an over-all point of view can b e imposed on all systems.
"D epending on the aircraft," Puckett continues, "part of the monitoring is being done on a systems basis, part on an equipment basis. Some. projec!s have already used a central computer for diagnostic routines-creating a stimulus to the equipment and t::valuating the response to determine operational status.
"We're trying in most cases to integrate the performance-monitoring capability that's there, and also to get these concepts into new equipment early in the design process," he says.
Several paths
Enough new systems have already been designed
to give an indication of where things are headed.
As could be guessed, they've been heading in sev-
eral different directions since the first extensive in-
flight monitoring arrangement became operational
three years ago aboard the Navy's E-2A Hawkeye
airborne early warning, command, and control craft, Dual role. Displays in the cockpit of the A·6A are now
a plane developed by the Grumman Aircraft Engi- also used for in-flight checkout of the avionics' operation.
neering Corp.
One basic approach is represented by the Mark II
· avionics now being integrated for the FB-111 and
Systems integrators are now introducing self-
F-lllD fighter-bomb er by Autonetics, a division check capabilities into aircraft originally designed
oi the North American Rockwell Corp. The Mark II without them, such as Grumman's A-6A Intruder.
system uses the central computer not to compare And the International Business Machines Corp. is
preset limits with performance data but simply to studying the possibility of adding what the com-
program tests; the testing and evaluation are done pany calls Automatic System Self-Test (ASST) t,o
"Tight in the avionics boxes.
the A-7D/E Corsair. IBM is integrating the A-7 s
Another approach is taken in the Malfunction avionics, as well as supplying the on-board digital
Detection, Analysis, and Recording ( Madar) sub- computer.
system developed by the Lockheed-Georgia Co. and Several companies, among them Autonetics, GE,
now being produced by the Lockheed Electronics and the Boeing Co., apparently sense a retrofit mar-
Corp. for the Air Force's huge C-5A transport. ket in the making here. They're working to develop
Madar ties almost 1,000 test points dispersed ~hroughout the airplane into a central fault-mon-
standard interfacing modules with which in-flight
aoring and diagnosis system that digests raw analog
:, ignals sensed in the individual black boxes, quan-
tizes this data, and compares it with the limits and
references stored in a central computer. The com-
puter indicates on a console any malfunctions in
the aircraft's subsystems and directs the flight engi-
neer to the source of the trouble, right down to a
line-replaceable module.
Other aircraft
Besides the Mark II and Madar projects, various kinds of self-testing and checkout arrangements are being integrated into such helicopters as the Lockheed-California Co.'s AH-56 Cheyenne, and the IHAAS and ILAAS craft. Built-in test equipment is also a feature of the A-New avionics going into Lockheed's P-3C patrol plane. A Univac generalpurpose computer derived from the Model 1230 will perform the tests on the P-3C, and a high-speed printer, a cathode-ray tube, and an audio system will provide warnings of any malfunctions.
Intruder. The avionics' systems integrator for the A·6A added computer-aided checkout features after each subsystem had been designed.
I Electronics April 29, 1968
83
Diagnosing console. Subsystem malfunctions displayed on the console of the C·5A's Madar system can be isolated with the help of a random-access film store and oscilloscope.
monitoring features could be easily added to a plane's avionics.
Shape of the future
The Mark II avionics system contains many of the features projected by Heinzmann for the total system of the 1970's. Among these are .automatic switching from a degraded mode to an alternate by computer, and the production-on paper tapeof permanent fault data to aid in maintenance.
Harvey I. Hylton, the computer design engineer in the F-111 project office at Wright-Paterson Air Force Base, Dayton, Ohio, notes that the Mark II
system was designed specifically to reduce ground maintenance work and speed the F-lll's turnaround time between missions.
Test circuitry is built into all the LRu's in the avionics, Hylton says, so that each unit undergoes end-to-end internal self-testing. Any malfunction is signaled to the central computer, which addresses each LRU over a serial digital channel. The computer then flashes a light on a specially designed status board to alert the pilot to the problem. The status board, as well as the maintenance-data recorder, was built by the Kearfott group of General Precision Systems Inc.
Information gatherer. Remote acquisition unit in Madar senses test-point signals. A one-piece multilayer cable is used to interconnect its circuitry. Signal conditioning circuitry-the black packages-takes up a large amount of space, may be left out of unit being considered for adva need Madar design.
84
Electronics I April 29, 1968
Signals from the avionics equipment go to a box that combines the functions of multiplexing and analog-to-digital conversion. Most of the information is already in digital form, Hylton explains, but synchro-type equipment does produce analog data.
All self-testing and limit-comparison is done in the LRu's themselves. The digital computer merely scans the signals from the units to determine whether there has been a malfunction, and to decide, if necessary, to which alternate mode to switch the operation.
This monitoring of LRU status requires no more than 5% of the on-board computer's memory capacity, Hylton points out.
With one exception, failure thresholds in the subsystems are set by hard wire in the factory. The exception: the limit conditions for the multiplexerconverter's self-test, which are set in digital registers within the converter by a code word from the computer.
Comparing the capabilities of the Mark II avionics with those of the Mark I in the F-lllA's now flying out of Thailand is like comparing a Cadillac with a Model T. Although the Mark I system includes built-in-place test equipment, there's no central computer directing the monitoring nor is there any recording of fault information. Lighted lamps on subsystem control panels indicate malfunctions but ground personnel must isolate the faults. However, a malfunction in the terrain-following radar, the first such system operational in a tactical fighter, is displayed on the aircraft's caution panel.
Checking out a giant
Lockheed's Madar is designed for automatic or manual step-by-step, troubleshooting by an operator while the plane-the C-5A-is in flight. Indicator lights linked to the 10 major subsystems aboard the huge craft are displayed on one side of a threepart console.
When a malfunction occurs, step-by-step maintenance procedures, such as would be found in a maintenance manual, are selected from a 10,000frame random-access film store and are projected on the other side of the console.
Also included in these frames are pictures of the waveforms that should be found at the various test points. Based on the information in the frame, the operator can call for a live waveform from any of the manual test points in the system and display it on a two-channel oscilloscope that is also part of the console. Following the directions given him by the film store, and using the waveforms presented on the scope as a guide, the operator can quickly trace the fault to a specific LRU. He can then decide how to remedy the problem or how to operate around it.
Madar operates through 32 remote signal-acquisition units installed throughout the plane. Twenty are scanned automatically and 12 are tied into a manual on-demand system controlled by the operator as he checks the equipment. Each acquisition unit scans 30 test points, multiplexes the analog sig-
nals-ranging from d-c to 400 hertz and up to 200 volts peak-to-peak-and feeds them, in a standard +5 volts peak-to-peak range, to a central multiplex adapter. This adapter then multiplexes the incoming signals through a common analog-to-digital converter to a digital computer.
Each remote acquisition unit weighs about 31h pounds, dissipates 3.75 watts, and measures 4112 by 9 by 5 inches. A flat multilayer cable developed by Lockheed and manufactured by Sanders Associates Inc. eliminates the need for connectors in the package; the unit's elements, mostly silicon monolithic integrated circuits, are fl.ow soldered to the cable.
Metal oxide semiconductor field effect transistors are used in the multiplexing unit, principally because a junction FET would remain closed if power failed, thereby interconnecting all the test points.
All 600 automatically monitored test points are scanned at a IO-kilohertz rate. A Nortronics 1060A computer is used solely to store limits and fault data and to control the scanning system. The central multiplexing unit controls a magnetic recorder for storing changed or out-of-limits data, a crash data recorder, and a paper-tape printer that presents the flight engineer with a numerically coded statement of what's gone wrong.
Within limits
The Lockheed engineers had to work, in some cases, with existing subsystems in designing their in-flight monitoring systems, observes Joseph Barrett, Madar program manager. In the communications subsystem, for example, the LRu's were already designed and Lockheed had to go with those test points that were available. However, the multimode radar was specially developed for the C-5A, and Lockheed could specify, in this case, where it wanted the test points.
A next-generation version of Madar has already been proposed for a NASA space mission, Barrett says. In this system, each remote acquisition unit will have its own a-d converter. The central multiplexer will scan waveforms at such a high rate that there'll be no need for the oscilloscope display; the amplitudes will ibe stored and processed in the digital computer memory.
Lockheed is investigating hard-wire storage of limits data in a fast ferrite-core memory. The company also wants to reduce the size of the signalacquisition units and place them closer to the LRu's. To achieve this, engineers are working with lowpower MOS devices and thick-film interconnections between hybrid and monolithic circuits. The goal, according to Leonard Merel, chief design engineer for Madar, is to put an eight-channel signal-acquisition unit-with its own a-d converter-into a 2-inch cube.
Upgrading
Grumman is planning to redesign its in-flight monitoring system for the next version of the Hawkeye. In the E-2A monitor shown on the cover, up to 77 alarm channels feed directly in from built-in-place
Electronics I April 29, 1968
85
test equipment circuits at various points in the avi-
onics to energize indicator lights at the top of the
console. Using a cross-bar switch, the operator can
select live waveforms from the appropriate test
points for oscilloscope display; voltage values at
other points can be read out on a digital voltmeter.
Then, following the instructions in a manual of
fault-diagnoses routines, the operator can isolate
the fault and choose alternate modes of operation.
There's no computer in the E-2A monitoring
setup, but all the test gear in the advanced Hawkeye
will be linked to a stored-program digital processor.
"The new system will have a flexible machine with
a large core-memory capacity," says Julius Cohen,
Grumman's E-2 program manager. "We've learned
from experience with the E-2A what additional
points should be monitored. Diagnostic procedures
will be able to trace faults to even lower levels than
the LRu's."
Monitoring limits will be set in the computer,
says Cohen. Grumman is trying to decide now
whether to build a-d conversion circuitry into each
subsystem or use a separate signal-conditioning unit.
Also under consideration is a multiplexing system
to cut down on the wiring.
The primary alarm readout being studied for the
advanced system is an alphanumeric message dis-
played on cathode-ray tubes at each of the three
crew stations in the Hawkeye. There will also be a
panel of lights similar to the one in the E-2A but
much smaller, a test oscilloscope, and a digital volt-
ohmmeter at the radar operator's console. The light
panel will indicate malfunctions in the central com-
puter and the equipment-cooling system-faults that
could prevent an alphanumeric message from being
displayed.
Each crewman will be able to call for alphanu-
meric readouts of system status and to initiate tests.
Only the radar operator, however, will be able to
examine a waveform from a specific test point or get
a reading on the digital volt-ohmmeter.
·
In the case of its A-6A, Grumman has added a
self-monitoring capability to an avionics system orig-
inally designed without it-"and without adding
equipment,'' according to Grumman's George A.
Walz. "We used equipment supplied to us by the
subcontractors,'' he says.
The company inserted diagnostic routines into
the drum memory akeady on board the aircraft, and
hooked the whole system into display equipment
akeady on hand. "Data such as airspeed and pres-
sure altitude coming in from the air data computer
can be presented on digital readouts akeady in the
cockpit," says Walz.
Fundamental split
All discussions of automatic in-Hight checkout come back to the basic question of whether evaluation should be done by a central computer.
In the technique exemplified by the Mark II avionics, both test and evaluation circuitry is designed right into each piece of equipment. A self-contained monitor in a radar, for example, circulates its own
test signals through the subsystem, and such parameters as time, amplitude, and pulse width are compared to references set up within the subsystem. Operational capability is assessed on the spot by calculating, say, signal-to-noise ratio, subclutter visibility, and detection sensitivity.
When questioned by the central computer, the built-in circuih·y simply reports its own evaluation of its operational stah1s. The computer, of course, is programed to take action in the case of a malfunction-warning the pilot and initiating a diagnostic procedure.
In much of the Madar system, the test-stimulation hardware is built into the equipment to be monitored, but the evaluation capability is not. Evaluation is the function of the computer, which periodically addresses all of the test points in the system. The tolerable limits for the parameters checked at these points is stored in the computer, and from these it determines when performance is falling below standards. It also isolates the faults and keeps track of trends in equipment operation. The degree to which a computer could actually forecast failures is, according to GE's Tracy, "limited only by the imagination of those designing the data-evaluation system and the programing."
Process control
Autonetic's Foster predicts that the computer in the systems of mid-1970's will set the tolerances and limits for the test points throughout the avionics. But the Air Force's Hyllon contends that "we don't know if there's really a need for such set-point control to be done by the computer. It would be just like a process-control computer setting limit points on the basis of what's going on inside the process. For in-flight monitoring, it's quite possible that setting the limit points by hard-wire-tailoring a resistor network, for instance-may be adequate."
Hylton maintains that "there isn't a need to change limit points so rapidly," and warns that "you might need more complex circuitry in the LRU. You'd need holding registers for storing the limits. The great advantage, of course, would be the flexibility; you could tighten or loosen set-point tolerances based directly on operational experience."
Other systems problems complicate the basic question. Tracy points out that the operating speeds and complexity of radar systems have reached the point where it would be just about impossible for an external computer to assess a radar's performance.Analog-to-digital conversion of signals to measure amplitudes, timing, and pulse width would require fantastic bit rates, he says, "especially with the 100-to-200-nanosecond resolution required in the coherent radars we're designing."
The answer, Tracy states, "is a happy mix of both techniques, even within the same piece of equipment. Radar test signals have to be circulated anyway during interpulse periods to tweak up the system. Better to use these signals for self-monitoring instead of converting them to digital form and h·ansmitting them to a computer."
86
Electronics I April 29, 1968
SENSOR INPUT
CONDITIONING NETWORK
INPUT AMPLIFIER
VOLTAGE
STOP
> - -.... COMPARATOR
CONTROL GATE
N PULSES OUT
ADDRESS . . . - -.... REGISTER
8 DECODER
SERIAL
ADDRESS INPUT
SELF TEST REFERENCE
REGULATOR 8
POWER
REFERENCE - - - - GATE
Conversion. Circuit proposed by RCA would sense the levels of analog signals at remote test points and send digital data to a central computer.
POWER BUS
As Tracy sees it, "The computer would monitor the results of these self-tests and at the same time make detailed assessments of the performance of less complex subsystems based on limits stored in its memory."
Challenge and burden
The job of implementing the complex new monitoring systems is falling increasingly on the integrating contractor. Eventually, says Convair's Heinzmann, he will specify all airborne monitoring requirements, much as he now specifies weight and power.
Autonetics' Foster agrees. "A subcontractor in future won't just be told to supply a radar that contains a monitor," he says. "He will be told to supply a radar that performs specific and exacting selftests."
But the management techniques needed for the procurement of these systems have yet to be developed. Engineers connected with the Air Force's Airborne Warning and Control System (Awacs), for example, are frankly concerned about the gigantic procurement task that faces them. One estimates that as many as 10,000 test points will be monitored in this system, more than 10 times the number in the C-5A. It's clear that the systems managers in charge of the monitoring will have to get busy very early in the design phase.
This kind of designing from the ground up is fine for future avionics, but the military may also be interested in retrofit systems. The Air Force is reported to be considering retrofitting the C-141 and B-52H, and several companies are developing circuitry to do the job.
Autonetics has something called Focas, for Fast Operational Checkout Avionics Systems, a group of sensors that will interface between test points in the subsystems and a central monitoring unit. Siliconon-sapphire and MOS circuitry will be used in the signal-conditioning section. Autonetics hopes to add Focas sensors to the avionics carried aboard
such tactical aircraft as the F-4 and the F-105. The company's aim is to eliminate the need for
ground-support equipment on the Hight line. Because Focas monitors down to the LRU level, a faulty black box can be replaced on the Hight line; maintenance crews won't have to tear down the whole system.
Data from Focas' sensors is sent through a signalconversion network to a central computer or several separate processors, where it is evaluated on a go/ no-go basis. Norman Gortz, one of the system's developers, says the test sensors can monitor any signal at the interface between the connector and the r.nu-"a-c, d-c, synchro, low-level noise, whatever is desired."
A recording device, perhaps located in the aircraft's bomb bay, stores data on the condition of the various avionic subsystems for later analysis. If a monitored LRU malfunctions and the problem is of concern to the pilot, a light Hashes on his control panel. Focas has a self-testing capability to determine if it, rather than the avionics gear, is inoperative, Gortz notes.
In addition to its avionics-monitoring ability, the unit can be applied to such other aircraft systems, as hydraulics, fire control, and the engine. Once monitoring is begun, it continues throughout the mission.
GE, too, is developing a family of general-purpose sensors. "We're trying for a whole shopping list of basic sensing modules," says Tracy. "These will be in chip and thick-film form, with go/no-go limits tailored, for example, by hitting taps on a voltage divider network before the unit is attached to a monitor point. A half-dozen modules could meet the majority of testing requirements, and 1 cubic inch per module is the design goal."
In another paper to be presented at the NAEC01' meeting next week, Donald Bowie, a research engineer at Boeing, will discuss another development effort in this field. Bowie stresses the need for great care in selecting the additional test points required to give a fault-detecting system the capability to
Electronics I April 29, 1968
87
isolate the cause of a malfunction. Locations should be determined on the basis of failure-mode and failure-effects analyses carried out in the initial design phase, he says.
The test points should be conditioned to provide standard indicator signals, and Bowie suggests the use of high-density packages, such as flatpack differential amplifiers and single-chip shift registers to minimize the effect of this conditioning on overall equipment size.
Bowie's paper especially emphasizes the need to keep the fault-isolation system as separate as possible from the operational systems. To this end, Bowie recommends that the signal-conditioning circuits, as well as the stimulus generators for initiating tests, be contained within the LRU. With internal conditioning, the operational signals don't enter the monitoring system; access is only to the conditioned test points.
Describing the Boeing project, Bowie says both test and operational signals would be fed into what the company calls a RAu-for remote access unit. Located adjacent to the LRU, the RAU converts the signals to digital form and time-multiplexes them on common transmission lines to a digital computer. A multiplex conh·ol and computer buffer provide power, timing control, and synchronization for the unit, Bowie explains. Test points would be both sequentially and randomly accessible.
Boeing has actually built a RAU-type unit using l\IOS FET components. Bowie predicts that the application of large-scale integration techniques can bring the size of the RAU down to 1 cubic inch, and estimates that the unit will consume about 1 watt of power.
Bowie observes that removal of the remote access unit wouldn't alter the operating characteristics of the LRU; the line-replaceable unit could thus be used in avionics systems without integrated self-testing.
Way out
The Aerospace Systems division of RCA is considering the development of standard signal-sensing packages for on-board monitoring and maintenance during long-term space missions in the 1970's.
For a projected orbiting laboratory that would carry 10 or 11 people for five years, RCA is studying what it calls an Adaptive Dynamic Analysis and Maintenance (Adam) system. Adam would check all the spacecraft's critical parameters against limits stored in a central computer, according to Richard R. Schellenbach, senior staff scientist at the Aerospace Systems division. "Spares would be carried on board or ferried up from earth," he adds.
"We estimate there'll be roughly 5,000 points monitoring the health of the craft and taking data from experiments," Schellenbach says. "Another 3,000 points will be needed to isolate a fault to an wu. To make our design problems easier, we're looking at a mix of sensing modules that will handle analog, digital, and discrete parameters."
Thus far, Schellenbach has studied the powersupply and communications subsystems that might
be aboard the spacecraft to determine what points should be monitored and what test-stimulus generators should be employed to isolate a fault. He found that by using the test points by themselves and in combinations, not every module in the supply would have to be tapped.
"Of the 360 separate circuit modules in the supply, only 250 sensor points would be needed to determine which module failed," Schellenbach says. "Only 10 stimulus generators would be needed to· exercise the various parts of the system."
It would also be possible, he says, to use stimulus generators already built into the operational part of the subsystem. "Frequency synthesizers in the communications set could be used as generators in other parts of the equipment, and reference voltages could be used in making limit checks."
Studies by Schellenbach have shown that d-c and a-c analog voltage monitoring would account for roughly 90% of the instrumentation. A standard analog module, on page 87, would be addressable by the central digital computer, and monitored amplitudes would be fed digitally back to the computer. The goal, again, is a I-cubic-inch module, Schellenbach indicates.
Monitored new world
If monitoring subsystems in a craft orbiting a group of scientists around the earth for five years sounds pretty far out, consider the closing statement in Heinzmann's paper on future systems :
"Automatic integral checkout will be part of all future vehicles. Even the automobile will have its share. A future designer may well specify LRUS with one of several standard checkout features. But the technique will not stop with the LRU: why should the SST pilots' physiological parameters not be monitored? And why should a comprehensive checkout system merely display and record a fault?
"Automatic repair action, initially perhaps limited to substituting good components and manipulating variables, is certainly within the grasp of our technology. A faltering propulsion plant may be restored to satisfactory operational condition by fast, automatic manipulation of the fuel and ignition systems. If the engine must fail, the future automatic checkout system will at least select the optimum degraded mode operation. Much work lies ahead, but the results cannot fail to be interesting and rewarding."
In the next issue
Developing a system to monitor the performance of modern avionics in Hight is especially complex when the process and equipment are to be integrated throughout the aircraft. In the next issue, F.H. Hardie and G .E. Simaitis of the International Business Machine Corp.'s electronics systems center in Owego, N.Y., describe how they've tackled the job with the Automatic System Self-Test (ASST) design.
88
I Electronics April 29, 1968
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What else could we call our new DM 7520?Especially after we found out that it's the only unit on the market that can divide by any number without having to use an additional electronics network.
It's programmable, so you can easily vary the digital input code to determine the exact number you want to divide by. And, using multiple packages of the 7520, you can divide by any number you want.
It's an MSI monolithic TTL circuit which performs brilliantly in frequency synthesis up to 10 MHz.The package is dual in-line, with the military version DM 7520 priced at $25.00 each and the commercial version DM 8520 priced at $ 12.50 each for 100 to 999.
For more information, including where to get our great divider now, call or write: National Semiconductor Corporation, 2975 San Ysidro Way, Santa Clara, Calif. 95051. Phone (408) 245-4320.
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I Electronics April 29, 1968
Circle 89 on reader service card 89
Main Frame OMS 3200A - $375 (or OMS 3200P Main Frame with printer output - $450)
Shown with DC Voltmeter Plug-in
DC Voltmeter Plug-in DP 100
$175
1 MHz Counter Plug-in DP 150A
$230
Ohmmeter Plug-in DP 170
$275
Capacity Meter Plug-in DP 200
$275
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The HICKOK OMS 3200 Digital Measur ing System is a precision elect · ronic measuring device which displays readings in digital form instead of the relatively inaccurate and difficult -to -read moving -pointer meter display . A companion PR 4900 Digital Printer allows the displayed readings of the OMS 3200 System to be printed in permanent form for storage and future reference .
Because the OMS 3200 System consists of a main frame which will accept a number of " plug -in" units, it can be used to measure a variety of electrical parameters. The main frame provides display of the read· ing; the plug -in determines the appli cation .
Depending on the plug -in selected , the instrument can be a:
DIGITAL DC VOLTMETER
Range : 00 .1 mv to 999 . volts
Accuracy : ± 0.1 % of reading ± 1 digit
DIGITAL EVENT COUNTER
Counting Rate : 0 to 1,000 ,000 counts/ second
DIGITAL 1 MHz COUNTER
Frequency Measurements: 00 .1 Hz to 999. kHz Period Measurements : 00 .1 ms to 999 . seconds
± Accuracy: 0 .0005% of reading ± 1 digit
DIGITAL OHMMETER
Range : .001 ohm ( 1 milliohm) to 999 . megohms
Accuracy : ± 0 .1% of reading ± 1 digit
DIGITAL CAPACITY METER
Range: 001. picofarad to 9 .99 m i llifarads (9 ,990 microfarads)
Accuracy: ± 0 .1% of reading ± 1 digit
Other plug-ins to be annou need:
AC VOLTMETER, HF COUNTER, TIME INTERVAL METER, CURRENT METER
Through overrange capabilities of many of the plug-ins, the three-<ligit display actually provides resolution capability equivalent to that of 4-, 5 -, 6· and 7-<ligit displays in many cases.
The OMS 3200 System is designed for rugged industrial and laboratory applications. Solid-state construction and conservative design ratings insure long, trouble-free life. By utilizing a design which has the opti · mum combination of accuracy capability and number of digit display, the OMS 3200 meets the general purpose measurement needs of ;ndus· try for reliable digital measurement equipment in the $500 price range.
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90 Circle 90 on reader service card
Electronics I April 29, 1968
DM7830
DM7820
LINE DRIVER
LINE RECEIVER
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This unique new combo works together like no other. No nonsense. No added circuitry. And no shopping around. They're together now at our distributors. And, even though it seems a shame, we'll also sell them separately.
Our DM7830 dual line driver works on a single 5-volt power supply. It's DTL/TTL compatible, performs logic on inputs, drives a 5000 pF capacitance load and delivers a 5-volt differential output signal. Short-circuit protection is built-in, and diodes, on all outputs, clamp positive and negative common mode transients. The price is $16.00 for 100-999, or you can get our DM8830 commercial version at $8.00.
I Electronics April 29, 1968
Our DTL/TTL compatible DM7820 is a dual line receiver that operates from a single 5-volt power supply yet rejects common mode input signals up to ± 15 volts. Response time can be controlled with an external capacitor to eliminate noise spikes, and each channel can be strobed independently. Termination resistors for the twisted pair are included on the chip. The DM7820 has a differential threshold voltage of zero, but you can get another version of it, the DM7821, that has a threshold of 1.5 volts.100-999 price for the DM7820 is $24.00, and the commercial DM8820 is $10.00.
For more technical data ... write to National Semiconductor, 2975 San Ysidro Way, Santa Clara, California 95051. (408) 245-4320.
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Circle 91 on reader service card
91
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Circle 92 on reader service card
Probing the News
The arts
Signal gains for electronic music
The one-time ugly duckling of the arts shows signs of becoming a swan of sorts as serious composers work with random-sound effects, computers, and synthesizers
By Peter J. Schuyten and Stephen W. Fields
Assistant editors
Electronic music is reaching the point where little Johnnie, instead of enduring a weekly piano lesson, may soon be learning to switch his signal sources and vary voltages on a synthesizer.
Right now, the bleeps, blaps,
commercials. And a sizable number of respected institutions in the U.S. and overseas have made substantial investments in electronic equipment.
Today, a composer dissatisfied with conventional musical instruments and techniques can tum to electronics. His only problem is deciding whether to use computers,
trodes to his head and blinks his eyelids rapidly to produce brain waves that are converted into sound.
In another vein, Max Neuhaus, a freelance percussionist and composer of electronic music from New York City, has invented what he calls the Max-Feed, an "instrument" that produces random sounds somewhat easier on the ear than the output of Lucier's system. The Max-Feed houses a transistor
Composer Douglas Leedy adjusts
screeches, and oogahs produced by sine-wave generators, frequency synthesizers, and even computers are forcibly arresting the attentions of skeptical purists from the world of serious music.
Reprise. Less than a decade ago, electronic music was largely the province of a few establishment outcasts splicing tape and working with crude reproduction equipment. Their efforts were generally treated with indifference or scorn. But in recent years the medium has gathered momentum; it is now heard in concert halls, on records, at World's Fairs, and in television
frequency generator to get tone that
synthesizers, or a mixed bag of electronic gadgetry that can produce only random sound.
Body and soul
Random sound, one of three principal forms in the world of elech·onic music, is variously produced. Alvin Lucier, a composer who directs Brandeis University's Elech·onic Music Laboratory in Waltham, Mass., has devised one of the more exotic methods. He attaches electroencephalogram elec-
is mixed to form a complete measure.
radio, an amplifier, and a microphone in a transparent plastic box. The microphone picks up an audio signal from the radio and feeds it into the amplifier, which sends the signal back into the radio. The output-a function of the original broadcast signal-is chance music, a highly random sound that Neuhaus says, "expands our perception of the world around us. Put 100
Electronics J April 29, 1968
93
For love - and money
Although electronic music is still largely a noncommercial proposition, some composers are using their talents to good account in the business world.
For example, Morton Subotnick, a free-lance composer, recalls when he would do electronic music for one-minute commercials and settle for only $50 a spot. "I've wised up now," he says. "If I need a $5,000 fourtrack tape recorder, I work very hard for a couple of weeks turning out only a few 60-second spots. And I have it." Subotnick's credits include the theme music for the Columbia Broadcasting System's program The 21st Century, and background music for the Western Electric and Vote toothpaste broadcast ads.
And Ferretti-Lay Inc., an MIT spinoff that set up shop a year ago, is bent on selling visual and aural presentations for radio and television broadcasts as well as backgrounds for dance and drama productions. Equipment is still being installed at the firm's Newton, Mass., facility, but the company hopes to start looking for outlets soon.
94 Circle 94 on reader service card
Max-Feeds in a room and they create a symphony."
Organization men. But other composers feel that there is more to electronic music than pure
chance. J. vV. Beauchamp, a mem-
ber of the engineering faculty at the University of Illinois and a composer of electronic music, says: "Music is more interesting if it is built around a logical framework. Although music should be full of surprise and variety, it's still Lhe organization of the sounds that counts."
Ercolino Ferretti, co-founder of Ferretti-Lay Inc., Newton, Mass., a spinoff from the Massachusetts Institute of Technology that produces electronic music for profit, bristles at the idea of randomness for its own sake: "There are two sides to human behavior, randomness and redundancy. Unless randomness is used within highly limited bounds, it is pretty useless. If I have a handful of marbles and I throw them down 100 times, you might find one pattern that is pleasing, but what about the other 99? I can't prove that random music is a point of no return, but until something tells me different, random sound will continue to be just one of the parameters of my music."
State-of-the-art muse. Also at odds with the random-sound school are computer composers. Using highly complex equipment, they must laboriously program five sound parameters for every note: timbre (the quality of tone distinguishing inslruments or voices), attack (initiation of performance, especially with respect to the degree of unanimity with which a
phrase is begun by several inshuments), pitch (a musical tone determined by the frequency of vibration of the sound waves that strike the ear), decay (decrease in quantity, volume, or force of sound), and rhythm (regularity or How of movement). To hear what he has created, the composer must connect a digital-to-analog converter with frequency and envelope generators, as well as modulators, to his computer outlet.
'Vhile such music can be controlled to the nth degree, most would-be composers find that trying to justify computer time for such applications at today's prices is a tough proposition.
Calculated disks
However, things are looking up for the computer composer. Several years ago the Bell Telephone Laboratories developed two programs -Music IV and V-that a composer can use in working up his own piece. 'Vritten in Fortran, the Bell programs are based on a pulsecode-modulation sampling scheme. Comparable software is in various stages of dress and undress at other computing centers around the U.S., including the University of California at Santa Barbara and the University of Illinois in Champaign-Urbana.
Overseas, too. Sweden's government-owned Radio Stockholm is now debugging a $500,000 electronic music studio that Jon Appleton, head of Dartmouth Collcge's recently opened Griffith Electronic Music Studio, says "is a good 10 years ahead of its time."
Among other things, the Swedish
Electronics I April 29, 1968
facility features a special-purpose computer designed solely for music composition. The machine has a selective memory and analog conve1ter that automatically stores on tape what is being composed, making playbacks a simple matter. A composer can also store the completed portions of his work on magnetic tape when he's through for the day, leaving the entire memory free for other composers to work with.
Another indication that computer-composed music is starting to come into its own is that the International Federation for Information Processing is holding a competition for such works. The three top entries will be played at the IFIP Congress in Edinburgh, Scotland, this August.
Medleys
Synthesizers are the third route being taken by composers of electronic music. Such machines are a series of modules controlled by fixed or varying voltages. The modules combine frequency or tone generators, electronic switches or sequencers, modulators, band-pass filters, and amplifiers to produce an audio signal that's piped into a speaker system.
The audio signals originate with a set of voltage-controlled oscillators whose input is a signal from a keyboard or other voltage divider network.
The output is a single frequency tone, or range of frequencies, if the oscillator is being swept. The output is fed to an amplifier, a switch, a modulator, a mixer, or combination of such devices. Since the switches are controlled by a voltage signal, the rhythm they set can either be varied or held constant.
The output from the switches is then combined with other signals and further shaped and processed by the modulators. The shaping sets both the attack and decay time of the sounds.
Hark. After a final mixing of the various signals from still other modulators, mixers, and oscillators, the end product-music-finally reaches a waiting world through speakers.
In theory at least, a synthesizer can create almost any imaginable sound, including those of standard musical instruments. "But it's pointless to duplicate the sound of a conventional symphony orchestra on one," says Gerald Strang, chairman of the music department at California State College in Long Beach and himself a composer of electronic music. "The real value of electronic music lies in the creation of new forms that can't be reproduced any other way."
White elephant. During the early 1950's RCA built one of the first synthesizers. Strictly a commercial proposition, the Mark II was designed to save the company's Vic-
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s1ncLa1r rao10 LaeoraTor1es
Face the music. Morton Subotnick, a free-lance composer, works with a Suchla synthesizer at New York University's electronic music center.
Electronics I April 29, 1968
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Circle 95 on reader service card 95
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Technology's offbeat offspring
Music isn't the only lively mt to be touched by electronics. Technology's impact is now being felt in the visual media and even in literature.
A number of research institutions, including Bell Labs and the Lincoln Lab, are experimenting with computerized animation, using light pens, on-line color oscilloscopes and plotters, digital and analog generators of lines and symbols, and other peripheral gear. An off-line movie camera is usually used to record the computer's output, but Bell Labs has been able to put output directly onto microfilm in real time with a Stromberg-Carlson 4060 processor and a cathode-ray-tube display. And holography, still in the early stages of development, seems to have exciting possibilities.
Goodbye to the stone age. In the plastic a1ts, electronics has provided the means for a new medium of expression, kinetic sculpture. Using servomotors, stepping relays, silicon-controlled rectifiers, amplillers, lightsensitive semiconductors, sequence timers , and flip-flop circuits, sculptors are now creating vibrant and sometimes explosive forms.
In literature, the attempts to produce computer-written poetry are
.. rarely taken seriously, but computers may be of great value in critical
studies of meter and rhyme. ~~~~~~--------------~--------------
tor division the time and trouble of hiring musicians and songwriters. The machine was supposed to turn out new material as well as provide background music for pop standards. Eventually, however, the idea came a cropper to the tune of about $100,000. "The sound was too tinny and the rhythms too precise for the human ear. Frankly, it just wasn't pleasant to listen to for very long," says James Seawright,
technical advisor to the ColumbiaPrinceton Electronic Music Laboratories, where RCA sent the Mark II on "permanent loan."
With early synthesizers, editing was one of the most important steps in producing a finished piece of music. Equipment was only able to produce one sound at a time. Once the desired sound was made, it was put on tape and the synthesizer was reprogramed for the next
96 Circle 96 on reader service card
Two for the role. Ercolino Ferretti and Michael Lay, former MIT professors, have set up a company to produce electronic music on a commercial basis.
Circle 97 on reader service card-+-
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98 Circle 98 on reader service card
... the new synthesizers are on-line machines ...
output. The process continued until all of the sounds were taped. Then the editing began. Each sound had to be put in its proper place. Sounds that were to be used more than once, were duplicated and mixed in later. Such work was more a scissors-and-tape proposition than an electronic process.
Noteworthy. But modern syn-
thesizers can be programed to produce a complete composition. And wherea.s the RCA machine produces only one note at a time, the new devices are on-line. The real-time feature allows the composer to hear what he is composing immediately and eliminates the need for heavy tape editing.
Another attractive feature of the new machines is their portability. The R.A. Moog Co. in Trumansburg, N.Y., is now selling a device that can be carried around by pop music groups to augment the sound of their electric guitars and rhythm sections [Electronics, March 4, p. 41].
In Moog equipment, most of the interconnections between modules are made internally. In its simplest version, the device sells for around $1,500. Robert A. Moog, founder and president of the company, says: "The time will soon be upon us when people will start buying them for the home instead of an electric
Off the shelf. The Max·Feed produces random sound, one form of electronic music. Set's output is obtained from transistor radio and feedback network.
Electronics I April 29, 1968
organ or a piano." Playing jacks'. The only other
commercial synthesizer is made by Buchla Associates of Berkeley, Calif. The basic model-15 modules and a keyboard-sells for $2,400. In the Buchla unit all the modules are independent; interconnections arc made by plugging patch cords into input and output jacks on the front panels. Operating the Buchla thus requires a thorough knowledge of the many knobs and inputoutput jacks on the panels. Once mastered, though, the equipment is able to produce a greater range of sound dynamics than the Moog.
There is a drawback to the synthesizer-it has no memory. Although this can be partially compensated for by the addition of a tape recorder, such an arrangement is cumbersome for both composers and performers.
Hookup. "One solution to the synt:hesizer's memory problem would be to connect it to a small general-purpose computer," says Richard Friedman, a systems programer at New York University's Courant Institute Computing Center. "This would satisfy everyone. Not only would it lower composing costs considerably, but it would give the random composer as much freedom as he wants." Friedman, who is also a composer, thinks machines like the PDP-SS are suitable.
Douglas Leedy, faculty composer and assistant professor of music at the University of California at Los Angeles, feels that improvised concerts represent the real future of the medium. A musician who has played the French horn with several leading symphonies, Leedy is interested in the entire range of electronic music. His philosophy: "We live in a throwaway society. People aren't interested in preserving conventional art forms any more, but are trying to create new artistic experiences for today. Electronic music has taken what was once a very distant art form out of the hands of the elite and placed it within the reach of almost everyone. "
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Contributions to this report were made by Bill Bell in Los Angeles, Robin Carlson in Boston, Peter Vogel in San Fra ncisco, and Bruce Cross in Chicago.
Electronics I April 29, 1968
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Circle 99 on reader service card 99
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DISTRIBUTORS: Compar at all locations listed below. Semiconductor Specialists. Inc. (312) 279-1000; Terminal Hudson Electronics (212) 243-5200; Wesco Electronics (213) 684-0880; Wesco Electronics (405) 968-3475; Hammond Electr·nics (305) 241 -6601; Avnet Electronics Corp. of Massachusetts (617) 272-3060; Pioneer Standard Electronics Inc. (301) 427-3300; Kieruluff Electronics (206) RO 3·5510; G. S. Marshall (213) 684-1530; Milgray Delaware Valley (215) 228-2000; Universal Electronics Inc. (713) 781 -0421.
DOMESTIC REPRESENTATIVES: Jack Pyle Company (415) 349-1266; Ozark Electronic Marketing, Inc. (314) 423-7200. ACompar Corporation at the following locations: Alabama (205) 539-8476; Arizona (602) 947-4336; California (213) 245-1172; California (415) 697-6244; Colorado (303) 781-0912; Connecticut (203) 288-9276; Florida (305) 855-3964; Illinois (312) 692-4125; Maryland (301) 484 -5400; Massachusetts (617) 969-7140; Michiaan (313) 357-5369; Minnesota (612) 922-7011 ; Missouri (314) 542-3399; New Jersey (609) 429-1526; New Mexico (505) 265-1020; New York (518) 416-8536; New York (607) 723-8743; New York (516) 921-9393; North Carolina (919) 724-0750; Ohio (216) 333-4120; Ohio (513) 878-2631; Texas (214) EM 3-1526; Texas (713) 667-3420; Washington (206) 763-1711.
INTERNATIONAL SALES: France, Germany, Italy, Belgium, Holland, Luxemburg, Spain- Sovcor Electronique, 11, Chemin de Ronde, le Vesinet, (S.·&·O.) France. United Kingdom , Ireland, Sweden, Denmark, Norway, Switzerland, Austria, Portugal-Eledrosil Ltd., lakeside Estate, Colnbrook-By-Pass Slough, Buckinghamshire, Great Britain. Australla-Cornina:, 1202 Plaza Building, Australia Square, Sydney, N.S.W. 27-4318. Canada-Cornina: Glass Works of Can1d1, Ltd., Leaside Plant, Ontario, Canada (416) 421-1500. lsrael-Optronix, P.O. Box195, Ram at-Gan, Israel 724-437.. Japan-ASAHI Glass Co., Lid., Corning Products Sales Dept. No. 2, 3-Chome Marunouchi, Chiyoda-ku, Tokyo, Japan.
100 Circle 100 on reader service card
Electronics I April 29, 1968
Solid state
Second-source IC's on firm footing
Since device users generally insist on alternate suppliers for volume buys, semiconductor houses make a virtue of necessity and duplicate best sellers
Imitation, once considered the sincerest form of flattery, is becoming almost as important as innovation in the :field of integrated circuitry. Most IC customers prefer to have second sources, and semiconductor houses-for a variety of reasonsare generally anxious to oblige.
However, "generally" is the operative word in this context; even the industry's big three-Motorola lnc.'s Semiconductor Products division, the Semiconductor division of the Fairchild Camera & Instrument Corp., and Texas Insh·ument Incorporated-differ in their attitudes toward second sourcing. Motorola embraces the concept wholeheartedly; Fairchild professes, except in rare cases, to be disinterested; and TI occupies a middle ground.
Insurance policies. Realistic pricing and delivery protection are the big factors in customers' insistence upon second and even third sources for Ic's. "Strikes, :fires, dyspeptic engineers, or acts of God at suppliers can wreak havoc with production schedules," says Larry Steele, director of procurement at the Military Communications division of the International Telephone & Telegraph Corp. "Besides, the Government likes dual sourcing; it's the American way."
"With multiple sources of supply, prices are lower," says \Vinston R. Willmert, manager of purchasing at Honeywell Inc.'s Electronic Data Processing division. ''I'd rather have at least two parties :fighting for my business. With a sole source, you might get better device performance, but never more realistic price or delivery.'' His colleague, Robert R. Leonard, group director of circuits and hardware, points out: "During development of our 4200 and 8200 computer lines, we were paying through the nose for an IC supplied by a single source. When we began purchasing in volume from a number of suppliers,
the circuit's cost dropped by a factor of three or so."
Fat copycats
Pro:flts motivate IC houses to produce competitors' devices. "Second-sourcing gives our salesmen more to work with and affords us a
marketing edge," says Thomas J.
Connors, vice president and director of marketing at Motorola's semi-
was developed in-house, Motorola entered all of these markets as an alternate source.
Connors warns, however, that there are three prerequisites for a supplier's becoming a second source. First, there must be a sizable market; second, the company must be able to compete in highvolume, low-cost situations. And third, enh·y must be carefully
Choice item. Best-selling IC's like those in this digital assembly from Tl are widely copied by other semiconductor houses.
conductor unit. "We don't worry about the not-invented-here aspects. And since we don't have the time, money, or facilities to innovate everything, we'll try to duplicate any assembly that's created a market.''
At the moment, the company offers just about every commercially available digital assembly, including resistor-transistor logic, diodetransistor logic, and three different versions of transistor-transistor logic. With the exception of its emitter-coupled logic series that
timed. "If you get in too early, you'll watch your investment go down the tubes for a while," he says.
Nudging. Connors notes customers often urge his division to become an alternate source for a new IC family. "If the big suppliers haven't made a device, their customers beat on them to become second sources. And the smaller the sole-source supplier is, the harder the customers lean on the leaders to get into the business and provide
Electronics J April 29, 1968
101
... customers call the shots on duplication of characteristics ...
a back-up delivery capability." Strategem. The Semiconductor
division of Sylvania Electric Products Inc. furnishes an interesting example that re makers are also mindful of such considerations. "There was a time when we feared that TI would push its 54/74 series by lining up a second source and signing up some potential customers for our SUHL (Sylvania Universal High-Level Logic)," says Harry M. Luhrs, re marketing manager. "Transitron was not as good a second source as we would have liked. Buyers tended to think of them as a specialty or quick-reaction house rather than a volume producer. We wanted Motorola and hoped, too, for Signetics. So we went out and lined up accounts and got them looking for second sources. We then offered limited engineering advice, some masks, and a selection of chips to Motorola. They went for it. Soon after, the dam broke and Westinghouse, Philco-Ford, and Raytheon as well as Transitron also came into the fold. Our SUHL was on firm ground."
There's still no hard-and-fast corporate policy on second-sourcing at Sylvania. "We'll do it if it seems
profitable, but we prefer to innovate. In this industry if you don't, you are continually playing 'catch up,'" says Luhrs.
Sylvania second sourced Fairchild's 930 DTL line for a time, but dropped it after the field became overcrowded and pmfits harder to oome by. Interestingly enough, the company is now turning out n's 54/74 assemblies for the International Business Machines Corp. "With a single, big customer, we have only one set of specs, deadlines, and qualification procedures to meet," says Luhrs. "And since we don't push our second-sourcing, we avoid confusion."
Reluctant dragon
Texas Instmments also prefers to be an originator but is always ready to go after targets of opportunity. Ed O'Neill, re marketing manager, estimates that about onethird of the company's re business is in second-source items. Most of this volume is in DTL lines. In TIL and other complex circuits, TI does almost no second-sourcing; its assemblies are, however, extensively copied. One reason for this may be that the geometry and configura-
Tough act to follow. Fairchild hopes to d.iscourage would-_b~ imitators by developing more complex devices; this 32-gate LSI unit 1s an example.
tions developed for TIL represent a feeder technology for mediumscale-integration and large-scale-integration assemblies as well as flipflop circuits and gate work As a result, TIL has caught the attention of engineers throughout the electronics field.
O'Neill cautions that there are no guarantees in second-sourcing. "Even the best are bound to flop occasionally," he says. "A house depending entirely on secondsourcing will be hit harder by a miss than one with balance-the more established a line is, the lower will be prices and profits."
Customers usually call the shots on ensuring duplication of characteristics by maintaining elaborate testing facilities, O'Neill says. He doesn't consider this a real problem for a company with resources, but admits the difficulties are considerably more complex with re's than discrete components.
Consuming interest
Users of re's agree-albeit warilythat most second-source assemblies stack up pretty well against those from originators. "There's a fairly close match on characteristics and packaging,'' says Richard Stewart, manager of the advanced technology department in the Data Systems division of the Hughes Aircraft Co. "However, we still have to ·guard against 'specmanship' by the marketing departments of second sources. At times, they push assemblies that aren't compatible with our ·requirements. We look closely at our originals and decide what criteria our alternate suppliers will have to meet."
Similarly at the General Dynamics Corp.'s Pomona division, there is a policy that all systems be so designed that at least two re sources can be used. In cases wh ere there is no time or money to run proofing tests, the company will stmggle along with its prime supplier. "We've found variations occur even on licensed devices, so we run proof tests on all suppliers," says Robert Martin, group engineer. "How the device performs in a system is the key to its acceptability.''
Field trials. The Autonetics division of the North American Rockwell Corp. uses second sources for re's because of Government and in-
102
Electronics I April 29, 1968
house requirements that back-ups be available. "There are no particularly divergent patterns in the performance of IC's from originators and second sources," savs Arthur Lowell, assistant director of Autonetics' Research and Engineering division. "Most of our suppliers work both sides of the street, and we make a pretty thorough facilities evaluation check on all of them. This is important in the case of small specialty houses when a large volume of devices is required."
Although most IC users make a virtue of the necessity of riding herd on their suppliers, some doubt the efficacy. "There's always some diHerence between a prime and second-source product," says William R. Rodrigues de Miranda, senior reliability engineer at the communication and data processing operation of the Raytheon Co.'s Equipment division. "To get complete matches, we would have to define all measurable parameters which might affect operating characteristics. They aren't exactly common knowledge, though. Manufacturers are still trying to relate parameters-and not just those you find on a spec sheet-to actual performance."
An equally tolerant approach is taken by James Mintern, senior components engineer, at Raytheon's Space and Information Systems division. "The need for second sourcing depends on one's primary sources and on the nature of the product," he says. "Second sources are always preferred on standard Ic's, but often individual situations make this impossible or even undesirable. Highly individualized specifications or ultrahigh reliability call for so much emphasis on information exchange between user and vendor that second-sourcing becomes an encumberance-even more so when the user must try to protect the secrets of individual vendors while getting equal performance from them. In such cases, you give one man all the business. Make sure he knows it, and usually, he'll come through for you.
"In the case of an S-band power amplifier for the lunar module portion of Apollo, I insisted on a single source," says Mintern. "We needed reliability and quality. And this
was an instance where there was no justification for price shopping."
Trouble. Most users have at least one horror story to tell about using a sole source. The experience of LTV Electrosystems Inc., a subsidiary of Ling-TemcoNought Inc., is typical. "We used a metal oxide semiconductor IC as a 50-bit shift register in a recent piece of equipment," says C. F. Turrentine, director of materials at the company's Garland division. "Only one supplier produced it and we felt we had to go with him. But we ended up getting into all kinds of trouble. The source ran into delivery problems and we had to stop our production lines on a number of occasions. We scoured the industry for an alternate supplier, and while some came close to meeting our requirements, we would have had to invest extra money on design to work with them. We finally had to stick with the sole source and help overcome the difficulties."
Stranger than fiction. In the main, however, semiconductor houses are convinced that their IC customers need and want second sources of supply. And a marketing aide at one IC maker even admits to having printed one of his own company's data sheets on the letterhead of a rival concern just to give a potential buyer the impression that there were two suppliers. The ruse worked. Subsequently his company bought the second which then began to turn out the circuits.
Above the strife
Some IC concerns, notably Fairchild, disparage second-sourcing. Says Jerry Sanders, the Semiconductor division's marketing manager: "If everyone second-sources, we'll cannibalize our industry. All we'll do is drive the cost per gate down and down. I'd like to see the dollars wasted in solder, printed circuit boards, overhead, and tl1e like put into 'vertical integration' to guard against pricing ourselves out of business. Otherwise, we'll give more and more for less and less until we evenhrnlly fly up our own tails."
Refusing to second-source is the company's way of protecting its own contributed value. Fairchild wants to integrate more and more of the system onto the chip, maintaining its contribution and keeping prices
I Electronics April 29, 1968
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Circle 103 on reader service card
103
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104 Circle 104 on reader service card
at a high level. Fairchild, of course, is an inno-
vator and still a leader in the IC field. But not every concern can afford to b e so aloof. Raytheon's Semiconductor division, which got a late start in the business, furnishes a case in point. "We've been second-sourcing since our inception," says Paul Sullivan, IC marketing manager. "It's a good business, p er se, but we've also gained the know-how to turn out products of our own design."
Back door. Similarly, ITT Semiconductors' IC output is 100% in second-source items. Robert F . Graham, the division's director of marketing, considers such a role a natural for latecomers with resources. "The phenomenal growth of 1c's, together with the industry's poor record on deliveries, makes for excellent opportunities," he says. "Technical talent can be found anywhere; manufacturing and marketing skills have now become the keys to success."
The company has done well hitching rides. It caught the crest of the DTL wave and is now setting its sights on TIL and MSI assemblies.
In another vein, Intersil Inc., a small specialty IC house formed last year by Jean A. Hoerni, inventor of the planar process, is embarking on its corporate life with a refreshing chutzpah. It intends to reverse the field's normal procedures and convince one or all of the big three to make its volume proprietary circuits as they are developed. As for second-sourcing, Ward Gebhardt, the company's director of marketing, says: "Our role will be to contribute to the store of new products. But we have no hang-ups about second-sourcing, and if it helps our customers, we'll do it."
Second class. One of the reasons for the smaller houses' obvious reluctance to build reputations in second-source operations is the fear that making good could ultinmtely do harm. "Secondsource houses will not attract the engineering talent they need to put them into the innovation markets," says William Berg, marketing manager at the Signetics Corp. , a subsidiary of the Corning Glass Works. However, Signetics recognizes customers' need for alternate
Electronics I April 29, 1968
Is it true that you can generate 50 watts of electricity non-stop, twenty-£our hours
a day for five years? Without refueling or maintenance?
Yes. What do you have in mind?
Man: Who are you? Are there any more like you back home? Generator: I'm the largest of the Martin Marietta family of nuclear generators. I've smaller 25-watt and 3-watt relatives. We're rugged, dependable and available. We're not laboratory curiosities. You can put us to work right now. Man: What do you do? Generator: We can fill your low-power requirements in any remote location where it's too expensive-or downright impossible-to use a conventional power source. With my 50 watts, for example, I'll give you more than 2-million watt hours. And I'll guarantee my output for five years on a single feeding. Man: You're pretty sure of yourself. Generator: Why not? There's nothing to go wrong. Just give me my fuel capsule when you put me to work, and then forget me for five years. I've no moving parts, so I can't wear out. And I need
absolutely no maintenance. Man: Suppose I need more power. Generator: Well, you could buy two or more of us. We work fine in tandem. But better yet, my 50 watts of power can be stored on a cyclical basis, so that my system output can be stepped up to several hundred watts. Man: How about working conditions? Generator: As rugged as you like. Put me to work anywhere-on an icy mountain peak, in a steaming jungle, or hundreds of fathoms under the sea. I'm not affected by heat, cold, dust, gasses, or anything else you can think of. Man: Prove it. Generator: Right now, one of my brothers is powering an oceanographic measuring station on Fairway Rock in the middle of the frozen Bering Strait. A cousin has been powering a navigational homing device 15,000 feet down in the Atlantic for two years. One of my sisters married a buoy and has gone
to sea off Puerto Rico. (She talks to satellites, ships and planes.) A cousin is stationed on a floating weather platform in the Gulf of Mexico. Other cousins power a wellhead-control system for subsea oilwells. Man: What else can you do? Generator: We can power aircraft and ship navigation beacons, microwave repeater stations, radio transmitters, and many types of remote monitoring and control systems. In underdeveloped regions of the world, especially, we nuclear generators can prove very useful far from conventional power sources. If you need dependable power in far-out places, why not go nuclear?
We're versatile, so just tell us what you have in mind. Write our manager, John Morrison, Box 1100L3 Nuclear Division, Martin Marietta Corporation, Baltimore, Maryland 21203.
MARTIN MARIETTA
Circle 105 on reader service card
suppliers, and has an exchange
agreement with the Sprague Elec-
tric Co. "They use the same
masks," says Berg. "And for all
Now, the next time · youneed
practical purposes, Sprague and Signetics Ic's are interchangeable."
And the National Semiconductor Corp., also espouses the secondsource concept with enthusiasm. In the IC business only a year, National has a surprisingly well-bal-
just a spool-full anced and profitable product line that includes both original items and best-selling alternates. "We've
or so of BrandReXj
concentrated most of our design talent on up-for-grabs markets like the linear and MOS fields and chosen to second-source TIL in the digital area," says Don Valentine,
youcanjust run around the
the company's marketing manager. "This way the money comes in fast, and we can apply the profits to other areas with good potential."
Teledyne Inc.'s Amelco Semi-
corner to your nearest
conductor division is also working both sides of the IC street. About 25% of IC dollar volume is attributable to second-source items. But Amelco also makes its own 809 op
Bimbach
amp and 58 different logic devices. Isolated case. In a few instances,
Brand Rex* IC makers can come up with devices that defy imitation. In this category are the dielectrically iso-
distributor lated assemblies built by the Microelectronics division of Radiation Inc. High-cost markets, where low
to medium volume is required, are
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If you hadn't heard of a Bl BR distributor before, that's because there wasn't one before. Now there is. Nearby. And it means you can buy the full range of Brand-Rex electronic products, in a full range of quantities . If you don't know just where to find your local Bl BR man, drop us a line . We'll corner him for you.
Birnbach arand ·Rex,435 Hudson Street, New York, 10014 Phone: 2 12·255-6600
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m
IHRNBACH IMNO REX
the company's prime targets. But being in a class by one's self has drawbacks as well as advantages. Says William Weir, director of marketing: "VVe have a problem finding second sources for our more complex Ic's. The Government and original-equipment manufachuers
want back-ups. But if you're mak-
Circle 106 on reader service card ing a device that others can't dup-
licate profitably, the customer has
to pay for it." Weir concedes that
Our little black book has
the widespread availability of technical talent will eventually inten-
over 100,000 phone numbers.
sify competitive pressures. "But right now, our process know-how
separates us from the rest of the
You never had a black book like it. Over 1,500 pages. And those phone numbers! More than l 00,000 telling you who to call/where to go, for the over 4,000 different product categories listed and advertised in the yellow
pages of the Electronics Buyers' Guide. It's the industry's one-stop shopping
pack, and we have no intention of p eddling it away for the few dollars it might bring in," he says.
center that lets you find the products and services you need quickly. You can depend on EBG.
Electronics Buyers' Guide
A McGraw-Hill Market Directed Publication 330 West 42nd Street, New York, N.Y. 10036
Contributions to this report were made by Walt Barney, Peter Vogel, and Bill Arnold in San Francisco; Lawrence Curran and Bill Bell in Los Angeles; James Brinton in Boston; Marvin Reid in Dallas; and Mark Leeds, Howard Wolff, and Peter Schuyten in New York. It was compiled by Eric Aiken.
106
Circle 107 on reader service card-+-
Tells how rotary stepping switches can improve performance of products that count, control, monitor, select, indicate, or time.
Tells all. Shows all. Plenty pictures. Diagrams, too. It's free. Fill out coupon below and send in. Too hot for mail. Your AE representative will deliver in
·------------------------------ plain brown wrapper right to your desk. No obligation.
"-, V. E. James, Director, Relay Control Equipment Sales \Automatic Electric Company, Northlake, Illinois 60164
'., ' I would like to read the complete and unabridged version of "HOW TO USE ROTARY STEPPING SWITCHES," now in paperback. I understand an AE representative will deliver my free copy in a plain brown wrapper.
Name--------------------
Title-------------------Company_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ __
Address------------------City__________state_ _ _ _Zip_ __
AUTOMATIC ELECTRIC
SUBSIDIARY OF GENERAL TELEPHONE & ELECTRONICS
-·
by
AIR PAX
Exacting customer specifications are met by the quality, glass insulated terminals manufactured by Airpax.
A wide variety of terminal designs are producible and glass can be color coded for identification. (We like blue, one reason is that blue is supposed to be difficult.)
Leads can be kovar, or sleeved solid copper, or tubular. A large choice of standardized pins and lugs permits quick delivery to your specific needs. A 90 page catalog giving technical details is yours for the asking.
AIRPAX ELECTRONICS
CAMBRIDGE DIVISION, CAMBRIDGE, MARYLAND 21613 Phone 301-228-4600
108 Circle 108 on reader service card
Electronics I April 29, 1968
April 29, 1968
New Products
Components
IC's poaching on op amp preserves
But assemblies with discrete components are stil l thriving in applications wh ere design specifications are demandi ng
Don't count out the discrete opera-
tional amplifier! It may be losing some ground to the monolithic integrated-circuit device, but assemblies with discrete components are still making their way.
"Op amp applications are certainly expanding, and so far IC's are having an impact in medium-highfrequency, low-power, and low-voltage areas," says Jim Balderson, linear IC product manager at Texas Instruments Incorporated, Dallas. "But when specifications get tight, Ic's can't compete. This is where the smaller producers of op amps will have to take refuge. They'll have plenty of room for growth, but will find the range of their market is smaller."
Versatility is at the root of op amps' growing popularity. They can do just about any kind of computing job-addition, subtraction. integration, differentiation, sign and scale changes, calculation of fractional and higher-order powersand can control, compare, process, regulate, and detect both linear and nonlinear signals.
Open road
Although precise data isn't available, op amps appear to be climbing into the very-big business category. Dale Dukes, manager of management information and services at the Burr-Brown Research Corp., Tucson, Ariz., pegs the 1968 market at $90 million, about $20 million ahead of last year's. Jerry Metzger, product manager at the Fairchild
Camera & Instrument Corp.'s Controls division, estimates monolithic units' share at $30 million-up 20% from 1967's record. And by the early 1970's says Dukes, IC op amps may be ringing up sales of over $100 million a year.
Might have been. "I can't help but wonder what would happen if the IC had been a few years late. We'd probably have a $100 million market on our hands," says Ray Stata, marketing vice president at Analog Devices Inc., Cambridge, Mass., a firm with 40 or so conventional op amps in its catalog. "The advent of Tc's poured cold water on our dreams, but the fire's not out yet."
"Op amps with discrete components and hybrid arrangements with 1c's will be around for a long time," says David Ludwig, director of engineering at Philbrick/Nexus Inc., Dedham, Mass., a division of Teledyne Inc. "It's always possible to reach much higher levels of technical performance with a unit you can adjust. So, for the b es t commonmode rejection, highest input impedance (without having to resort to Darlington inputs) , lowest offset current, highest input voltage, maximum frequencies, and the like, users will continue to specify units with discrete components."
Analog D evices' Stata isn't ready to throw in the towel. "Companies
Shrinking. Op amp with discrete components at the right is Analog Device' s cheapest model at $13. Company saves both space and money in modules like the 420A multiplier at left by using an IC op amp. This assembly sells for $1 6 5.
I Electronics Apri l 29, 1968
109
... op amp companies will never be plowed under by the IC houses ...
like ours will never be plowed under by the IC houses," he says. "We'll always be one step ahead, applying our best units and improving on them. At the veiy least, we'll supply the design engineering needed to use circuits in the most elegant way." As evidence, Stata cites the company's model 420A amplifier, which has two µ,A-726 monolithic dual-transistor pairs on a temperature-conh·olled substrate.
Where it's at
Integrated circuits, however, are continuing to make significant inroads at the low end of the linedevices selling for $10 to $18 each. "There are a number of unsophisticated assemblies at this level that will be displaced in the next year or so," says David Taskett, marketing manager at Zeltex Inc., Concord, Calif., a firm that offers 60 different versions of op amps. Fairchild, for example, dropped its low-cost AD047 op amp because it couldn't compete with 1c's. Similarly, all of the company's chopper-stabilized devices have been discontinued. But Fairchild is readying a hybrid assembly to take their place. Called
the AD0-70B, the unit has an IC input stage.
Arresting gear. "The 709-type monolithic units have cut into the growth of our AD5 and SQ5 op amps that sell for under $10," says Daniel Sheingold, a staff consultant at Philbrick/Nexus. "However, unit sales continue to climb by as much as 10% because of follow-on orders." Fairchild's Metzger also notes the impact of repeat business.
With Ic's chipping away at the low end of the line, Philbrick/ Nexus is turning to larger, more complex op amps like its recently introduced model 1003, which has a field effect transistor input. "This device has only a few picoamps leakage and a temperature coefficient of 1 microvolt per degree Centigrade, and it has no Ic's," says Ludwig. "We haven't abandoned the IC and are looking at unpackaged chips and discrete components on ceramic substrates. This would give us some of the size advantages of integration. But we'll do this only if we don't have to add too many components to get the Ic's operating parameters up to snuff."
Examples of Philbrick/Nexus'
more complex units are the Meter Mates introduced at last month's IEEE show in New York. Presently, there are two versions-a high-impedance input device and a unit that converts a zero-center meter into a null-center meter that reads logarithmically on either side of center. The first a-c Meter Mate is expected to be available next month; it will yield root-meansquare, peak-to-peak, or full-wave rectified average voltage from an audio-frequency input. Both linear and log readouts will be offered.
Burr-Brown's Dukes says discrete op amps tend to offer more design flexibility than Ic's and thinks that design fundamentals still favor discrete components where performance is critical. "But in standard production-line op amps where costs and size count most, Ic's are superior," he states.
Magic number. Fairchild's Metzger agrees with the proviso that 100,000-unit runs are a minimum requirement to make the monolithicunit production economically feasible. Analog D evices goes so far as to steer customers to Ic's when they seem appropriate. "If a purchaser's application permits loose specs and he's ordering in volume, we point him toward IC's. vVe're casting our bread upon the waters against the time he'll need tighter parameters," says Stata.
Long haul
Hedged bet. Zeltex, an op amp maker, is diversifying its product base by adding wares like tl1is element for hybrid/analog function generator.
Over the long run, technology will force change in the character of op-amp outlets. Future assemblies will be largely modular amalgamations of Ic's and discrete components. Moreover, products will increasingly be specified in terms of their function within a system rather than as an operational or differential amplifier with given characteristics.
Stata says Analog Devices plans to take advantage of the best the IC houses have to offer, and then, by outboarding components and building larger modules, to improve on their offerings. "As far as the market is concerned," he says, "the winning companies now are making the correct guesses as to which modules to work on now. Active filters are obviously a good bet as are the multipliers and chopperstabilized amps."
But the inbred nature of the op-
110
Electronics I April 29, 1968
Over 80% of current magnetic shield designs originated at MSD. Some were pretty simple
IT
MSD,
or simple solution, MSD's vast design, engineering and fabricating experience is available
·.. and some were pretty complicated. Each was so successful that they have made MSD the world recognized standard in magnetic shield design and fabricating.
Whether your specific shield problem requires a complicated
THE
to you. Write for EMC Engineering and
Procurement Catalog.
1UfiNUISWUAILY 1~~;;~:" ···'";;~;.~. LosAngeles.Calif.90064 F LIFE 213, 836-6806 213, 871-0055
Menlo Park. Calif. 94026 415, 3 22-8461
MAGNETIC SHIELD DIVISION
Originators of permanently effective non-shock sensitive shielding alloys
Perfection Mica Company · 1322 N. Elston Avenue, Chicago, Illinois 60622 · Phone: 312, EV 4-2122 · TWX 910 221-0105
Electronics J April 29, 1968
Circle 111 on reader service card 111
ACTUAL SIZE
Cambion Cage Jacks fight connector fatigue
Can more than 40,000 insertion/extraction cycles be wrong? These are all the "ins" and "outs" CAMBION cage jacks must endure to meet CAMBION standards for connector reliability for both printed circuits and conventional circuits.
It's the cage that does it. Unique compound curvature design keeps full pressure contact
with over 60 % of the plug circumference
(most competitive jacks can't do half that). Metallurgical engineering ensures integrity even after repeated high temperature soldering. Delivery is off the shelf.
It figures. This quarter square multiplier introduced by Burr-Brown has a rated output of ± 10 volts at 5 milliamps; unit cost is $195.
ACTUAL SIZE
CAMBION plugs are just as easy to obtain. There's at least one for every CAMBION jack, in 6 basic pin diameter sizes: .016"; .020"; .030"; .040"; .062" and .080". Regular, insulated, printed circuit, MlL-type 4-point crimp, combinations plug/jack and piggyback patch cords answer a wide range of needs. Over 93 basic types with hundreds of varieties ... all standard, all available. The increasing number of CAMBION plug and jack configurations means you have more of a complete selection to choose from for edgemounted connectors, patchcords, patch panels, patch strip assemblies .. . and for applications including printed, standard and stacked circuits, socket boards and wire connections. For every connector part, there's a perfect CAMBION mate ... we guarantee it. For complete data on reliable CAMBION circuit interconnections, write Cambridge Thermionic Corporation, 447 Concord Avenue, Cambridge, Massachusetts 02138. Phone: (617) 491-5400. In Los Angeles, 8703 La Tijera Blvd. Phone: (213) 776-0472.
®Reg., U.S. Pat. Off.
3/4 SIZE
amp business is a danger, says Stata. Companies are looking over their shoulders and second-guessing like mad. "If Burr-Brown brings out a gidget, or if we do for that matter, it sets off ripples throughout our industry," he says.
Repeat performance. "Market planning is tough right now; it's very hard to get opinion on samples because customers haven't been exposed to the sort of devices we look forward to selling," says Stata. "It's almost like the situation in the 1950's when General Electric tried to estimate the (now profitable) market for the unijunction transistor and found none since nobody knew what the company was talking about. They didn't have applications data either, and we face almost the same situation now.''
Some companies are now making data amplifiers with rack mounts and selling them for $500 to $600. Stata believes his company should be able to do the same thing in a miniature package for about $225. Analog Devices model 601, which includes a µ.A-726 temperature-controlled transistor pair, represents a step in this direction.
"We recommend the 601 for use as a bridge amp, a thermocouple amp, or high-impedance differential amp among other applications," says Stata. "The 601 has a common mode or rejection of about 120 deci-
bels over a band of d-c to 60 hertz, and a bandwidth of 30 kilohertz. The 60l's potential looks good to us, and there will be 602 along in the middle of this year to broaden our coverage here."
Burr-Brown is concentrating on specific functions rather than universal modules, says Dukes. "We're interested in the market for specialized versions of general-purpose, building-block devices."
"Our high-cost, high-performance op amps get a large part of our engineering effort. Complexity is rising along with price in this area," says Philbrick/Nexus' Ludwig. "Our list of customers shouldn't change much; we'll just be selling them a larger part of the system."
And with the advent of Meter Mates, it is only natural for the company to expand into instrumentation. "We'll be looking for holes in the instrumentation field left untouched by the Hewlett-Packards and the General Radios, but which present real customer needs," says Ludwig. The company has already introduced two 5000-series measurement devices, essentially specialized Meter-Mate modules with panel meters and controls.
Contributions for this report were made by Peter Vogel in San Francisco, Bill Bell in Los Angeles, Marvin Reid in Dallas, and James Brinton in Boston. It was compiled in New York by Eric Aiken.
112 Circle 112 on reader service card
Electronics J April 29, 1968
Integrated
circuit package
sealing ap1lication centers opened by CTI
COMPANY
ABC CORPORATI ON
DATE 3 / 28 / 68
PRODUCT
TIMER POWERSTAT ELECTRODE
114" x 114" ABC CLAD LID Au-S n
No.1 On-Off 0-92
No. 2 Prt hH t On-Off
0-0
No.3 Pu r11 On·Ofl
~-25
No. 4 No. 5
vacuum Pressure On-Off On-Oft 26·l0 31·14
No. 6
Hut On-Off 33 -70
No. 7
On-Off 11 ·90
4 14
Size 1A" x ¥ 4 11 IR-PT CPramic Wafer
Material
HEAT SINK
PRESSURE
3\2 lbs.
SEALER MODEL NO. FP-VP-103
ATMOSPHERE Purge 15 PSI N,, PRESS 10 PSI He
PREHEAT
Typical profile for Y·" x Y.." flat pack sealinr cycle on
DIX FP·YP· 103 Sealer.
GTI has opened two new application centers to assist engineers in developing reliable procedures for her· metically sealing packages for integrated circuits , thin and thick film packages . These centers are located in Costa Mesa, California and Providence, Rhode Island.
As leading suppliers of both integrated circuit pack· ages and sealing equipment, GTI is uniquely qualified to provide expert counsel in this field .
To utilize this service, engineers are invited to submit samples of their flat packs, and information on the model of DIX sealer they are using or are contemplat· ing using. GTI will develop a complete sealing cycle profile such as this of the recommended procedure:
Flat·Pack Sealers from Dix are offered in both produc tion and laboratory model s. All feature perimeter heating that rapidly and efficiently creates a hermetic seal wh ile keeping the device temperature at a safe , lower level.
Production models are available with three , five and ten package stations. The laboratory and pilot production model is a single head unit with great versatility.
GTI also offers extensive technical assistance in setting up equipment, trainin g your personnel and develop· ing sealing profiles for maximum quality and yield.
Just fill in the coupon to see how GTI can help you maximi ze your flat pack production. Send at least ten packages, lid s, and braze preforms and complete sealing specifications.
----------------------------------------------To: GTI Integrated Circuit Package Sealing Application Center
Dear Sirs: Please develop a sealing profile fo r the enclosed fl at packs.
We are D curre ntly usi ng, D considering these sea lers: D DIX FP-VP-10 five station sealer; D DIX FP-VP-210 ten station sealer; D DIX FP-VP-103 three station sealer; D DIX FP-VP-1 si ngle station sea ler.
D Please send information on DIX sea lers.
Name=- - - - - - - - -- - - -- - - - - - - - - - - - - - Position:_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ ___ _ _ _ _ _ _ __
Company:_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ __
EAST
GTI Providence Division
100 Niantic Avenue Providence, Rhode Island 02907
Attn: John Springob
WEST
GTI DIX Division
1399 Loga n Avenue Costa Mesa, California 92627
Attn: Major St. John
Add ress: City_ _ _ _ _ _ _ _ _ _ _ __ State_ _ _ _ _ _ _ Zip_ _ _ __
L-----------------------------------------------...1
I Electronics April 29, 1968
Circle 113 on reader service card
113
Fastest way to start asavings account
The data this unimpressive-looking little instrument can save you defies computation.
Because-CEC's new 1-366 Differential Amplifier has an overload recovery time of less than 1 microsecond. No DC amplifier known to us, or our customers, is able to match this achievement.
As a result, the solid-state, wideband 1-366 is proving invaluable in all signal conditioning applications where critical information must be recorded immediately upon cessation of the initial pulse. A current use is that of securing data 1 microsecond after shock waves, such as those encountered in mechanical and explosive shock testing.
Other significant advantages:
·Frequency response-±1 db, DC to 1 MHz.
· Common mode rejection at 1 MHz-greater than 20 db, regard-
less of gain.
·Input range-up to ±5 volts peak. · Output- ±5 volts at ±50 ma minimum.
For complete information about this advanced new transducer amplifier, call your nearest CEC Field Office. Or write Consolidated Electrodynamics , Pasadena, California 91109. A subsidiary of Bell & Howell. Ask for Bulletin 1366-X4.
CEC/TRAnSDUCER PRODUCTS
BELL Em HOWELL
114 Circle 114 on reader service card
Electronics IApril 29, 1968
New Components Review
Adjustable-stop, single p-c wafer rotary switch type RS275 has a switching matrix of 20 inputs and 5 outputs. It meets applicable portions of MIL-S-3786. Applications include computers, checkout equipment, test equipment, and programing. Price is approximately $130; delivery, 30 days. Chicago Dynamic Industries Inc., 1725 Diversey Blvd., Chicago 60614. [341]
Miniature coaxial cable, with a 0.150-in.-diameter shield, has an inductance of only 0.061 µh per ft measured at 100 khz. The center conductor has an o-d of 0.059 in. and dielectric is solid polyethylene. Cable's attenuation is 18 db per 100 ft at 400 Mhz, and operating temperature range is -55· to +85°C. Times Wire and Cable, 385 Hall Ave., Wallingford, Conn. 06492. [342]
JC breadboard panels in the Omny-Pac series feature advanced laminer bus bar-capacitor design and 16 or 32 dual in-line IC sockets. Each socket is designed for easily inserting 14-pin !C's. The MBB-1000 (16-circuit panell measures 61/2 x 8'12 in., and the 32-circuit panel MBB-2000 is 13
x 8'/2 in. Methode Mfg. Corp., 1700 Hicks Rd., Rolling Meadows, Ill. 60008. [343]
Military grade aerospace relays models FCL-400 and FCL-1 save energy by using power just to transfer the contacts, not to hold them. The 10-amp FCL-400 operates on as little as 35 mwsec; the 2-amp, half crystal can size FCL-1, on 2 mw-sec. Once transferred, contacts remain in the last operated position with zero power drain. Struthers-Dunn Inc., Pitman, N.J. 08071. [344]
R-f filter type 550 is suitable for use in communications equipment, aircraft instruments, etc., which may be interfered with or damaged by high power radio energy, It gives average attenuation of 75 db of r-f energy in a range from l Mhz to 20,000 Mhz. It comes in l amp, 0.45 amp or 0.3 amp ratings. ElliottAutomation Ltd., Airport Works, Rochester, Kent, England. [345]
Solderless gas-tight connectors are for connecting flat cable or individual conductors to wire wrap or solder posts and to various types of p-c board contact systems. The contacts make up to 63 connections simultaneously, and can handle wire sizes from No. 30 Awg to No. 22 Awg stranded. 3M Company, 3M Center, St. Paul, Minn. 55101. [346]
Miniature relay series AZ430, with a 6 Form C contact arrangement, is designed for multipole switching applications. It is available with low-level bifurcated, 2 amp or 5 amp silver alloy, heavy duty contacts. Coil voltages range from 6 v to ll5 v d-c. Over-all size is 47/ 64 x l 13/32 x l 3/16 in. American Zettler Inc., 697 Randolph Ave., Costa Mesa, Calif. 92626. [347]
Card-edge connectors series 6309 are designed for high packaging density (mounting on 0.300-in. centers) in programed wire wrap applications. They are suited for mounting on chassis, p-c boards and metal plate assemblies. They incorporate contacts spaced on
0.100-in. square grid, and accommodate 1/16-in. p-c cards. Elco Corp., Willow Grove, Pa. 19090. [348]
New components
Semiflexible cable turns the corner
Right-angle connector has vswr under 1.15; precision casting of outer shell reduces bend radius to 1 inch
Bending brings out the worst in semillexible cable. The inner conductor and the solid aluminum outer conductor crease and the inner conductor goes off-center. Reflections appear in the line and the voltage standing-wave ratio goes up.
Engineers at the Times Wire and Cable division of the International Silver Co. found that the vswr rose when the radius of the bend was less than 10 times the diameter of the cable. They developed special tooling, and were able to get the bend radius down to four times the
Match up. The connector can join two semiflexible cables, or a semiflexible to a standard cable.
diameter of the cable. But much of Times' semillexible
cable was going into aircraft systems and bending the cable still took up too much room. So the com-
Electronics I April 29, 1968
115
For Those Who Think Smal I
$128 _ _ _.___, Low Cost
Small Size and Weight
I
·i"°' --~.-:=:....J--------n Solid State Reliability
Here's Data Instruments 536A-proof that you can reduce the size of a scope without reducing its performance. The 536A is small. So small, in fact, that four of them take up littl e more than a square foot of panel space. This makes it desirable for field, production line, classroom and systems applications where panel and shelf space are critical. But there's more to it than that. The 536A matches their performance requirements in a way usually reserved for larger and more expensive instruments. The flat-faced 3" CRT, with a viewing area of 4 x 6 cm and a finely focused trace, provides it with excellent legibility; the 1.5 MHz bandwidth makes the 536A adaptable to a wide range of app lications. And its unusual sensitivity-better then 20mv/cm-makes possible precise measurements of regularly recurring waveforms over its entire bandwidth.
Moreover, it has the features to back up its performance. All amplifiers are so lid state, multistage, DC coupled and fully compensated. The a~tenuator has a variable trimmer, and a built-in ca librator stabilizes time and voltage. In addition, there is a full year's warranty and complete field and factory service.
The specifications:
I I VERTICAL AMPLIFIER
BANDWIDTH DC-1 MHz
SENSITIVITY/ CM 20mv
A3TTpoEsNU+ATvaOrR.
ACCURACY ] ±.5 db
IMPEDANCE
1Mf! + 22pf
SWEEP/CM
HORIZONTAL AMP
CRT
10µs-10ms
2Hz-500KHz
3"
(4 ranges)
300 mv/cm
PHYSICAL
SY2 " x 7~" x 12" 11 lbs.
But why not see it in action? We'll gladly arrange a demonstration in your plant. You ' ll find that everything about the 536A is designed for those who think small, Everything except the Price. That is for those who think microminiature.
Data Instruments Division · 7300 Crescent Blvd. · Pennsauken, N. J. 08110
116 Circle 116 on reader service card
air used as the dielectric
pany developed a right-angle con-
nector with a I-inch bend radius
and a maximum vswr of 1.15-about
the same as that of the cable.
Into the turn. Ralph Kragle, man-
ager of connector operations at
Times, says the bend is made as a
smooth coaxial transition by pre-
cisely casting the connector's outer
shell. Bends have normally been
made by drilling, in a solid cas-
ing, two boles that meet at a 90°
angle. So when the inner con-
ductor was inserted, it was bent
sharply. The inner conductor of the
Times' connector is a solid piece of
berylium copper that bends
smoothly in the casing, and the di-
electric is air. Short sections of low-
loss dielectric are at each end for
compensation. Kragle says the key
part of the connector is the Teflon
bead that supports the conductor.
"The bend is very smooth, and the
head is almost reflectionless."
The cutoff frequency depends on
cable diameter. Connectors are
available for diameters from 114 to
% inches. For the largest diameter,
the cutoff is 4 gigahertz, and for
1/2-in cable, the connector's vswr
stays under 1.15 up to 12 Ghz. In-
sertion loss is low; for a %-in con-
nector, it's 0.2 decibels.
Highly eligible. The unit can
mate with semillexible cable at
both ends, or it can be fitted to
mate with type N, type C, or the
General Radio Co.'s type GRL-874
connector.
The unit was first used on Lock-
heed Aircraft Corp.'s C-5A cargo
plane, and has been sold to Pan
American \i\Torld Airways, Inc. The company says th~ connector
will be useful wherever high isola-
tion and low loss aluminum-
sheathed semiflexible cable is
needed. Principle applications arc
now in aircraft, missile, and sub-
marine systems. Times expects the
use of semillexible cable to increase
in commercial communication sys-
tems, like cable tv.
·
Prices are $50 to $100 for small
quantities. Connectors for 50-ohm
systems are available within a
month, and units with other imped-
ances can be designed.
Times Wire and Cable Div., 358 Hall Ave., Wallingford, Conn. 06493 [349]
Electronics J April 29, 1968
here's a practical way to avoid technical obsolescence
Are irregular hours. travel and family obligations keeping you from attending classes-even though you worry about becoming technically obsolescent? Check into the Specia l Programs in Electronics for Engineers developed by CREI. the Home Study Division of the McGraw- Hill Book Company.
These are not simply courses. but comprehensive programs in advanced electronics offering major electives in such fields as:
Communications Engineering, Aeronautica l and Navigationa l. Television Engineering. Automatic Control Engineering, Missile and Spacecraft Guidance. Radar and Sonar Engineering, Nuclear Instrumentation and Control. Computers.
Industry- recognized CREI Programs make it possible for you to catch up on new developments in electronics through study in your own home. at your own pace.
your own schedule. Free book gives comp lete information and detai ls of technical material covered. For your copy, mail coupon below or write: CREI. Home Study Division. McGraw- Hill Book Company, Dept. 1818G, 3224 Sixteenth St.. N.W.. Wash ington . D.C. 20010.
founded 1927
m!>D
Acaed1ted Memlm of the Na1ion1/ Home S1udy Council
i.fCI
CRE I. Home Study Division, McGraw-Hill Book Company Dept. 1818G, 3224 Sixteenth St., N.W. Washington, D.C. 20010
Send me free brochure describing CREI Programs in Electronics for Engineers.
Electronics I April 29, 1968
CITY_ _ _ _ _ _ _ _ _STATE_ _ _ _ _ _ _ZI P CODE _ _ __ CO MPAN Y_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ __ TITLE _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ __
Circle 117 on reader service card 117
.I
j\f/ff4f
Semtech has extensive environmental and power burn-in facilities available to process your military and high reliability requirements .
Contact your loca l representative for immediate delivery -
s·an Francisco - 941 E. Charleston, Suite 10, Palo Alto, California 94303 (4 15) 328-8025 Chicago - 140 N. La Grange Road , La Grange, Illinoi s 60525 (312) 352·3227 I TWX: 910-683-1896 Dallas - 402 Irving Bank Tower, Irving, Texas 75060 I (2 14) 253-7644 New York - 116-55 Queens Blvd ., Forest Hills, New York 11375 (212 ) 263-3115 I TWX : 710-582-2959 European Sales - Bourne s A. G. , Alpenstrasse 1, Zug , Switzerland (042) 4 82 72 /73
118 Circle 118 on reader service card
Do you need
MIL Jype Rectiliers?
(JAN or JAN TX Types)
1 amp Fast Recovery Rectifiers MIL-S-19500/ 359A (USAF) 1N4942, 1N4944, 1N4946, 1N4947 and 1N4948 1 amp General Purpose Rectifiers MIL-S-19500/ 2868 1N4245, 1N4246, 1N4247, 1N4248 and 1N4249 3 amp General Purpose Rectifiers MIL-S-19500/ 367 (USAF) 1N5197, 1N5198, 1N5199, 1N5200 and 1N5201 High Voltage Sub-miniature Rectifiers MIL-S-19500/ 279 (NAVY) 1N3644, 1N3645, 1N3646 and 1N3647
652 Mitchell Ro ad, Newbury Park, California 91320 (805) 498-2111 , (213) 628-5392 I TWX : 910-336-1264
Electronics I April 29, 1968
New Instruments Review
Current sensors 2006H utilize magnetoresistors to detect current in ranges from 0 to 25 amps to o to 300 amps a-c or d-c. Output from the sensor is suitab le for remote transmission in automatic checkout equipment. Price is $298.50 each in lots of 1 to 9 and delivery is 2 to 4 weeks. American Aerospace Controls Inc., 129 Verdi St., Farmingdale, N.Y. [361]
Dig ital readout, universal measuring bridge type 8-150 is for both laboratory and production use. The 24 ranges of measurement include inductance 0.15 µh to 120 henrys, capacitance 0.2 pf to 1,200 µf, resistance 0.002 ohm to 12 megohms, with an over-all accuracy of 1%. A 1-khz oscillator is included. Whittaker Corp., Gencom Div., 80 Express St., Plainview, N.Y. 11803. [362]
Pressure transducer model 434/ 534 covers pressure ranges from 1 psi to 5 psi with high accuracy during 35 g vibration. The 434 covers absolute pressure ranges, while the 534 covers various differential and gage pressu re ranges. Power rating is 1 w at 165°F. Insulation resistance is 50 megohms at 200 v d-c. Bourns Inc., 6135 Magnolia Ave ., Riverside, Calif. 92506. [363]
·,-::.: .
.
--.-.-.~ .-.-- --- · ~
Line impedance bridge 6363-2 is for measuring r-f impedance and phase angle without direct connection to power line. Two current transformer probes couple to unknown impedance providing measurement magnitudes from 0.3 to 1,000 ohms and phase angles ± 100° from 15 khz to 30 Mhz. Price is $1,365. Solar Electronics Co., 901 N. Highland Ave ., Hollywood, Calif. 90038. [364]
Logarithmic converter model 2277 provides accurate db measurements of complex waveforms or d-c voltages. Features include 120-db dynamic range, bipolar input, and d-c to 200 khz frequency response. Applications inclu de oscilloscope preamp, log arithmic null voltmeter, and production comparison voltmeter. Optical Electronics Inc., Box 11140, Tucson, Ariz. 85706. [365]
Automatic circuit test set model AP-502 is a completely portable unit (weighing less than 40 lbs) that will make up to 1,200 cont inuity or insu lation tests per minute. The automatic sequencing and simple controls permit operation by unskilled personnel. Price is $4,950; delivery 45 days after receipt of order. Teleproducts Inc., 351 New Albany Rd., Moorestown, N.J. 08057. [366]
Meter calibrator 760A reads percentage error directly of any a-c/d-c, ampere, or voltmeter on its own front panel meter. D-c accuracy is ±O.l % from 0.001 to 1,000 v. Current range is 1 µa to 10 amps with ±0.25% accuracy. Resistance is O to 10 megohms, accurate to ± 0.1 % . A-c accuracy is ±0.25%, 0.001 to 1,000 v. John Fluke Mfg. Co., Box 7428, Seattle, Wash. [367]
Absolute reflectance transmittance photometer model 209 is for narrow band measurements between 1,650 Angstroms and 2.4 microns. It is a double-beam a-c null balance photometer to be coupled to a monochromator or narrowband interference filters. The double-beam system permits rapid scanning. Kaye Scientific Corp., 39 Manhattan St., Stamford, Conn. 06902. [368]
New instruments
Oscillator serves many functions
Nyquist plotting, spectrum analysis, and digging a signal out of noise are just a few applications
A programable filter oscillator has bobbed up Down Under and the maker, AIM Electronics Ltd. of Melbourne, Australia, claims it's the only one of its kind available. The oscillator is the newest addition to AIM's modular instrumentation system.
The unit, PFO 166, has a variety of operating modes, including filter accept, filter reject, and oscillate. Variation of the applied programing voltage between 1 and 5 volts alters the oscillator output frequency by up to 400:1 within an available frequency range of 15 to 50 kilohertz.
When used as an oscillator or accept filter, it also gives a quadrature output (an identical frequency 90° out of phase). The quadrature signal in a feedback loop means the equipment will phase-lock a lock-in amplifier or a tracking filter. It also permits the unit to be used for automatic Nyquist plotting.
In spectrum analysis, the unit can be either a conventional oscillator or a filter. Two PFO 166 units can be used to inspect the electrical characteristics of circuits or equipment: one as an oscillator with programable frequency driving the input of the circuit under test, and
Electronics J April 29, 1968
119
ClairexType 7H cells offer faster decay time... .0006 sec. at 100 ft-C
Circle lo4 on reaoer service card
WIDEBAND RECEIVER
one as a filter at the output to assist examination of the resulting frequency spectrum. A third PFO may be used as a reject filter to reject the dominant harmonic of the input signal and reduce its distortion to less than 0.1%. The resulting signal may be displayed on a meter, oscilloscope, or an x-y recorder. For display purposes, a ramp waveform must be used as a time base and as the programing voltage.
In the presence of noise, the PFO 166 can also be applied in signal recovery where an amplifier is required to lock to an unknown frequency and phase. The technique requires a local phase-locked reference generator, consisting of a phase-sensitive detector and the voltage programable filter. The PFO generates a reference signal and adjusts its frequency automatically to the incoming frequency. A phase-sensitive detector referred to the quadrature output provides an error voltage that is applied to the PFO to maintain the phase-lock.
In Nyquist plotting, the unit is used to generate a variable frequency sweeping through the full 400:1 range. The in-phase quadrature outputs are connected to two phase-sensitive detectors, and these resolve the signal from the system under test into two components. These can then be automatically displayed on an x-y recorder or oscilloscope.
Other possible applications are as a tracking filter and as a programable comb filter where several units are used in combination.
AIM Electronics Ltd ., Melbourne, Australia [369]
The 977 VHF Receiver monitors the spectrum from 30 to 300 MHz ... AM, FM, CW, pulse signals ... IF bandwidths: 60 kHz, 300 kHz, 3 MHz ... Dualgate MOS FETs in all gain-controlled stages ... Wide
l ~ z dynamic range ... Call or write for specifications. SUBSIDIARY OF WATKWUJOHNSON
COMMUNICATION ELECTRONICS
6006 Executive Blvd., Rockville, Md. 20852 · 301I881-3300 · TWX 710-824-9603
120 Circle 120 on reader service card
New instruments
Place on panels sought for meters
French-made digital unit displays voltage, current and resistance readings
Not content with manufacturing Europe's lowest-priced digital multimeter, France's Schneider Radio
Electronics I April 29, 1968
Television has now come up with the Continent's lowest-priced digital panel meter. Called the VT-100, the meter displays digits from 0000 to 1999 and is priced in the neighborhood of $175. U.S.-made panel meters cost about $295.
Schneider is aiming the new instrument at the original-equipment market. "We wanted to develop as inexpensive a meter as possible so that equipment makers wouldn't have to raise their prices," says Martin Birnbaum, head of the company's Professional Electronics division.
The company has yet to set a price for the meter in the U.S. and still hasn't decided on a distributor. Honeywell Inc. distributes Schnei-
Gallic display. The VT-100 panel meter reads out to 1999.
der's multimeter, called the Digitest, in this nation. Priced at $300 in Europe, the Digitest sells for $525 in the U.S.
Several ranges. The VT-100 measures voltage, current, and resistance; it reads out d-c voltage over three ranges, d-c current over five ranges, a-c voltage over three ranges, a-c current over three ranges, and resistance over five ranges. The instrument's input impedance is 1 megohm, and its measuring cadence is one per second. Resolution is 1 millivolt.
Part of VT-lOO's circuih·y is made up of diode-transistor-logic integrated circuits, with the rest dis crete solid state components. Birnbaum says the whole unit could have been made with 1c's, but this would have meant a higher production cost.
The unit measures 5.8 by 2.9 by 7.8 inches, and features automatic zeroing. It was exhibited for the first time at the annual Paris Components show last month.
Schneider Radio Television, 12 rue Louis Bertrand, lvry, France [370]
I Electronics April 29, 1968
C180 : fl ,1t
C280f\1 : " Cold en Nugg et"
C28 I : m o lded
We don' t kn ow of a si ngle appl ica tion, p ro fess ional o r entertainm ent, wh ere me talli zed po lyca rbonate film ca pac itors ca nno t repl ace me talli zed M ylar®... wit ho ut changes in prod uctio n se tup ... and do a be tter job, all aro und .
Th e adva ntages offered by Amp erex metallized po lyca rbonate film capac ito rs over meta llized M ylar® in clude: stabil ity, low er lea kage, no vo ltage deratin g to 125° C and neg ligibl e ca paci tance change ove r the operating temperature ran ge.
Vo lume prod ucti on effi ciencies have sharply red uced th e pri ce o f A mperex metallized polyca rb onate capac itors so that th ey are now co mpetitive with metalli zed M ylar®.
In th e rec tangular " Go lden Nu gge t" style, A mperex C280M seri es ca pac ito rs offer va lu es fro m 0.01 to 6. 8 µf, mount rigi dly on p rint ed circui t boa rd s and are especially easy to identify wi th th eir h igh-vi si bilit y embossed markings . Th e C281 molded axial-lea d types in va lues to 6.8 µf are idea l for co nsumer and p ro fessio nal appli ca tions.
For detai led data and sam pl es o f Am pe rex fixed film capaci tors or Amperex va ri able capacito rs (wi th cera mi c o r film di electrics) , wri te: A mpe rex Elec tro nic Co rpo ratio n, Component D iv., Hauppauge, L. I. , N.Y. 11 787.
Ampere»
TO \IQRR OIV "S THI KING IN TODAY "S PRODUCTS
®: A Du Po n I tr.1ci£> mark .
Circle 121 on reader service card
121
Quick response on Ram Air Turbine Systems.
Garrett now has30typesof RATS (Ram Air Turbine Systems) to choose from, and more standard designs are on the way. That's how we can promise quick response .
But what if we don't have a model that meets your exact needs? No problem -we can design and build one that does, and we'll do it quickly.
Take a look at our lineup: Electrical RATS - power outputs from 500 watts to 40 KW .
Mechanical RATS -ratings up to 60 shaft hp at speeds from 600 to 60,000 rpm.
Hydraulic RATS - reliable power at pressures and flow rates compatible with current hydraulic designs.
Combination RATS -versatile performance with any combination of electrical , mechanical, or hydraulic outputs.
We supply more than 90% of all Ram Air Turbines for externally-stored systems -applications that provide military aircraft with a mission flexibility unsurpassed by any other type of secondary power system .
Like to hear more about our RAT capabilities? Drop a line to Ai Research Manufacturing Division , 9851 Sepulveda Blvd., Los Angeles, California 90009.
hHlf" 6iR~~~ys~r~h
122 Circle 122 on reader service card
Electronics I April 29, 1968
New Microwave Review
Custom-engineered zero returnloss diplexer is basically a narrowband bandpass filter, but it terminates out-of-band signals into an internal load rather than reflecting them back to the input. Over the 2.97-3.13 Ghz passband, inse rtion loss is less than 0.9 db. At 2 and 4 Ghz, insertion loss is greater than 40 db. Sage Laboratories Inc., 3 Huron Drive, Natick, Mass. 01760. [401]
C-band tunable filter model 51923-1 comes in a waveguide assembly consisting of cylindrical cavity resonators, power dividers, and high power loads. It is designed to eliminate the rfi problem in an operational weather radar system. Tuning range is 5.45 to 5.65 Ghz, bandwidth 20 Mhz, power handling 400 kw peak, and vswr 1.5: 1 max. AA! Corp., Cockeysville, Md. 21030. [402]
C-band beacon antenna DMAQ200-1 will survive heat pulses to 3,000'F and will operate for 5 minutes in a l ,OOO'F environment. It weighs 5 oz, is 1.5 in. long and has a 1.13 in. diameter. Frequency range is 5.4 to 5.8 Ghz, vswr less than 1.5:1 and power handling capabil ity l kw peak, 10 w average. Dorne and Margolin Inc., Veterans Memorial Highway, Bohemia, N.Y. [403]
X-band preamplifier model APX-2, designed for radar applications, is a fi xed-tuned parametric amplifier providing a 50-Mhz bandwidth anyp lace in the 8.5 to 12 Ghz range. Noise figure is 3.5 db max with 16 db of gain. The unit handles up to 200 mw c-w input without damage. It measures 4 x 5 x 6 in. Melabs, 3300 Hillview Ave., Stanford Industrial Park, Palo Alto, Calif. 94304. [404]
A line of 20-w stripline terminations features a metal-film element deposited on a beryllium oxide substrate. Model 12520W-T is for insertion in l/ e-in. stripline. Vswr rating is 1.1 or better below 1 Ghz and 1.25 or better below 4 Ghz. Dimensions are 0.250 x 0.375 x 0.065 in. Price is $35; delivery, 2 to 3 weeks. EMC Technology Inc., 1133 Arch St., Philadelphia, Pa. [405]
High power limiter operates over the frequency range of 2 to 8 Ghz. The device can limit peak r-f input powers up to 500 w and average power up to 5 w. Maximum r-f power output is 100 mw. Low power insertion loss is 1.25 db maximum and input vswr is 1.75 to 1. The unit comes with DSM or TNC connectors. Micro State Electronics, 152 Floral Ave., Murray Hill, N.J. [406]
Microwave pulse signal source 03-54-00 provides up to 40 kw peak power output and tuning range of 700 to 850 Mhz. The instrument offers stable frequency, variable pulse width, repetition rate and power output as well as external and internal pulse synchronization which permits separate use of modulator. Applied Microwave Laboratory Inc., Andover St., Andover, Mass. [ 407]
Directional couplers covering 200 Mhz to 12.4 Ghz provide high accuracy coaxial measurement. They are suited for broad-band swept reflectometer set-ups or consta nt vswr monitoring systems. Minimum directivity for the 5 cou plers that cover the band ranges from greater than 40 db at the low end to more than 30 db at the high end . Emerson Electric Co., Calabasas, Calif. [ 408]
New microwave
Tiny tee in attenuator increases range
Voltage-controlled unit, with ferrite hybrid junction, has phase shift under 5 °, operates from 50 to 2,000 Mhz
"It seemed as though Lady Luck were on our side. Every time we thought our designs were going to be stymied, along came the hardware that could do the job." That's how Allen Podell, director of development at the A-R Anzac Electronics Co., described how Anzac
engineers came up with a voltagecontrolled attenuator (VCA) that offers high performance from 50 to 2,000 megahertz.
Anzac's first attempt to make a VCA was hindered by isolation and phase-shift problems. Company engineers built a device but it was
Down to 20 db. Since the ferrite magic tee (in center of attenuator) is small, phase shift is low.
Electronics I April 29, 1968
123
We're not the nation's best-kept secret any more! Albuquerque ... Sunshine. No crowds. No smog. You can golf and ski on the same winter day. Two universities, outstanding recreation outdoors. Symphony, opera, much more, in unique New Mexico Contact: Albuquerque Industrial Development Service
400-Z Elm N.E., Albuquerque, New Mexico 87103
Circle 124 on reader service card
Our little black book has over 100,000 phone numbers.
You never had a black book like it. Over 1,500 pages. And those phone numbers! More than 100,000 telling you who to call/where to go, for the over 4,000 different product categories listed and advertised in the yellow pages of the Electronics Buyers' Guide. It's the industry's one-stop shopping center that lets you find the products and services you need quickly. You can depend on EBG.
Electronics Buyers' Guide
A McGraw-Hill Market Directed Publication, 330 West 42nd Street, New York, N.Y. 10036
124
Rat only up to 8 decibels. It's magic. Podell thought of us-
ing a magic tee-a four-port junction-in the attenuator because of its high isolation. He wanted two ports for the input and output and, across the other two ports, he intended to connect adjustable resistors. But when he analyzed the system, he found that for a low voltage standing-wave ratio, the resistance at one port must increase when the other resistance decreases. He saw no way to do that.
Then, along came the p-i-n diode, a device whose resistance goes up with increasing d-c current. Podell put two p-i-n's in series across the two ports, and, by biasing one diode, he could control the attenuation and, at the same time, keep the vswr down.
But the dynamic range was still low because of large phase shifts. Then, along came ferrite magic tees, five-millimeters thick Podell, by putting one in the vcA, reduced the attenuator's electrical length, cutting phase shift to under 5°.
Anzac's attenuator has a dynamic range of 0 to 20 db, and a maximum vswr under 1.2. Insertion loss is 1.0 db for low frequencies, and 1.5 db at higher values. For a given control voltage, the plot of attenuation versus frequency is a line with a slope of 0.000025 db per Mhz.
On the level. Anzac expects its VCA to replace mechanical attenuators, popular because of their flat attenuation over broad frequency bands. "We're close to them in performance now," says Podell. He claims there is no other vcA that can match its performance under 1 gigahertz.
Anzac hopes to sell to the military and to makers of sweep generators. One use suggested by Podell is matching the outputs of a pair of antennas tracking the same object.
The vcA could also be used to regulate the output of a sweep generator.
If more than 20-db attenuation is required, the vcA's can be cascaded. The devices are normally controlled by a current source, 5.8 milliamps for 0 db to - 0.58 milliamps for 20 db attenuation.
The cost is about $200 and delivery time is four weeks.
A-R Anzac Electronics Co., 121 Water St. , Norwalk, Conn . 06854 [409]
Electronics I April 29, 1968
NEW EFFICIENCY FOR ULTRASONIC TRANSDUCERS
What price performance in a quality filter?
, 0.31
_L
less than $15
with Clevites compact ceramic ladder filter.*
TL40D9-72A
rr type
NA type
Now, adding new efficiency to ultrasonic propagation, Tokin introduces VIBROX- unique ferrite magnetostrictive vibrators. VIBROX has minimum eddy current loss and a far greater electro-mechanical transduction efficiency than conventional vibrators. A wide range of application embraces ultrasonic cleaning and degreasing; metal, textile, and chemical processing; and echo-sounding and navigation devices such as depth-sounder, fish-finders, etc.
Tokin VIBROX is supplied in two shape-types with nominal frequencies ranging from 15 to lOOKc. Termed NA and rr respectively, both make use of associated permanent magnets to totally eliminate the need for DC bias- despite the fact that VIBROX is magnetostrictive.
For further information and brochures, write to:
Tohoku Metal Industries, Ltd.
1·4, GINZA ·HIGASHI, CHUO -KU, TOKYO, JAPAN Telephone: Tokyo ( 542) 6171 Cable Add ress: TOHOKU METAL TOKYO
Main Products: Permanent Magnets (Cast, Ferrite), Tape Wound Cores, Bobbin Cores, Magnetic Laminations, Fe-Co Alloys, Sendust Cores, Ferrite Cores, Memory Cores, Memory Matrices, Pulse Transformers
Circle 155 on reader service card
.Q
c
Ill
...Ill
0
z 50
0 j:::
a::
~ 40
z
a::
:i:.::i 30
0 D..
20
10
370 390 410
490 510 530
FREQUENCY kHz
Here's the smallest (less than 0.07 cu. in.), most rugged fixed-tuned filter on the market today!
Clevite's 9-disc miniature filter is packaged in a hermeticallysealed cylinder, exceeds all military environmental specifications, is ideal for transistorized i -f amplifier circuitry in AM and FM sets plus many other applications that call for a fixed -tuned filter. Stop band rejection : 50 db. Center frequency tolerance : ± 3kHz. Stability : within + 0.2% for 5 years ; within 0.2% from - 40"C to +85"C. Impedance (in and out) 2000 ohms for B / W less than 12 kHz; 1000 ohms for broader bandwidths.
Following models standard at 455 kHz (A) or 500 kHz (C) (custom models on special order) :
Model Number
TL1009 - 20 (A or C) TL1609 -32 (A or C) TL20D9 -38 (A or C) TL30D9 - 57 (A or C) TL40D9 -72 (A or C)
B/W
min. u 6db
max. @ 60 db
10 kHz
20 kHz
16 kHz
32 kHz
20 kHz
38 kHz
30 kHz
57 kHz
40 kHz
72 kHz
*PRICES: 1- $25 ea; 25- $20 ea; 100- $17.50 ea; 500 - $15 ea; 1000- $13.75 ea; 2500 - $12 ea.
(Prices subject to change without notice)
Send order or request for Bulletin 94021 to : Clevite Corporation Piezoelectric Div., 232 Forbes Rd ., Bedford, Ohio 44014, U.S.A. Or: Brush Clevite Company, Limited, Southampton, England .
CLEVITE
Circle 125 on reader service card
125
These new keyboard switches feature unusually precise action and low-cost mounting. See for yourself-write for samples.
These elegantly styled key switches are especially suitable for computers, learning and business machines, and other advanced control equipment.
Designed by Raytheon, they have a featherlight touch that is precise and reliable. Just a 3-oz. touch activates the switch. Because of the unique design, this action can be repeated more than 10 million times. Yet the switches cost as little as 60¢ in production quantities.
Raytheon key switches are available in a wide range of standard- and custom-cap shapes, sizes, colors,
and alphanumerics. The characters can be illuminated by backlighting. All switches are made of high-quality materials: stain-resistant caps; polycarbonate body parts; stainless steel springs; beryllium and stainless steel contacts. They are available in single- and double-level wipe-action types, and in dry-reed, hermetically sealed single-and double-level types.
Write for samples. For free samples, write on your letterhead describing your application to: Raytheon Company, Industrial Components Operation, Dept. 2351-EL, Quincy, Massachusetts 02169.
[fAYTHEON)
Simple, low-cost mounting. Rayth eon switches plug into .125" PC board . Contact pins snap in ,
firmly lock switch in place for soldering. This permits you to use flow soldering techniquescut keyboard assembly time and costs.
126 Circle 126 on reader service card
Electronics I April 29, 1968
New Subassemblies Review
Read-only transformer memory systems series LBS have bit capacity ranging from 32,768 to 262,144 bits. The nondestructive read-only cycle time is 300 nsec. Access time is 250 nsec. The
system provides a parallel readout of up to 128 bits. Operating temperature range is 0° to +50°c. Memory Technology Inc., 223 Crescent St., Waltham, Mass. 02145. [381]
D-c servo amplifier model A505 can provide a 70-amp peak pulse output at 40 v d-c for fast acceleration and deceleration of high-response d-c motors. It has an integrally mounted blower to provide for adequate cooling and increased steady state rating . Voltage gain is 50. Power supply can be 28 or 40 v d-c. Westamp Inc., 1542-15th St., Santa Monica, Calif. [382]
Active low-pass filter type 171 is designed to reduce noise, restrict bandwidth, and provide data correlation. Cut-off frequencies from 2 to 2,000 hz with Butterworth, Bessel, or gaussian characteristics are available by switch selection. Input impedance is greater than 100 megohms. Price is $590. Neff Instrument Corp., 1088 E. Hamilton Rd., Duarte, Calif. 91010. [383]
Core memory systems in the Com Rae series will be available in several models. Model 100 exhibits a cycle time of 1 JLsec, an access time of 0.45 JLsec, and is available in capacities up to 4,096 words by 24 bits or 8,192 by 12 bits. The memory is packaged in plug-in assemblies 71;4 x 91/4 in. Information Control Corp., 1320 E. Franklin Ave., El Segundo, Calif. 90245. [384]
A-c/d-c power modules series RA80 are adjustable from zero to max. output and externally programable in several modes. They come with outputs of 0-10 v to 0-160 v d-c, power to 1,000 v. Regulation and ripple characteristics are good, and efficiency up to 80%. Units operate at base temperatures to 80°C. Technipower Inc., Benrus Center, Ridgefield, Conn. 06877. [385]
.........
High-reliability 100-tap delay line model BF-14-419 is especially designed for memory systems. It features a maximum rise time of 30 nsec, for a delay of 1,000 nsec, with distortion at the taps held to less than 5%. The unit is available from stock at an Impedance of 93 ohms. Custom-engineered units are also available. Bel Fuse Inc., 198 Van Vorst St., Jersey City, N.J. [386]
Power supply model 5002-10 delivers up to 2,012 v d-c and up to 10 ma. Highly regulated, its output varies only 0.0025% or 2 mv for a 100 % load change or 10% line change. The unit can operate at either positive or neg ative polarity with a temperature coefficient less than 50 ppm/'C and stability of 0.005%/hr. Raytheon Co., Richards Ave., S. Norwalk, Conn. 06856. [387]
Integrated circuit memory system model CE-150 is available in capacities of 4096, 8192 and 16,384 words with word lengths variable in 4-bit increments from 8 to 36 bits. The random access unit has a full cycle time of 1.5 JLsec and an access time of 750 nsec. It has application in small computers. Lockheed Electronics Co., 6201 E. Randolph St., Los Angeles 90022. [388]
New subassemblies
Three-wire design speeds up memory
Smaller cores and combined sense-inhibit line permit nanosecond access with conventional 3-D organization
A large ferrite-core memory that has the cost advantages of threedimensional design but attains unusually high speeds by using smaller cores will be shown this week at the Spring Joint Computer Conference in Atlantic City, N.J. The memory is the Ampex Corp.'s
new model 3DM-750 unit, which has a 750-nanosecond cycle time and a 300-nsec data access time. These speeds-perhaps double those of the usual large 3-D memory-are made possible with cores only 18 mils in diameter threaded with three wires.
Three wires for speed. New 3-D memory fits in 19-inch rack.
Electronics I April 29, 1968
127
now... adozen tools tor dozens 01 iobs
in ahiP pocket set I
XCELITE, INC., 130 Bank St., Orchard Park, N. Y. 14127 In Canada contact Charles W. Pointon, Ltd.
128 Circle 128 on reader service card
Conventional 3-D memories use 22-mil cores and four wires-for x-select, y-select, sense, and inhibit functions. Most high-speed ferrite-core memories-such as Ampex' last major development, the model RM [Electronics, Nov. 13, 1967, p. 201]-are 2-D or 21/2-D. But these cost more than the 3-D because they require more electronic drive and sense circuits in proportion to the amount of information they can store.
The basic 2-D memory has two orthogonal sets of wires, one set containing a wire for each word and the other a wire for each bit in a word. At each intersection of the two sets, a word wire and a bit wire pass through the hole in a toroidal ferrite core. A third set, the sense wires, is parallel to the bit wires.
To read data from a 2-D memory, a current strong enough to switch to 0 all the cores that it threads flows along a single word wire. Cores that switch from 1 to 0 generate voltage pulses in the sense wires. To store data, a current, half the magnitude of the read current, passes through the word wire in the reverse direction, and another half current passes along those bit wires threading cores that are to store l's. The two currents combine to set the proper cores to 1 where only the half-current flows, the cores don't switch.
The conventional 3-D memory is a series of stacked planes, each containing one bit of each word in the memory. In each plane two orthogonal sets of wires permit any core in the plane to be addressed; the corresponding wires in all planes are connected in series to select all the bits of a word. In each plane a sense wire detects the change in magnetization of any core, and an inhibit wire opposes the current in one of the two select wires to store a 0.
To read data from a 3-D memory, a half-current passes along one wire in each of the two orthogonal sets, in such a direction as to switch to 0 all cores that the two wires thread. Cores that switch generate voltage pulses in the sense wires; where only the halfcurrent flows, the cores remain unswitched. To write data, a halfcurrent runs through each of the two wires in the opposite direction,
+25v
II +7v
switching cores to 1 except where the inhibit current opposes them.
Because the larger cores take longer to switch, and because the longer wires are accompanied by more parasitic effects that tend to reduce speed, the speed of the 3-D has generally been thought to be limited. Getting four wires through 22-mil cores is difficult; nobody has seriously considered trying it on a production basis with smaller cores. But Ampex engineers sidestepped both difficulties by designing a 3-D memory with only three wires through each core, combining the sense and inhibit functions on a single winding.
The key to the design is what the designers call an antibalun transformer. This is a transformer with a 1:1 turns ratio, whose two coils are connected with opposite polarities to the two sides of the inhibit line, as shown above. These two sides, as in conventional 3-D memories, pass in parallel through adjacent rows of cores, exchanging positions at the center of the row; this arrangement minimizes the noise picked up while data is being read out. If the resistance of both sides of the winding is exactly equal, the same amount of current flows through both coils of the transformer. If
Electronics I April 29, 1968
for some reason the current through one side tends to increase, the transformer generates a back voltage on that side to hold back the current and an opposite voltage on the other side to increase the smaller current-thus tending to keep the two currents equal. Because the currents in the two c:oils tend to remain equal and in the same direction, the connection is called an antibalun.
Because the two coils have opposite polarities, the two currents see a low common-mode in1pedance in the antibalun and build up quickly when the transistor switch at the top of the diagram turns on. ·when it turns off, if the currents haven't been equal, a correcting Hux has built up in the transformer, creating circulating currents in the sense-inhibit line. Because the resistance of the line plus the transformer coils is only a few ohms, the ratio L/R in the winding is high and the time constant is long -so that these circulating currents could continue for many microseconds. To increase R and reduce the time constant, two diodes at the bottom of the antibalun pass normal inhibit current with hardly any resistance but increase the resistance to circulating currents to several megohms.
'i\Tith the circulating current thus quickly decaying and the transistor switch turned off, the inhibit line is effectively floated electrically at the end of th e inhibit cycle. The differential voltage generated during a sense cycle sees a very high impedance in the antibalun, providing a maximum input to the sense amplifier.
The basic module in the new memory contains 16,384 words of 40 bits each and is packaged in a unit that occupies 5114 inches vertically in a standard rack 19 inches wide. Smaller memories are available in the same package. Any word count that is a multiple of 4,096 is available, and the word length can be anything from four to 40 bits. Up to eight of the 5114inch modules can be stacked, building a memory as large as 65,536 words of 80 bits each-more than 5 million bits. The price range is $12,000 to $250,000, including the drive and sense circuits.
Ampex Corp., 401 Broadway, Redwood City, Calif. 94063 [389]
I Electronics April 29, 1968
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129
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New Semiconductors Review
Silicon rectifier diodes series BYX are for heavy industrial use. The BYX25 controlled-avalanche units are used from 600 to 1,000 v at 20 amps average current. The 600-v units have avalanche breakdown ratings from 750 v to 1,880 v. For 1,000-v diodes, minimum avalanche breakdown rating is 1,250 v; maximum, 1,880 v. Amperex Electronic Corp., Slaters-
ville, R.I. 02876. [436]
Single-chip diode array RDA-10 is for core driver applications. It shrugs off surge currents to 1,000 ma with a steady state forward current of 200 ma. The device features working inverse voltage of 30 v, and provides max. reverse recovery time of 20 nsec, even at extreme switching conditions. Rated power dissipation is 400 mw. Radiation Inc., Melbourne,
Fla. 32901. [437]
I I I I I I I bl
Pressure-sensitive diodes employ impurities that are highly sensitive to semiconductor stress effects. Variation of resistance is 103· Sensitivity increases in proportion to the impurity concentration (atoms per cm3l. Operating temperature range is -30° to +60°C. Rated working voltage is 20 v d-c max. Matsushita Electric Corp. of America, 200 Park Ave., N.Y. 10017. [438]
Dual 50-bit dynamic serial shift register MEM 3100 is constructed on a single monolithic chip utilizing 656 MTOS P-channel enhancement mode transistors. It utilizes 4-phase operation and requires only two external clocks. Features include low power dissipation, high noise immunity, and input data selection. General Instrument Corp., 600 W. John St.,
Hicksville, N.Y. 11802. [439]
Pnp silicon power transistors in T0-111 cases CSDT3301-4) and T0-5 cases CSDT3321-4l have breakdown voltages of -40, -60,
-80 and -100 v respectively. Minimum gain is 10 at collector current of 5 amps, and gain range is 40-120 at collector current of 2 amps. Gain-bandwidth product is 40 Mhz min. Solitron Devices Inc., 1177 Blue Heron Blvd.,
Riviera Beach, Fla. 33404. [440]
Silicon, step-recovery power varactor diodes provide 17 w of output power at 2 Ghz CP1n = 30 wl. Type MV1809C offers a minimum doubling efficiency of 52% at 20 w input power, and the MV1809Cl guarantees a 58% minimum efficiency at 25 w in. Both units are available in the standard cartridge package. Motorola Semiconductor Products Inc., Box 955,
Phoenix, Ariz. 85001. [441]
Static shift register 3300 is a serial access, 25-bit MOS IC. It operates on 1.5 mw per bit at 250 khz and has 25 flip-flops arranged serially in 16-, 8-, and 1-bit strings. There are over 200 components in the 70 by 75 mil chip. In a temperature range of -55° to +85°C, price is $27 each in lots of 1-24. Fairchild Semiconductor, 313 Fairchild Dr., Mtn.
View, Calif., 94040. [442]
X-band and Ka-band Schottky barrier detector diodes D5754, D5691, and D5733 feature high burnout resistance (typically 5 to 10 w peak pulse power). Small junction areas permit tangential signal sensitivities in excess of -50 dbm at X-band and up to -45 dbm at 40 Ghz. Prices Cl to 9) range from $12 to $50. Sylvania Electric Products Inc., 730 Third Ave., N.Y. 10017 [443]
New semiconductors
FET reaches for the high ground
Higher operating frequency and reduction of static-charge problems are the principal features of a new transistor
A specialist in field effect transistors has decided to respecify the devices so an engineer knows what he is dealing with. At the same t irnc, Siliconix Inc. has developed a FET that reaches the gigahertz range.
Designed for low-noise ampli-
fiers, oscillators, and mixers, the 2N5397 has a minimum gain of 15 decibels and a maximum noise of 3.5 db at 450 megahertz. Its competitors, one of which Siliconix second-sources, are rated at 10 db gain and 4 db noise and 13 and 4 db, respectively, both at 400 Mhz.
Math counts. Change in geometry resulted in a higher operating frequency for FET.
Electronics IApril 29, 1968
131
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132 Circle 132 on reader service card
The FET's improved performance is partly due to changes in geom-
etry that the designer, J.B. Comp-
ton, senior engineer, considers proprietary.
Customer's man. According to Compton, "vVe tried to spec the device the way the customer will use it." Minimum transconductance is 5,500 micromhos measured at a drain current of 10 milliamps. Competitors claim 4,500 micromhos at zero bias.
"Transconductance specified at zero bias will not necessarily yield a usable transconductance at that value in a practical circuit," Compton says. He cites a competing device that would probably yield a transconductance of 3,400 micromhos at an operating current of 5 milliamps, even though it's rated at 4,500. He says the 2N5397 reaches 6,500 micromhos at zero bias.
"This kind of specification tells the circuit designer more," Compton asserts. Typical circuits would be in two-way radios, military telemetry systems and low-noise microwave amplifiers.
By the chip. The cutoff frequency of the 2N5397 is not higher than other FET's, but it's limited to 900 Mhz by its package, a T0-72 can header, Compton says. The device has a maximum usable frequency of 1.5 gigahertz in chip form. Siliconix also plans to sell chips individually for higher-frequency hybrid applications.
Being a junction FET, the 2N5397 is less subject to the handling problems of metal-oxide semiconductor high-frequency FET's. Mos FET's are commonly subject to static-discharge problems around the gates, causing them to burn out.
Climbing up. With a chip p eakin g at 1.5 Ghz., higher ranges must b e near. Compton thinks there's a good chance of 3 Ghz in 18 months. Improvements in photomasking techniques should raise cutoff frequencies even higher, without any fundamental breakthroughs , Compton b elieves. However, he does sec a materials limitation for silicon FET's at about 10 Ghz.
Prices are $5.70 in lots of 100 or $8.50 apiece for th e 2N5397 and $4 and $6 respectively for the 2N5398 indush·ial version.
New semiconductors
Optics aid
pulse amplifier
Photo diode and light sensor form input stage for IC amplifier
A new semiconductor technology using optical coupling to obtain complete elech·ical isolation within a standard integrated circuit package has led to the development of an optoelectronic pulse amplifier by Texas Insh·uments.
Designated the SNX1304, the device is b eing offered for engineering evaluation and consists of an re feedback amplifier witl1 an input from a light-sensitive diode in the silicon chip. Fixed to the surface of th e chip is a gallium-arsenide pn-junction light emitter. This is placed on top of the diode.
Applications include transmission of a-c or d-e signals across computer-subsystem interfaces where circulating currents prevent interconnection of ground leads, and where rejection of commonmode noise at the end of a long data-transmission line is required. The hi gh input-to-output isolation ( ± 100 volts) of the optical coupling allo\\'s the device to function as a broad-band pulse transformer with response extending from d-c to 100 kilohertz.
The device has a forward input threshold current of 4 milliamps and a fonvard input voltage rating of 1.2 volts. Its off voltage is 5 and its on voltage is 0.2 volt. Rise and fall times are 250 and 350 nanoseconds respectively, and it comes in a standard 10-leac.l T0-89 flat pack.
Silicon ix Inc., 1140 W. Evelyn Ave., Sun- Texas Instru ments Inc., Dal las, Texas
nyvale, Calif. 94068 [444]
[445]
Electronics I April 29, 1968
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CIRCLE 969 ON READER SERVICE CARD
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Electronics I April 29, 1968
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133
New Books
Solid Statements
Fundamental of Silicon Integrated Device Tec hnology, Volume 11Bipolar and Unipolar Transistors R.M. Burger and R.P. Donovan Prentice-Hall Inc. 480 pp., $15
The two pillars of integrated-circuit technology, bipolar and unipolar (junction and surface) transistors, are discussed from the simple models of their d-c operation through their more complex relationships. The authors include second-order effects, such as drift currents and small parasitics.
Sections on bipolars include carrier and current th eory, capacitance, parasitics, small-signal and largesignal behavior, stmctures, and topological design. The authors compare the IC and discrete versions and provide data on metalization, multiple structures, diodes, and complete IC design.
The discussion of junction and
surface elements includes static and dynamic characteristics, noise, temperature effects , stability, and design. Among applications covered are linear and logic circuits, radiation effects, and IC constmction.
The material can be grasped easily by those who haven't read Volume I of this series, which covers oxidation, diffusion, and epitaxy and is geared to processing rather than final design.
The book has two minor drawbacks: the minimal treatment of passive elements and the overabundance of tutorial presentation.
Fielder's choice
FET Applications Handbook Jerome Eimbinder Tab Books 288 pp., $12.95
To this compilation of articles on field effect transistors which originally appeared in the EEE magazine,
Jerome Eimbinder-the managing editor of that publication-has added a number of papers presented at applications clinics and seminars sponsored by his magazine.
Through this technique, a variety of topics is covered by more than 20 experts. The reader gets a fairly thorough discussion of FET theory, substantial design information, and numerous examples of FET application. But, despite its considerable merits, this anthology does not fulfill the promise of its title nor can it be used as a single source of information on FET applications.
The anthology approach is selfdefeating. With each of the contributors expressing his special point of view and using his own terminology, there is the inevitable loss of a unifying p ersp ective and continuity. This is particularly evident when the reader comes upon different symbols for identical terms or repetition of material he has already read in a slightly different form earlier in the book.
The editor has organized his ma-
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terial so that basic FET characteristics and simple applications are presented first. This permits the reader to make his way through to the more complex sections without too much difficulty.
Included in this survey of fieldeffect technology are discussions of a-c and d-c amplifiers, attenuators, r-f amplifiers, limiters and choppers. Also covered are complementary FET's, FET biasing, oscillators, FET noise, and preamplifiers as well as switches, serial arrays, commutation, photo-FET's and electrometers.
The magnificent seven
The Art of Computer Programing Volume I: Fundamental Algorithms Donald E. Knuth Addison-Wesley Publishing Co. 634 pp., $19.50
Computer programing is an art that has grown from the cameo to the heroic. Donald E. Knuth decided in 1962 to bring together most of the writings on computers. He envisioned a book of 12 chapters.
But before long he knew he
would need a seven-volume work. "Fundamental Algorithms" is the first of the projected seven.
Knuth packs into the first 120 pages all the mathematical derivations of computers, allowing an engineer who knows them to skip that section. But then he presents his feeling that there are "intriguing connections" between computers and the abstract mathematics that is his forte.
To back up that idea, he discusses computers and their ties to algorithms, mathematical induction, sums and products, permutations and factorials, binomial coefficients, and harmonic and fibonacci numbers.
Knuth has created an imaginary computer he calls "MIX," and a machine language to go with it. He applies MIX programs to his discussions of permutations and programing techniques such as subroutines, co-routines, interpretive routines, and input and output.
Other subjects covered, for which Knuth has prepared exam-
pies and graded practice exercises, are allocation, lists, trees, and multilinked structures. A working understanding of calculus and advanced algebra is necessary to appreciate this work, which might best serve as a graduate-level text.
Stephen Strell
Recently published
Introduction to Calculus, Donald Greenspan, Harper & Row, 439 pp. $9.95
Treats derivatives, integrals, differential equations and other fundamentals of calculus; also develops theory, techniques, and applications relating to discrete functions, difference quotients, finite sums, and nonlinear difference equations.
Applied Mathematics for Electronics, J.H. Westlake and G.E. Noden, Prentice-Hall Inc., 608 pp., $12.25
Covers the important middle ground between basic mathematics and the sophisticated topics associated with modern electronicssuch as computers, filters and amplifiers. As each new principle is introduced, its application is discussed and illustrative examples are presented.
Electrochemistry, C.W. Davies, Philosophical Library Inc., 234 pp., $20.00
Gives an up-to-date and concise account of the principles of electrochemistry. Is suitable for novices and for the industrial scientist who is looking for guidance in this field. Covers electrolytes, ionization, surfaces, cells, and kinetics.
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Technical Abstracts
By wire
Field distribution of plated wire memory elements and its effect on memory characteristics Judea Pearl Electronic Memories Inc. Hawthorne, Calif.
In a plated wire memory, the way the magnetic field is dish·ibuted on the surface seriously affects several important factors: adjacent bit interactions, drive currents, and sense signal amplitudes. An analysis shows that there is a characteristic length associated with the applied field and the magnetic properties of the wire that defines the shortest length in which the magnetization can be localized.
For a wire of diameter, d, and film thickness, t, and with a hardaxis susceptibility, x, the length is equal to the square root of the product of d, t, and x. In a typical plated wire, the characteristic length varies between 0.020 and 0.025 inch,
which corresponds to a maximum bit density of 40 to 50 bits per inch.
\i\Tith these results, universal curves also can be plotted that give the required word current for the geometries chosen.
Presented at the 1968 Intermag Conference, Washington, April 3-5.
Pcm for privacy
Transmission performance of telephone networks containing pcm links D.L. Richards Post Office Research Station, London
Military men and others worried about eavesdropping can relax a little. A new pulse-code modulation coder-decoder designed to fit inside a telephone set can be used to digitize and scramble voice signals before they get on a line, making it difficult to tap in. The new device also permits large offices to economize on wiring by carrying all internal calls on wide-band digital circuits.
One such coder-decoder, using integrated digital-logic circuits in 40 Hat packages and analog thinfilm circuits, takes up only four cubic inches. Its power dissipation is less than 500 mw.
Analog-to-digital conversion begins when a narrow pulse opens a sampling gate, whose pulse amplitude output then excites a damped tuned circuit. The result is a decaying wave with an initial amplitude proportional to the sampled analog voltage. A Schmitt trigger generates an output pulse for each peak until the wave's amplitude falls below a set threshold. Thus, the number of pulses for each sample is a measure of its compressed amplitude. A standard binary counter then keeps track of the number of pulses, and a shift register converts the parallel output from the counter to the pcm train.
The decoder generates a fixedarnplitude pulse with a width that's proportional to the incoming line pulses. The same sort of counting techniques used in the coder determine the pulse length. Next, the
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pulse is applied to an RC network that charges twice as fast as it discharges. The neh ¥ork's voltage is sampled for a fixed time that equals or exceeds the pulse width, producing the expanded decoder output, which is proportional to the original coder input.
Advantages of the pcm coder-decoder include a minimum amount of analog circuitry, the acceptance of positive and negative signals without the need for inversion or rectification, and a threshold level high enough to minimize drift.
Presented at the Colloquium on Pulse-Code Modulation, London , March 4 .
Telltale heat
Infrared analysis of second-breakdown modes in power transistors A.S. Dostoomian Raytheon Co. Wayland, Mass. M.F. Nowakowski NASA Huntsville, Ala.
Testing a transistor for second breakdown without destroying or degrading the device has long been
a problem. Now a system that senses the imminence of second breakdown through thermal tests with a fast-scan infrared microscope eliminates this problem; the destructive effect of second breakdown is never reached. Thus, there is no permanent damage to the device.
The transistor is energized by a pulse that is synchronized with the microscope's scan cycle. This pulse can be delayed to allow the detector's instantaneous field of view to be phased to the infrared flash caused by second breakdown, at whatever point it might take place. As the transistor is scanned, the system's display shows a pulse, whose amplitude depends on the intensity of the hot spot, and a thermal map of the area scanned.
A complete raster scan of 150 transistors was taken at the secondbreakdown current level, at half that current, and at two-thirds that current. For almost all lower current levels, the location of the initial hot spot occurred at the same point as the heat peak observed
during second breakdown. At the full second breakdown current level, about 30 transistors showed hot spots; second breakdown in these transistors occurred at a lower current level than the other transistors. Transistors that showed hot spots when scanned at current levels less than the rated maximum tended to go into second breakdown at lower current levels than units th at exhibited no hot spots.
When testing for second breakdown in the forward- and reversebias directions, about half of the transistors showed hot spots occurring at the same point. The probable reasons for hot spots differing are the presence of more than one anomaly, and the temperature increase during testing.
After infrared testing, a number of transistors were again subjected to second breakdown. In the units that failed, melted areas occurred at the points where the initial heating was observed with the infrared micros cope.
Presented at IEEE International Convention, New York City, March 18-2 1.
· · · · c--:-_ --: cmF
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New Literature
Single channel terminal. Lenkurt Electric Co., 1105 County Road, San Carlos, Calif. 94070. A flysheet describes the 46A single channel .terminal that furnishes a voice channel with choice of in-band or ·out-of-band signaling. Circle 446 on reader service card.
Videotape recorder. Ampex Corp., 401 Broadway, Redwood City, Calif. 94063. Bulletin V158 contains features, specifications and a description of the VR1200A high-band color and monochrome videotape recorder for broadcast and sophisticated closed circuit tv use. [447]
Reed relay. Solid State Electronics Corp., 15321 Rayen St., Sepulveda, Calif. 91343, has issued a bulletin on the model 7001 Microreed relay, a single-pole double-throw unit designed to be driven by transistors. [448]
Miniature terminals. Robinson Nugent Inc., 802 E. Eighth St., New Albany, Ind. 47150. A six-page catalog illustrates 94 different miniature and subminiature terminal styles. [449]
Antenna system. Andrew Corp., 10500 W. 153rd St. , Orland Park, Ill. 60462. Bulletin 266 covers a 350-450 Mhz
remote controlled receiving antenna system. [450]
Microwave equipment. Microwave Systems Co., 6915 Lakewood Place, Denver, Colo., 80215, offers a product line catalog describing large passive repeaters, guyed and self-supporting towers, and microwave accessories . [451]
Shielding materials. Russell Industries Inc., 96 Station Plaza , Lynbrook, N.Y. 11563. Catalog No. 70 covers the full spectrum of shielding materials for electromagnetic and radio-frequency interference problems. [452]
Heterodyne mixer-oscillator. Weinschel Engineering, Gaithersburg, Md. 20760, has published an illustrated catalog sheet on the model H0-1 heterodyne mixer-oscillator. [453]
Elapsed time indicator. ENM Co., 5306 W. Lawrence Ave., Chicago 60630, has issued a catalog sheet describing the series T5B economy model elapsed time indicator. [454]
Wirewound resistors. Kelvin, 5919 Noble Ave., Van Nuys, Calif. 91401. Bulletin HR400-20-4 outlines the
specifications and test procedures set up by the company to approach the maximum in reliability goals for precision wirewound resistors. [455]
Electronic tachometers. Airpax Electronics, P.O. Box 8488, Fort Lauderdale, Fla. 33310. Bulletin F-11 describes the Tach -Pak, an electronic tachometer that converts rpm, speed or frequency into an output current or voltage linearly proportional to the input signal usually generated by the motion of a rotating component. [456]
Xenon flashtubes. Torr Laboratories Inc., 2228 Cotner Ave., Los Angeles 90064. A four-page brochure describes the Torrlite series of xenon flashtubes. [457]
Power amplifier. Beckman Instruments Inc., 2500 Harbor Blvd., Fullerton, Calif. 92634. Data sheet 68266 covers the unity voltage gain model 821 power amplifier, a unit that can increase power output of IC operational amplifiers as much as 40 times. [458]
Incremental shaft encoders. Disc Instruments Inc., 2701 S. Halladay St., Santa Ana, Calif. 92705. The use of Rotaswitch shaft encoders for automatically
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High Sensitivity 7" H,O produces 2 volt
linear n% ) output.
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Video: President of MTI , Frederick J. "Jack" Beste Audio: I could tell you all about the MTI quality in three or four more pages of print. But we believe in proof. All you have to do is call us in for a side by side demonstration with any equipment on the market today - even those at prices above MTI. Another point - since we make the most complete line of equipment in the world our sales engineers can recommend a camera and / or system to meet your needs. So don't just buy a camera - buy the right camera for your needs - buy the right system for your needs.
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New Literature
controlling the positions of industrial work-tables is described in Bulletin 454. [459]
Chemical etching equipment. Western Technology Inc., 220 W. Central Ave., Santa Ana, Calif. 92707. An eight-page brochure describes a complete line of precision laboratory and production chemical etching products. [460]
Power supply. Analog Devices Inc., 221 Fifth St., Cambridge, Mass. 02142. A one-page data sheet describes a lowcost, p-c mounting power supply for operational amplifiers. [461]
IC telemetry receiver. Defense Electronics Inc., Rockville, Md. 20854, offers a bulletin containing engineering features, performance specifications, functional block diagram and outline data on an IC telemetry receiver for ground-based, special airborne, mobile and portable applications. [462]
Audio connectors. Switchcraft Inc., 5555 N. Elston Ave., Chicago 60630. Catalog C502a provides the engineer and designer with an up-to-the-minute guide to the latest in audio connectors. [463]
Rectangular connectors. ITT Cannon Electric, 3208 Humboldt St., Los Angeles 90031. Catalog 2D-D covers a line of double density "D" rectangular connectors. [470]
Rfi components. Filtron Co., 131-15 Fowler Ave., Flushing, N.Y. 11355. A complete line of filters and components for suppressing radio frequency interference is presented in 24-page Catalog P-68. [471]
Ferrite material. Krystinel Corp., Fox Island Road, Port Chester, N.Y. 10573, has available a specification sheet on the K-940 advanced, high permeability ferrite material that permits the miniaturization of magnetic components. [472]
Time-delay relays. Plessey Airborne Corp., 1414 Chestnut Ave., Hillside, N.J. 07205. The "UltDelay Economini" time delay relays are described in two page illustrated bulletin PS-19. [473]
Power supplies. Raytheon Co., Sorensen Operation, Richards Ave., Norwalk, Conn. 06856, has issued short-form catalog 68A covering its d-c power supplies and a-c line regulators. [474]
Tone transmitter and receiver. Quindar Electronics Inc., 60 Fadem Rd., Springfield, N.J. 07081. Bulletins 1007 and 1008 cover the QT/QR-50 tone transmitter and receiver. [464]
Tuning fork oscillator. Solid State Electronics Corp., 15321 Rayen St., Sepulveda, Calif. 91343. Model TF-120 silicon transistorized tuning fork oscillator is illustrated and described in a single-sheet bulletin . [465]
Spark gaps. ITT Electron Tube Division , Box 100, Easton, Pa. 18042, has available a brochure describing its line of two-electrode spark gaps, which protect circuit components from damage by overvoltages. [466]
Test equipment. Beckman Instruments Inc., 89 Commerce Rd., Cedar Grove, N.J. 07009. Insulation test equipment, electronic test and measuring instruments, high-voltage power supplies, and automatic component testers are comprehensively covered in 40-page Catalog 31. [467]
Wave filters. ADC Products, 6405 Cambridge St., Minneapolis 55426. A 14-page catalog contains a general approach to wave-filter design and a discussion of the problems encoun tered in writing wave-filter specifications. [468]
Pressure switch. Control Products Inc., East Hanover, N.J. 07936, has issued a bulletin illustrating and describing the P-6000 pressure switch. [469]
Strip-chart recorders. Foxboro Co., Foxboro, Mass. 02035. Bulletin C-14 describes the ERB series of electronic strip chart recorders. [475]
Resin dispenser. Hardman Inc., 600 Cortlandt St., Belleville, N.J. 07109. A catalog sheet describes the Triplematic 700 resin dispenser for microminiature shots. [476]
Terminal blocks. Thomas & Betts Co., 36 Butler St., Elizabeth, N.J. 07207. Eight-page, illustrated bulletin 500.2 describes a new line of terminal blocks and their accessories. [477]
Electronic components. Switchcraft Inc., 5555 N. Elston Ave., Chicago 60630. A 25-page booklet covers such major product categories as jacks, plugs, switches, connectors, indicating devices and audio accessories. [478]
Subsystems. Reeves Instrument Division Dynamics Corp. of America, Garden City, N.Y. 11530, offers a 24page brochure detailing subsystems in such areas as telemetry, digital rang ing, airborne radar, tactical radar, satellite and spacecraft tracking radars, analog computers and aerospace ground equipment. [479]
Coil bobbins. Gries Reproducer Co., 400 Beechwood Ave., New Rochelle, N.Y. 10802, has published a pocketsize booklet covering the advantages and design features of its precision molded thermoplastic coil bobbins. [480]
140
To Find-Out How
Motorola's New
MC1539/MC1439 1/C Op Amps Offer Six Performance Improvements ...
See
The following 2-Page insert
Or
If the insert has already been removed and filed by one of your associates ...
Circle this Reader Service Number
324
11
MOTOROLA
Sen1iconcluct:or Products Inc~
Electronics I April 29, 1968
MC1539 Offers Six Performance Improvements!
- ·;."o"...._,.,..._....,_._,,o__-~,.,_.....,.,._......_.,,;,---2.00
1, FR EQUENCY (kHz)
Our engineers say the MC1539 integrated circuit operational am-
plifier is "the finest I/C Op Amp available today. Period." The six advantages below and the specs on the next page offer strong supporting proof:
1. Input Offset Voltage - 2.0 mV lower than comparable circuits ... requires less input bias compensation.
2. Input Offset Current - almost an order of magnitude lower . .. making it ideal for high input impedance circuitry.
3. Output Short-Circuit Protection and Input Over-Voltage Protection - built-in to provide "accident-proof" operation
and transient suppression. 4. Guaranteed minimum gain over
full temperature range - twice that of previous types ... for higher performance - with stability. 5. Power Bandwidth - typically an order of magnitude better (See Inset) . 6. Slew Rate - typically 34
VIµ.sec at Av= 100 .. . twice as
high - for extremely fast comparator applications. Best of all, the MC1539 (and, a low-temperature range version, MC1439) are 100-up priced at a low $12.00 and $7.50, respectively, in the 8-pin (T0-99) metal package. And, the pin configuration is the same as the 709 and 101.
fURN PAGh -----~
MOTOROLA
S emi c onductor Product s Inc.
- w/.etre tkp~ ituj~ ij f!LlllR,/
Here's Detailed Data For The MC1539/0p Amp Compare The Specs For All Three*
... proof that it's "The Best I IC Op Amp Vet!"
@ ~":';!.~;~~~~!~rs
MONOLI THIC OPERATIONAL AMP LIFIER
.. designed for use H 1summm91"'91ifiet, integntor, or1mplilier
w11h ope'rllllfl9 cti..rac::1erist1cs as 1 function of 1he einerl\ill feedl>Kk coml]Of'lef11s.
· Low Input Ofhet Volt· - J _Q mV max
· Low Input Offset Current - 60 nA mu
· Lit~ P~ Bandwidth - 20 Vp p Output Swmg 11 20 kHz min
· Outpul Short CifC\lll Protection
· tnputOve!'VoltageProt11e11on
· CIHS AB Oulpul for Ellcellenl linearity
- · Slew Rall 34 V JISIVP
MAXIMUM AATINGS t . " 1'"(: _ _ _ -
b ....
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OPERATIONAL AMPLIF IER INTEGRATED CIRCUIT
MONOLI THIC SILICON EPITAXIAL
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CIRCUIT SCHEMATICS
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2.
*Compare the specs for all three
CHARA CTER ISTIC
f:! ";o~l~o~~af; ~in ss·c
Sym bol Avot
MC1709 25 ,000
-..·..-. 101 Type
25,000
Unit V V min
to + 12s ·c1 Output Impedance (f = 20 Hz )
Input Impedance f = 20HzJ
z.., z.·
150 150
-©
,00
...4k
U typ
k !! min
Output Voltage Sw1n1 (RL= lOk!?) (RL= 2.0k !J}
v· ·
~ 12
::':" 10
±12 ·10
±+ 1Il0l&_ 'm~l"o
Power Bandwidth (AV ::; I, Rl= l.Ok !? THO <!: 5 %, Vo= 20 Vp...p
Input Common MOde Volta eSwin
Common Mode Re 'ection Ratio
Input BIHCurrenl
I~= !!.¥
(TA = + 25. C) (T,. - _55·c 1
Input Offset Current
=: : (l.· = li - h )
H:: ~ :: ~: ~_±]~;~61
Input Offset Voltage
l1!; ~ ~;~Jc . + 125·c1
Step Response Gain = 100
Gain = 10
Gain = l
Pow
CMV , .
CM,.
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70
500 1500
,..200
-©
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,7.0.
1500
,2.0.0
20
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dB min
..
75
200
200
1S
v..
5.0 6.0
800
" dV-~P<ld.!f!L
380 12.0
,, 600
.,.,.dV~i°'d.!.@_
340 1.7
2200 1300
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50 6.0 -{j) -{j) -{j)
3.0 4.0
......100 .....
....400
mV mu
nstyp
vnsa~2.J
nstyp
v~lle.J nstyp
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Equivalent Input Noise Voltaae (Open Loop) (Rs= 10 kf! , Noise Bandwidth = 1.0 Hl f = 1.0 kHl)
cd'il·i
90
-{j)
30
'"
Ave rage Temperature Coefficient of Input Offset vona11e
L};! ~ ~1h:T~=-.:s5sc ~0itt~~·~·b
DC Power Dis sipation (PowerSupply =.:!: 15V, VMt - Ol
Positive Supply Sensitivity (V- conslantJ
~'.f3~~vnesf:tt~ly Sensitivity
TCv,,
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1'5
150
150
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TYPI CA L O UTP UT C HARACTE R ISTI CS IV' ·l$V«.V-·-l $VCIC. T1o· 1!i"CI
FI GURE CURVE
NO.
NO.
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FIGURE 2 - POWER BANDWIDTH (LARGE S IGNAL SWI NG - · FREOUENCYl
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3. 4. For further information write:
MOTOROLA Semiconductor Products Inc. P. 0. Box 955, · Phoenix, Arizona 85001
Newsletter from Abroad
Europe ponders place in space
April 29, 1968
West European space officials face a round of harsh decisions now that Britain has decided to call it quits on two key international programsthe Europa rocket and the proposed European television-relay satellite.
The British move puts the fate of Europa, a joint effort by the seven countries in the European Launcher Development Organization (ELDO), up to France and West Germany. They need the rocket for their Symphonie communications satellite and most likely .will find a way to keep the program going after Britain drops out in 1971.
There's scant chance, though, that France and Germany can convince other ELDO governments to help them pick up Britain's share of the tab-a hefty 27%. So far, about $400 million has been allocated for the project. Italy was losing interest in ELDO even before Britain adopted its new stance toward prestige space projects. Nor can Symphonie's promoters expect any substantial help from Belgium and the Netherlands; both have tight space budgets.
ELDO's sister space body, the 13-nation European Space Research Organization (ESRO), has its own woes, even though Britain will boost her contribution to ESRO's work slightly over the next three years. ESRO, set up to handle scientific programs, has been switching its emphasis to corrununications satellites. Britain's decision not to support a tv-relay satellite is a setback for ESRO, which seemed likely to be named project manager.
Europe's space ministers will meet in Bonn this July and may attempt a salvage effort then. The eventual result could be a single program combining the projects that survive.
Australia uneasy over F-111 order .
A row is in the offing in Australia over the two .dozen F-lllC fighterbombers ordered from the U.S. Defense officials in Canberra have let out that the cost of the 24 swingwing aircraft will likely come to $270 million, some $79 million more than the government's original estimate. What's more, the opposition Labor Party has been raising a fuss over the decision to buy the planes every time a U.S. F-111 has been lost.
Defense Minister Allen Fairhall will air the government's stand on the F-lllC order in late April or early May. Because of the spiraling costs for the initial 24 planes, the government almost surely will drop its plan to buy an additional six F-lll's fitted out with special electronic recon- . naissance gear.
Japan clearing up patent picture
Japan's electronics industry is moving fast to straighten out its patent position regarding color television and integrated circuits.
Insiders say eight of the country's dozen color-set makers have asked the government to approve a deal that would license them to use the basic color-tv patents held by the Hazeltine Corp. The royalties, on an if-used basis: 15 cents a set. Japanese manufacturers held off making a deal until it became apparent that the need for licenses wouldn't be eliminated by the legal fight between Hazeltine and the Zenith Corp. ·
The end is almost in sight, too, for Japan's IC patent problems. Five major producers have signed up for licenses from Texas Instruments. Still to be signed, though, is Nippon Electric. Since it holds the Japanese
+Circle 325 on reader 5ervice card
143
Newsletter fram Abroad
rights to Fairchild Semiconductor's planar-process patent, which is complementary to Tl's basic IC patent, Nippon Electric wants a special deal with TI. The U.S. company plans to go into IC production in Japan through a joint venture with the Sony Corp. and presumably will come to terms with Nippon Electric in the next month or two.
Contacts point way to new transducer
Researchers at the Fuji Electric Co. have come up with an oscillating semiconductor transducer they think may turn out a winner. Its output frequency varies with either applied voltage, light, or temperature. The frequency ranges from several hundred hertz to several megahertz. But with an added external capacitor of about 100 microfarads, the value drops to well below 1 hertz.
Fuji calls the device a point-contact transducer. It has two rectifying point contacts on a silicon chip having a high-resistivity n-type layer atop
+ a low-resistivity p layer.
Relaxation oscillation starts when the voltage applied between the contacts rises above a threshold level-around 3 volts. But the oscillation stops when the voltage goes too high. Shining light onto the n-layer changes the values at which oscillations sta1t and stop.
Touch phone lets caller see number
Italian semiconductor maker SGS-Fairchild has readied still another integrated-circuit device for the telephone market. This time it's a keyboard telephone set that displays the number punched into it, something current touch phones can't do. Earlier, the company developed a cut-out that prevents unauthorized long-distance calls.
In the latest SGS unit, the number punched into the keyboard is
stored in a memory until the call is completed. Meanwhile, the number glows on a display of 16 cold-cathode tubes.
SGS expects to price its touch-phone unit between $100 and $130. This makes it a candidate for small switchboards, where it could catch ·wrong numbers in long-distance calls. The prototype, built around 25 IC packages, can be adapted for electronic switching simply by changing one capacitor.
U.S. may duck Paris Air Show
To the dismay of the aerospace industry, it appears that there'll be no U.S. Government participation in next year's Paris Air Show.
The Defense Department apparently intends to stick with its decision not to go, and other Government agencies will probably follow suit. This means that manufacturers will have to arrange their own exhibitions without the traditional help of the Commerce Department and without space in a U.S. pavilion. The upshot: many small companies will be forced to skip the show.
Bonn seeks F-104 warning system
144
West Germany's defense ministry has called on the Nortronics division of the Northrop Corp. to design an integrated status-reporting system for the Lockheed F-104G Starfighter, the Luftwaffe's standard fighterbomber. The ministry says it may install the gear in all of its more than 600 F-104G's after evaluation tests early next year. The voice-based system would be sin1ilar to the one used in U.S. Air Force B-58 bombers for several years.
Electronics I April 29, 1968
April 29, 1968
Electronics Abroad
Volume41 Number 9
Japan
Three-shot gun
The Sony Corp. has decided to
drop the Chromatron tube from the
new 7-inch color tv set it will start
shipping to the U.S. this June and
use instead a tube right out of the
laboratory. But Sony engineers in-
sist that if they had followed the
lead of other color-set makers and
used a shadow-mask tube instead
of working with the Chromatron,
they would never have come up
with their new baby-the Trinitron.
Despite production-line difficul-
ties with a 19-inch Chromatron it
used in a set made for the Japanese Yoke-less. With the Trinitron gun, Sony's tube needs no convergence
market, Sony originally planned to yoke and panel. Flyback, shown resting on tube, does the job.
incorporate the tube in its 7-inch
model because the Chromatron's automatic beam convergence.
gun version. The problem here was
brightness and convergence char- To simplify the color-switching that the Chromagnetron only works
acteristics are superior to those of setup, Sony went to a three-gun well in a line-sequential system
the conventional shadow-mask tube version. But despite the inclusion and requires switching at about
[Electronics, June 26, 1967, p. 208]. of a dynamic convergence genera- 3.58 megahertz. It uses two color-
Tradeoffs. Among the produc- tor and yoke, plus 12 convergence switching yokes-one to separate
tion problems is the fact that the adjustment controls, this Chroma- the beam so that it appears to
one-gun Chromatron requires hard- tron suffered from the same kind of originate at different sources, and
to-make color-switching grids with misconvergence that plagues shad- the other to cause the beam to re-
alternate wires insulated, a high- ow-mask tubes.
converge on the faceplate.
power switching input for the So, combining the advantages of Trio. Instead of making one
grids, and switching at the elec- the first two models, Sony came up cathode do the work of three, Sony
tronic gun's input. With this com- with the Chromagneh·on, a one-gun engineers decided to add two more,
plicated arrangement, the one-gun tube that employs the simplified placing them where the other two
model offered the advantage of color-selection grid of the three- beams in the Chromagneh·on ap-
pear to come from. In this way, the
GRID 1 GRID 2 GRI D 3 GRID 4
Trinitron evolved.
AP ERTURE GRILL
The Trinitron gun doesn't need
a convergence yoke. It has five
CATHODES
grids and produces three separate
RED--- ~_.t--r-;----~
GREEN---i+-=r.-.;-------?~-----'------::~E--o·..J.---
BLUE --~
RED beams from the three cathodes. The cathode assemblies are aligned behind three holes in the number one grid. Directly in front of this grid
is another, also with three holes.
Grids three, four, and five are tubu-
lar structures that surround the
three beams. And at the muzzle of
the gun is an elech·ostatic conver-
gence arrangement consisting of
Color-full. The three beams are bent and shaped by five grids. Deflection plates, controlled by the flyback circuit, cause the beams to converge.
four flat, vertical plates. The two inner and two outer plates are elec-
I Electronics April 29, 1968
145
Electronics Abroad
trically tied together, with the center pair being slightly positiveabout 100 volts-with respect to the outer pair.
The three beams leave the gun in a single horizontal plane after the deflection plates have caused them to converge b ehind the center of th e faceplate.
Sony points to several advantages this one-gun, three-cathode scheme offers. For one, the Trinitron uses only about a third the number of parts required by a three-gun arrangement. For another, electron density is far lower th an in conventional tubes b ecause the Trinitron grids' diameter is large and the b eams are focus ed at the point where they cross-at the center of grid number four.
The neck of Sony's tube has a diameter of only 29 millimeters , but the company says the total beam current is 50% greater than that provided by the three guns of a shadow-mask h1be, which has a 36-mm neck. Sony stresses that the 50% added current is not a maximum but ratl1er an arbih·ary limit at which the tube will maintain a better focus and brightness than the three-gun delta arrangement of the shadow-mask
Well-shaped. The increased brightness results from the use of a slat-like struch1re called an aperture grill. This device, an array of vertical slots in front of vertical phosphor strips on the face of the tube, is formed into a cylindrical shape b efore the slats are etched. The faceplate is therefore also cylindrical. Because of this geometry, heatin g from wasted power merely causes the aperhue grill fram e to expand slightly in a vertical direction; th ere's no relative motion between the grill and the phosphor strips on the faceplate in a direction that would upset registration.
Sony notes that beam width is usually so narrow that only the color h·io beneath one slot is excited at any given tin1e. The sha<low-mask tube's b eam normally excites dots three holes awayvertically and horizontally-from its center, blurring the picture to a degree.
Big gainer
Until now, Japanese tv-set makers looking to design high-gai11, integrated-circuit i-f sound ampliliers into their receivers have had to use U.S.-made 1c's b ecause domestic units produced only 50 decibels of voltage gain at 4.5 megahertz. The Nippon Electric Co. has moved to fill this gap, though, with a circuit having a gain of 72 db at th at frequency.
The company has aheady star ted to distribute samples to prosp ective customers. In production quantities, tl1e cil"cuits will b e available in either a silicone plastic dual inline package or a 12-lead T0-5 can. The JC is expected to sell for b etween $1 and $1.10 in large quantities, compared with the $1.20 large-order price for a comparable RCA device.
Nippon Electric's circuit is basically similar in content to the one pioneered by RCA; it has tl1ree high-frequency differential-amplifier stages, a ratio discriminator, and a Darlington audio amplifier. But there is some difference in design.
Zener. The Japanese firm clain1s tliat its circuit is the first of its typ e to incorporate a zener diode in the regulated power supply. The zener, it says, makes for more consistent operation over a wide range of power-supply voltagesabout 7 to 12 volts-and eliminates the need for the string of forwardbiased diodes that p erform the same function in the RCA design. The zener, which is diffused into th e tran sistor emitter isolation area,
has a voltage almost the same as the transistor emitter reverse breakdown level-about 6 volts.
The rc is designed for Japanese and American television sets, which have a carrier frequency of 4.5 Mhz, and European sets, which have a 5.5-Mhz carrier.
Nippon Electric says distortion of the ratio detector-mostly tl1ird harmonic-runs under 1%, against about 1.8 % in the RCA device.
A current sink in the commonemitter lead of the differentialamplifier stages is used to improve limiting characteristics.
Bias push. Silicon diodes with threshold voltages of 0.6 to 0.7 volt are used in a ratio detector. At this level, a voltage input of Blore than 10 volts would b e needed for undistorted detection. To improve the characteristics of low-signal inputs, the drop across diodes D1 and D2 is used to push a forward bias of about 16 microamperes tlU'ough the ratio-detector diodes, which are both forward biased.
A portion of the ratio-detector bias is fed into the Darlington audio stage. No radio-frequency bypass capacitors are provided, but distributed capacitance of the resistors and the low impedance of the forward-biased diodes provides sufficient bypass action.
About 2 milliamperes can be tapped from the voltage regulator circuit for use in other circuits. However, one must be careful and not connect a large electrolytic cap acitor to these terminals b ecause the high inrush cunent could produce enough heat to evaporate th e aluminum wiring in the IC.
Regulated. Zener diode, shown in color, provides regulated voltage for i·f circuit and also supplies 2 milliamps to external circuits.
146
Electronics I April 29 , 1968
Electronics Abroad
West Germany
Training aid
Germany's federal railroad system seems to be going all out for electronics when it comes to streamlining operations and traffic control. The past year saw the start of large-scale trials in computeraided train routing, freight handling, and train breakup and makeup at several facilities including Seelze and Kassel-Bettenhausen in northern Germany [Electronics, Sept. 4, 1967, p. 206]. At Frankfurt's main freight terminal, work is in progress on re-equipping a train classification yard where track switches and car braking are electronically controlled.
The $4-million system, expected to be completed by mid-1969, will be capable of handling up to 5,000 cars a day on 51 makeup tracks. Already, 18 makeup tracks, complete with switching and braking gear, have been put under electronic control.
The yard will be controlled by Siemens AG digital equipment in the main control tower. The electronic gear, most of it already in place, costs about $350,000.
Train gang. The old facility requirnd 15 control towers for yard operations, but the new one will have only two, and 24 people will do the work of 80.
At the terminal, information on individual freight cars-final destination, identification number, and other data-is radioed by a dispatcher to a nearby freight office. Each car is assigned a number that corresponds to the makeup and destination track into which it must be switched. The information is then coded and sent by teletypewriter to the main control tower.
At the tower, another teletypewriter prints out the incoming data and simultaneously produces a tape, which is put into a tape reader. The reader output programs the electronic control equipment.
The first step in making up new trains at the Frankfurt facility is determining a car's weight and
Fast brake. Operator at control panel of automated railway yard monitors movement of freight cars while controlling switches and braking apparatus.
speed as it comes from a ramp toward the automatic braking facility.
Car weight is determined by a bridge circuit arrangement in which a piece of track forms one branch of the circuit. As the car wheels move over that part of the track the branch resistance changes, unbalancing the bridge. The cirouit output is then a measure of the car's weight. The amplified output is processed and evaluated in the control equipment, which then determines how hard the brakes are applied.
Car speed is measured by a radar set installed between the rails just ahead of the braking apparatus. Radar pulses reflected from the car's undercarriage are sent to the control equipment for processing and evaluation. The output acts to release the brakes when the car has been slowed to its proper roll-out speed.
On their way to the makeup
tracks, cars pass over as many as five track switches. Equipment in the tower controls the position of the track switches in accordance with the program derived from the punched tape.
Magnetic rail contacts are used to count the number of car axles that pass over each track switch. If part of a car is still over the switch, the electronic control equipment is prevented from putting out a track-switching signal.
When the Frankfurt and Seelze facilities are connected, perhaps next year, the computer in the north will be linked by teletypewriter to one at Frankfurt.
Fair weather
The mood of this year's Hanover Industrial Fair, which opened April 27, leaves no doubt that West Germany's electronics industry is riding high once again. It contrasts sharply with the gloom that surrounded the 1967 fair, held at a time when the country's industry was going through one of its worst slumps in postwar history. The industry's sales last year fell an estimated 3% to 4% from the 1966 level.
"This year, though, it looks as if we'll see production expand at a rate of 7% or more," says an executive of a leading German compo-
Electronics J April 29, 1968
147
Electronics Abroad
nents manufachuer. Pump-priming efforts by the Kiesinger government are paying off, with gains being registered across the board.
Last year, the government directed about half of the $625 million it added to the budge t to the post office and the federal railroad system, the country's two biggest users of telecommunications gear.
Another boost to the electronics industry is promised by Bonn's efforts to shift its military hardware purchases away from foreign suppliers, a policy expressed recently by \Vest Germany's defense minister, Gerhard Schroeder.
Renaissance. But by far the biggest gains this year reflect a revival in the consumer electronics market. "Confidence again prevails in the entertainment electronics industry," says Guenther Huecking, head of the radio and television section of the electrotechnical industry's trade association. Huecking predicts that 1.9 million blackand-white sets will be sold this year, against 1.56 million in 1967.
However, sharp production cutbacks during the 1967 slump have resulted in low inventories, and some producers are afraid they 'vvon't be able to meet the renewed demand for monochrome receivers.
Even with this demand for blackand-white sets, sales of color sets are expected to continue climbing. Huecking predicts that from 250,000 to 300,000 color receivers will be produced this year for both domestic and foreign markets. A big boost will come later this year when each of the country's two major networks expands color programming from the present four to five hours a week to b etween eight and 10. At the end of 1967 there were about 100,000 color sets in W est German households.
IC gains. Although sales of integrated circuits to makers of consumer products are off to a healthy start, they account for less than 20% of the total West German re market. However, marketing specialists at Hanover are forecasting a rise in over-all re sales to about $20 million a year by 1975 from the present $1.5 million.
By far the biggest user of re's
in consumer products is Grundig vVerke GmbH, whose share of \Vest Germany's black-and-white tv market is around 20%-the largest single slice. Grundig says it uses more than 1,000 re's a day.
The circuit it's talking about is the TAA 350 produced by Valvo GmbH, a subsidiary of Philips Gloeilampenfabrieken of the Netherlands. It's made up of four differential amplifiers and incorporates 21 transistors and 24 resistors on a 18-millimeter-square chip housed in a T0-74 can. The circuit, used in the sound i-f stage of the tv receivers, has an SO-decibel amplification and operates at 12 Mhz.
Great Britain
Down the tubes
Producers of precision metal tubing usually have to rely on the subjective judgment of a young lady with a microscope to determine the quality of steel tubing samples. She's the one who compares with graded charts the number, size, and coloring of microscopic nonmetallic particles, known as inclusions, and classifies the sample accordingly.
Now, however, researchers at Tube Investments Ltd., Binningham, one of Europe's leading producers of precision tubing, have developed an instrument that automatically reads a polished metal surface.
Their machine, called an inclusion counter, classifies the nonmetallic particles and gives a digital readout of the number of each and the part of the total taken up by each type of inclusion. The operator need only set up the instrument to distinguish among sulphides, oxides, and holes in the surface of a given batch of samples.
Illuminated samples. Four prototypes of the counter have b een built, and 12 preproduction units are b eing made under license by Hilger and Watts Ltd. of London.
A sample of polished metal tubing is passed over a scanning pinhole. The sample is illuminated
through the pinhole at a constant level, producing an illuminated area one micron in diameter; smaller inclusions don't affect quality. The light reflected by the metal is focused onto a photomultiplier.
Bright pure metal returns nearly all the light and stimulates a sh·ong signal from the photomultiplier; the grayish sulphides rehun less light and stimulate a weaker signal; and oxides, darker still, stimulate an even smaller response. The signals are h1rned into pulses inversely proportional lo the amplih1des by adjustable discriminators, which then divide up the amplih1de range into a bright metal part, a sulphide part, and an oxide part, with the oxide producing the widest pulse and the bright metal the narrowest.
The three signal-level discrin1inators are conventional Schmitt trigger circuits fed via emitter-follower buffer stages from the sliders of potentiometers, which are used to set the minimum response levels. Logic gating is used to separate the discriminator outputs and in this way distinguish among metal, sulphides, and oxides. The logic gates then route the discriminator output to the appropriate counting mechanisms.
Slits vs. holes. The inclusion counter provides the operator with four simultaneous digital readouts, incrementing continuously during the duration of the scan: the total number of oxide inclusions, the proportion of oxide, the total number of sulphide inclusions, and the proportion of sulphide.
The fraction measurements arc obtained by counting the pulses from a 45-kilohertz pulse generator during the duration of the discrin1inator outputs. Average inclusion size must be worked out manually.
To overcome this, the research laboratories at Tube Investments are now working toward substituting narrow slits for the pinholes. In this case, as the slit passes sideways across the inclusions, the photomultiplier's output is in proportion to the length of the inclusion relative to the length of the slit. By using a series of slits of different lengths, it will be possible to classify the inclusions by size.
148
Circle 149 on reader service card-+-
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SINGLE OUTPUT SOLID STATE REGULATED P OW E R S U PPLI
A m b ient t emp rat ur rating 0 to 155 C
/l. A A
1 "
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A
A A
2N3866 2N4440 2N3733
2N5214
120W PEP
> 30W carrier
150 MHz
5 transistors
AM Mod. 2N5216
2N5217 2N5216
J
> 60W carrier
400 MHz 7 transistors
Only ITT delivers so much broadband RF power with so few transistors
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150 Circle 150 on reader service card
Electronics I April 29, 1968
Electronics advertisers April 29, 1968
·.. ···..·.·.·I.·.II·.·.·,.
· ·
· Acopian Corp.
149
Mort Barish Associates
Airpax Electronics, Inc.
108
Welch, Mirabi le & Co., Inc.
Allen-Bradley Co. Fensholt Adv. Agcy.
27, 29
Allen Electronics Div., Allen Organ Co. 14 Rex Reichert Assoc ., Inc.
·AMP, Inc.
21
Garceau, Hallahan & McCullough, Inc.
· Amperex Electronics Corp., Div. of
North American Philips Co.
121
Sam Groden Inc.
· Amphenol Corp.
73
Marsteller, Inc.
Automatic Electric Co., Sub. of General
Telephone & Electronics Corp.
107
Marsteller, Inc.
· Birnbach Co.
106
Kornazagra phic
Bissett·Berman Corp.
152
S. F. Associates
· Brush Instruments, Div. of Clevite Corp. 46 Carr Liggett Adv., Inc.
· Burroughs Corp., Electronic
Components Div.
56
Conti Adv. Agcy., Inc.
Cambridge Thermionic Corp.
112
Chirurg & Cairns, Inc.
Cerro Copper & Brass Co.
96
Feeley & Wheeler, Inc.
Cimron Division of Lear Siegler, Inc.
80
Phillips·Ramsey, Inc.
· Clairex Corp.
120
Michel-Cather, Inc.
· Clevite Corp., Piezoelectric Div.
125
Carr Liggert Adv., Inc.
Communication Electronics, Inc.
120
Wi lliam C. Estler-Public Relations
co5~g~i~:1:~iEie~~~~Yi"amics Corp., 114
Hixson & Jorgensen, Inc.
Corning Glass Works Electronic
Div.-Capacitors
92
Rumrill Hoyt Co., Inc.
Coto Coll Co., Inc.
132
Williams Co., The
CREI, Home Study Div. of the
McGraw-Hill Book Co.
117
Henry J. Kaufman & Associates
· Dale Electronics, Inc., Sub. of Lionel Corp. Swanson, Sinkey, Ellis, inc.
Data Instruments Division Technical Marketing
Delco Radio Div. of General Motors Corp. Campbell-Ewald Co.
3rd Cover 116
18, 19
Eastern Shopping Centers, Inc.
13 2
Miller Adv. Agcy., Inc.
EG&G,lnc.
34
Culver Adv., Inc.
Electro-Rents
11
Anderson-McConnell Adv. Agcy., Inc.
Erie Technological Products Co., Inc.
31
Altman-Hall Associates
· Fairchild Instrumentation
33
Faust/Day, Inc.
Gamco Industries, Inc. Creat ive Adve rtising
Garrett Corp., Airesearch Mfg. Div. J. Walter Thompson Co.
General Radio Co. Horton, Church & Goff, Inc.
G. T. I. Corp. Meek and Thomas, Inc.
· Gudebrod Brothers Silk Co., Electronics Div. Ramsdell-Buckley & Co.
Electronics IApril 29, 1968
32 122
17 113
98, 99
Heinemann Electric Co.
8
Thomas R. Sundheim, Inc.
· Hewlett Packard, Microwave Div. Lennen & Newell, Inc.
· Hickok Electrical Instrument Co.
90
Parsells Advertising Service
Honeywell, Computer Control Div.
79
Franklin P. Folts, Inc.
Hooker Chemical Corp., Durez Div.
130
Rumrill -Hoyt, Inc.
Indiana General Corp., Ferrites Div.
24
Griswold & Eshleman
Industrial Foundation of Albuquerque 124 Geha-Paskind & Assoc., Inc.
International Electronics
94
Philip Stogel Co.
International Instruments, Inc.
104
Thomas R. Sundheim, Inc.
International Technical Surveys, Inc.
20
· ITT Jennings Mfg. Co.
74
West, Weir & Barrtei, Inc.
ITT Semiconductors Div.
150
Neais & Hickok, Inc.
· Machlett Laboratories, Div. of
Raytheon Co.
9
Fuller & Smith & Ross, Inc.
· Magnetic Shield Div, Perfection
Mica Co.
111
Burton Browne Adv.
Martin Marietta Corp.
105
Redmond Marcus & Shure, Inc.
Maryland Telecommunications,
Inc.
134, 135, 136, 137, 138, 139
Raymond E. Finn Advertising
Metal Removal Co., The
16
Advertising Producers Associates
Microdot, Inc.
15
Gumpertz, Bentley & Dolan Advertising
Midtex/Aemco
49
Chuck Ruhr Assoc. Adv.
Motorola Semiconductor Products, Inc. 12, 13, 35, 54, 55, 140, 141 , 142 Lane & Bird Adv., Inc.
Mullard, Ltd.
28
Rumrill-Hoyt, Inc.
National Semiconductor Corp. Jay Chiat & Associates
· North Atlantic Industries, Inc. Murray Heyert Associates
89, 91 129
Princeton Applied Research Corp.
36
Mort Barish Assoc., Inc.
Sprague Electric Co., The Harry P. Bridge Co.
Stow Laboratories, Inc. Marketing Assistance, inc.
Systron·Donner Corp. Bonfield Assoc., Inc.
5, 10 139 6
· Tektronix, Inc.
43
Hugh Dwight Adv., Inc.
·Tohoku Metal Industries, Ltd.
125
Hakuhodo, Inc.
TRW Semiconductors, Inc.
41
Fuller & Smith & Ross, Inc.
· Trygon Electronics, Inc.
44
Kameny Assoc., Inc.
· Tung.Sol Div., Wagner Electric Corp.
103
Feeley & Wheeler, Inc.
United Control Corp.
45
Botsford, Constantine & McCarty Inc.
· United Transformer Co., Div. of
TRW, Inc.
2nd Cover
Ph i lip Stogel Co .
· Unitrode Corp.
47
Silton Brothers, Inc.
Varian Associates, Eimac Div.
68
Botsford, Constantine & McCarty, Inc.
Westinghouse Semiconductor Div.
2
McCann/ITSM
·Weston Instruments, Inc., Newark Div. 22 Arndt, Preston, Chapin, Lamb & Keen, Inc.
Xcelite, Inc.
128
Harold Warner Adv., Inc.
Classified Advertising
F.J. Eberle, Manager
EMPLOYMENT OPPORTUNITIES
133
Newport News Shipbuilding &
Dry Dock Co.
133
U. S. Marine Corps Ai r Station
133
EQUIPMENT
(Used or Su r plus New)
For Sale
133
Fishman Philip
265
Goodheart, R.E.
133
Radio Corporation of America Al Paul Lefton Co.
Radio Materials Co., Div. of P. R. Mallory & Co M. M. Fisher Assoc., Inc.
· Raytheon Co., Industrial Components Div. Fuller & Smith & Ross, Inc.
Raytheon Computer Co. Martin Wolfson Advertising
4th Cover 48
126 97
· Sangamo Electric Co.
30
Winius-Brandon Co.
Semtech Corp.
118
Burress Advertising
Signetics Corp., Sub. Corning
Glass Works
100
Cunn i ngh am & Walsh, Inc.
· Siliconix, Inc.
7
Graphics West
Sinclair Radio Labs., Inc.
95
John E. Hayes Co., Inc.
· Sorensen Co., Raytheon Operation
53
Urrutia & Hayes, Inc.
Sperry Rand Corp.,Sperry Microwave
Electronics Div.
50
Neals & Hickok, Inc.
· For more information on complete product line see advertisement in the latest Electronics Buyer's Gulde
Electronics Buyers' Guide
George F. Werner, General Manager [212] 971 -2310 Ray Smyth, Eastern Regional Manager [ 212] 971 -6538 Regina Hera, Directory Manager [ 212] 971 -2544 Thomas M. Egan, Production Manager [ 212] 971 -3140
Circulation and Research
Milton Drake, Man age r [21 2] 971 -3485 lsaaca Siegel, Assistant Circulat ion Manager [2 12] 971 -6057 David Strassler, Ass istant Research Manager [212] 971 -6058 Chloe D. Glover, Research Associate [ 212] 971 -6057
151
UNDETECTABLE E-CELL* TIMER WON'T TICK, HUM OR RADIATE
Problem: Arm or safe an ordnance device using self-destruct or selfsterilize methods with prec1s1on components that emit no sounds or electromagnetic energy. Solution: Use an E-CELL timing component in an all solid-state circuit (see schematic) and your timer will have no moving parts, mechanical functions, or energy radiation . When the pre-set interval has elapsed (it could be anywhere from seconds to months), the E-CELL will deliver an output signal in the 1-volt range. Your complete timer will occupy less than one-half cubic inch of space, will consume only microwatts of power, will work in hostile environments, and will wurk every time!
i R LOAD
CLAMP
E-CEL L
* E-CELL timers are used in many of today's advanced ordnance
weapon systems. E-CELL timers are also ideally suited for scuttling sonobuoy transmission, in addition to many industrial control applications. Patents applied for.
Environmental Tolerance E-CELL devices have been tested and approved' by users for severe shock and vibration toleran ce, and are des ig ned to meet or exceed the following requirements:
Altitude: MIL-STD-202C, Method 105C Test Condition B. Ordnance: MIL-STD-303A, 304,.306, 314, 358, 828, etc. Airborne: MIL-E-5400, MIL-E-5272, Procedures I, II, VIB, etc. and air
drop, hi-shock service. Marine: Requirements for air-dropped sonobuoy use.
Actual size
For technical information and application notes , contact: Component Division. The Bissett-Berman Corporation, 3860 Centinela Avenue, Los Angeles, California 90066 ; Phone (213) 390-3585.
BISSETT
BE~MAN
152 Circle 152 on reader service card
Advertising Sales Staff
Frank E. LeBeau [212] 971-6464
Advertising Sales Manager
Wallis Clarke [212] 971 -2187 Assistant to sales manager
Donald J. Austermann [212] 971 -3139 Promotion Manager
Warren H. Gardner [215] LO 8-6161
Eastern Advertising Sales Manager
Atlanta, Ga. 30309: Michael H. Miller, 1375 Peachtree St., N.E. (404) 892-2868
Boston, Mass. 02116: William S. Hodgkinson
(M61c7G)racwo-H2i·l1l 1B6u0ilding, Copley Square
Cleveland, Ohio 44113: William J. Boyle, 55 Public Square, (216] SU 1-7000
New York, N.Y. 10036 500 Fifth Avenue Donald R. Furth (212] 971-3615 James R. Pierce [212] 971-3616 John A. Garland [212] 971-3617
Philadelphia, Pa. 19103: Jeffrey M. Preston
Warren H. Gardner, 6 Penn Center Plaza, (215] LO 8-6161
Pittsburgh, Pa. 15222: Warren H. Gardner
4 Gateway Center, (412] 391-1314
'
Rochester, N.Y. 14534: William J. Boyle
9 Greylock Ridge, Pittsford, N.Y.
'
[716] 586-5040
J. Bradley MacKimm [312] MO 4-5800
Midwest Advertising Sales Manager
Chicago, Ill. 60611: Robert M. Denmead, J. Bradley MacKimm, Ralph Hanning, 645 North Michigan Avenue, [312] MO 4-5800 Dallas, Texas 75201: Richard P. Poole, 1800 Republic National Bank Tower, [214] RI 7-9721 Houston, Texas 77002: Kenneth George, 2270 Humble Bldg., [713] CA 4·8381 Detroit, Michigan 48226: Ralph Hanning 856 Penobscot Building (313] 962-1793 Minneapolis, Minn. 55402: J. Bradley MacKimm, 1104 Northstar Center [612] 332-7425 St. Louis, Mo. 63105: Robert M. Denmead The Clayton Tower, 775l·Carondelet Ave. [314] PA 5-7285
James T. Hauptli [415] DO 2-4600
Western Advertising Sales Manager
Denver, Colo. 80202: Joseph C. Page, David M. Watson, Tower Bldg., 1700 Broadway [303) 255-5484 Los Angeles, Calif. 90017: Ian C. Hill, John G. Zisch, 1125 W. 6th St., [213) HU '2·5450 Portland, Ore. 97204: James T. Hauptli, 218 Mohawk Building, 222 S.W. Morrison Street, Phone [503] 223-5118 San Francisco, Calif. 94111: James T. Hauptli, 255 California Street, [415] DO 2·4600
Pierre Braude Tel: 225 85 88
European Director 88-90 Avenue Des Champs-Elysees, Paris 8
Brian Bowes Tel. Hyde Park 1451 United Kingdom and Scandinavia 34 Dover Street, London Wl Milan: Robert Saidel 1 via Baracchini Phone: 86-90-656 Frankfurt/Main: Hans Haller Elsa-Brandstroem Str. 2 Phone: 72 01 81 Geneva: 1, rue du Temple Phone: 31 95 60
Tokyo: George E. Olcott, 1, Kotohiracho Shiba, Minato-Ku [502) 0656 Osaka: Ryoji Kobayashi 163, Umegae-cho Kita -ku [362] 8771
Business Department
Wallace C. Carmichael, Manager [212) 971-3191 Stephen R. Weiss, Production Manager [212) 971-2044 Thomas M. Egan, Assistant Production Manager [212] 971-3140 Dorothy Carmesin, Contracts and Billings [212] 971-2908 Frances Vallone, Reader Service Manager [212) 971 -2865
Electronics I April 29, 1968
20 years of stabilitYJ
... a job for DALE Metal Film Resistors
Twenty years-the design life of Len kurt's versatile "76" Microwave Systems - puts stringent demands on a resistor. To meet them, Lenkurt uses Dale MFF Metal Film Resistors to maintain bias stability in critical amplification circuits. Their evaluation: "Good performance."
Here's how Dale multiplies the advantages of metal film for your application: Broader design choice - From subminiature 1/20 watt through 12 watts of housed power plus microresistive package and networks to your specification. Proven failure rate - See data at right. Faster delivery Expanded production facilities let you call the shots on shipment of both MF and MFF types.
Call Dale today ... 402-564-3131 or circle 181 for complete Resistor Catalog A
~-------
GENERAL SPECIFICATIONS TYPE MF* MIL-R- 10509F
DALE TYPE MIL. TYPE
MF50 RN-50
MF-1/10 RN -55
MF-1/8 RN -60
MF-1/4 RN -6 5
MFS-1/2 RN -70
MF- 1
RN -75
MF-2
RN -80
125' CRATING (Char. C& El
l /20w 1/ 10 w l /Bw l/4w 1/2 w lw
70" CRATING !Char DI
l /lOw l /Bw l /4w l /2w 3/4w
2wt
RESISTANCE RANCE (Ohm s)
30. l to 80.6K 30.l to 301K 10 to l M!l lOto l Mn lOto 1.5 M!l 25 to 2.6 M!l lOOto 10 M!l
* Also available in conformal coa ted (MFF) and
IChar. B.
housed chassis mount (0) styles with power to 12 watts.
Tolerance:::!:: 1%, ::!:.5%, :t:.25%, :t: .10% standard. Characteristics D, C, or E apply depending on T.C. required.
Proven Failure Rate: .004% per 1,000 hrs. (60% confidence at 50% power, 70' C ambient). Based on 16,320,000 hrs. of load life testing without a failure 1100% rated power, 70' C, failure defined as AR> 1%).
Gard Testing is avai lable to meet Established Reliability requirements at signif ican t time/cost savings over typical 100 hr. burn in·. Write for Test Report # 19590.
for optimum value in metal film resistors
DALE ELECTRONICS, INC., 1300 28th Ave. Columbus, Nebraska 68601 In Canada : Dale Electronics, Canada, Ltd .
RCA announces
Medium-Povver DTL
CD2300Line
at economy prices
45 types I 3 package styles I 2 Temperature Ranges Gates I Expanders I High Fanout Gates Clocked Flip-Flops I Hex Inverters 2Kn and 6Kn Output Pull-Up Options
· For Your Military Applications:
CD2300 Series-1 5 circuits in RCA's Unique Ceramic Flat Package.
CD2300D Series-1 5 circuits in RCA's Unique Ceramic Dual In-Line Package.
· For Industrial and Commercial Applications:
CD2300E Series- 15 circu its in RCA's Dual In-Line Sil icone Package.
· Compatible with RCA CD2200 and 2200D Low-Power DTL Series.
exact replacements for 830 and 930 series DTL
~
Circuit and Pull-up Option
I
14-Lead Ceramic Flat Pack
-55° C to + 125° C Operation
Price (1000 Units)
14-Lead Ceramic Dual In-Line Package
J 0° C to + 75° C Operation
Price (1000 Units)
14-Lead Dual In-Line Silicone Package
Price (1000 Units)
NAND Gates Dual-4 Expandable (6Kn) Dual-4 Expandable (2Kn) Dual-4 High Fanout, Expandable (transistor output pull-up)
Dual-4 High Fanout Expandable (no output pull-up)
Triple-3 Input (6Kn) Triple-3 Input (2Kn) Quadruple-2 Input (6Kn ) Quadruple-2 Input (2Kn)
Hex Inverters Diode Input (6Kn) Diode Input (2Kn) Expandable Input (6Kn) Expandable Input (2Kn)
Flip-Flops Clocked RS with JK Capability (6Kn) Clocked RS with JK Capability (2Kn)
Input Expander Dual 4-Diode
CD2300/930 CD2301/961
CD2306/932
$2.50 $2.50
CD2300D/930 CD2301 D/961
$2.75 CD2306D/932
CD2307/944 CD2308/962 CD2309/963 CD2302/946 CD2303/949
CD2310/936 CD2311/937 CD2312 CD2313
$2.75
$2.75 $2.75 $2.75 $2.75
CD2307D/944
CD2308D/962 CD2309D/963 CD2302D/946 CD2303D/949
$2.90 $2.90 $2.90 $2.90
CD2310D/936 CD2311 D/937 CD2312D CD2313D
CD2304/945 CD2305/948 CD2314/933
$3.00 $3.00
CD2304D/945 CD2305D/948
$2.25 CD2314D/933
$2.50 $2.50
CD2300E/830 CD2301 E/861
$2.75
CD2306E/832
$2.75
$2.75 $2.75 $2.75 $2.75
CD2307E/844
CD2308E/862 CD2309E/863 CD2302E/846 CD2303E/849
$2.90 $2.90 $2.90 $2.90
CD2310E/836 CD2311 E/837 CD2312E CD2313E
$3.00 $3.00
CD2304E/845 CD2305E/848
$2.25
CD2314E/833
$1.05 $1.05
$1 .15
$1.15 $1.15 $1.15 $1.15 $1.15
$1.45 $1.45 $1.45 $1.45
$1.90 $1.90
$ .90
Ask your RCA Representative for det ai ls. See your RCA Distributor for his price and deliverY. For technical information, write Commercial Engineering, Section ICN 4·5, RCA Electronic Components, Harrison, N.J. 07029.
Integrated Circuits
Acrobat 11.0.23 Paper Capture Plug-in