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FOR ENGINEERS AND ENGINEERING MANAGERS - WORLDWIDE

MARCH 1, 1978

Pick a calculator, any calculator. More computing power is packed into all machines. Displays are easier to read, and reliability is better. But problems persist. Poor

keyboard designs still give false entries. Live NiCd batteries play dead. And complex features of programmables make selection tougher than ever. See p. 40.

Sure, you've already made a smart decision, choosing networks over discrete resistors. After all, the cost per resistor in a network package can be 40% less; they require only 10-15% of the P.C. board space needed by dlscretes; and component count is reduced as much as 95% with resistor networks.
But, when choosing a network supplier, you should also consider these points:
1. Bourns has the broadest network product line in the industry - over 1000 part numbers in all. And our standard DIP circuits range from simple pull-up configurations to Thevinin-equivalent ECL terminators and memory interface circuits.
2. Bourns Krimp-JointTM offers both a mechanical and electrical bond that lap or butt joint construction doesn't provide. The lead is crimped onto the network element and a high-temp, reflow-resistant solder is used to prevent failure during wave soldering and in circuit thermal cycling and vibration.
3. Bourns was the first manufacturer to offer a complete line of off-the-shelf, super low profile SIPs with demonstrated automatic insertion capability.
These are the facts. So, now you can be even more "discreet". We're sure you'll specify Bourns Resistor Networks - direct or through your local distributor.
Send today for our new 1977 Resistor Networks Catalog.
TRIMPOT PRODUCTS DIVISION, BOURNS, INC., 1200 Columbia Avenue, Riverside, CA 92507, Telephone 714 781-5415 - TWX 910 332-1252.

International Marketing Offices: European Headquarters - Switzerland 042/23 22 42 · Belgium 02/218 2005 · France 01/2039633 · Germany 0711/24 29 36 · Italy 02132 56 88 · Netherlands 70/87 44 00 · United Kingdom 01/572 6531 · Norway 2/71 18 72 · Sweden 764/20 110 · Japan 075/921 9111 · Australia 02/55-0411 03/95-9566 · Israel 77 71 15/6/7

For Immediate Application - Circle 130 For Future Application - Circle 230

' ·

ELECTRONIC

Sundial courtesy of Franks AnllQue Clock Shop, San Jose. Gahfornia
The World's First LED Displays You CanView in Bright Sunlight.

Now avai lable from Hewlett-Packard are displays designed for high ambient conditions. These seven-segment

displays optimize the contrast between the digit segments and the background. A specially designed P-N

junction and larger top contact metallization permit operation at high peak currents. This feature enhances display

light output and permits strobed operation of long display strings. Combined with proper filtering these

displays can be used under high ambient lighting as bright as 10,000 footcandles! !!

Available in H igh Efficiency Red and Yellow, the HDSP -3 530/ 4030 series are designed for use in outdoor

terminals, gas pumps, airplane cockpits, instruments , weighing scales,

agricultural instrumentation and point -of-sale terminals.

The High Efficiency Red (HDSP-3530/ 3730 Series) displays

are priced at $2.05* (7.6mm/ 0.3") and the Yellow (HDSP-4030/ 4 130 Series) displays are $2.25* (10.9mm/ 0.4 3") in quantities of 1000.

HEWLETT"' PACKARD

For immed iate delivery, call any franchised HP distributor. In the

U.S . contact Hall -Mark, Hamilton/ Avnet, Pioneer-Standard, Schweber,

Wilshire or the Wyle Distribution Group (Liberty-El mar). In Canada,

01803

call Hamilton/ Avnet or Zentronics , Ltd. ·u.s. Domestic Prices Only.

1507 Page Mill Road, Palo Alto, California 94304
For assistance call: Washington (301) 948-6370, Chicago (312) 255-9800, Atlanta (404) 955-1500. Los Angeles (213) 8 77-128 2

E1.l'CTRON1 c DESIGN 5, March I, 1978

CIRCLE NUMBER 2

Experience, state relay t milestone wi solid state r MIL-R-28750:
M2t M2t M2t
These SSI reliability re ~ switching a~ support equ1

Advanced Micro Devices announces an
mad1.vcaronpcreodcecsosum.rsge. in microprogrammable
Step by step, function by function, month by month, we'll build a fast, powerful, microprogrammed machine.
And on December 31 ,1978 , you'll know what we know. As it turns out, that's quite a lot.

~ I

BUILD A MICROCOMPUTEI

THIS YE ·

2

CHAPTER ONE: COMPUTER ARCHITECTURE.
Modern digital processors are built using one of two techniques: A fixed-instruction MOS processor, such as the 8080A or 8085, or a microprogrammed TTL design. Because of the extremely low cost and small size of the microcomputer built around a fixed-instruction microprocessor, this approach is dominant.
But, not all problems can be solved with an 8080A or 8085. They may not be fast enough. And, applications requiring more than 8 bits of precision, substantial amounts of arithmetic processing, adherence to a predefined instruction set or blazing speed need something more than MOS has to offer. You need microprogramming capability. You need bipolar LSI.
During the year, you'll be meeting several new members of the Arn2900 Family, a series of low-power Schottky LSI devices specifically designed for microprogrammed machines.
Your microcomputer can have instruction execution as short as 100 nanoseconds, multiplication as fast as 4 microseconds and division in just 8 microseconds.
So clear some space. In your office. In your home. In your brain.

BUILD YOUR LIBRARY, TOO.

Each of these messages is backed by a ton of theory and applications information. Send in this coupon, and we'll send you Chapter One and tell you how to get the whole book.

1---------------~-----,

Advanced Micro Devices 901 Thompson Place Sunnyvale, California 94086

3/78-ED

I want to build a microcomputer this year. Sign me up.

Title _ _ _ _ _ _ _ _ _ Mail Stop_ _ __ Company _ _ _ _ _ _ _ _ _ _ _ _ _ __

Address _ _ _ _ _ _ _ _ _ _ _ _ _ __

City

State

Zip _ __

L---------------------~

Advanced Micro Devices
~
Multiple technologies. One product: excellence. 901 Thompson Place, Sunnyvale, California 94086
Telephone (408) 732-2400

Next month, Chapter Two: Microprogrammed Control.·

I want to show you

Publisher
William Maass

our reliable system for removing flux

Editors
Ed itoria I Offices 50 Essex St. Rochelle Park, NJ 07662
(201) 843-0550 TWX : 710-990-5071 (HAYDENPUB ROPK) Cable: Haydenpubs Rochellepark

Editor-in-Chief George Rostky

Managing Editors: Ralph Dobriner Michael Elphick

Senior Associate Editor Stanley Runyon

MS-190 and MS-190H D removes flux quickly, efficiently, economically without harm to components. Flux does not migrate by etching its way into critical parts causing failures at a later date.
WHAT'S NEW ABOUT THE SYSTEM? The M-S system utilizes a patented Cobra® Solvent Spray Brush, the solvent is an accurately directed, metered spray combined with a scrubbing action of the brush for maximum cleaning with minimum waste. Nonflammable. Available in gal., 5 gal and drum quantities. For further information, call or write MillerStephenson.
~ miller-stephenson ~chemical co.,inc.
Danbury, Connecticut 06810 (203) 743-4447

Associate Editors: Sid Adlerstein Nicholas Bodley Dave Bursky Morris Grossman Gene Heftman Andy Santoni Max Schindler
I Contributing Editors: Peter N. Budzilovich , Jules H. Gilder, Sidney Moskowitz, Nathan Sussman
Editorial Field Offices
East
Jim McDermott, Eastern Editor P.O. Box 272 Easthampton , MA 01027 (413) 527-3632
West Dick Hackmeister, Western Editor 8939 S. Sepulveda Blvd ., Suite 414 Los Angeles , CA 90045 (213) 641 -6544 TWX-1 -910-328-7240
Dave Barnes, Western Editor 465 S. Mathilda, Suite 302 Sunnyvale, CA 94086 (408) 736-6667
Editorial Production
Marjorie A. Duffy, Production Editor James Keane, Copy Editor

miller-step enson chemical company, inc. Danbury, Connecticut06810, (203) 743-4447

Art
Art Director, William Kelly Richard Luce , Anthony J. Fischetto

___ Write our Technical Director for application ~--~ information of MS-190, MS-190HD and MS-226
Cobra Solvent Spray Brush.
_ _ Enclosed is $5 for Trial Pack MS-190/MS-190H D/MS-226 Cobra Brush
_ _ Send Literature and prices. __________ Title/Dept.

Business Manager
Thomas E. Vachon
Production
Manager, Dollie S. Viebig Nancy Hurey
Circulation
Director, Barbara Freundlich Senior Assistant, Gail Stone
Information Retrieval
Paula Greenleaf

_______ state _____ Zip _ __

Advertising Promotion
Judith Nappo

" Registered trademark. For Industrial Use Only. Trial Units must be sent to Company address.

Reprints

LOS ANGELES ·CHICAGO· DANBURY. CONN. ·TORONTO

Maxine Sassano

CIRCLE NUMBER 4 6

ELECTRONIC D ESIGN 5, March I, 1978

Aeross the desll

Putting the brakes to radar brake control
Your article on automobile radar systems in the U.S. for brake control (ED No. 23, Nov. 8, 1977, p. 30) indicates that noticeable progress has been made in the U.S., butl remember the Japanese reporting approximately this much success at a conference in Detroit around 1972. It appears from your article, though, that the most serious questions raised in 1972 haven't been solved by the approaches you describe, including:
· Inability to determine a real threat. An oak tree or a bridge abutment is a threat. An empty trash can is not, but it has a beautiful radar cross-section.
· Water splash or heavy rainfall problems. Ironically, these bad conditions can occur when braking help might be most needed.
· The braking systems don't know what you're thinking. For example, if you pull out to pass with a car coming on, the systems in your article could brake you just before you turn back into your lane, leaving you in a rather bad position.
· EMI and reliability. The danger from some stray signal is very serious. Likewise, the over-all reliability of the electronics will have to be several orders of magnitude better than anything of this general level of complexity ever built. It will be hard to prove that the units save a life, but rather obvious when it causes a serious accident.
There is nothing wrong with using radar to warn a driver, but taking control raises serious questions. I, for one, would not want the system(s) you describe to control my car.
W.T. Walton 38 Windward Dr. Severna Park, MD 21146
A few changes
The article, "Exploit Existing NOVA Software by Designing computer Systems Around the Micro NOVA" (ED

No. 19, Sept., 13, 1977, p. 54), contained several inaccuracies.
The last two sentences of p. 56 should read: "During a Refresh operation, the CPU specifies a group equivalent to. 1/64 of all the memory locations to be refreshed, but transfers no data. The refresh address is selected by a 6-bit refresh address register placed on the lower six address lines."
Also, Fig. 8a on p. 63 should be corrected as indicated.
Daniel Falkoff Design Engineer Data General Route 9 Westboro, MA 01581
Misplaced Caption Dept.
Our engineers react positively to design reviews. Our younger engineers, in particular, look forward to these inputs.
Sorry. That's "Massacre of the Barbarians," from the Column of Marcus Aurelius located in Rome.

Electronic Design welcomes the opinions of its readers on the issues raised in the magazine's editorial columns. Address letters to Managing Editor, Electronic Design, 5CI Essex St., Rochelle Park, NJ 07662. Try to keep letters under 200 words. Letters must be signed. Names will be withheld upon request.
ELECTRONIC D ESIGN 5, March I , 1978

OPTRON OPTICALLY COUPLED
ISOLATORS
NEW JAN 4N22A SERIES OFFERS
HIGHEST RELIABILITY

You can 't buy a more reliable optically coupled isolator than one of OPTRON's new JAN 4N22A series. The popular JAN 4N22A, 4N23A and 4N24A all feature fully qualified JANTX and JANTXV ratings.
These new OPTRON isolators consist of a high efficiency, solution grown gallium arsenide LED and a silicon N-P-N phototransistor in a hermetically sealed 6-pin T0-5 package. Minimum input-to-output isolation voltage for the series is 1000 volts and minimum current transfer ratios range from 25% for the 4N22A to 100% for the 4N24A.
New "A" version OPTRON isolators are a significant improvement over the older 4N22 series since the case is isolated from the sensor and LED to eliminate the need for an insulating spacer in many applications.
OPTRON also offers a new JEDEC registered series of high reliability isolators in a 4-pin T0-18 package. The 3N243 series includes three devices with the same reliability and similar characteristics as the JAN 4N22A T0-5 series, yet in a smaller package .
In addition, OPTRON's complete line of optically coupled isolators includes other immediately available standard devices in high-rel metal cans and low cost DIP and other plastic config-
3N243 urations for almost every application .
Detailed technical information on
optically coupled isolators and other OPTRON optoelectronic products ... chips, discrete components, limit switches, reflective transducers, and
interrupter assemblies ... is available from your nearest OPTRON sales rep-
resentative or the factory direct.

@

OPTRON, INC.
1201 Tappan Circle Carrollton ,Texas 75006, USA TWX-910-860-5958 2141242-6571

CIRCLE NUMBER 5 7

Intel delivers the niicro co01ponents designers

There's no more efficient way to solve

The dedicated function components

your interface and control requirements

below are available now, with more on the way.

for microcomputer,based systems than our Here's a brief description of their versatility.

peripheral components.

8271 Programmable Floppy Disk

They're single,chip solutions to even O.mtroller. Provides full control of up to four

the most complicated operations, integrating standard or minifloppy drives. (Available

early 1978.)

"I can accomplish almost any 1/0 function 8273 SDLC/HDLC Protocol Controller.

with one cliiP. using lntels versatile

For SDLC and HDLC communications.

dedi~. hdeenviilciencteoinftarcoelslerasn!d'

8275 Programmable CRT Controller. Provides fully buffered interface .and control

of almost any raster scan CRT display.

8278/8279 Programmable Keyboard/

OisP.lay Interfaces. Keyboard/sensor

array input scan, and output scan

for LED, incandescent

and other displays.

128,key or 64,key input.

8251A Programmable

Communications Interface.

Industry standard USART

for synchronous or

asynchronous serial data

up to 22,000 transistors per chip to replace transmission, including bisync.

circuit boards full of discrete logic with a

8253 Programmable Interval Timer.

single component. Result: you cut parts cost, Contains three independent 16,bit counters,

reduce package count and board space, and programmable modes from de to 2MHz.

simplify both development and operating

8255A Programmable Peripheral Inter,

software.

face. General purpose 1/0 interface with

We've designed each of these peripheral 24 individually programmable 1/0 pins.

chips to be an intelligent, programmable

8257 Programmable OMA Controller.

component in your system and to perform Provides four,channel, high speed direct

most functions with minimal cpu supervision. memory access independent of CPU.

The resulting decrease in cpu overhead pro,

8259 Programmable Interrupt Controller.

vides your system with higher performance Handles eight levels of vectored priority

and increased throughput.

interrupt. Expandable to 64 levels.

co01puter peripheral are talking al)out.

UPIAlTM is Intel's Universal Peripheral PromptTM 48 Design Aid, the lntellec®micro,

Interface, bringing distributed intelligence to computer development system with resident

microcomputer systems for the first time.

UPIA1/MCS,48 Macro Assembler. Plus appli,

p - Actually a highly integrated, user,

programmable microcomputer, UPIAl '!4.Jld, for my special 1/0 requirements,

is a new solution that obsoletes

Intel~ UPl-41 Universal Peripheral Interface

custom LSI and specialized discrete is user

to control ~

designs for interfacing most low

any other pen·pheral devi "

and medium speed peripherals

ce.

with an MCS,so:M MCS,85TM

cations assistance

or MCSA8TM microcomputer. Intel delivers UPl,41

worldwide, full documentation,

in two versions that make it easy for you to implement your own designs. The 8741 includes an erasable and reprogrammable lK, byte EPROM, for develop, ment, testing and low volume production. Then the 8041, with masked ROM, provides maximum economy in high volume.
We've taken the UPIA1 concept a step further with the 8278, described at left. The 8278 is the first of several prepro, grammed 804l's that we've adapted to specialized applications.
Because UPIAl is a

training classes, design seminars and a rapidly expanding users' software library.
Intel's periph, eral components, and the MCS, 80, ,s5 and AS microcomputers they support, are available through: Almac/Stroum, Component Specialties, Cramer, Hamilton/Avnet, Harvey Electronics, Industrial Components, Pioneer, Sheridan, L.A. Varah, Wyle/Elmar,Liberty and Zen, tronics. For your copy of our Peripheral Data Handbook use the reader service card or write: Intel Corporation, 3065 Bowers Ave., Santa Clara, CA 95051. Telephone: (408) 987,8080.

microcomputer, we've given it the same high level of support we give all our microcomputers. up1,41 is supported by our

inter delivers
CIRCLE NUMBER 6

"We can use anybody's .050''centerline cable with AMPLIMITE HOFconnectors.
And get mass
termination efficiency."

And there are no exceptions. AMPLIMITE High Density Flexible connectors work with all .050" centerline 28-30 AWG round conductor ribbon cable. You get an axial cable-to-connector interface second to none in strength and ruggedness.
AMPLIMITE HDF connectors provide complete packaging flexibility. They are available in 15-, 25- and 37-position sizes, and have through-cable capability for "daisy chain" applications. They intermate with other D-type connectors, including AMPLIMITEall-plastic right-angle headers. HDF connectors are at work in computer peripherals, modems, instrumentation, industrial controls, and word processing systems. They are completely compatible with transmission specification RS-232.
AMPLIMITE HDF connectors give you another plus. AMP technical assistance and support. It's thorough, complete, professional aid you can call on even during project planning. It can help make sure your design will be efficient and effective right from the start.
There are more advantages with AMPLIMITE HDF connectors: · Probe-ability for convenient circuit
testing with connectors in place. · Compatibility with "dead center" and
"dead edge" designs.

· Matched application tooling assures highest production rates and lowest applied cost.
· Integrated cable strain relief.
For more information on AMPLIMITE HDF connectors, just call Customer Service at (717) 564-0100. Or write AMP Incorporated, Harrisburg, PA 17105.

AMP has a better way ... Mass Termination.
AMP pioneered the concept and today is the acknowledged leader with the industry's widest range of application experience. We have mass termination connectors for discrete wire and virtually any type of cable: ribbon coaxial, flat etched, twisted pair, round conductor, flat flexible . All have preassembled contacts, eliminate costly wire preparation and offer productivity savings and benefits never before possible. If you would like details on any of our other mass termination ideas, call Customer Service at (717) 564-0 I00.

SEE US AT NEPCON SOUTHEAST, ORLANDO

CIRCLE NUMBER 7

AMP & AMPLIMITE are trademarks of AMP Incorporated.
AIVIP INCORPORATED

The Analog Devices' AD534 Analog Multiplier. A new, monolithic, laser-trimmed, four-quadrant analog m u ltiplie r destined to smash the myth that

and use, Jn RatioCom-
puting. The percentage deviation func-

analog m u ltipliers are more complex than the computing fu nc tion they solve.
T he AD534 has a guaranteed maximum multiplication error of ±0.25 % without external trims of any

tion is of practical

value for many appli-

OUT

cations in measure-

...--.~~-X2

Z1

AD534

ment, testing and

Y1

Z2

EouT · 100 ABB

kind. This level of accuracy you'd normally expect to find onJy in expensive hybrids or bulky discrete
modules. Excellent supply rejection, low temperature

control. The AD534 is shown in a circuit that

e INPUT

Y2

c+oNLYJ

A INPUT o----------'

coefficien ts and long-term stability of the on-chip thin

computes the percentage deviation between its two

film r esistors and buried zener reference preserve

inputs. The scale factor in this arrangement is 1% per

the AD5 34 's accuracy even under the most adverse

volt although other scale factors are obtainable by

co nditio ns.

altering the resistor ratios.

The AD534 is the first general purpose, high performance analog multiplier to offer fully differential

and use,

In Sine Wave Function Generation.

high impedance operation on all inputs. And that's what gives the

.---1N_91.4..·..·~

AD534 its amazing flexibility FREauENcY

and ease o f use.

coNTRoL

'.c~-,._1_N5_23_ 6 _ _ _ _ _ _ _ _ _ ~. ouT
10 "" 12.,1100 E,N11
.-----~.......,.,______,

The voltage controlled 2-phase oscillator uses two AD534's for integration with controllable time constants

INPUT
T h e AD534 is a com- / ....--t--t x1 OUT

ple tely self-contained, self-

x2 z1

sufficient multiplier which EoN

AD534

xi ouT

x2

z1 ~~,__- ''" ouT

ADSJ4

10 001 12n11oo EtNll

in a feedback loop. The frequency control input, ErN, varies the integrator

can gen erate co mpIex trans- 0------1 Y1 Z2

fer functions very close to

Y2

Y1

Z2

Y2

gains, with a sensitivity of IOOHzN and frequency error

theoretical. O ur active laser trimming o f thin film resis-

typically less than 0.1 % of full scale from O.IV to IOV.

tors on the chip to adjust scale factor, feedthrough and

offset allow you to plug in the AD534 and run it vir-

tually without adj ustment.

In a ddition to straightforward implementation of

standard MDSSR functions (multiplication, division,

squaring and square rooting), the AD534 simplifies

analog computatio n (ratio determination, vector addi-

tion, RMS conve rsion); signal processing (amplitude

modulation, frequency multiplication, voltage con-

trolled filters); complex measurements (wattmeters,

phasemeters , flowmeters) and function linearization

(transducers, bridge outputs, etc.) You can set up the

AD534 to per form complex calctilations by using

va rious feedback arrangements to manipulate the

AD534 transfer function of

and use, (X1- ~)(Y1 - Y2) =
10 (Z I - Z2)-

J12 Frrquency

M l l {LipficatioJZ. A''" wt

Nonlinear

siN,~~~AL

----o X1 OUT

A'
10 (1-cos 2wtl

OOUBLE FREOUENCV

X2

Z1

OUTPUT

and use. In a VolLage
Controllrd Filter.

The output volt-

age, which should ·- coNTROL -.. INPUT
be unloaded by a follower, responds Ea 511~PNu~L

X1 OUT

X2

Z1

AD634

II< REo·~

Y1

Z2 t - < 1 - - - 0 1 + ~ p

as though Eswere applied directly to

,___v2_ ___, c ~ 0.002

the RC filter but with the filter break fre-

ti ti ti 10 · ~
\\\

quency proportional to the
(i.e. input control voltage f = ~)· The frequency 0 207rRC
response has a break at f0 and a 6dB/octave rolloff. These uses ofour new Single Chip Analog Com-

puter, the AD534, are only the beginning. For the big

picture call Doug Grant at (617) 935-5565. Or write

for a copy of our new Multiplier Application Guide

and the data sheet on the AD534.

circuits which f\ . accept sinusoidal V

AD634

V1

Z2

M

inputs and generate

V2

sinusoidal outputs at

two , th ree , four, five or more times the input frequency

m ake use of trigonometric identities which can be

r.ANALOG WDEVICES

implem ented quite easily with the AD534 as shown. For this frequency d oubling circuit the output should

The real company in analog computation.

be AC-couple d to remove the DC offset resulting from

the trigonom e tric m anipulation.

Analog De1-ices, l nc.. Box 280. Non.'OOd , MA 02062 East Coast: (617) 3294700; Midwest: (312) 894-3300; West Coast: (213) 595-1783; Texas: (214) 231-5094; Belgium: 031/37 48 03; Denmark : (02) 845800; England : Ol/9l I0 46 6 ; France: 68&-7760; Germany: 089/53 03 19; Japan: 03126 36 82 6; Netherlands; 076/879251; Switzerland: 022/319704; and representatives around the world.
CIRCLE NUMBER 40

MIC
HIGHER LEVEL LANGUAGES
FortranN Basic-single/multiuser Business BASIC
RUN TIME 1/0 SOFTWARE SUPPORT
Communications Access Manager (CAM) Sensor Access Manager (SAM) RJE/80 (2780,3780), HASP II DG/L Programming Language

IJ
MICRONOYA PROCESSOR
Single chip 16-bit NOVA computer, Integral MUL/DN,
RTC, DMA, hardware stack, and memory refresh
Available as a chip, board microcomputer or packaged minicomputer

Card Cage/Power Supply General Purpose Interface High Speed DMA Cabling Prom Programmer

Synchronous with CRC Asynchronous 4~line Asynchronous Mux

SENSOR 1/0
AID, DIA, Digita!I/O DG/DAC Sensor 1/0 Subsystem

Data General Corporation, Westboro, MA 01581, (617) 366-8911. Data General (Canada) Ltd, Ontario. Data General Europe, 61 rue de Courcelles, Paris, France, 766. 51. 78. Data General Australia, Melbourne, (03) 89-0633

IENTS TO MAKE 10UAHERO.

OPERATING SYSTEMS
Diskette Operating System (DOS) Real-Time Operating System (RTOS) Extensive Program Development Utilities

SYSTEM PERIPHERALS
Dasher Displays and Printer Terminals Single and Dual-Diskette Subsystems Line Printers, Paper Tape

AVAILABLE MEMORIES
Expansion to 64K bytes with:
8KB and loKB RAM 4KB and 8KB PROM

Our microNOVA line is now of heroic proportions. 17 new enhancements make it the broadest line of 16-bit microcomputer products available. Here are all the basics so the design engineer can bite into the real challenge. Without having to waste time developing the tools he needs. Call 800-225-7282. Or write for free brochure.
t ·DataGeneral
We make computers that make sense.
Data General Ltda., Sao Paulo, Brazil, 543-0138. © Data General Corporation, 1978 microNOVA and DASHER are trademarks, and NOVA is a registered trademark ofData General Corporation. CIRCLE NUMBER 10

New Type FM resistor. Tight on tolerance. Tight on TC.

Meet the newest member on the board . Allen-Bradley's Type FM . It features the accuracy and stability of metal film technology. It provides you with the tight tolerance , tight temperature coefficient and stable performance you may need for precision applications. Approved to MIL-R-10509. Style RN55 , Characteristic E. all tolerances. This high quality metal film resistor adds another dimension to Allen-Bradley 's line of hotmolded carbon composition and cermet film fixed resistors of high reliability. We have what you need . Write for Publ ication EC 54 .

PtJWM,~

~ ~ ;1:::'::=:1~:1::::::;,:,:"J l :!:1%,:!: 0.5%, :!: 0.25~0
:!: 0 .1% an d:!: 0 .05%

:!: 25, :!: 15, :!: 10 PPM /° C

................... rI r.· ... .. .. .........

''"' '"''"'" ''

~

i"""""'""'A

0 .25 watt at 70° C 0 .1 watt at 125° C
.098 " max.
12.49 m m ma> I

- 55 oc to + 175oc

1~ . 281 " max. - - J
I (7,14 mm max.) -

~~~

Quality in the best tradition.
,,,,7)J ~~~~~;~s~~~LEY
CIRCLE NUMBER 11

New Desl·gn Concept

1

The Struthers-Dunn line of standard tdrs was achieved by combining a proven hybrid solid
state timing module with the entire line of standard general purpose relays . In most cases the module lits within the existing relay cover , and therefore does not affect unit size or ease of mounting .

Imagine , more than 6000 combinations of timing , voltage , contact arrangement and

Broad Selection

2

mounting . New concept permits any standard general purpose relay to be equipped with
built-in time delay function. Standard off-the-shelf models are U.L. recognized . Hermetically sealed models meet the requirements of MIL-R-83726 . It adds up to the most complete

Desl"gn flex1"b1"l1"ty

3

line available anywhere.
The versatility of these timing modules offers a wide variety of alternatives when the control circuit must include time delay. Instead of searching tor a timer to fit the circuit, simply choose the type of relay you want with the assurance that ii is available with lime

delay capability .

RedUCe C0Sts

4

The new ldrs will cut costs in many applications . If , for example , a system now uses a conventional electromechanical timer and a separate relay as many circuits do , the designer may substitute a single tdr and cut his component cost in half . Cost of mounting and wiring the component is also reduced.

Forget previous voltage limitations . Our ldrs are available for all standard voltages from
Standard Voltages & Sockets 5 12 VAC to 240 VAC and from 12 voe to 125 voe . Plug-in models available for most common sockets : Octal , square base , miniature or 12 pin rectangular plugs with quick connect , solder , printed circuit or front connect terminals .

T·Im·1ng & Sett"1ng Range

6

Standard off-the-shelf models offer seven different timing ranges with adjustable setting: 0.1-1 second, 0.2-2, 1-10 , 3-30 , 6-60 , 18-180 and 30 to 300 seconds . Settings are available three ways : Fixed (factory preset) , knob adjustable or remote adjustable

Rell"abl"ll"ty

7

from a central control panel.
These ldrs incorporate two time-tested components-electromechanical relays and solid state timing modules . Thus there is no weak link to cause premature failure . Repeatability of ± 3% at 20 to 25°C and ± 10% accuracy within voltage and temperature range is assured . Life

8 Transl·ent & Polar"Ity Protecti"on

expectancy is 50 million mechanical operations or 500 ,000 operations minimum at full load.
Time delay operation is protected for transient voltages as long as 5ms duration with
exponential slope from ovol!s to 20 microsecond peaks of ± 2000 volts . oc models are
inverse polarity protected . Tdrs will not operate with polarity reversed, but will function

False Contact Pro·teCtl"On

9

normally once wiring is corrected .
Another added operational protection . With our on -delay relays , false transfer of contacts is prevented should the voltage be interrupted during timing cycle . With off-delay relays , if control switch closes during delay period , liming resets to zero and contacts do not transfer .

Total Relay Capab1.l.lty 1 0 Full timing is assured when control switch opens again . Dependability and know-how , that 's what you get from more than 50 years experience. You , too , can count on a relay line-up with unmatched diversification . We provide solutions to control problems with ten key relay functions: General Purpose , Latch Sequence ,

Sensitive , Reed , Solid State & Hybrid , Motor Control , Military , Special Assemblies and ,

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Available Through 140 Stocking Distributors Canada : Struthers-Dunn Relay Div., Renfrew Electronic Marketing , Ltd.

Dual Density
DUEL

Newsseope
MA RCH l, 1978

Schottky-diode/FET logic bring VLSI into the real world

Gallium arsenide substrates, Schottky-barrier diodes and depletion-mode FET gates will help pave the way for the coming generation of very-largescale integrated circuits. With these elements, entire digital systems will be manufactured on single chips.
"Mainframe central processors of present-day technology are performance-limited by the propagation-delay time that data bits encounter traveling along circuit-board paths and backplane wiring," says Dr. Richard Eden, Rockwell's principal scientist at the firm's Solid State Electronics Dept. in Thousand Oaks, CA. It takes roughly 100 picoseconds for a bit to travel a single inch in any direction.
However, in order to bring a system's logic gates any closer together, the heat generated by its logic gates must be drastically reduced-concentrating the system's volume without reducing its power consumption will only cause it to burn up.
By using GaAs, Schottky-barrier diodes for logic inputs, and (low-power) depletion-mode FETs for gain and inversion, Rockwell has reduced the

gates' switching energy (speed X power) from several tens of picojoules to 1/20 of one picojoule, and cut gatepropagation delay to less than 100 ps, Dr. Eden announced at a technical session during the recent International Solid-State Circuits Conference.
At the same time, complete systems made with Schottky-diode/FET logic could be very small: Rockwell's new circuit technique "isn't even intended in systems with more than a single IC package, according to Eden.
Schottky-diode/FET logic uses small (1 micron square), low-capacitance (l0·1"F) Schottky-barrier diodes to replace active elements at the gates' inputs. This helps reduce the chip's power dissipation to 500 µ.W per gate. Output FETs operate in the depletion mode-normally on-so level shifting is necessary.
The gate's input diodes by themselves provide about 1 V of level shifting. But an additional series diode allows for less-critical output FETs, higher supply voltages, and wider signal excursions (see Fig.)
Rockwell is still several years away

l Voo

ELECTRONIC DESIGN 5, March I, 1978

The look of very-large-scale integration. This scanning-electron microscope image (left) shows functional logic gates implemented with Schottky-diode FET logic (right).

from a VLSI production line, but Eden already envisions broad application areas where Schottky-diode/FET logic can "overcome the speed and power shortcomings of silicon-gate technology." Computer mainframes, cache memories, and data-communications systems in particular are all likely candidates.
"As data rates need to be increased, present-day methods will become hard-pressed to keep up with the demand for performance," Eden warns. Optical fibers, for example, are capable of much higher data rates than can currently be exploiterl.
"Communications in the 1980s will be increasingly handled by solar-powered earth satellites," Eden predicts. "But high-speed silicon bipolar technology is hindered in space applications because of power budgeting." With GaAs Schottky-diode/FET logic requiring four orders of magnitude less power, VLSI will be well prepared to meet the challenges of outer space.
'Strapping changes modes in 16-bit microprocessor
The 16-bit 8086 microprocessor from Intel Corp. can be configured for small systems or for larger, buffered systems simply by wiring one pin the MN/MX line, to 5 V or ground. As a result, seven pins change their meanings depending on the way the MN/MX line is wired. And with pins having dual capabilities, the 8086 can be housed in a 40-pin package.
In a minimal, small-system configuration, the 8086 requires a clockgenerator chip and digital latches to tie to memories and input/output lines. In the maximum mode, the 8086 ties through a bus controller that generates five of the seven signals not available from the processor after it is switched out of the minimum configuration.
The maximum mode has faster access to memory components-440 ns against 490 ns with no wait states at a 5-MHz clock rate, and 215 ns against 265 ns with no wait states at an 8-MHz clock rate.
The standard maximum clock rate is 5 MHz, with 8-MHz parts available at extra cost. Prices have not yet been set for either version.
The Intel 8086 is built with n-channel, depletion load, silicon-gate technology like that used in the Santa
19

Clara, CA, firm's 2147 4-k static RAM. The processor addresses memory logically as a linear sequence of 8-bit bytes, but speeds access with a 16-bitwide physical path to memory.
Speed is also increased by internal pipelining and overlapped instruction fetch and execution.
The 8086 can use programs written for the 8080, but only after they've been recompiled or translated and reassembled. Intel's 8080-to-8086 translator, the CONV86, converts most source programs, including macros, controls, and source text. But the translator, which runs on the firm's development systems, doesn't support instruction-set dependencies such as timing, size and encoding, nor can it handle self-modifying code or interrupt sequences.
But the 8086 does offer features beyond those of the old 8-bit model. It can address up to 1 Mbyte of memory over a 20-bit bus; handle bit, byte, word, and block operations; and perform floating-point and integer arithmetic. Moreover, the 8086 provides for signed or unsigned arithmetic operations as well as 16-bit multiply and divide.
Incorporating the 8086 into multiprocessor systems is simplified by a locked-exchange or "test-and-set-lock" mechanism . A 1-byte prefix may precede any instruction and cause the processor to assert its bus-lock signal for the duration of the operation caused by that instruction. External hardware should be designed so that other bus masters are disengaged during the period of assertion.
CIRCLE NO. 3 19
Carter's to blame for energy crisis, says NSPE
The Carter administration is not handling the energy crisis effectively, according to 90% of the engineers surveyed by the National Society of Professional Engineers. Not only that, but almost half the respondents blame the U.S. government for causing the problem.
The responses came from a special energy survey conducted during the NSPE's Winter Meeting in New Orleans, which was attended by 500 elected delegates representing 54 state and territorial regions. The Society sponsored the survey to determine what the nation's leading engineers, representing all major disciplines, con-
20

sider the critical issues in the energy crisis.
Almost everyone surveyed felt that there indeed is an energy crisis. But opinion was almost evenly divided as to the nature of the problem. Production and distribution got 51% of the vote, while resource shortage garnered 49%.
Who's to blame? The lion's share went to U.S. government policies (48%), while the country's energy consumption habits got most of the rest (38%). Interestingly, only 7% of the respondents blamed foreign energy sources, and just 6% felt the energy industry was the culprit.
As a matter of fact, more than six of every 10 respondents considered the energy industry a more reliable source of information than the U.S. government. And seven of every 10 didn't think the public had been given enough information to form a realistic judgment about the energy crisis.
The economic outlook didn't look very promising to most of the respondents. While 39% felt that by 1985 energy costs would rise by 50%, 43% predicted that by 1985 the energy they consume would cost 100% more than it does today.
Geothermal logger to read temp, pressure, flow rate
An electronic geothermal well-logging tool that simultaneously reads temperature, pressure and flow rate is being developed at Sandia Laboratories, Albuquerque, NM. An early model, which reads only temperature, has been successfully tested recently in a New Mexico geothermal well.
There is great interest in geothermal energy, says Tony Veneruso, supervisor of Sandia's Drilling Technology Div., which conducts tests of the new logging tool. He points to the new power-generating plants being constructed at the Geysers site (north of San Francisco), where geothermal electricity has been produced since the mid-1920s. This site now produces 500 MW of electricity at reasonable rates.
But conventional oil and gas logging tools aren't reliable in the unusual rock formations and high temperatures of geothermal wells, Veneruso adds. Early tests indicate that Sandia's geothermal logging tool will operate for hundreds of hours over a continuous range from room temperature to more than 300 C (575 F). It uses a combination of commercially available hybrid thick-

film circuits and junction field-effect transistors, with JFETs in all active circuit devices.
A 3-in.-long platinum thermometer at the tip of the electronics package provides temperature readings. A magnetic sensor keeps track of well depth by counting the number of steel casing pipes the tool has passed. The entire package, which weighs about 5 lbs in its present form, slips into a 4ft-long, 1-1/ 2-in.-diameter housing.
We won't forget how to make microwave tubes
Microwave tubes won't disappear in the 1980s and 1990s, thanks to a special program supported by the Air Force, Stanford University, and a number of microwave tube companies.
Tubes are anything but old-fashioned in the microwave field, because solid-state devices do not yet approach their high power and wide bandwidth -particularly at the higher frequencies. Yet university-level teaching and research on microwave tubes dried up in the late 1960s. Worse still, the average age of microwave-tube engineer·s is over 45, and many are close to retirement.
When this situation was recognized, a number of people organized the Air Force Thermionic Engineering Research Program. Stanford University was chosen to provide the teaching because it is near the greatest concentration of tube companies.
Varian, Watkins-Johnson, Litton, Teledyne Microwave, Raytheon, and Hughes are sponsoring one student apiece. Each student receives $4500 from his sponsoring company for schooling, as well as a salary of $10,000 from the Air Force.
The courses combine standard applicable graduate courses with special courses on tubes, the latter taught by Dr. Marvin Chodorow, professor of applied physics and electrical engineering. His lectures are being videotaped, and currently the tapes are air-expressed to the students on the east coast. But, that won't be necessary fo, much longer.
The first transcontinental satellite instructional-TV link will soon provide two-way communication between the Stanford Instructional Television Network in Palo Alto, CA and Varian's plant in Beverly, MA. Interestingly, Dr. Chodorow's lectures on microwave tubes will be carried via microwave tubes.
ELECTRONIC DESIGN 5, March I, 1978

SUPER-FAST LO· VF

- METOXILITE SILICON RECTIFIERS

Featuring 30 nanoseconds
Reverse Recovery Time
A breakthrough in junction technology makes Super-Fast silicon rectifiers possible. These new high speed silicon rectifiers feature low forward voltage drop at higher operating currents and reverse recovery lime better than 30 nanoseconds. In addition, these devices have extremely low reverse leakage and high surge ratings. SuperFast rectifiers use Semtech's proven Metoxilite non-cavity monolithic high temperature construction. Designed for high frequency applications, such as high speed switching regulators and converter circuits. Semtech's Super-Fast silicon rectifiers are stocked for immediate delivery.

Types: 1N6073, 74 &75 (Trr 30ns) PIV: 50, 100 &150V Reverse Current (Max.) : 1µA DC@ 25°C Instantaneous Forward Voltage@ 1.5A :
1.0V @ 100°c Capacitance @ 12V DC (Max.): 24 pF
Single Cycle Surge Current: 35A Dimensions (Max.): Body .070" Dx .165" L
-Leads .029" Dx1.25" L
Types: 1N6076, 77 & 78 (Trr 30ns)
PIV: 50, 100 & 150V Reverse Current (Max.): 5µA DC@ 25°C Instantaneous Forward Voltage@ 3.0A:
1.0V@ 100°c Capacitance@ 12V DC (Max.): 58 pF
Single Cycle Surge Current: 75A Dimensions (Max.): Body .11 O" Dx .165" L

Types: 1N6079, 80 &81 (Trr 30ns) PIV: 50, 100 & 150V Reverse Current (Max.): @ 25°C 10µA DC Instantaneous Forward Voltage@ 5.0A:
.BV@ 100°c Capacitance@ 12V DC (Max.) : 230 pF Single Cycle Surge Current: 175A Dimensions (Max.): Body .165" Dx .165" L
Leads .038" Dx .1.1O" L
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CIRCLE NUMBER 14

E u ·CTRON 1c D1: s1r;N 5, Ma rch I, 1978

21

News

With cassettes, video tape recorders have found a new home in the home

After nearly two decades of technical advancements-and false startsvideo tape recorders are finally finding a place in the home. What's brought them home is a packaging technique borrowed from audio recorders-tape cassettes. Consumers are much more interested in video recorders now that they can just pop in a cassette containing 1/2 - in. wide tape instead of having to thread tape carefully by hand through a maze of guideposts.
A fistful of suppliers - all of them Japanese-is now selling home VTRs under more than a dozen brand names.
Unfortunately, videocassettes developed by Sony Corp., Sanyo Electric, Victor Co. of Japan Ltd. (JVC) and Quasar Electronics (both JVC and Quasar are subsidiaries of Matsushita Electric Industrial Co. Ltd. of Osaka) are incompatible with each other. But Sanyo has now introduced a second machine that is compatible with the Sony Betamax system, and Quasar has introduced a JVC-compatible video home system (VHS) recorder. Along with Quasar and JVC, Matsushita is in the VHS camp with a recorder bearing its own Panasonic trade name, and is building VHS recorders for such marketers as GE, Magnavox, and RCA. But with firms like Zenith and Toshiba in the Betamax lineup, Betamax joins VHS in dominating the VCR field .
Playing time increases
The major battle between VHS and Belamax is finding new ways to stretch the playing time-though not the dimensions-of a tape cassette that can cost $25. Sony's original Betamax machine could record and play up to an hour on a cassette, and the first VHS recorder, introduced shortly afterwards by JVC, had a two-hour limit.
Andy Santoni Associate Ed itor
22

Now, four-hour VHS machines and two-hour Betamax recorders are the norm , with a three-hour Betamax expected from Sony this year. In addition, Sony has an optional $100 tape changer that doubles recording time.
In both systems, recording time is increased by eliminating the Guardband spacing between tracks. According to the video recording standard developed by lhe Electronic Industries Association of Japan (EIAJ), the guard band is 63 µm wide and the video track 110 µm wide. So nearly a third of the tape is unused .
The guard band has been eliminated by actually taking advantage of a basic problem of magnetic tape recording: The signal that can be picked up from the tape drops off quickly if the playback head gap is even slightly off parallel with the recorded signal. Since video tape recorders paint and retrace alternate lines with two different heads, each can be slightly off perpendicular to tape travel, yet pick up its own signal properly. If the offset is
Compact, $1000 video recorders using plug-in cassettes are finding a niche in consumers' homes.

in opposite directions, the difference between azimuth angles for the two heads is twice the offset. The offset in VHS is 6°, and in Betamax it is 7°, drastically reducing crosstalk and making guard bands unnecessary.
Azimuth recording, most effective at higher frequencies, is less valuable at lower frequencies. Since chrominance (color) signals are recorded at lower frequencies (688 kHz for Betamax and 629 kHz for VHS) than are luminance (black and white) signals, crosstalk attenuation on a color signal is inadequate even with azimuth recording. Color flicker and color distortion result, which explains why slanted azimuth recording was not used for years after its development.
Changing phase cuts noise
To cut crosstalk even in a lower frequency chrominance signal, both Betamax and VHS recorders use phase inversions, though in somewhat different forms. In a VHS machine, the signal fed to one recording head is advanced in-phase by 90° every horizontal picture-scanning line; the signal fed to the other head is delayed by 90° every line.
In playing back through the first head, the signal is delayed by 90° every line, so that signals from the tape that were recorded with this head come out in-phase. Signals from the second channel that appear as crosstalk in the first channel are delayed 180°. All signals are then fed through a one-line delay circuit, then the original and delayed versions of the signal are added. Since each scanning line is about the same as the last, the desired signal component is almost doubled, and the unwanted crosstalk is almost eliminated.
In the Betamax system, signals to one head don't change, while signals to the other get delayed 180° on alternate scans. Again, a delay-line filter cuts
ELECTRONIC DESIGN 5, March I, J978

crosstalk on playback. The VHS system suppresses noise
further in the black-and-white part of the video signal with a double-limiter playback circuit. The signal is separated into lower and higher frequency components, which are limited separately. If they were limited together, high-amplitude, low-frequency signals would so saturate the limiter that lower-amplitude, high-frequency signals wouldn't be amplified enough to bring them out of the noise.
The color signal on a VHS recorder comes in for further processing, too, to improve signal-to-noise ratio. The burst signal that is in every color transmission to guarantee sync between the broadcast signal and the playback signal is doubled before recording, then halved on playback. This raises the signaHo-noise ratio to 43 dB, the highest of any 1/2 - in. home VCR and about 3 dB better than other systems, says Tom Shinozaki, assistant national service manager at JVC in Maspeth, N.Y.
Player size cut
As a result of all these noise-cutting tricks, the drum that holds the heads in a Betamax machine is only 74.5 mm in diameter, and the VHS drum is only 52 mm. Without the noise reducers, a larger head drum, like the 115.8-mm drum of the EIAJ standard, would be needed to achieve acceptable s/n at the low tape speeds of these VCRs.
The smaller head drums help reduce the size of the over-all package. The JVC Vidstar unit, for example, is less than 18 x 6 x 15 in. and weighs less than 30 pounds.
This diminutive package also results from a tape-threading mechanism JVC calls "M-loading." Tape is pulled out of the cassette by two parallel arms, one on either side of the head drum, so that the final tape path is in the shape of an M.
In Betamax sets, on the other hand, tape is pulled from the cassette at one point by a rod that swings around the drum. As a result, loading takes more time and the size of the tape-transport mechanism is bigger than in a VHS set. However, this "U-loading" is more reliable than M-loading since the tape goes through fewer bends, says Yasuo Ohkura, consumer video product planner at Sony in New York.
In either case, the tape touches slightly more than 180° of the drum, which means that tape is always in contact with one or the other head-
ELECTRONIC DESIGN 5, March I, 1978

-Al -Bl

A2

- - - )( AO

Al

- so Bl

A2 --Bi -- -

I H Oetay LINE

- - - 2AI 2A2 2A3-··

(Ao+ Bol + (A1 + B1) =2A

y

- - - Al

A2

A3 ---

Bi 82 83---

Phase inversions and a delay line help cut distortion in VHS tape recorders. Crosstalk components end up cancelling each other out. while desired signals are boosted, in a summing network. Beta max machines use a similar technique.

ARROW REPRESENTS PHASE POLARITY OF COLOR SIGNAL

COLOR SIGNAL SPECTRUM

VECTOR REPRESENTA--

I ,. I I I SIGNAL ON

flON OF PHASE POLARITY

TRACK A

l : : l SIGNAL ON

THACK B

..Il.l.Ill...1U1lI.LL'

PLAYBACK SIGNAL FROM TRI.CK A

-

-

-

-

~COMBINATION OF ·l 7 7 7

1H 0L -

TRACK SIGNALS

.

NVVV\ CHARACTERISTIC OF COMB FILTER
j_JJj_L OUl PUT OF TRACK A - - t, I: ~~~~1~fi'cs~n.u<

Only one signal is phase-inverted in the Betamax system to eliminate crosstalk. As in VHS , Betamax has no guard bands between tape tracks to keep signals from spilling over.

hence the tape-path description "omega wrap."
Along with basic record and playback functions and longer playing time, all VCR manufacturers are looking to add features that will separate their machine from the rest of the pack. For those machines that don't have one built in, accessory timers permit unattended recording of broadcasts while the viewer is asleep or away. In most Betamax machines, the timer sits atop the player. VHS machines have timers that are built-in or, in the case of JVC's Vidstar, plug into the unit's front panel as an option.
But with four-hour unattended recording now possible, and six-hour capacity coming soon, a simple on/off timer won't be enough. The next generation of timers will include programmable station selectors so that the recorder can store broadcasts on different stations sequentially. Almost all timers today simply turn the machine

on at a specified time and shut it off at the end of the tape.
In addition, future Videocassette recorders will feature freeze-frame and slow-motion playback. Even more interesting than that, JVC is working on a double-speed playback machine with automatic audio-frequency correction to eliminate the "Donald Duck" distortion of higher-speed playback. This will allow higher-speed scanning of programs and make a precise point on a long tape much easier to locate.
The price future is down
But even as VCR's of the future promise more and advanced performance, increasing sales volume is expected to bring prices down. Basic VCR's here today cost around $1000, better than 30% below the price for a Betamax when it was introduced two years ago. Open-reel home video tape recorders on the market a decade ago also sold for $1000, but the dollar was much more valuable then.
The price decline will be dramatic, though not as sharp as the drop for other consumer products like calculators and watches. After all, much of the cost of a videocassette recorder is in mechanical, not electronic, parts.
The future of videocassette recorders is far from clear, however. One small cloud is the video disk, which some consumers may favor over tape. After all, a fair amount of interest in VCRs is for playing back prerecorded material, not in taping new programs. And if movies and television shows become available in low-cost, stamped-out plastic discs, consumers may choose to bypass the more-expensive tape medium. That's been true of audio recordings, for example.
At any rate VCRs seem to have caught the consumer's fancy. The only question is whether their popularity will continue, or if they will turn out to be a fad like simple video games and CB radios...
23

News

Designing a large-screen display is more than a matter of size

Making the picture of a large-screen TV display acceptable to the average viewer may be even more difficult than you think. That's the conclusion of researchers at RCA Laboratories in Princeton, NJ. In fact, one aspect of display quality-brightness uniformity-has been analyzed thoroughly enough to determine that the kinds of large-screen TV displays now under development will have to be 200 times better than present television CRTs, says Roger W. Cohen, a group head in the display systems lab at RCA. Cohen's group is studying perception to advise other RCA lab groups that are working not only to develop the best large-screen, direct-view TV displays at the lowest cost, but also to improve aircraft and shipboard displays used by the mi litary. Some of the research has been done for the Navy.

Direct-view displays can be made brighter than the projection-type displays now used for large-screen TV pictures, says Cohen. But the directview CRT now used in television sets cannot be made much larger than the 25 in. now common in console sets. The problem is, all the techniques being investigated as CRT replacementsincluding electroluminescence, gas discharge, and light-emitting diodes-require some form of matrix addressing to control each element in the hundreds of rows and hundreds of columns of display needed to obtain enough resolution. And the brightness at each of these points must be tightly controlled.
"You have to keep the nonuniformity to something less than 1% in luminance fluctuations," says Cohen, adding that current color televisions have centerto-edge brightness variations that can

approach a factor of two. The gradual drop-off in brightness from the center of the screen to the edges isn't noticeable to most observers, Cohen notes, but even small differences from one point to the next wou ld be disturbing.
Pictures break into frequencies
High uniformity is essential because when an observer looks at a scene, the eye and brain break up the picture into spatial frequencies, much as electrical signals are broken into distinct frequencies through Fourier analysis, explains Cohen. This leads to simplified mathematical analysis of images, he notes, and makes it possible to describe display quality quantitatively.
Unfortunately, such an analysis

Sometimes, measurements don't tell the whole story

The eye and brain form a complicated system for interpreting images, so simple measurements like brightness and contrast can't always determine if a picture is good.
Here, the image at the left was made by taking the average brightness of the original, analog image in each pixel, or picture element. The image at the right is

made by taking the minimum brightness within each pixel.
Most observers agree that the left-hand picture looks sharper and has better contrast than the righthand picture, yet the right-hand picture looks more "natural." There is no quantitative method for describing why most observers would choose the right-hand picture to, for example, identify a mugshot.

24

25 -ln CRT

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50 -ln MATRIX -ADDRESSED
DISPLAY

POSITION
Matrix-addressed displays have to be better than standard CRTs fo r th eir images to be perceived just as well. With CRTs, the eye sees the gra du al change in brightness as a low spa ti al frequency (that of the sine wave shown by a dotted line), whe re perception is tolerant to bright ness variations. But the abrupt changes in brightness of a matrix display are seen as high frequ ency signa ls, wh ere the eye is more sensitive.
ELECTRONIC DESIGN 5, March I, 1978

More muscle for your microprocessor: Nowttol1terr1·e9's1earsaimtrpK·leKr, way
drive a digit, or light up a lamp.

One of our new addressable drivers can control up to eight peripheral devices in any bus-oriented system.

Next time you put a microprocessor to work, it may have more to manipulate than data. Real-world µ.P applications often require the kind of muscle that our new NE590/591 Addressable Peripheral Drivers can provide-simpler and less expensively than the usual combination of discrete power transistors and resistors. Another First From Signetics. Either of
these new devices can give you a powerful alternative way to address and drive as many as eiglit different peripherals, using bits extracted directly from a bus. Each of the 8 latched Darlington outputs can drive a 250-mA load current, subject to power dissipation limitations. That's plenty of muscle for turning on (or off) LEDs, SCRs, stepping motors and a host of other commonly used peripheral components.
Most applications can be handled by the 16-pin NE590, which has 8opencollector (current sinking) outputs. The NE591 is an 18-pin version with open-emitter (current sourcing) outputs. Simpler Designs at Lower Costs. A quick parts count and cost evaluation will demonstrate the device's dollar savings. The NE590N costs only $1.95 in

YOUR MICROPROCESSOR

100 quantity, the NE591N, $2.45. You can do the same job with an addressable latch, but you'll need extra driver transistors and resistors that will bring your total parts cost-exclusive of assembly, testing and related expenses-to a considerably higher price.
Use NE590 or NE591 whenever you have multiple high-current peripherals
to drive in any bus-oriented system. You'll simplify your design, improve reliability, reduce component and assembly costs. In short, you'll get more muscle for
your money. Addressable Peripheral
Drivers. Available only from Signetics. Call your nearest distributor or send the coupon to us today for your data sheet, a sample, or quick attention to any application questions you have.
!ii!IDDliC!i
a subsidiary of US. Philips Corporation

Part No.
NE582
ULN2001 series NE5501 series DS3611 series UDN5711 series

OTHER SIGNETICS DRIVERS

Description

Output Current

LED digit drivers

400mA

Power drivers

500mA

High-voltage power drivers
Peripheral drivers
Peripheral drivers

500mA 300mA 300mA

E 1 1-< i ~ 0N 1 c [) 1-s 1c, N 5, March I, 1978

No. of Drivers
6

SigiellCS Caporation 811 East Arques Avenue &rrlyvale.Caifoma 94086 ~ 408/ 739-7700
r-------------------, To: Signetics Information Services, 811 E. Arques Ave. P .O. Box 9052, MS 27, Sunnyvale, CA 94086
D Send me your NE 590/591 Data Sheet D Send me a sample of the NE590 for evaluation. D I need data on these other devices shown in the table:

7

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CIRCLE NUMLBE-R 1-5 -----------------~
25

shows that the dissection of images into separate frequencies makes today's matrix-addressed displays inadequate for large-screen viewing. A curve plotting brightness as a function of position across the screen of a matrix-addressed display is a series of straight lines, each at a slightly different level. Using Fourier analysis to break up such a step-function curve into single frequencies yields a large number of high-order terms, and the human eye and brain are very sensitive to these frequencies. Even the small

brightness variations are disturbing. In present CRTs, on the other hand,
the gradual increase then drop-off in brightness from one end of the screen to the other can be plotted as a single, fairly low-frequency sinewave. The eye is relatively insensitive to brightness variations at low spatial frequencies . According to Cohen, the eye's sensitivity to brightness variations ranges from as little as 0.01%at some frequencies to nearly 100% before the difference is noticeable at other frequencies where the eye is least sensitive.

Another area that can benefit from improved displays is medical imaging: x-rays, ultrasound, and computerized tomography. Here, one unresolved question, is whether the eye can better detect differences when an image is printed in white on a black background or vice versa. Given the same contrast between black and white, the eye sometimes distinguishes shapes better when the picture is displayed in one mode and sometimes in the other, says Cohen. So, which mode is better? No one can say for sure yet. ··

Distributed microprocessing enters the business world

The . first electronic typewriter makes it easier for businesses to move toward distributed processing-decentralized computer power. And the typewriter itself uses distributed microprocessing-a master Z-80 controller and a pair of F-8 chips-to handle drive motors.
In its basic form, the typewriter, developed by the Qyx Division of Exxon Enterprises Inc., Lionville, PA, does far more than a standard office typewriter. Yet it goes for just $1390-not much higher than the nearest comparable mechanical machine (about $900).
The Qyx typewriter has 70% fewer moving parts than electromechanical typewriters, says Dan Matthias, general manager of Qyx. Microprocessors controlling linear motors replace conventional cables, pulleys, and gears.
The Z-80 microprocessor, from Zilog Corp. (another Exxon Enterprises affiliate), Cupertino, CA, handles overall system control and memory operations. A pair of F-8 microprocessors from Fairchild Semiconductor, Mountain View, CA, controls the linear motors that position the carriage and the rotary print head.
The Qyx typewriter can be expanded beyond its basic functions by adding plug-in boards and changing keyboards -without sending the machine back to the factory and without expanding the size of the typewriter itself.

and proportional spacing (each character takes up only as much space as it needs). The rotary "daisy wheel" print head is coded for type format, so changing print heads automatically resets the typewriter.
The typewriter can even center a line of type automatically and automatically type columns of decimal numbers so that the decimal points line up. Stock phrases and formats can be stored and called up to speed typing repetitive forms.

In addition, the basic typewriter has automatic erase backspace. A lift-off tape, like that used in the IBM Correcting Selectric, pulls an erroneous character off the paper so that a correction can be typed. According to Matthias, Qyx has developed the first daisywheel printer that can position its print head accurately enough for this function. This is accomplished by building the rotor of the linear print head-drive motor into the $25 print head itself and by feeding-back position information

Typewriter built in blocks The Qyx Level 1 features dual pitch
(either 10 or 12 characters to an inch)
26

The first electronic typewriter, from the Qyx Division of Exxon Enterprises, distributes computer-aided typing throughout an office while itself taking advantage of multiple processors-three µPs.
ELECTRONIC DESIGN 5, March I, 1978

Now you can specify Spectronics opto couplers for every isolation requirement.

Spectronics offers industry's broadest choice of optically coupled isolators. Available in popular 6- and 8-pin dual in-line versions, they are completely interchangeable with standard industrial types. The complete Spectronics line includes high-speed, high-gain circuits in IC, phototransistor, photodarlington and photo SCR versions. Check the Spectronics isolator for your application:

D 200VSCR When switching an SCR or TRIAC, specify our 200V SCR rated at 300 mA. The SCS11 C1-11 C3 also
features 5000 voe isolation and
11mA IGr· D 1 or 5or10mA Controlled Gain You specify the input current at 1 or 5 or 10 mA, and we'll provide controlled gain. SPX 7110, 7130 and 7150 provide 10-50%, 30-80% and 50-125% CTR at 1 mA. The SPX 7530, 7550 and 7590 have 30-75%; 50-125% and 90-200% CTR at 5 mA'. The SPX 7270-7273 series offers controlled gain at 10mA: 10-50%, 45-90%, 75-150%, 125-250%.
o TTL Compatible
Choose the SPX 74A1 for TTL interface with guaranteed logic level/compatibility, over the full 0°c to 70°C range. Use it as an ideal transistor coupler for eliminating current loops. Our standard isolation voltage is 4000V rms.

try our 6N135 and 6N136 with up to .8 µ.S rise and fall at 19% CTR, or the 6N138 and 6N139 with up to 1.0, µ.s tPHL at 500% CTR. You can drive them with as little as .5 mA.
D 4N25 to 4N38 We provide the industry's standard work horses, off the shelf. Outputs include transistors and darlingtons.
Your critical requirement may be BVc.., le, CTR, T,, TF or isolation. You won't find one coupler to fill all your needs, but one company can. Only Spectronics has all the design choices!
For more details and delivery information, call us today at 214-234-4271. Or write: Commercial Component Division, 830 E. Arapaho Rd., Richardson, Texas 75081 .

D 1 MBIT/SEC For high-speed data transmission,

4N25to4N38 Eu: CTRON IC D ES IGN 5, March I , 197 8

1 MBITISEC

1 or 5 or 10mA Controlled Gain

CIRCLE NUMBER 16
27

NOW!
LINISTORSTM
sensitive linear negative temperature coefficient thermistor
assemblies

-
···
Linistor assemblies will provide
you with an accurate straight line resistance/temperature plot from 0°C to 100°C.
Linistors are ideal for temperature sensing and temperature compensating d evices. They are now available in four stand ard encasements to satisfy most design appl ications . Write for Data Bulletin l -601.
Thermistor Division St. Marys, PA 15857 814/ 781-1591 ·Telex 91-4517 CIRCLE NUMBER 17
28

A linear stepper motor controls the position of the Qyx carriage, while a microprocessor controls the motor. The ribbon cartridge is mounted on the typewriter's case, instead of on the carriage, and flexible guides lead the ribbon to the lightweight carriage.

through a light-emitting diode and photodetector sensor.
With an optional $850 display module, a typist can read a line of copy as it i~ entered, then have it printed after it has been typed correctly. The red LEDs read out upper and lower-case characters in a 5 X 7 dot matrix format.
The carriage itself rides on a linear motor that is controlled by one of the F-8 microprocessors. Instead of a rotary motor and a series of pulleys and gears, the linear motor can move and position the carriage correctly for character spacing.
Expand to word processor
By adding plug-in boards and modules for data storage, the Qyx typewriter can expand to perform most of the functions of a word-processing system, yet retain its physical dimensions.
An advanced model, the Qyx Level 2, adds store and edit features; add, delete, and move commands; and righthand justification, when needed. Up to 10,000 characters can be stored in random-access memory.
The Qyx Level 3 typewriter adds a buried-media diskette drive to the Level 2 machine. This drive can store up to 60,000 characters.
In the Qyx Level 4, the diskette drive is accessible from the front of the machine and accepts standard 5-1/4-in. diskettes. The accessible drive is slightly different from the fixed drive, says Leon Staciokas, assistant general manager at Qyx, since the accessible drive must be able to position removable media precisely and the nonaccessible drive must not wear out a· semipermanent disc. Yet both use linearinduction drive motors and linear

stepper motors to position the read/ write head.
The diskette drives are about half as thick as commercially available diskette drives so that they can fit within the typewriter case. Qyx has no plans to offer the drive as a separate OEM product, according to Matthias.
Change a phrase everywhere
The top-of-the-line Qyx Level 5, priced at $7750, includes two diskette 120,000 characters of storage, and features "global change." A word or phrase that appears throughout a manuscript can, with but one correction, be changed throughout the typescript each time it appears.
Any Qyx typewriter can communicate with another Qyx typewriter over standard telephone lines with the addition of a $500 communications module. The module incorporates the features of a modem and a data-access arrangement, so it can be tied to a telephone line directly. The numbers on the typewriter's keyboard can be used to dial the call, and communications moves at 1200 baud. The interface is proprietary, but "will soon be expanded to include communication with Vydec word processors and even to computers," says Matthias. Vydec is another Exxon affiliate.
All typewriters will be available in New York, Washington, and Philadelphia first, and other cities will be added later in the year, according to Matthias. With the typewriters, companies will be able to perform many of the functions of word-processing departments-like duplicate letters-at a secretary's desk, instead of in a separate operation.··

EL ECTRONIC DESIGN 5, March I, 1978

~SWITCHER' OUTPUT
FILTER CAPACITORS THAT REALLY PUTOUT

If you're working with switchingtype power supplies, you'll want to know about new electrolytic capacitors featuring low equivalent series resistance (for example, 3 mO @ 57,000 µF/7.5V) and low internal inductance. Type 6220 EXTRALYTIC® capacitors are the first of their type to meet the power supply designer's need to know, for worst case design, the maximum and minimum ESR of a capacitor, as well as the need to hold the nominal ESR to a tolerance of ±30% at 20 kHz. To simplify calculations for the

equipment designer, Type 6220 capacitors have a symmetrical capacitance tolerance of a tight ±20% instead of the wide asymmetrical tolerance customarily associated with low-voltage electrolytic capacitors. These new capacitors are designed for operation over the wide temperature range of - 55°C to +85°C. They are
furnished in a 1%" diameter case with lengths ranging
from 2W' to 5%". capacitance values from 2,800 to 67,000 µFare available as standard, and voltage ratings range from 5 to 55 WVDC.

For complete technical data, write for Engineering Bulletin 3459 to: Technical Literature Service, Sprague Electric Company, 347 Marshall Street, North Adams, Mass. 01247.

THE BROAD-LINE PRODUCER OF ELECTRONIC PARTS

Eu:crnoN 1c DESIGN 5, March I, 1978

CIRCLE NUMBER 18

4SE 712BRI

SPRAGUE

® a General

THE MARK OF RELIABILITY

-cable \/

subsidiary

29

K E P C CJ ® For complete specs. write Dept. BTF-05.

CIRCLE NUMBER 19

KEPCO, INC. · 131-38 SANFORD AVENUE· FLUSHING, N.Y. 11352 U.S.A. · (212) 461-7000 ·TWX #710-582-2631 ·Cable: KEPCOPOWER NEWYORK

Washington report

John Rhea, Washington Bureau

NASA seeks fifth Shuttle, war ns of costly delays
Further delays in deciding on a fifth Space Shuttle orbiting spacecraft will increase its cost to $600-million, a top space agency official told the House Science subcommittee.
President Carter approved four Shuttle spacecraft when he reviewed the fiscal 1979 budget for the National Aeronautics and Space Administration, but deferred a decision on the fifth for another two years. Now, NASA Associate Administrator John F. Yardley says the fifth spacecraft is needed and would cost $365million if procurement were to begin in fiscal 1979.
The other $235-million will stem from a more inefficient production rate and the higher cost of purchasing smaller quantities of parts from subcontractors, according to Yardley. In the past NASA has estimated the additional cost of waiting for another two years at $100-million to $200-million.
Yardley bases his case on the belief that the Space Shuttle will be used extensively during the 1980s and that five of the reusable spacecraft will be needed in case of unforeseen delays in ground operations or in case one of t he craft is lost in an accident. NASA has predicted 560 Shuttle flights during the 1980 to 1991 period, but critics have doubted that the Shuttle will be that popular.
Both the Air Force and NASA plan to launch almost all their satellites from the Shuttle during that period. Under the present plan NASA will get two, t he Air Force one, and the two organizations will have to share the fo urth orbiter. But if the fifth spacecraft is approved, NASA will be assured of three and the Air Force of two.

U-2 spy plane slated to return

Next year the Air Force plans to reopen production of the U-2, the famous spy plane of the 1950s. A new version of the aircraft, designated the TR-1, will be produced at Lockheed Aircraft Corp.'s "Skunk Works" in Burbank, CA.
Unlike its predecessor, which conducted strategic reconnaissance from high altitudes and thus became obsolete with the development of spy satellites, the new aircraft is intended to support Army and Air Force tactical units under battlefield conditions.
The Pentagon has attempted to keep the program under wraps, but Defense Secretary Harold Brown told the House Armed Services Committee that the aircraft would be able to provide continuous standoff surveillance of a battle area, including such activity as nighttime operations, and even during bad weather. The TR-l's complement of electronic sensors will include long-range, side-looking radar for covering ground targets from outside enemy airspace.
Since Lockheed halted U-2 production more than a decade ago, the company has been experimenting with what has been called a "stealth aircraft" under

ELECTRONI C DESIGN 5, March I, 1978

31

the sponsorship of the Defense Advanced Research Projects Agency. Techniques developed for that aircraft, such as new types of paint and new electronic countermeasures to make the aircraft Jess visible to optical and radar detection, are expected to be adapted for the TR-1.
The Air Force is requesting $10.2-million to begin procurement of the TR-1 next year, but defense officials won't say how many they plan to buy or what they expect the planes to cost.

Laser weapons eyed to protect air bases
The Air Force has become interested in high-energy laser weapons to protect its European bases against enemy cruise missiles.
Studies will be sponsored by the Air Force's Armament Development and Test Center at Eglin Air Force Base, FL, which has asked interested companies to submit proposals. These are expected to be strictly paper studies aimed at figuring out the best ways to protect the bases from 1985 to 1995.
In addition to laser weapons, the studies may also cover guns, surface-to-air missiles and missiles launched by aircraft. The European bases are considered particularly vulnerable to a variety of weapons, including cruise missiles, standoff missiles launched by aircraft, and TV-guided glide bombs.

Computer data entered via voice system
The Defense Mapping Agency is now using a voice-input system to put hydrographic data on ocean-depth measurements into its computer at Suitland, Maryland.
The voice system was developed by the Air Force's Rome (New York) Air Development Center in conjunction with Threshold Technology of Delran, NJ, and is based on the analysis of voice-frequency patterns. Operators at the DMA's Hydrographic Center have trained the system to recognize 14 words and numbers.
As the numbers are read-in for each depth entry, a visual display gives an immediate feedback to allow the operator to correct any errors. Each operator's speech patterns are prerecorded to create an individual speech program, which the system converts into a digital format. This is done by repeating the word to be added to the program 10 times. Speech patterns are averaged out, and a general pattern for each word is established.

Capital Capsules: The National Bureau of Standards is planning a major increase in its
program to develop new federal data-processing standards, as required by Public Law 89-306-the so-called Brooks Act named after its sponsor, Rep. Jack Brooks (D-TX). Funding would nearly triple from $6.4-million this year to $21million in the new budget. The over-all NBS budget would go from $71.5-million to $94.3-million, the largest jump in the organization's history-if Congress approves....The first of 19 passive tactical reconnaissance systems will be delivered by Litton Industries Amecon Div. (College Park, MD) late next year to the Air Force for installation on RF-4C aircraft. The firm won a $30million production contract late last year after a successful development program it began in 1971. The reconnaissance system is designed to spot enemy radar systems around surface-to-air missile (SAM) sites. The company previously installed similar passive detection systems on the Navy's E-2C aircraft.

32

ELECTRONIC DESIGN 5, March I, 1978

Tailor-made to Mixanll Match.

If your rack is bulging at the seams with monolithics, maybe it's time to have it fitted with a trim set of TM 500 instruments from Tektronix.

TM 500 is the family name for ~early 40 configurable instruments:

DMMs Counters Generators Amplifiers

Power Supplies Oscilloscopes Logic Analyzers Word Recognizers Custom Plug-ins

They all interface electrically through a common mainframe with a built-in "mother board:' A TM 500 system gives you performance that's compact, convenient and flexible.

TM 500 mainframes come in six different versions, portable or stationary. You can load an ATM ?06 Rackmount Mainframe, for instance, with up to six different plug-ins, all interchangeable. You can mix and match combinations of instruments with ease, without pulling plugs. Pull out a pulse generator and slide in an oscilloscope, just like that.

The ATM 506 Rackmount

~ainframe comes equipped with a

high-powered fan designed to take

on the high ambient temperatures

of enclosed racks or console

environments without any sweat.

Grab hold of its strong lateral grips

and slip the instruments

manadinafrlla, mfreo~

your

stationary rack into a TEK Model 7

Rack Cart. It puts your test and

For Technical Data, Circle 20

measurement station on wheels complete with desk top and ' storage.
TM 500 can help you stretch your budget, too, since TM 500 instruments share the mainframe's common power supply. You won't be paying for an unnecessary power component each time you need a new instrument. You'll be able to update your system's performance or add on new capabilities without starting from scratch or bucking the budget.
~herev~r your rack might be, in aircraft, in a van, a ship or a submarine, TM 500 can help trim your space requirements and save valuable dollars. Every extra inch consumed by monolithic racks on a crowded production floor or in a specially equipped van costs hundreds, even thousands of dollars. When figuring your rack cost, extra size and weight can really add up to mean extra dollars. Because of its convenient, compact size more of TM 500 fits into less rack space.

And because TM 500 mainframes plug-ins and accessories are ' designe:d and manufactured by Tektronix, you can get technical assistance, parts and service all across the U.S.A. and in 50 other countries around the world.
Ask your Tektronix Field Engineer
about TM 500. He can tailor a
TM 500 system that fits your application, your budget and your rack space requirements.
TMSOO
Desi9ned for Conf1gurability
If you would like more information about TM 500 configurability write for a copy of our TM 500 concepts brochure. Tektronix, Inc., P.O. Box 500, Beaverton, Oregon 97077,
(503) 644-0161, Ext. 5283.
In Europe: Tektronix Limited, P.O. Box 36, St. Peter Port, Guernsey, Channel Islands.
TektronOO
For Demonstration, Circle 21

We don't hand out our new REC (rare earth cobalt) magnets to just anybody. Only to those manufacturers who want to make their magnetic circuits smaller, for instance. And to those who are only satisfied with the best possible temperature characteristics and overall performance from the smallest possible magnet sizes.
Just like with people, looks can be deceptive. You probably wouldn't guess that these magnets pack a residual flux density (Br) of 11 k-gauss, a coercive force (rHc) of 6.5 kOe and a maximum energy product of 30 MGOe. These features make them worth a second look especially if you've got problems in magnetic circuits and other applications where ordinary cast magnets and ferrite magnets are just not good enough.
Even though they're so small, REC magnets are guaranteed to retain their magnetic punch. And because they 're made of hard materials, they can be processed to a very high degree of precision. You can slim them down and give them any number of poles, too.
Whether you want them now or later, take a hard look at TDK's REC magnets. After all, you'll agree that when it comes to any race for the highest energy product, they'll win handsdown with 30 MGOe.
·REC magnets are just another topperforming creation from TDK. They're what you would expect from one of the world's top producers of ferrite magnets.
Our magnets earn their living and reputation for quality in motors, speakers, chucks and a host more products. Their shapes, materials and specifications meet even the strictest requirements.
Our ferrite magnets, for instance, can be molded into any shape and mass produced. Our plant in Mexico knows all our production secrets. It's our ferrite magnet specialist.
So if you've got questions about magnets, con tact us. You'II get the answers firsthand.
34

Our magnets win llands-down.

@TDK~

TDK CORPORATION OF AMERICA
2041Rosecrons AvertJe, Suite 365, El Seg.indo. Cd1lomo 90245 US.A f'liooe, 12131644-8625 >O BRANCH 2906 West fl.terson Avenue, Cficogo. Illinois 60659 US.A f'liooe, 13121973-1222 .cW YORK BRANCH 755 Eostgote BW. Gorden Oty. N Y11530 US.A f'liooe, 15161248-5230
El PASO BRANCH 3501 Frutos Street, El Paso Texas 79905 USA f'liooe, 19151533-5799 TDK CE MEXICO S .A. de C .V.
Corr JuOtez-Fbrvem, Porque Ind A.1 BermUdez, Cd. Ju6rez, 0-.n, lv'exoco f'liooe,3-88-27

TDK ELECTRONICS CO.,LID. Tokyo Japan

CIRCLE NUMBER 22

EL ECTRO NIC D ESI G 5, March I, 1978

Fast Relief forthe
"Typical Spec" Headache

"Typical Specs" Area Pain
The next time you're searching through component spec sheets for a characteristic best suited to your design, the word to watch out for is "TYPICAL." Typical specifications can be devilish creatures. Ask any design engineer who has ever believed in them. When you need answers in black and white, they tum gray and disappear in the fog. Until you determine what the MIN., MAX, or typical value really is, you've got headaches. Headaches not just for you, but for everyone on down the reliability Iine -from QC to your field service people.

Curve Tracer A Quick Cure
There's an age-old cure for the headaches caused by typically elusive specifications. It's called a Curve Tracer. TEKTRONIX Curve Tracers aren't new. We introduced our first one in the days of vacuum tubes. Since then Curve Tracers have performed wonders for semiconductor manufacturers, component evaluators, incoming QC inspectors and reliability engineers. We prescribe them for design engineers because the earlier you can diagnose a problem, the less of a problem it will be.

A Picture of Health
If you need to examine a component, it's a good idea to start with its vital signs - current and voltage. And we all know that the best way to understand the voltage/ current relationship is to look at a graph.
Two Op Amp gain curves at different sensitivities in the storage mode. TEKTRONIX Curve Tracers graph voltage vs. current in digital and linear ICs, 2- and 3-terminal devices ...transistors, diodes, rectifiers, thyristors, optoisolators and more. At a glance, you can pinpoint parameters such as an Op Amp's offset drift at various loads, or zero in on the actual breakdown voltage in a power transistor.

With a Curve Tracer, you can assign proven values to several components and select the one that you know performs best in the environment you've created. Just think of it as a little preventive medicine to help you and your organization avoid headaches in the future.
Why Prolong Suffering
Fast relief can be on its way. For detailed information - application notes, specifications, a demonstration and the prices of our Curve Tracers and their Test Fixtures simply call your Tektronix Field Engineer. Or, write:
Tektronix, Inc. P.O. Box 500 Beaverton, OR 97077 In Europe: Tektronix, Limited, P.O. Box 36, St. Peter Port, Guernsey, Channel Islands.
CAUTION TEKTRONIX Curve Tracers are mildly habit-forming. Once you use one, you'll won· der how you ever survived without it.

COMMITTED TD EXCELLENCE

So put down those aspirins and take one CurveTracer.

For Technical Data, Circle 23

For Demonstration, Circle 24

The Teledyne Zener Report
At 100 nanoamps... Our knee makes their knee look sick

Ours

II

II

II

II

I:
-= -= -=
II

-=
Theirs ~ -===

If your logic circuit needs an extremely constant reference voltage, but you want to draw as little current as possible, our new LVA zener is your only choice.
That's right. Your only choice. Other zeners can give you a stable voltage at 50 microamps. Only we can do it at 100 nanoamps.
Teledyne low voltage avalanche zeners are available in a range of voltages from 4.7V to 10V at your tolerance requirement. Let us know what you need, and we'll give you exact specs. And the most pleasant surprise of all may be the price.
For complete information and/or evaluation samples, contact Jerry Kramer at (415) 968-9241.

/

~

II

II

11

n

_.,~TELEDYNE SEMICONDUCTOR
1300 Terra Bella Avenue, Mountain V iew, Cali forn ia 94043 · (415) 968-9241
SALES OFFICES : DOMESTIC : Salem , N.H. (603) 893-9551 ; Stony Brook , N.Y. (516) 751-5640 ; Des Plaines, IL (312) 299-6196; Los Angeles , CA (213) 826-6639 ; Mountain View , CA (415) 968-9241 INTERN ATIONAL : Hounslow, Middlesex, England (44) 01-897-2503; Tie ngen, Wesl Germany 7741-5066; Kowloon. Hong Kong 3-240122; Tokyo, Japan 03-403-8141
CIRCLE NUMBER 25 36

ELEcTRONIC D ESIGN 5, March I. 1978

Editorial
The typewriter
Charlie's new job as chief engineer brought with it a large corner office. Charlie liked it. He didn't spend an inordinate amount of time at it, but he did take a few hours, with his secretary, to furnish the office more to his tastes and comforts: He got a few plants, pictures and souvenirs and sprinkled them around the place. After all, he would be spending lots of hours there.
But something was lacking, and Charlie couldn't work effectively. Ah-a typewriter. So he sent a requisition for a typewriter, indicating that any old typewriter would do. He didn't object to a good electric, but a 20-year-old manual would be fine. And then came the trouble. The head of the Office Services Department asked if his secretary wasn't suitable. "Oh sure, she's fine," he responded. Then, in the course of the next few days, a small army of people came to ask mysterious questions relating to this typewriter until, finally, Charlie's boss gave him some avuncular advice.
"Charlie," he said, "you aren't entitled to a typewriter. You are Management Code Level 7. You're suppose to be issued a pencil and a pad. Your secretary is supposed to type for you. Nobody above Code 4 ever gets a typewriter."
"But that's ridiculous," Charlie told him. "My handwriting is atrocious. Even I can't read it. And while I certainly use my secretary a lot, I do a lot of my thinking at the typewriter, I make quick notes to myself, to you and to my people on the typewriter. I brew up ideas at the machine. When I have an idea, I want to put it on paper right away, and if I did it in handwriting, we'd need a Sanskrit expert to decipher it. Hell, if we can't manage it through channels, I'll buy my own typewriter."
Well, Charlie won. And for weeks he was the talk of the office, as people would wander by and point with amazement at the executive with the typewritera man at Management Code Level 7, no less.
In time, Charlie hopes to break down a lot of other organizational structures that get in the way of getting things done.
GEORGE ROSTKY
Editor-in-Chief

ELECTRONIC DESIGN 5, March I, 1978

37

Picking a scientific calculator is getting tougher all the time, despite the fact that the number of calculators to choose from-and manufacturers-has gone down rapidly over the last three years. But what the fo.dustry has lost in numbers, it has more than gained in calculating features and computing power. Keyboards have been improved. LED and fluorescent-display technologies have been refined. And more computing power has been packed into all machines, with top programmable calculators beginning to take over for computer terminals. Re-
Jim McDermott Eastern Editor

liability has been upgraded-and so has service availability.
Unfortunately, increased machine complexity is making it harder to compare units. And a fast-growing generation of powerful user-programmable calculators is further confusing the picture.
Three years ago, you could get only one hand-held programmable, the $795 HP-65-today there are more than 15 new ones. They range from a $35 Sinclar unit with 36 program steps to a $300 Texas Instruments TI-59 with several hundred program steps to a $750 Hewlett-Packard HP-97 with a 224-step program and

The continuous CMOS memory of the HP-25C retains data stored in its 49-step program memory as well as that in eight addressable registers. Special functions often used, but not preprogrammed in the machine, can be stored.
40

Fifty fully merged program steps of the Tl-57 store up to 150 keystrokes. Eight multi-use, addressable memories store data, calculation results, and intermediate answers. The machine has full editing capabilities.
ELECTRONIC DESIGN 5, March l, 1978

a printer. Specifying a calculator, no matter what type, is not
as straightforward as specifying components or hardware, because the specs aren't generally comparable. That is, purely personal factors, like experience and habit, play a major role in your choice. For example, it's up to you to decide how readable a display is, and how the keys feel when you enter data. And the type of arithmetic operation you choose-algebraic or reverse-Polish notation-may be the one you have become most comfortable with.
And finally, with the growing preponderance of

programmables come many new considerations-not only machine architectures and programming features, but also the availability and quality of software and programming-teaching materials.
Where do you start?
If you use a calculator just to do some simple math once or twice a week, you'll have no problem picking one. Several suitable machines selling from $30 to $50 have powerful preprogrammed trigonometric, logarithmic and other math functions. Scientific notation

Table 1. Calculator keyboard functions.

Instructions to calculator

Scientific functions

(]!]or~

Clears entry (previous entry and memory unaffected)

[§I]

Clears calculator

I ENTER !orcm!Jor(I] Enters number into stack*

lR+i
m

rolls stack to review contents Completes pending operation+

OJand[l]
Ix· vi IList xI ·

Parentheses+ Exchanges x and y register contents Recalls last x entry·

[:mil or !+1- !

Changes sign

CmJ or CID
cm

Enters exponent (for scientific notation) Fixed notation

[ED

Scientific notation

llrmJ

Engineering notation (n x lQJ,6,9·. .)

·RPN only +Algebraic only

Sets angular functions in degrees mode Sets angular functions in radians mode Sets angular functions in grads mode Computes tangent or arc tangent Computes sine or arc sine Computes cosine or arc cosine Computes hyperbolic tangent Computes hyperbolic sine Computes hyperbolic cosine Displays pi (3.14159...) Converts displayed decimal hours (or degrees) to hours/min./sec. format Converts displayed hours/min./sec. to decimal hours (or degrees) Rectangular coordinate conversion Polar coordinate conversion

Mathematical functions

Statistical functions

m
cm::J
(!]
llZ!J CD
CZJ
in-!
Ci!]
[!£f)
D!iJ Cii!l
[E] Ci!J CiD

Addition Subtraction Multiplication Division Computes reciprocal of displayed number Computes x percent of y Squares displayed number Extracts square root of displayed number Raises number in y register to power in display Extracts xth root of previously entered number Computes common log of number Raises 10 to the power in display Computes natural log of number in display Raises e (2.718...) to the power in display Computes factorial ( 1 x 2 x 3...x n)

[§1

Summations Negative summation (for deleting data) Standard deviation Mean (arithmetic average) Linear regression Linear estimate Variants Correlation coefficient Normal distribution Poisson distribution Gaussian distribution Binomial distribution

ELECTRONIC DESIGN 5, March I, 1978

41

NORMAL DISCHARGE 04ARACTERISTIC
I
~ OAi--~~-+~~~--~~~-+-~~--.
s
1. A "memory" effect in NiCd rechargeable cells results in an apparent loss of capacity with repetitive chargedischarge cycles. This effect is reversible and can be cured by giving the cell a deep discharge and a recharge. as well as 12 digits-10 mantissa and 2 exponentare now found in low-cost units.
For once-in-a-while use, get one of the low-cost LED or fluorescent-display units that runs on AA dry cells. Keeping nickel-cadmium batteries recharged when a calculator is idle most of the time is a nuisance. Or buy an LCD model, and forget the batteries for a year.
But if you're going to make serious, professional use of a calculator, you're going to have to look long at several key features:
·The kind of arithmetic programmed into the machine. It may be ordinary algebra, algebra with a
F. a a a a i! s

hierarchy, or reverse-Polish notation. ·Keyboard design and accessibility. · Display types and viewability, the number of
digits and special display features. · Care and feeding of batteries. · Power of preprogrammed math, trigonometric,
statistical and other functions. ·Use of floating point, scientific and engineering
notations. ·Accuracy. · Basic programmable features. · Printer applications. · Programmable machine features. · Software and its availability.
Which arithmetic?
You'll probably feel most at home using a calculator with the math system you've grown up with-say, ordinary algebra. But two other math systems, algebra with a hierarchy and reverse-Polish notation, may be better in the long run because they are more efficient (use less keystrokes) and can solve complex problems easier and faster.
Ordinary algebra, the simplest and most straightforward, is found in all scientific calculators except those of Texas Instruments and Hewlett-Packard. Tl's calculators use algebra with a special hierarchy while HP's line incorporates reverse-Polish notation.
Ordinary algebraic operations are, for the most part, executed in the sequence you enter them. For example:
2 + 3 x 4 = 20.
For long strings of calculations, make sure that your machine has at least two levels of nested parentheses, but preferably more-as well as a one or two-register memory. Canon's F-7 calculator, for one, has seven levels of parentheses and two registers.
An algebraic-entry system with hierarchy, together with a pair of parentheses keys, makes up what TI calls its Algebraic Operation System (AOS). Its problem-solving capabilities are comparable to those of HP's reverse-Polish (RPN), but for most problems AOS requires more keystrokes.
If you were brought up on ordinary algebra, AOS may be somewhat confusing at first. Where a calculator using ordinary algebra obeys you and performs the arithmetic in the entering order, an AOS calcu-· lator grabs your key entries, both function and digit, sorts out the data in the order it wants, and performs the calculations in its own sequence. The Tl-59, for example, defies you to set up an equation any other

With a 36-step program capacity, this vest-pocket Sinclair
programmable calculator handles frequently used programs in math, physics and engineering. For $35 the machine and a library of 290 programs are supplied.
ELECTRONIC DESIGN 5, March I, 1978

l lON

~ 1 1:. N l lr K: CAl.C'ULATOH

CAaea/x-3000 I 0'0 ··:o:;
so ~

1111111111···1·1

1111·11·

1111·1111

1r

,\ Ol!L

Silver-oxide cells provide 700 hours of use for this Casio fx-3000 calculator with a liquid-crystal display. This type display permits packaging the power of a 38-function, 10digit machine in a slim billfold case.
way than the machine wants it. Computations are always performed in the following order:
1. Special single-function key entries, such as those for trig and log functions, and squares, square roots, reciprocals and conversions.
2. Powers and other roots. 3. Multiplications and divisions. 4. Additions and subtracti<ms. In other words, if you were to key in the previous equation, the answer wouldn't be 20:
2 + 3 x 4 = 14
With AOS the 3 and 4 are first multiplied, and 2 is then added.
The battle of keystrokes
But is AOS more efficient than RPN? This continuing controversy has been joined by calculator users on both sides. Examples have been created that "prove" one or the other to be more efficient. This, of course, can be done by selecting problems specially suited to one calculator architecture and not the other.
But the pros and cons of the efficiency of one arithmetic system over another become more or less academic, because TI concedes that RPN is somewhat more efficient than AOS architecture. However, Rich-
ELECTRONIC DESIGN S, March I, 1978

ard Cuthbert, applications manager for Tl's professional calculators, points out that the general need for more keystrokes per program by TI machine users is intentional.
"It's intrinsic that you use more space with the AOS architecture,'' Cuthbert says. "But we have deliberately taken this approach to make it easier for the user to program. Our AOS, like higher-level languages in large computers, takes more room than assembly language. But assembly language is a lot tougher for the neophyte. While our approach imposes additional overhead, we have a lot more storage in the machine."
RPN does save a few keystrokes. But there's much more to choosing a calculator language than counting keystrokes. The machine itself should be adaptable to the user's background and needs. A survey of HP and TI users has shown that, by and large, those who have learned to operate programmable machines of one type or another become "addicted" to the machine they learned on. As a matter of fact, over 2000 calculator owners belong to an HP Users Club and 500 to a TI Users Club, both of which are unaffiliated with the manufacturers.
Graduating from an algebraic calculator to an RPN can be a problem because data in the RPN system are entered and manipulated differently. The RPN procedure is a lot like the entry of data into computers.
With algebraic entry, the arithmetic functions of plus, minus, times, or divide by are placed between the numbers of a two-number operation. But with RPN entry the arithmetic function is placed after both members of a two-number operation.
In other words, for problems having two numbers and one arithmetic operator, the first number is keyed in and saved in a stack register by pressing an ENTER key. The second number is keyed in and followed by the arithmetic operator. An expression like (3 X 4)
+ (5 X 7) would be evaluated in an RPN machine by
the following steps:
3 ENTER 4 X (12.00 is displayed),
5 ENTER 7 x (35.00 is displayed)
+ (47.00 is displayed).
While RPN, like AOS, is at first awkward for those accustomed to working with algebraic system entry, users experienced with both AOS and RPN say that with frequent use, they become either as proficient or more proficient at using RPN.
Keyboards are growing
Unfortunately, the amount of keystrokes isn't determined simply by the math language you choose. Because of the abundance of functions preprogrammed into all of today's advanced scientific calculators, keyboards have two, and in some cases, three functions assigned to one key. The more functions per
43

key, the more keystrokes it takes to solve a problem. Try to pick a calculator with more single-function keys for faster and more accurate keyboard operation.
Some calculators signify data entry with keys that snap or click when they are depressed, so you don't have to verify each entry visually. One Sharp calculator even has keys that "beep." But other calculators have keys with a very light touch and no positive feel, which means that you've got to watch the display to make sure a number or function is entered. That type of key is more prone to unintentional multiple-digit entry on low-quality keyboards. Not surprisingly, most users prefer the more reliable snap action keys and their tactile feedback.
Keys should be far enough apart so that you can operate them without accidentally depressing an adjacent key. One indication of a good keyboard is that the number keys are somewhat larger or spaced farther apart than the rest of the keys.
A frequently neglected but important consideration is to make sure that your calculator has a moisture barrier under the keyboard to keep liquids like coffee from getting into the keyswitch or into the calculator circuitry.

Check off your functions
Finally, inspect the keyboard markings to verify whether or not a calculator has all the key-addressable functions you'll need-arithmetic, trigonometric, statistical or whatever. One calculator specialist suggests that you draw up a list of the formulas and equations on the basis of those you regularly use, those employed occasionally, and those encountered infrequently.
Check your list against the Table, which contains key-addressable functions that will be needed for a wide range of problems. Not all of these come on all calculators. And whether the machine is costly or inexpensive doesn't necessarily have any bearing on whether certain functions are contained.
For example, anyone who wants to work hyperbolic problems won't find the special keys on the high-priced HP-67 or HP-97. But solutions are included in HP's $35 Math Pac I software.
Texas Instruments doesn't do any better with its TI-58 or -59, which have no hyperbolics on the keyboard. The company recommends the formulas in a standard math handbook.
What's happened is this: The hyperbolic keys and functions have been sacrificed in most programmable calculators (the APF MK 90 is an exception) to make room for other programming keys and functions. The point is, compare your math-function list carefully with the keyboards you look at. Other functions may have been omitted, too.
Another thing: You may be able to calculate the values of a function only through extra keystrokes. For example, with most calculators you determine the value of an inverse function by striking an "F" or
44

Over 70 preprogrammed functions are available in this 72-step programmable calculator, the MK 90 by APF Electronics. Five keys control program loading or runn ing. Data are stored in 10 registers. Full editing features are provided for program debugging.
transfer key to access that function on a second key. But TI has packed so much computing into the TI-58 and TI-59 that it takes an added keystroke to get at the inverse sine. But this is a trade-off you can probably live with.
Today's engineering calculators display very large or very small numbers in scientific notation. On some machines when the displayed numbers exceed acertain maximum value or drop to less than a specified minimum, the display automatically switches to this notation. On others, you do the switching.
Scientific notation consists of a mantissa that carries the significant digits of a number, and a two digit exponent, which in most cases ranges from 10- 99 to 1099· The mantissa commonly consists of 8 or 10 displayed digits, with two or three undisplayed digits carried in the machine.
Engineering notation-a form of scientific notation in which the exponent is a multiple of 3, is also common. It is particularly desirable for problems in the electronics field. Many machines offer a special key (EE or ENG) for converting floating-point into engineering notation.
ELECTRONIC DESIGN 5, March I, 1978

Another desirable feature to look for in advanced calculators is a fixed-point key (FIX), which allows you to select the number of digits to be displayed after a decimal point. If the digits in the calculated result or the original entry exceeds the number selected with the FIX key, the calculator automatically rounds the least-significant digit displayed, while continuing to perform all calculations.
Look at displays
Having gone over keyboards, you -should literally look at displays. Your eyes are the best judge, for a display should be easy and comfortable to read. The .two most common displays for scientific calculators are red LED~ and the blue-green electrofluorescent units. Unfortunately they both demand a relatively high battery current. But liquid-crystal displays, which substantially reduce battery current and boost battery !ife a thousand hours or so, are emerging in slim preprogrammed calculators, such as APF Electronics' MK 8602, Casio's fx-3000, Commodore's LC63SR and Sharp's EL-5806.
LED displays vary in quality. Watch out for the display that enlarges tiny digits with plastic bubbletype lenses. Its field-of-view is narrow, and the calculator must be positioned exactly right for decent viewing-which literally can give you a pain in the neck.
In addition to showing data, a display indicates errors, entry of false data, overflow, underflow, data in memories and a low battery. Unfortunately, the low-battery indication generally is as effective as idiot lights on automobiles. When it flashes, pull over and stop calculating until you plug in a new battery pack or put the charger on.
Does your calculator lie?
Assuming now that you've made a tentative selection of a calculator, the next question is: "Can I trust it?"
The answer is: "Most of the time, yes. But not exactly all of the time." For example, try the following exercise on your machine: Enter 2, and take its square root 20 times. Now hit the square key 20 times. The answer should be exactly 2. But it won't be. An HP-97 will give you 1.999897829. A TI-59 will give you 1.99999681. And a National Semiconductor 4660 will give you 1.99993871.
Take another example: Subtract two functions that are mathematically equal. The answer should be zero. But the calculator may not display that. For instance, take a TI-59 and subtract the cos of 45° (0.7071067812) from the sin of 45° (0.7071067812). A remainder of -7. -13 is displayed, showing that there is a discrepancy in the 13th digit.
Irregularities like these occur because designers have to fit algorithms into digit strings of a given length-and at a specified cost. The designer may have
ELECTRONIC DESIGN 5, March I, 1978

The program memory in this 128-step programmable PC-1201 calculator by Sharp can be partitioned into 13 separate programs; or it can hold 12 subroutines. A CMOS memory powered by silver-oxide cells hold a program for a year, which is equal to silver-cell life.
decided to chop off guard digits, additional digits used in calculators to preserve the accuracy of results. For example, the TI-59 displays 10 digits, but actually uses 13 for most operations. For some functions the 13th digit is chopped off. More accurate results would be obtained if the 13th digit were first rounded off by adding 5, then chopped.
Anomalies in equations used to fit functions within a machine's architecture may sometimes be unknown even to the designer. They will be found only when the calculator gets into the field.
So what do you do about it? Where can you find out whether or not there may be some unexpected errors associated with the functions and numerical ranges you'll be most concerned with?
That's not easy to answer. Some Owners Manuals list the expected accuracies of various functions within stated calculation boundaries. They frequently point out that "accuracy is low around singular and deflection points." But how low? How do you find out? Other manuals ignore the problem entirely.
Don't try to get inside information from the manufacturers. Many of the errors are the result of discontinuities in proprietary machine algorithms. To openly identify critical data regions could give the competition useful insight into a calculator's architecture.
Discrepancies uncovered by calculator users have been reported to two private groups-the HP-65 Users Club, and the SR-52 Users Club.
Excellent information on calculator inaccuracies appears in reports by Dr. William Kahan, professor
45

Table 2. Comparison of scientific calculators and key features.

00 I-

°'

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Preprogrammed functions

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Texas Instr.

· · *HP-97 750 55 L RPN 10 10/2 · · · · · · · · · · · · · ·

·· ·

*HP-67 450 35

· · 10 10/2 · · · · · · · · · · · · · ·

·· ·

*HP-19C 345 31

8 812 · · · · · · · · · · · · · · ·

·· ·

*HP-29C 195 30

8 812 · · · · · · · · · · · · · · ·

·· ·

* HP-27 175 30

8 812 · · · · · · · · · · · · · · · · · · · ·

· · *HP-25C 160 30 ~ ~ 8 8/2 · · · · · · · · · · · · ·

·· ·

· · *HP-25 125 30 L RPN 8 812 · · · · · · · · · · · · ·

·· ·

*Tl-59 *Tl-58 *Tl-57

300 45 LAOS 10 10/2

i ·· · 125 · 45
i · · 80 40

10 10/2 10 10/2

· · ·

· ······· ·· · ········· · ······· ··

· · · · · ·

· · · SR-51-Il 60 40 LAOS 10 812

·

- PC-lOOA 200

1fnnterJ.:or Tl -58/ 59)

10 10/2 ..._

· ··············· NA

· · 224 4 26 M 3

· · 224 4 26 M

· · 98 4 30

3.4

· · 98 4 30

4

· · · · · 4 10

· · 49 4 8

4

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· · 480 9 60 S,M 5

· · 240 9 30 s 5

· · 50 9 8

· · · · · 93

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*PC-1201 90 40 F OA 10 10/2

Electronics *EL-5001 5() 39 F

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2

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APF

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Electronics MK 56

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· · 8 8/2 · · · · · · · · · · · · · · · · · · · · · · · · · · · 72 4 10 9 · · 8 8/2 · · · · · · · · · · · · · · · · · · · · · · · · · · · 4 10 9

MK 8601 35 38 LX

8 · 8/2 · ·

·

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··· · ··· ·· ·· 22

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fx-120

30 39 F

· 10 812 · ·

·· · ·········· ·

· ··

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fx-3000 50 39 LX

· 10 812 · ·

·· · ·········· ·

· ··

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F-7

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· · 8 812 ·

·

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·

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· ·

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·

·· ···

· ·· ·

·· 21

11

Sinclair

Program able 35 19 L OA 8 5/2

·

·

·· · ·· ·

· 36 l 1

*Programmable calculators (see text) 1. L = LED; F = flourescent; LX = liquid crystal 2. OA =ordinary algebra; AOS ~ hierarchical alegbra ; RPN = reverse- Polish notation 3. Calculator has integral printer. 4. Calculator has CMOS memory for long-term

program storage. 5. Program and data memories can be exchanged. See text 6. Printer has tullialpha -numerical and plotting capability. 7. Can subdivide program memory into 13 programs or 12 subroutines. 8. Calculator has six thumbwheel -acces-

sible programs built in . 9. Converts cartesian to spherical coordinates and inverse. 10. Has cube root instead of n-th root. 11. Has decimal-degree to radian to grad and inverse conversions. 12. Six thumbwheel programs inc lude: (1) Linear and

\Q ~

polynomial plots; (2) Statistics; (3) Quadradic equations; (4) Polynomial integration; (5) Complex number algebra and coordinate conversion; (6) Vector algebra and coordinate conversions.

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Thermal-printer tapes show a trace listing of a simple program executed on an HP-97 (left) and a verification listing of program steps (right) produced by a Tl PC-lOOA printer controlled by a Tl-59 in the printer cradle.

of Mathematics and Computer Science at the University of California at Berkeley. Kahan specializes in numerical error analysis and has conducted independent studies and reported them in "Can You Count on Your Calculator?" and "And Now for Something Completely Different, the Texas Instruments SR-52."
One simple way to find out if and where your calculator has errors is to perform a forward-function calculation and then an inverse-calculation with functions and values in the region of suspected inaccuracies. The displayed answer should be identical to the original entry. If not, there is an error in the forward-function or the inverse, or both.
For example, take the cos of 0.05°. Then press the inverse-function (cos- 1) key. The answer probably won't be 0.05. Try the same approach on the sine and tangent functions.
You can use the forward-inverse method on other functions, such as natural logs and antilogs. The natural log of zero, or of a negative number, should indicate ERROR. Make this check in the vicinity of 2, say, from 1.99 to 2.04, and in the vicinity of 1. Use the following table to verify your results:

Number 1.1 1.01 1.001 1.0001

In
9.53101798043247 x 10- 2 9.95033085316808 x 10- 3 9.99500333083532 x 10- 4 9.99950003333083 x 10- 5

ELECTRONIC DESIGN 5, March I, 1978

STEP
3
5
9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31
·

KEV
F i HLT
F ; HLT
! F : HLT
! : F HLT

KEV CODE
! 55 00
F : 12 55 01 F 12 55!02 F I 12 56 03
Fl 12

STEP
32 33 34 35 36 37 38 39

: Ix
i 2

54 41 02 42

x

54 43

- F ' " ' j F x2

F 41 44 45
56 J 04 46 47

x

48

: RM 0
x
i RM

i 65 ' 00 49

l

54 50

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'

01 53

84 54

+/-

82 55

55 05 56

I RM i 4

65 04 57

I

x

54 58

I RM! 0

84 60

tx-M: 0

55 : 00 61

: x

54 62

RM i 2

MEMORY

4 t-2·f

·

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0

KEV
RM ! 5
:' x-M:' 6
+ RM! 3
i 'x
RM i 0
: I : RM I 5
! I
i +/M+ i 7
! RM I 6
: I RM i 7
F :-xy :' x-M·' 7
I I
LABEL 4 5 6

KEV CODE
84 45
45 F 64 55 06
45 56 07 : 65 02
74 65 03
54
84 : 45
65 ' 05 : 45
F : 64 : 45
! 82
76 ; 07
l T 45
44 66 : 06
45 84 45 65 : 07
F i 74
45 55 07
I 45

2 Rs

8

2

8

Rp

9

3

9

2. Program lists, like this one for solving series-resonant circuit problems, are found in Sharp's PC-1201 software manual. Each program is supplied with a sample problem and step-by-step directions tor its execution .

1.00001 0.99999 0.9999 0.999 0.99 0.9

9.99995000033333 x 10- 6 -1.00000500003333 x 10-5 -1.00005000333358 x 10-4
-1.00050033358353 x 10- 3 -1.00503358535014 x 10- 2 -1.05360515657826 x 10- 1

Another check is to add mathematically equal functions of opposite sign, or subtract equal functions of the same sign:
tan 89.99° + tan 90.01 ° = ?
sin 45° - cos 45° = ?

The answer should be zero.
Can I count on my battery? Having determined whether or not your calculator
can be trusted, don't forget to check the batteries. Nickel-cadmium rechargeable batteries are the work-
47

horses that power the vast majority of scientific

calculators. But they're sensitive to heat and to cold.

Not only that, a perfectly good cell may stubbornly

resist taking a charge. And continuous overcharge will

cut capacity. And continuous deep discharge will do

worse.

To get maximum, continuous useful life and depend-

ability from NiCd batteries, you'd better know their

properties and characteristics. Unfortunately, calcu-

lator manufacturers offer little help. For example,

take the following statement from a "Battery Care"

section of an otherwise excellent 300-page User Man-

ual. The manual defines the point of battery discharge

as follows: "If the calculator fails to turn on you should

substitute a charged battery pack, if available, for the

one in the calculator."

A typical NiCd battery pack consists of two or three

AA-sized, sealed cells, each with a nominal voltage

of about 1.25 V. Pressure-relief seals are designed into

the cells so that when internal pressure builds up, it

can be relieved.

Most calculators use what are termed "slow-charge"

batteries that are designed to be fully charged in "14

to 16 hours, or overnight." One reason is that these

batteries are not harmed by a continuous overcharge.

However, a sustained overcharge does lower the

discharge voltage.

Note that nickel-cadmium batteries apparently lose

capacity from repetitive use patterns. This phenome-

non, known as "memory," acts like this: If you charge

your battery fully each night, and discharge it by 25%

during each working day, after a while the battery

develops a memory that makes it think it has only

25% of its original capacity (see Fig. 1): It acts like

a battery that is only one-fourth its actual size. So

whereas the calculator should normally operate off

the battery for, say, four hours, it will now last less

than one.

Fortunately, "memory" is only temporary and can

be corrected easily: Subject the battery to a deep

discharge, then recharge it to restore it to its original

performance. One calculator manufacturer suggests

that a battery occasionally be discharged by leaving

the calculator on until the display digits go out, then

recharging it fully. To avoid the situation in the first

place, all you have to do is make your charge-discharge

patterns random.

Attention: Don't subject the battery to extended

deep discharges, such as those caused by neglecting

to turn the calculator off for a day or two. Two bad

things will happen. First, since the two or three cells

in the battery packs don't have identical charge

capacities, one usually discharges to 0 V before the

others. It is then reverse-charged by the voltage in

the other cell or cells, and hydrogen gas is generated

internally. The resultant pressure rise may then vent

through the pressure-relief seal, with a loss of battery

moisture.

'--'!

Second, a deeply discharged cell is more likely to

short internally than one that is fully charged. That's

48

Advanced programming features plus a battery-operated printer are found in the HP-97. The printer is valuable for editing and debugging, giving printouts that trace each step number, function and results of every step.
because a fully charged cell has sufficient energy to vaporize, or clear, the shorted path. A near-dead cell won't have enough energy to do so.
Nickel-cadmium batteries are designed to live in an ambient of 20 C (68 F) room temperature. Charging them at greater than, or much less than 20 C shortens their !ife. Don't make a practice of charging your calculator batteries in a cold room. Or in a hothouse.
Fully charged NiCd batteries, standing idle at 20 C, lose about 1% of their charge per day because of chemical self-discharge. So in about a month or so, the battery will have lost about half its capacity, which calls for a recharge.
Hint: To keep idle batteries charged for extended periods, wrap them in a moisture-proof bag and store them in the food-not freezer-compartment of your refrigerator. The ~ 40 F temperature reduces the normal self-discharge to one-fourth, and extends the 50% discharge time to over six months. Caution: Be sure the batteries are warmed to room temperature before recharging.
So far, you've been trying to select a scientific calculator in general. But a new breed-calculators you can program-is fast emerging, and you'd better be ready for them.
The year of the programmables
As 1975 was the year of the preprogrammed scientific calculator-more than 40 kinds were available then-1978 is the year of the programmables. Five out of eight of HP's scientific machines can be programmed, as can three out of five of Tl's new line. Programmables are also appearing from APF Electronics, Casio, Commodore, Sharp and Sinclair.
ELECTRONIC DESIGN 5, March I, 1978

Programmable calculators are "grown-up" preprogrammed machines that tell you, in effect, "Leave the driving to us." They can learn a sequence of keyedin instructions and automatically execute that sequence on command. They store constants and other data. The program sequence, or list, is stored in a program memory while the data are stored in registers that can be accessed by the program.
To teach a programmable calculator a program, you switch to a PRGM or LEARN mode and enter a problem in a sequence of keystrokes dictated by the calculator's program list. The needed software may be prepared by the calculator manufacturer, or you can write it as an original program.
To execute the program, you switch the machine to a RUN mode, key-in initial problem values and let the program take over. You'll save a substantial amount of time when you have to solve similar problems over and over: You can use the same program, instead of going through single-key entry of every step. Great? Sure. But wait.
Turn the calculator off. Then turn it back on and try to run the program. Chances are, you can't, because the program was wiped out when the power went off. Now you have one important yardstick for comparing programmables: In one class of machines, the program must be keyed in again when the power is turned back on. So if your problems involve 100 or 200 program steps, get to work early. Or leave your calculator plugged into the charger and turned on as long as you want to keep the program in. However, when you do so, you'll be trading inconvenience for potential battery trouble.
One way to retain the program is to use low-power CMOS memories, which, with an auxiliary battery, keep the program and its data for months after a calculator is shut off. Such memories are designed into the $160 HP-25C, $195 HP-19C and the $345 printerequipped HP-19C. Sharp's $90 PC-1201 has a standby CMOS memory, powered by two silver-oxide cells, that will hold program information for about a year.
Magnetic cards also keep programs. Machines like the $300 TI-59 come with a magnetic-card handler and can store programs on the cards and read them back at any time. Magnetic cards are also used in the $450 HP-67 and $750 HP-97. In addition, libraries of prerecorded or "canned" programs are available in HP's Engineering Application Pacs.
The newest approach to programs that won't vanish when the machine is turned off is the Solid-State Software ROM modules that plug into the TI-58 and 59. The Master Library module, which corresponds to HP's Standard Pac of magnetic cards for the 67 and 97, has some 5000 program steps that provide 25 different programs in mathematics, geometry, statistics, engineering conversions, finances and games. Each of the programs can be loaded into the program memory and data registers with a few keystrokes, and run independently. Or the program can be called in by the machine to run as a subroutine
E LECTRON IC D ES IGN 5, March I, 1978

of a larger program.
A universal and frequently vexing problem with programmables is how to debug a program you have written. For most programmables, debugging is a time-consuming operation that requires you to singlestep through the entire program listing, comparing the program step numbers and associated key codes (two-digit numbers that tell which keys were depressed to enter the program) that appear in the display against your master list. If a mistake has been made, you may have to delete or back step, or add steps, moving other portions of the program forward or backward. And you must repeat the single-step check of the program until the listing is correct.
The answer to a programmer's prayer for aid in debugging is found in printers that can be called on to list or trace through a portion of or an entire program. Such printers are incorporated into HP's 19C and 97. And TI has produced a free-standing print/security cradle, the PC-lOOA, in which the SR-52, SR-56, TI-58 and TI-59 can be mounted and locked in place. Locking-in helps solve another problem-theft.
HP's printer machines have a limited alphanumeric capability that identifies the kind of program step entered as well as other functions keyed into the program, for instance, ENT (enter), STOl (store data in register 1), SIN, TAN, etc. TI, however, has taken a giant stride with its $200 PC-lOOA printer, which, when used with the TI-58 and TI-59, can produce full alphanumerics plus 29 other useful symbols.
Not only can users of PC-lOOA list and trace program steps, but program headings and userprompting phrases (up to 20 characters wide) such as "ENTER INDUCTANCE" can be printed. In addition, you can make simple plots of data, such as sine curves, directly from the keyboard or automatically under program control.
Both HP and TI printers use nonimpact, thermal print heads. "Whisper-quiet operation" is claimed for both. After listening for a while, though, you may feel that the sound is more like a stage whisper.
Programmable benchmarks
The power and performance of most programmable calculators generall y can be described by the following criteria:
· The number of program steps that can be held. · The number of data registers. · The ability to manipulate program steps to edit a program. · The presence, or absence, of user-definable LABEL keys or other keys that identify a program or program segment simply by pressing the defined key. Comparing some of the lower-cost calculators, you find that Sinclair's 18-key Cambridge Programmable -the world's smallest programmable- has a 36-step program memory. APF's 45-key, $70 MK 90 has 72
49

program steps and 10 user-accessible data memories. Advanced program-editing features include singlestep, forward and backward program verification as well as jump commands.
Sharp's $90 PC-1201, with a permanent CMOS program memory, has 40 keys, 128 program steps, 12 data registers and 1 test register. It also has 12 useraddressable labels and can hold up to 12 subroutines. Conditional and unconditional subroutine jumps are possible, and full editing keys are included. As an added attraction, the entry of each program step is verified by a "beep."
An unusual calculator, the Sharp EL-5001, as six "most-used" engineering programs hard-wired into a program memory. These programs are selected by a six-position thumbwheel switch. They are equivalent to keyed-in programs ranging from 30 to over 150 program steps. For electronic designers, the machine has programs, impedance calculations, vector analysis, quadratic stability analysis, polynomial integration, and statistics. For more details, see Table 2 and News Scope, ED 3, Feb. 1, 1978, p. 21.
All these programmables use an ordinary algebraic language. You can, by studying manuals and looking at the machines, make reasonable comparisons.
Comparisons May Be Different
But you'll have a hard time comparing the performance of powerful machines like the HP-67/97 and the TI-58/59. First of all, data are entered and processed differently in each. And while the two architectures produce essentially the same results, they don't go about it in the same way. In fact, directly comparing the featu res of some of these machines may give only part of the story.
For example, Tl's brochure on the 57/58/59 compares the 224-step program memory of the HP-67/97 with the TI-59's maximu111 number of program steps (960). Looks like TI is ahead, right? But not if you look at the TI-59 architecture.
When the TI-59 is turned on, the program memory is configured with 480 steps, and there are 60 associated data registers, each able to store eight program steps. The TI-59 architecture permits you to allocate the data registers to program steps or the program memory to data. But if the machine is in the 960 program-step configuration, it can't store data, and you've got problems.
Using the 960 steps as your basis for comparison obscures the fact that the exceptionally versatile TI-59 can allocate nearly all the registers to data to handle a short program with many numbers, or allocate those registers to program steps for a long program with many operations, but few variables.
Meanwhile, HP contends that to get the 67/97's true capability, you should multiply 224 by 3. So-called "fully merged" codes are used in the HP architecture, which means that three keystrokes may be combined and executed as just one program step.
50

An independent printer that can be used with Tl's SR-52, SR-56, Tl-58 and Tl·59, the PC-lOOA has a full line of alphanumerics plus 29 other useful symbols. A worthwhile feature is a lock that secures the calculator in place.
Some comparisons start out as direct, but end up giving you more to consider. For example, both the TI-59 and the HP-67/97 have magnetic card read/write units, with TI claiming a capacity of 480 steps per card, against 224 for HP . But HP counters with the intelligence built into its "smart" card reader. When you load a card into an HP machine, its reader knows which side of the card carries the first 112 steps and which carries the second. And it also knows if a step contains data or a program. And you don't need to tell the 67/97 the status and flags.
With the 67/97, you can also write a program that turns the card reader on automatically and pulls a card through-calculating all the while. With this technique, program cards can be chained together to give, at least theoretically, an infinite number of program steps. The TI-59's reader has this feature.
You can keep comparing calculator features, but it will all boil down to this: No single programmable has all of the most desirable features. Because so much processing and memory and control and computing powers are packed into the advanced hand-held marvels, it's tough to make meaningful comparisons from spec sheets and brochures.
Veterans of the programmable "wars" will tell you to beg or borrow a programmable from a friend; or get one on a trial basis. Working with a calculator, you will learn in a few days what you may not learn even after months of second-hand research and study.
The power of any programmable calculator is only as good as the programs that run it. But program development is expensive, and you pay more for machines supplied with program libraries. But the cost goes down when you consider the qi.any hours you'd spend generating just a few of your own pro-
ELECTRONIC DESIGN 5, March I, 1978

grams. And with ready-made programs, you can start out immediately.
One good thing about writing your own, however, is that as you develop a personal approach, your storebought programs may not seem as good as they should be. You may want to rewrite them to make them shorter, easier to keep track of, or simply more comfortable to work with.
A major software benchmark when considering a programmable is the quality and depth of the machine's documentation. Check that the Owners Handbook or Owners Manual is comprehensive, and thoroughly describes the programming keys and their functions. And be sure there are plenty of clear sample programs with step-by-step explanations.
With the lower-cost machines, the Owners Manual will usually provide just a few programming examples. One exception is Sharp's PC-1201 programmable. Its instruction manual contains clear descriptions of the programming functions of the machine, along with a good sampling of test programs. But the bonus is a 266-page Application Manual listing 92 programs for math, statistics, electronics, engineering and other problems (See Fig. 2).
Preceding each program listing is its basic formula, a sample problem, and key-by-key directions for executing the program. Also, the program can be stored indefinitely in its special CMOS memory.
Software and documentation for HP and TI machines are ahead of the rest of the competition. And both companies continue to improve and enlarge their sizable libraries and Owners Manuals to capture a larger share of the programmable-calculator market.
In addition to their own software, both companies support in-house User Libraries of programs submitted by calculator owners. In line with this, newsletters from both manufacturers pass on program hints and announcements contributed by subscribers. HP's newsletter is "HP Key Notes" and Tl's is the "PPX Exchange Newsletter."
For the new TI-58 and TI-59 machines, Tl's SolidState Software library modules include the Master Library, which comes with the calculator, and Applied Statistics, Aviation, Marine Navigation, Surveying and Real Estate/Investment. No EE library is available, and at the time of writing there hasn't been any indication that one will be. For TI-programmablecalculator users, another source of software news is the SR-52 Users Club in Dayton, OH, which reports on all TI models.
Software for HP's 67/97 machines is available in two forms. One is a 40-book series of $10 "User Library Solutions," each containing 10 to 15 programs. Purchased separately they would cost $35 to $45. One book covers electrical engineering. Four books handle mathematics and three more have programs for chemistry, optics and physics. For these calculators, $35 magnetic-card Application Pacs are also available.
One independent source of HP program information and news is the HP Users' Club in Santa Ana, CA.
ELECTRONIC DESIGN 5, March I, 1978

The 2000-member club swaps programming techniques, applications and programs in its newsletter.
What about your old software?
Suppose you already have a programmable and want to step up to a new machine. You ask plaintively, "What do I do with the software that I've already spent a bundle on? Can I transfer my programs, say, from an SR-52 to a TI-59, or from an HP-65 to an HP-67?"
Yes you can. And HP and TI newsletters have tun articles telling how. But an ELECTRONIC DESIGN survey of long-term users of both kinds of machines elicits the following advice: Transfer programs from old libraries directly, and you'll lose efficiency in the translation. The best and quickest approach is to rewrite them according to the new machine's rules.
The thousands of HP and TI programmables now in use have also created a demand for software not available from the manufacturers. To satisfy this demand, calculator-software houses are appearing. One is the International Software Clearinghouse in Estacada, OR, and another is Horizons Technology, Inc., in San Diego...

Want more information?

Readers interested in learning more about the calculators mentioned in this article and of similar machines available may contact the manufacturers listed below or consult ELECTRONIC DESIGN'S GOLD BOOK. Types of calculators produced are indicated by the letters following the listing: P-preprogrammed; K-key programmable; M-magnetic-card programmable; S-solid-state-module programmable.
For readers who wish to learn more about the activities and services of the private calculator User's Clubs and of the software houses, the addresses are included below.

APF Electronics, Inc.. 444 Madison Ave., New York, NY 10022. (212) 758-7550.

P, K.

Circle No. 501

Canon, Inc.. 10 Nevada Dr.. Lake Success. NY 11040. (516) 488-6700. P.

.

Circle No. 502

Casio, Inc.. 15 Gardner Rd.. Fairfield, NJ 07006. (201) 575-7400. P, K.

Commodore Business Machines. 901 California Ave.. Palo AW~~·~AN;43~

(415) 326-4000. P, K. .

Circle No. 504

Hewlett-Packard, 1000 N.E. Circle Blvd.. Corvallis. OR 93770. (503) 757-2000.

P, K, _M.

Circle No. 505

Kingspoint Corp., 104 Harbor Dr.. Jersey City, NJ 07305. (201) 432-7707 . P.

.

.

Circle No. 506

National Semiconductor, 1177 Kern Ave.. Sunnyvale, CA 94086. (408)

732-5000. P., K.

Circle No. 507

Sharp Electronics Corp.. P.O. Box 588. Paramus, NJ 07652. (201) 265-5600.

P, K. . .

Circle No. 508

Sinclair Rad1on1cs, Inc. , 115 E. 57th St., New York, NY 10022. (212) 355-5005.

P, K.

Circle No. 509

Texas Instruments, P.O. Box 53, MS 5842. Lubbock, TX 79408. (806) 747-3737.

P, K, M, S.

Circle No. 510

Software clubs and houses:

HP Users Club. Richard J. Nelson, 2541 W. Camden Pl. Santa Ana CA 92704

(714) 639-7810.

'

·

.

SR-52 Users Club. Richard C. Vanderburgh, 9459 Taylorsville Rd. Dayton OH

45424. (513) 255-6502.

.

.

International Software Clearinghouse. Route 2 Box 965 Estacada OR 97023

(503) 631-2214.

'

.

·

.

Horizons Technology, Inc.. 8333 Clairemont Mesa Blvd. San Diego CA 92111

(714) 292-8331.

'

'

.

51

PRECISION SIGNALS

!Ml -!llllODUl.ATOOSI("""
' . . ... '

ITl>lJ :-:· · -·"~Y"~
. - _. I

Ext. AM/ Pulse

AM : 0 -100%

,,_

FM : 0 -1 M H z Dev.

1 M Hz Rate

--~·~ ·~ ....
/' -·-·-
- ...... @ :~-

,., '· - .·.

....

-' ~ . _.. . .. _

-- ""'

@ ·:~

......... ..... .....

!·

\_

,, >'

I-

. ·~:.y

A M : 0 -100% FM : 0 -100 kH z Dev, No D ri ft Ca rrier

[~-~~~ ~~·· l [1¥1] UHJ1w<l0u1AT....,'M.c1,,,,.

.... I ~~u· " "' ' ~ ' ~
r «-~-- ~~· 1
_.. . . l

Phase Modulation: --1------.-.,--
0 - 2000 .10 M H z Rate

-·~· ··: ~......:~.....
fl .:
') 't .., .,.,·:.'l'

Phase Mod u lation: 0 - 200°. 1 MH z Rate FM : 0-2 MH z Dev.
RF Section 10 kHz- 110 MH z
RF Section 1-1300M Hz
RF Section 1-2600 MH z

HP 8660C with 8 available
plug-ins.

..\l: ".' ":"" " "'" .

·

· .. ft,.

..

·~

.. . :·;.]] ::·: " "" "

/,£ ·

..... -~

.( '·
\ ·. . i

FROM 10 kHz TO 2600 MHz.

Your broadest selection of precision signals.
Choose a modulation capability for your exact frequency range. You can get the precise combination for the signals you need. And you won't

find a broader selection of modulation and output capabilities on the synthesizer market.
For manual operation, choose the HP 8660C mainframe. It features keyboard entry, digital readout, 1 or 2 Hz resolution, digital sweep, good signal purity and the operating convenience you need.
For systems operation, the HP 8660A mainframe features thumbswitch entry.

Both mainframes are completely

programmable with the HP Interface

Bus (IEEE 488) or BCD.

Complete systems start at $10,350*

and a typical keyboard mainframe

with 1300 MHz output and AM-FM

modulation is $19,875'."

For our 20 page brochure describ-

ing HP's synthesized signal generator

call your nearby HP field sales office,

Or write.

*Do m estic U.S. prices o nly.

04 704C
52

HEWLETT. PACKARD

1507 Page Mill Road, Palo Alto, California 94304
For assistance call : Washington (301) 948·6370, Chicago (312) 255-9800, Atlanta (404) 955-1500, Los Angeles (213) 877-1282
CIRCLE NUMBER 65

Elt:CT RON 1c D ESI G 5, March I, 1978

IN A MARKET FULL OF DROPOUTS,
OUR NEW
REGULATORS ARE
PHI BETA KAPPA.

Fairchild is introducing two new Linear regulators

that are a study in efficiency. Our µA78H05ASC

5-amp positive voltage regulator: And our

µA78P05SC 10-amp positive voltage regulator:

They're designed to provide extremely low

dropout voltage-typically 2 volts at 5 amps

on the µA78H05ASC and 2.2 volts at 10 amps

on the µA78P05SC. And as any student of

regulators knows, dropout like this just isn 't available

with monolithic designs.

STRAIGHT 'W' PERFORMANCE.
Since lower dropout voltage

provides more efficient power

supply designs, these regu-

lators, like all Fairchild voltage

regulators, require fewer

components than traditional

designs. And that reduces

design time considerably.

Features include short-

circuit and safe-area protection,

thermal shutdown and hermeti-

cally sealed T0-3 packages. And all

this at the same price you 'd expect to be paying

for regulators that graduate at the bottom of their class.
In fact, you can start designing in our new regulators for
as little as $5.00 in quantities of l 00 (µA78H05ASC).

IF YOU HAVE QUE5nONS, PLEASE RAISE YOUR HAND.
For more details on our new
enhanced voltage regulators, or l=AI R C H I L..c:J

information on our other Hybrid
products, contact your Fairchild distributor or representative. Or,

CALL US ON 1· le

for immediate results, call your nearest Fairchild sales office.
France: Fcorch1ld Camero & Instrument SA, 121 Ave.d'ltol1e, 750013 - Pons Tel 00331 584 55 66. Telex 0042 200614. ltoly: Foorch1ld Semicondutton S.PA., Vt0 Rosell1no, 12, 20124 Milano. Tel: 02 6887451 Telex 36522. Germany: Foorch1ld Camero & Instrument (Deutschlond)GmbH, 8046 Gorch1ng Hockbruck Do1mlerstr. 15, Munchen.Tel 089 320031 . Telex 52 4831 foord. England : Foorch11d Camero & Instrument (UK) Ltd., 230 High St.. Potter.; Bor. Hertfordshire EN6 58U Tel; 0707 51111. Telex 0051 262835. Sw eden : Foorch11d Semiconductor AB. Svortengsgoton 6, S· 11620 Stockholm. Tel: 8·449255. Telex 17759.

CIRCLE NUMBER 165

EL ECTRO 1c D ESIG 5, March I, 1978

53

Teehnolog~

Simplify conjugate bilateral matching
of complex impedances. A unified approach provides practical L, Pi or T solutions with a low-cost programmable calculator.

Matching complex impedances is an everyday but tedious circuit-design problem, especially in rf work. Now you can save time and reduce errors with five programs for an HP-25 that quickly and easily calculate L, Pi or T-circuit solutions for conjugate bilateral matching of a load to a source. One program solves L circuits, and the Pi and T circuits each need two. A sixth program helps the calculations by providing series-to-parallel or parallel-to-series conversion configurations of the impedances to be matched.
The programs for the three matching circuit configurations-L, T and Pi-handle all impedancematching combinations in a unified way, which isn't possible with most other methods. With the many manual methods you may have used, to reduce the large amount of labor involved, you were often forced to employ widely differing and "ingenious" approaches for each problem. Usually, each approach was limited to a specific configuration. And the simplifying assumptions you used often produced large errors.
Andrzej B. Przedpelski, Vice President of Developmen~. A.R.F. Products Inc.. 2559 75th St.. Boulder, CO 80301.

SOURCE IMPEDANCE
50
I-j l5
':'
F(111 0 -jl3.76 3

MATCHING CIRCUIT
':'
0

LOAD IMPEDANCE j6
2
':'
111
j6.67
20

':'

':'

CD

©

1. The first step in matching impedances is to convert the source and load impedances (a) into the most convenient form for doing the subsequent calculations. Parallel configurations (b) can be converted to series, and vice versa (c), depending upon use of an L, T or Pi.

-jl3.76

I

I

R;

I

4.13

I

I

j Xb JXa

I I I I

j6

I
R; > Ro L

_____ JI

':'

':'

0

-j l5.8
JXo j6.07

JX; j6
R; 2

,------1

JXb

I

I

I

jXa

I

I

I

_____ JI

- jl3.76

jXb
~
I JXa ':' -j 19.24

2. An L·section matching circuit (a) can have two so lu-

tions-a

low

(b)

and

high-pass

form

(c)-when

R; >

R 0

·

54

However, by reorienting the L matcher (d) so that F\, <
R;. you can often obtain two more solutions (e and f).
ELECTRONIC DESIGN 5, March I, 1978

Table 1. Parallel/Series/Parallel/Transformations

Display

Line Code

00

01

24 02

02

15 71

03

13 15

04

15 22

05

24 01

06

15 22

07

15 09

08

15 22

09

14 09

10

23 03

11

74

12

21

13

23 04

14

74

15

24 04

16

24 03

17

15 09

18

15 22

19

14 09

20

15 22

21

23 01

22

74

23

21

24

15 22

25

23 02

26

13 00

Key Entry
RCL 2 (g)x·O GTO 15 (g) 1/x RCL 1 (g) 1/x (g)·P (g) 1/x (f) ..R STO 3 R/S x:y STO 4 R/S RCL 4 RCL 3 (g) ..P (g) 1/x (f) ..R (g) 1/x STO 1 R/S x:y (g) 1/x STO 2 GTOOO

Remarks
R...s.. Xs
RP
Xp

Registers
Ro
R1 Rp R2 Xp R3 As R4 Rs Rs R7

The HP-25 fits the bill because it has just the amount of memory needed. Although the programs aren't the shortest possible, they have been written so that they can be converted easily for use on an algebraic-type calculator. A calculator without the programming feature also can be used; however, some flexibility is lost and errors will increase.
While the HP-25 programs don't provide the optimum matching solution automatically, they allow you to perform rapid "trials" of the three matchingcircuit configurations with all possible solutions of each.
Your choice of configuration is usually dictated by: · Whether you desire a low or a high-pass circuit. · The effect of including stray and coupled-circuit reactances as part of the matching circuit's components. · How much bandwidth the matching circuit should have. Unfortunately, the programs can't work directly with bandwidth: They employ the matching circuit's Q. As a matching network's Q goes up, the circuit's bandwidth goes down. Also, the greater the difference between the real parts of the matched impedances, the less bandwidth the matching circuit will have. But before you start the calculations, you may have to convert the forms of the load and source impedances into series or parallel forms.

Step

Instructions

1 STORE

OR

2 CALCULATE
3 RECALL (TO CHECK)

Input Data/ Units
Ap
Xp 0
0

Keys

STO

1

STO 2

STO 3

STO

4

Output Data/Units

0

STO 1

0

STO 2

As STO 3

Xs STO

4

R/S R/S

RCL

1

RCL 2

RCL 3

RCL 4

Rs or Rp Xs or Xp
Rp Xp Rs Xs

--------,

;, I I

I

R;

I

50

I

-I''~

I
I

I_

I

I

I

I

iXc

I

I

_J

'::"
R1 >Ro

'::"

'::"

0

JXo

Ro

j6.67

20

'::"

jXb

"MINIMUM Q"· 1. 22

JXb

j24.49

-j24.49

j X0 ] 2 3.71

JX c - j 6.6 7 T

Tl";"1-"7"1

LDW PASS

HIGH PASS

jXb
- J1.84

f.~ 5

- j2.16 T

--

--

3. Pi-section matching circuits (a) allow you to choose
circuit Q. Wideband matching is obtained with "minimum-
Q" solutions (b and c); more selective circuits (d and e)
are solved with Q = 10.

ELECTRONIC DESIGN 5, March I, 1978

55

r---------,

IX;

I

I

I I
I I I I
----'I

JXo j6
Ro
2

" MINIMUM 0° · 1.03

©

j l3.76 i Xo
j Xb 14

i Xc
E-o
-j8.06

'::'

JXo

i Xc

~ I -~ -JjX4b

©

LOW PASS

Q· 10

HIGH PASS

JXo

JXc

o--i....___~~

- jl4 .83

- j 26

jXb j ll.94

iXo

JXc

~~

I JXb '::'-] 65.62

~('----i----o
-JS
-J7.1 4 r
~
1 -]13.39 '::'

~tr -j22 j7.14'::'
~~
r j l7.22

~ r-j25 '::'

4. T·section matc hing circuits are equivalent to Pi-sections. but physical considerati o ns, component size. costs and layout may lead you to one type over the other.

5. The load may have no reactive impedance (a) or both source and load may have no reactive im pedance (b). but the programs can handle either case.

The load and source impedances may be physically in either parallel or series form. But to simplify the computations, you will have to calculate series or parallel equivalents, depending upon your choice of matching-circuit configuration (Fig. la):
· For an L or T matching circuit, you work with series forms.
· For a Pi matching circuit, you work with parallel forms.
The transformations require four formulas:

R. = ~---1_ __

(1)

1 + ( ~)2

x.

=

~ _(_~o.)_ _ 2-

(2)

1 + ( ~)2

56

l+ ( i -) 2
(4)
( ~ )2
Subscripts "p" denote parallel resistances and reactances and subscripts "s" denote series.
The program that performs these transformations (Table 1) uses polar coordinates, because polars need fewer steps. Parallel values stored in registers [R 1] and [R2] are transformed to series values and stored in registers [R~J and [R4), or series stored in [R3] and [R4] are transformed to [R1] and [R2]. But before you enter data always remember to clear the two registers not used to enter data.
Note: The program's R/S steps (11, 14 and 22) can be deleted, but then the answers won't be displayed,
ELECTRON IC DESIGN 5, March I, 1978

Table 2. L Section matching

Display

Line Code

00

01

24 02

02

24 01

03

15 09

04 15 22

05 14 09

06 15 22

07 24 03

08

71

09

01

10

41

11

14 02

12 23 00

13

74

14 2403

15

61

16 24 04

17

41

18 2306

19

74

20 24 01

21

15 02

22 24 02

23 ' 15 02

24

51

25 24 00

26 24 01

27

61

28 24 02

29

51

30

71

31

32

32

23 05

33

74

34

24 00

35

32

36

13 12

Key Entry
RCL 2 RCL 1 (g)·P (g) 1/x (f)·R (g) 1/x RCL 3
1 (f)/X STO 0 R/S RCL 3 x RCL 4 STO 6 R/S RCL 1 (g) x' RCL 2 (g) x'
+
RCL 0 RCL 1 x RCL 2
-+
CHS STO 5 R/S RCL 0 CHS GTO 12

Remarks
a
xb
Xa

Registers Ro Q A1 Ai R2 xi R3 Ro R4 Xo
~ Xa
Rs xb R7

Step

Instructions

1 STORE

Input Data/ Units
Ri
Xi
Ao Xo

Keys

STO

1

STO 2

STC 3

STO

4

2 CALCULATE

R/S

L O WP ASS

R/S

CONFIGURATION

R/S

Output Data/Units
a
xb Xa

3 RECALL (TO CHECK LOWPASS)

RCL

1

Ai

RCL 2

Xi

RCL 3

Ao

RCL 4

Xo

RCL

5

Xa

RCL

6

Xb

4 CALCULATE

R/S

-Q

HIGHPASS

R/S

Xb

CONFIGURATION

R/S

Xa

5 RECALL (TO CHECK HIGHPASS)

RCL

1

Ri

RCL 2

Xi

RCL

3

Ro

RCL

4

Xo

RCL

5

Xa

RCL

6

Xb

approach to solving the matching problem (Fig. 2a). The applicable equations for obtaining the impedances of a 111atching L are

(5)
QRi +Xi

and

Xb = QRo

(6)

where Q is defined as

just stored. Delete the store steps (10, 13, 21 and 25), and the answers will be displayed only .
The complex source and load impedances shown in Fig. la will be used throughout to illustrate application of the programs. The parallel source impedance was transformed into serial form (Fig. lb) and the series load impedance into parallel (Fig. le) with the program in Table 1. In solving matching problems, you use the appropriate form depending upon the matching circuit.
Using L matching circuits
If the impedances to be matched happen to be in series form, a simple L matching circuit is a good first
EL ECTRON IC D ESIG N 5, M a rch I, 1978

(7)
And the program for solving these equations is in Table 2.
Note that since Q can be positive or negative, Xa
and Xb can have a low or a high-pass configuration. (Figs. 2b or 2c). Most other methods for matching with an L consider only the low-pass solution. While such an approach always gives a valid answer, your application might be better served with a high-pass matching circuit.
Furthermore, note in Fig. 2a that Xa is attached to the port facing the external network with the highest
resistance, since Ri > R0· Again, while other methods
57

Table 3. Pi Section matching (Lowest Q)

Display

Line COcle

00

01

24 04

02

32

03

23 07

04

74

05

24 01

06

24 03

07

71

08

01

09

41

10

14 02

11

23 00

12

74

13

24 03

14

61

15

23 06

16

74

17

24 00

18

24 01

19

15 22

20

61

21

24 02

22

15 22

23

51

24

15 22

25

32

26

23 05

27

74

28

24 00

29

32

30

13 11

Key Entry
RCL 4 CHS STO 7 R/S RCL1 RCL 3
1
(f){X
STO 0 R/S RCL 3 x STO 6 R/S RCL 0 RCL 1 (g) 1/x x RCL 2 (g) 1/x
+
(g) 1/x CHS STO 5 R/S RCL 0 CHS GTO 11

Remark· Xe Q
Xb
Xa

Registers Ro 0 R1 Ri R2 Xi R3 Ro R4 Xo R__s_ Xa
R5 xb
R1 Xe

Step

ln1tructlon1

1 STORE

Input Data/ Units
Ri Xi
Ro Xo

Keys

STO

1

STO

2

STO 3

STO 4

2 CALCULATE

R/S

LOWPASS

R/S

CONFIGURATION

R/S

R/S

3 RECALL (TO CHECK LOWPASS)

RCL

0

RCL

1

RCL

2

RCL

3

RCL 4

RCL

5

RCL

6

RCL

7

4 CALCULATE

R/S

HIGHPASS

R/S

CONFIGURATION

R/S

5 RECALL (TO CHECK HIGHPASS)

RCL 0

RCL

1

RCL

2

RCL 3

RCL 4

RCL 5

RCL 6

RCL

7

Output Data/Units
Xe 0 xb Xa
0 Ri xi Ro XO Xa xb Xe
-0 xb Xa
-0 Ri Xi Ro Xo Xa Xb Xe___.

usually limit the configuration to this orientation and thus you are assured of valid solutions, you often can get two more solutions by turning the L circuit around.
In Fig. 2d, the input and output circuits are in-
terchanged, so that R0> Ri. Both new solutions, Figs.
2e and 2f, have low-pass configurations. It's wise to explore all possibilities for the most
convenient or economical component selections. If you prefer a low-pass solution, Fig. 2f might be a better compromise of inductor-vs-capacitor sizes than Figs. 2a or 2e. But if you want a high-pass matching circuit, your only choice is Fig. 2c.
However, with the R0> Ri arrangement, you don't
always get a viable solution-the valve of Qcould come out imaginary. For example, if Xi in Fig. 2d is reduced from j6 to j2, the answer is unusable. In such a case, the program will provide automatically an "error" indication in step 11 to show that Q is imaginary.
Matching with a Pi or T circuit
But if you want to be assured of the widest possible bandwidth you must use a Pi or T matching circuit.
58

A Pi or T matching circuit uses one more component than the L, but gives you more flexibility in choosing bandwidth. To get the maximum possible bandwidth, you must use a so-called "minimum-Q" solution, which also provides the lowest insertion loss for components having the same Q value.
For a Pi matcher, the parallel forms of the input and output circuits of Fig. la are used (Fig. 3a) and the applicable equations are

Xe = - Xo,

(8)

Xb R0Qmi01

(9)

xa =

-1
~ + Qmin

(10)

Xi Ri

where the minimum Q is

Qmin=±~

(11)

Ro

The program in Table 3 gives a low-pass and a highpass configuration for the positive and negative values of Qmin· Calculated matching sections for these two cases are shown in Figs. 3b and 3c.

EL ECTRONIC DESIGN 5, March I, 1978

Table 4. T Section matching (Lowest Q)

Display

Line Code

00

01

24 01

02

24 03

03

71

04

01

05

41

06

14 02

07

24 00

08

74

09

24 02

10

32

11

23 05

12

74

13

24 01

14

24 00

15

71

16

23 06

17

74

18

24 03

19

24 00

20

61

21

24 04

22

51

23

32

24

23 07

25

74

26

24 00

27

32

28

13 07

Key Entry
RC L 1 RCL 3
1
-
(tJ rx
STO 0 R/ S RCL 2 CHS STO 5 R/ S RCL 1 RCL 0
STO 6 R/ S RCL 3 RCL 0
x
RCL 4
+
CHS STO 7 R/ S RCL 0 CHS GTO 07

Remarks
Q Xa
xb
Xe

Registers Ro Q R1 Ri R2 Xi R3 Ro R4 Xo R~ Xa
R5 xb
R7 Xe

-11 r~,,

3

j ll.94

0

Step

Instructions

1 STORE

Input Data/ Units
Ri Xj
Ro Xo

Keys

STO

1

STO 2

STO 3

STO

4

2 CALCULATE

R/S

LOWPASS

R/S

CONFIGURATION

R/ S

R/ S

3 RECALL (TO CHECK LOWPASS)

RCL

0

RC L

1

RCL

2

RCL

3

RCL

4

RCL

5

RCL

6

RC L

7

4 CALCULATE HIGHPASS CONFIGURATION

R/ S R/ S R/ S R/ S

5 RECALL (TO CHECK HI GHPASS)

RCL

0

RCL

1

RCL

2

RCL

3

RCL

4

RCL

5

RCL

6

RCL

7

Output Data/Units
Q Xa
xb
Xe
Q Ri Xi Ro Xo Xa
xb
Xe
-Q Xa
xb
Xe
-Q Ri Xi Ro Xo Xa
xb
Xe . -

':"

'"'} l"'~

I~ G -JW

'·

i'

'VV'V'
J20

I~ 0 -JW ' ·

6. To check a solution such as the T section in Fig 4d, you add the source side's series configuration to the left series impedance of the T (a). Then the left-side capacitor and resistor, converted to a paral lel form, are combined (b). Finally, reconverting the left side t o series shows that the reactances ca ncel and real parts are equal (c).
ELECTRONIC D ESIGN 5, March I, 1978

Note the following precautions for the program:
· If you have no Xi or X 0 value, store the number 1099 (infinity) in its place.
· Orient the Pi so that Ri is always larger than

Ro. Also note that reactance Xe is the same in both low and high-pass solutions.
Similarly, a T matching circuit with characteristics like the Pi can be used for wideband work. Now, t he series form of the input and output circuits is used (Fig. 4a), and the applicable equations are

- xi,

(12)

- -R-i ,

(13)

Qmin

Xe - (Xo + Ro~in),

(14)

where Qmin is defined as in Eq. 11 for Pi matchers,
and also, only where Ri > R0· Table 4 contains t he
program for solving these equations. Figs. 4b and 4c

show the solutions.

59

Table 5. Pi Section matching (Higher selectivity)

Display

Line Code

()()

01 24 00

02 24 01

03

71

04 2402

05 15 22

06

51

07 15 22

08

32

09 23 05

10

74

11 24 00

12 15 02

13

01

14

51

15 23 06

16 24 03

17

61

18 24 01

19

71

20

01

21

41

22 14 02

23 23 07

24 24 00

25

51

26 24 01

27

61

28 24 06

29

71

30 23 06

31

74

32 24 07

33 24 03

34

71

35 24 04

36 15 22

37

51

38

15 22

39

32

40 23 07

41

74

42 24 00

43

32

44

23 00

45 13 02

Key Entry
RCL 0 RCL 1
-;-
RCL 2 (Q) 1/x
+
(g) 1/x CHS STO 5 R/S RCL 0 (g) x· 1
+
STO 6 RCL 3 x RCL 1
1 -
(t)IX
STO 7 RCL 0 + RCL1 x RCL 6
STO 6 R/S RCL 7 RCL3
RCL4 (g) 1/x
+
(g) 1/x CHS STO 7 R/S RCL 0 CHS STO 0 GTO 02

Remarks
Xa
Xb Xe

Registers
Ro 0
R1 Ri R2 Xi R3 Ro A4 Xo R5 Xa R5 xb R1 Xe

Step Instructions
1 STORE

Input Data/ Units
0 Rj
Xi Ro Xo

Keys
STO 0 STO 1 STO 2 STO 3 STO 4

Output Data/Units

2 CALCULATE

R/S

Xa

LOWPASS

R/S

Xb

CONFIGURATION

R/S

Xe

3 RECALL (TO CHECK LOWPASS)

RCL 0

Q

RCL 1

Ri

RCL 2

xi

RCL 3

Ro

RCL 4

Xo

RC L 5

Xa

RCL 6

xb

RCL 7

Xe

4 CALCULATE

R/ S

Xa

HIGHPASS

R/S

xb

CONFIGURATION

R/S

Xe

5 RECALL (TO CHECK HIGHPASS)

RCL 0

-Q

RCL 1

Ri

RCL 2

Xi

RCL 3

Ro

RCL 4

Xo

RCL 5

Xa

RCL 6

xb

RCL 7

Xe

desired selectivity higher than that obtained in the "minimum-Q" calculations. The L matcher's Q, how-

ever, is fixed by the input and output impedances. For a Pi refer back to Fig. 3a and apply the following
equations:

xa =

1

(15)

However, additional solutions are possible with Pi and T matching circuits with larger Qs. Where an L matcher has at most four solutions, both Pi and T matchers can have almost unlimited numbers, depending on your choice of Q.
You can design Pi and T circuits for almost any
60

xc =

(16) l+ Q2 1
(17)
ELECTRONIC DESIGN 5, March I, 1978

Table 6. T Section matching (Higher selectivity)

Display

Line Code

()()

01

24 ()()

02

24 03

03

61

04 24 04

05

51

06

32

07 23 07

08

74

09

24 ()()

10 15 02

11

01

12

51

13 24 03

14

61

15 23 06

16 24 01

17

71

18

01

19

41

20 14 02

21

24 01

22

61

23

32

24 24 02

25

41

26 23 05

27

74

28 24 06

29 24 06

30 24 01

31

71

32

01

33

41

34

14 02

35 24 ()()

36

51

37

71

38

23 06

39

74

40 24 00

41

32

42 23 00

43

13 02

Key Entry
RCL 0 RCL 3 x RCL 4 -+ CH S STO 7 R/S RCL 0 (g) x2 1 -+ RCL 3
x
STO 6 RCL 1
1 -
(f)fx
RCL 1 x CHS RC L2 STO 5 R/S RCL 6 RCL 6 RCL 1
1 (f)/X
RCL 0
+
STO 6 R/ S RCL 0 CHS STO 0 GTO 02

Remarks
Xe
Xa Xb

Registers
Ro a
R1 Ai R2 xi R3 Ro R4 Xo R5 Xa R5 xb R7 Xe

Step Instructions
1 STORE
~

Input Data/ Units
a
Ri xi Ro XO

Keys
STO _Q_
_s_IQ_ __1_
STO 2 STO 3 STO 4

2 CALCULATE

R/S

LOWPASS

R/S

CONFIGURATION

R/ S

3 RECALL (TO CHECK LOWPASS)

RCL 0 RCL 1 RCL 2 RCL 3 RCL 4 RCL 5 RCL 6 RCL 7

Output Date/Units
Xe Xa xb
a
Ai xi Ro Xo Xa xb Xe

4 CALCULATE

R/S

Xe

HIGHPASS

R/S

Xa

CONFIGURATION

R/S

Xb

5 RECALL (TO CHECK HIGHPASS)

RCL 0 RCL 1 RCL 2 RCL 3 RCL 4 RCL 5 RCL 6 RCL 7

-Q
Ai xi Ro Xo Xa xb Xe_

Q=-~

(18)

X;

An "error" indication in step 7 of Table 5 signifies this condition. Actually, Eq. 18 is a legitimate value

for Q. Such a Q makes Xa equal to infinity (an open

circuit), which reduces the Pi to an L configuration.
If, for example, you choose Q = 10, which is larger
than the "minimum Q" of 1.22 obtained in Figs. 3b
and 3c, you get the solutions in Figs. 3d and 3e.

Similarly, for a T configuration, refer again to Fig. 4a where now, the following equations apply:

x., = ( - x., + RoQ)

(19)

But now Qcan be almost any value higher than the

Xa

"minimum Q" obtained from Eq. 11 (or in step 11 of

Table 3). The program to solve Eqs. 15, 16 and 17 is

in Table 5. If you try to use a value of Q lower than

the "minimum Q," the program provides an "error"

indication in step 22. Above the minimum Q, only one

value of Q is impossible:

Ro (l+Q2)-l -~ (20)
R;
(21)

ELECTRONIC DESIGN 5, March I, 1978

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62

And the program for their solution is in Table 6. As in the case of a Pi, the value of Q can be any
value higher than that obtained in program-step 7 of Table 4 for a "minimum-Q" T.
If you again choose Q = 10, as was done for the Pi, which is larger than the "minimum Q" of 1.03 obtained for the solutions in Figs. 4b and 4c, you get the solutions in Figs. 4d and 4e.
For values of Q smaller than the "minimum Q," the program provides an "error" indication in step 20. Note that for Q = X0 /R0 , Xe becomes zero, and the T configuration becomes a simple L, as was the case with the Pi configuration under the conditions of Eq. 18.
Handling special cases
All sources and loads, however, don't necessarily contain reactive components. When either the input or output impedances, or both, have no capacitance or inductance, the number of possible matching solutions is reduced. Fig. 5a is an example of no reactive component in the output circuit and the four L solutions you can get for it. But if you attempt to obtain Pi and T "minimum-Q" solutions for the matching circuits, they will come out identical to the four L solutions.
For larger Qs (higher selectivity), the number of Pi and T solutions is virtually unlimited. But with no reactances in both the source and load, only two L solutions are obtained (Fig. 5b).
Verify with parallel/series transformations
Finally, you can easily verify that your matching circuit has no errors. You merely use the series/parallel transformations several times and add the resultant reactances. The input and output resistances should become equal, and all reactances should cancel.
As an example, insert Fig. 4d into Fig. 4a and add the series reactances. You get Fig. 6a. Convert either side, say, the left side, to a parallel configuration and combine the two parallel reactances to get Fig. 6b. Now convert the left-side parallel configuration of Fig. 6b to series and you get Fig. 6c, which shows that you have satisfied the conjugate bilateral matching requirements-the reactances cancel and resistances match ...
Bibliography
Charest, C. N., "Impedance Matching Can Be Easy," EDN, Jan. 1, 1969, pp. 48-51.
Henning, H. B., "Impedance Matching by Graphical Techniques," Microwave Journal, June, 1977, pp. 112-114.
Johnson, R., "Do Complex Impedance Matching in Seven Easy Steps," EDN, March 20, 1974, pp. 73-75.
Nardin, R., "Impedance Matching Made Easy: a 3-Step Uncomplicated Method," Electronic Design, Aug. 16, 1975, pp. 76-78.
Acknowledgement
The author wishes to thank Mr. James R. Jackson for stimulating and constructive discussions on the above subject.
ELECTRONIC DESIGN 5, March I, 1978

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© 1977 Texas Instruments

TEXAS INSTRUMENTS
INCORPORATED

Eu,crnoN 1c DESIGN 5, March I, 1978

63

Teehnolog~

Predict noise in digital systems
caused by transmission-line reflections. All you need is a programmable calculator to solve the lattice diagram.

Reflections on transmission lines are a major source of noise in digital systems, but you can predict them easily with a lattice diagram. To determine the reflective voltages for the diagram, you have to perform numerous calculations. But with a programmable calculator like the SR52 that's easy too.
Fig. la which shows a digital transmission system contains a step generator of voltage E with an output impedance, Zs , an interconnecting transmission line of characteristic impedance Z0 , and a line termination, ZL. Fig. lb shows the lattice diagram for the circuit of Fig. la, and the equations that must be solved to determine the voltage at every step.
A. R. Campbell, Senior Member, Engineering Staff, RCA Government and Commercial Systems, Moorestown, NJ 08057

The lattice diagram graphically represents the sig-

nal being reflected back and forth between signal

generator and load (see box). The voltages traveling

left to right are identified as Vs (send-side), and right

to left as VR (receive-side). The incident and reflected

voltages at points A and B combine to form successive-

ly smaller steps (Fig. le).

Fig. 2 shows the flow chart for a program to

calculate these voltages. Execute the program on an

SR52 calculator with the following steps:

1. Clear all registers and flags by pressing user-

defined key "E."

2. Enter circuit parameters (Z 0 , Z8 , ZR, E) into registers R00 through R03 as follows:
Register Content

Roo

Zo

Roi

Zs

lo · 93,n.

V5(t)

= ~ = 0.788V
l5 + l0

V5(t) =~ [! +PR + PRPs J l 5 + l0 = 0.9 1V

t =0 t =2T

V5(t)

- ~ (l + p, + P, P,
l5 + l0
+ P, P, 2 + P5 2P.' ) = 0.884V

~ V,(t) =

[l + PR + PsP· + PsP.'

l5 + l0 + P/ Pa +

P /P ~

+

p ~p~ J = o.aa9v

V5 AT POINT A

t = 4T t = 6T

Ps = Zs - zo
l5 + l0
= - .576

IV - - - - - - - - - - - - - - - - - - -

.9 1 .788

. 884

.889

PR = lR - lo

=

l,
+

+ l0
.365

t= T

VR(t) =~ ( 1 + pR )=l.075V
l, + l0

t = 3T

VR(t) = ~ ( 1 + PR + PsPR

+

l5 + l0
P, Pa

1 =

o .a49V

t = ST

~ VR(t) =

(1 +P R + Ps PR

l5 + l0
+ P, Pa + P/ Pa +

P/P~ I = o.B97v

VR AT POINT 8
IV 1. 0 7 5

.849

.897

2T

4T

ST

1. A step voltage from generator E travels down a transmission line until it hits a load (a) . If both the generator and the load are not properly matched , a diminishing part of

64

T

3T

5T

7T

the wave is reflected back and forth , as represented by the lattice diagram (b). At points A and B the waves add up to form the total voltage (c).

ELECTRONIC DESIGN 5, March I, 1978

NO

YES

E Z0 (1+p1 l Zs +Zo
· ___l_
I+ Ps
SUM Ro7
RCL R07
HLT

NO
Ro6 · PR
SUM R 07

HLT

Ps· -Z-s --Z-oRo.. Zs +Zo

P R

-
-

ZR -zo_
ZR +z o R05

HLT

NO
SET FLAG 3
E Zo(l+f'Bl Zs +Zo
SUM R11
HLT

YES
RIO · f. pR
SUM R II RCL R11 HLT

RESET REGISTERS
RESET FLAGS
H LT

2. The flow chart for calculating a lattice diagram consists of four segments. The user-defined keys determine which
ELECTRONI C DESIGN 5, March I, 1978

will be executed: clear flags (E) calculate common factors (D), calculate send (A) and receive (8) voltages.
65

LOCATIONS

CODES

000 002 8146 15

003 004 47 86

005 007 4614 53

008 010 430001

011 014 75430000

015 018 54555343

019 022 00018543

023 026 00005495

027 029 420004

030 033 53430002

034 037 75430000

038 041 54 55 53 43

042 045 00028543

046 049 000054 95

050 052 420005

053 056 43 00 00 65

057 060 43000365

061 064 53018543

065 068 0004 54 55

069 072 5343 00 00

073 075 85 43 00

076 078 015495

079 081 420006

082 085 43000665

086 089 53018543

090 093 . 000554 95

094 097 55530185

098 IOI 4300 04 54

102 105 95420100

106 109 43 0004 65

110 113 43000595

114 117 42000981

118 121 46116001

122 125 01 040350

126 129 01430006

130 133 55530185

134 136 430004

137 139 549544

140 142 0007 81

143 146 60020106

147 150 08 5002 43

151 154 00066543

155 158 00059542

159 162 00084400

163 167 07 43 00 07 81

168 171 43000865

172 175 43000995

176 179 42000844

180 182 0007 43

183 185 00 07 81

186 189 461261)03

190 193 02000250

194 197 03430100

198 201 44010181

202 205 43000965

206 209 43 010095

210 213 42010044

214 216 010143

217 219 010181

KEYS HLT *LBL E *CMs *rset

COMMENTS ~ RESET REGs.
RESET FLAGs.

*LBL D ( RCL 0 1 -RCLOO
l -:- ( RCL 0 1 + RCL 0 0) =

CALCULATE

> Zs- Zo

Ps=zz-+ s+ 0

R04

STO 0 4 ( RCL 02 -RCLOO h--( RCL 0 2 - RCL 0 0) = STO 0 5 RCL 0 0 x RCL 0 3 x ( 1 + RCL 04)-:( RCL 0 0 + RCL 0
I) =
STO 0 6 RCL 0 6 X ( I + RCL 0 5) =
-=-- ( 1 + RCL 0 4)

CALCULATE

>

ZR-Zo

PR=---+ Ros

ZR+Zo

CALCULATE

:> Zo (1 + Ps)

E

z s

+

z
0

-+ R06

CALCULATE
>EZo (I+ PR) R
Zs + lo -+ 10

= STO I 0

RCL 0 4 x RCL 0 5 = STO 0 9 HLT

>CALCULATE PR x Ps-+Rog

*LBL A *if fig I

I 4 3 *st fig

CALCULATE

I RCL 0 6 -:-- ( 1 +

zs+zo Zo(l+p5)
i> E

RCL 0 4 ) = SUM

I x I + P s -+ SUM Ro7

0 7 HLT

*ifflg 2 I 6

8 *st fig 2 RCL

0 6 x RCL 0 5 = STO

>CALCULATE Ros x PR-+ SUM Ro7

0 8 SUM 0

7 RCL 0 7 HLT

RCL 0 8 x

RCL 0 9 =

CALCULATE

STO 0 8 SUM 0 1 RCL

Ros x Ps PR2-+ SUM Ro7

0 7 HLT

*LBL B *if fig 3 CALCULATE

2 0 2 *st fig 3 RCL 1 0

>EZo (l + p R)-+ SUM R

Zs+ Zo

11

SUM 1 1 HLT

RCL 0 9 x

RCL 1 0 = STO 1 0 SUM 1 1 RCL

CALCULATE
>R10 x PsPR-+ SUM R11

1 1 HLT

*denotes the second key function

66

3. The SR52-program requires 219 entries.
Transmission line reflections
Signal reflections on transmission lines occur whenever a wave encounters an impedance different from that of the original line. Such a discontinuity can stem from a change in the transmission line. In the general case, an incident voltage (V 1) and incident current (11) wave travel along a trans-mission line with impedance Z1. When they en-counter a discontinuity of impedance Z2, a reflected voltage VR originates at the discontinuity and travels back toward the generator. The inci-
dent voltage on line B is, therefore, V1 + VR·
Reflected voltage VR = p V.V 1, where the voltage reflection coefficient is defined as

At the generator interface, Z1=Zc, and Z2=Zo, where Z0 is the characteristic impedance of the transmission line. The voltage that starts down the line is the result of a voltage division between the source impedance and the line impedance. The voltage proceeds down the line to the load, where it is reflected back toward the generator, then back to the load, and so on. The actual voltage at any time is the algebraic sum of all the individual reflected voltages up to that time.

LINE A WAVE-

DISCONTINUITY
I I

LINE B

1 Z1

I

Z2

l

Ro2

ZR

Roa

E

3. Press user-defined key "D" to execute the flow

chart segment D.

4. Press user-defined key "A" for the first Vs (t=O

to t=2T). Press "A" again for the second voltage

Vs (t=2T to t=4T) and so on, until all desired send--

voltages are calculated.

5. Press user-defined key "B" for the first VR(t=T

to t=3T), then repeat for the second VR(t=3T to t=5T)

and so on.

Programming your SR52 calculator requires 220

keystrokes. They are listed in Fig. 3, in groups of two

to four instructions...

ELECTRONIC DESIGN S, March I, 1978

TARE AELOSE LOOH
AT THESE BURROUliHS PLASmA DISPLAV BREAHTHROUliHS.

Easier to read

Greater brightness

Improved contrast

Larger matrix dot

The new Burroughs SELF-SCAN®II single register gas plasma panels are breakthroughs in visibility and readability, making them ideal for all types of applications- from audience information displays to instrumentation applications. They are digitally addressed to interface

easily with microprocessors and computers. Only 15 connections are required. These new units complement Burroughs' standard line of single register 16 and 32 character plasma displays.
The Burroughs SELF-SCAN 111 x 20 and 1 x 40 displays. Certainly worth looking into.
Burroughs ECO International, 11-15 · Betterton Street, Drury Lane, London, England. Telephone (01) 240-1479.

New 1 x 20 panel can be stacked and butted together to give a contiguous large audience information display of any number of characters.
New 1 x 40 panel for instrumentation, data terminals, computers and hundreds of other applications.

Yau EDD IH thl! dlffl!rl!Dl:I!
Burroughs

SELF- SCAN is a registered trademark of Burroughs Corporation.
CIRCLE NUMBER 163 FOR GENERAL INFORMATION CIRCLE NUMBER 170 FOR DETAILED SPECIFICATIONS

Ideas for design

Reduce sampling errors by adding an RC network to your sample-and-hold

Include an RC network in a high-speed sample-andhold circuit, and you can restore an otherwise lost charge to the holding capacitor.
Sampling errors are caused when the drain-to-gate capacitance of a sample-and-hold's switching FET draws off charge from the holding capacitor. In Fig. 1, R3 and Cc form a network for controlling the amount of charge injected into holding capacitor CH. Of course, small values of CH are required to allow a full charge to accumulate during the sampling period.
But small holding capacitors are affected by the FET's drain-to-gate capacitance, Cnc· The value of Cc is selected to be larger than the FET's expected C0 c;. When the FET's gate voltage switches from high to low, c;s voltage goes from low to high, which provides a charge pulse equal and opposite to that of the FET's ·capacitance.
To understand the RC network's effect, examine a sampling-circuit model without the network (Fig. 2) and see what happens. The step voltage on the FET's gate causes Cnc to take a charge, which comes from holding capacitor CH. Assume that CH is charged to 1 V and C0 c of the dual MOSFET is 2 pF. Then the

5V
I_
OV

I I
~Cos
I
J...coo
--- -"·"I"

2. Drain-to-gate capacitance of a sample·and·hold's switching FET causes charge to be drawn off holding capacitor CH. If charge isn't restored, the result is sampling errors.

charge on Cnc is:

Q = CDG (Ci.V),
where ei.V = 15 - 1, or 14 V.
Therefore:
Q = 2 x 10- 12 (14) = 28 x 10- 12 coulombs.
The effect on CH is:

V =

ei.Q CH

= 28 x 10-12
1 X lQ-9 = 28 mV.

FET

V IN
R2

1- - - - - - - -
5V 0--JV>h--+-I --l~

-,
I I
I
_J

>----<---o VOUT

Cc
12pF 5V

R3 USED TO ADJUST

.----------<R3

AV OF Cc

1. Lost charge can be restored to holding capacitor CH by adding the R3, Cc compensation network to
68

a fast sample-and-hold circuit. The network controls the amount of charge injected into CH.
ELECTRONIC DESIGN 5, March I, 1978

How to tell aSUper·VOM from just the everyday garden-variety Brand X.
ONLY THE SUPER·VOM (Triplett's New 60) HAS ALL THESE FEATURES:

$102

Nobody else offers these features in a VOM at any price. So for only$102 , the Model 60 is

the safest, most versatile, most honestly priced quality VOM you can buy. And, for just $8

more, you can have the Model 60-A that has 1Y2 % DC accuracy, plus a mirrored scale.

That's the kind of Triplett one-upmanship appreciated the world over by value con-

scious users in industrial production and maintenance. TV - Radio - Hi-Fi shops, vocational

training and hobbyists, airconditioning, appliance and automotive $ervice, R & D, and application engineering . .. anyone who wants to be more productive with the latest in VOM technology. Model 60 Type 2 Approved by MESA, Approval 2G-2880.

-

Drop in on your nearest Triplett distributor or Mod Center and drop the new Model 60.

Ask for a no-obligation demonstration of every feature. Compare it with any other VOM.

You'll know why Triplett Models 60 and 60-A eliminate over 90% of the costly repairs from

VOM misuses. Cultivate a profitable habit for selecting Triplett design-firsts.

TRIPLETT
BLUFFTON, OHIO 45817
Circle # 29 For Information Circle # 30 for FREE Demonstration

Triplett. The easy readers

Ideas for design
Without an RC network, the uncompensated voltage appears as in Fig. 3a, where the step error is /':,.V. In fact, the step error can even exceed the total sag, dv/dt; of the hold circuit. You can get a smaller error by reducing the FET's gate voltage, but the resulting increase in on-resistance causes other problems. Choosing Ccas 12 pF (Fig. 1) with a CnGof 2 pF limits the step error as shown in Fig. 3b. Fig. 3c and 3d show output error for other values of Cc.
Unfortunately, FET capacitance varies with drainto-gate voltage, so the injected charge can be completely canceled only at one potential. If you know what voltage range to expect on CH? you can compensate for errors by adjusting R3.
Bob Marshall, Jr., A pplications Engineer, Signetics Corp., 811 E. A rques A ve., Sunnyvale, CA 94086.
CIRCLE No. 311

SAG

I

dv/dt · ....!...

CH

FET GATE lt'OLTAGE OUTPUT VOLTAGE UNCOMPENSATED
OUTPUT VOLTAGE

©

OUTPUT VOLTAGE
llQDG < llOcc
OUTPUT VOLTAGE
dQDG > 110 cc

3 . A sample·and·hold's uncompensated out· put (a) shows an error, t::.V, caused by loss of charge on the holding capacitor. Adding an RC network to the circuit reduces the error (b), but the capacitor's value must be greater than CoG · or the error (c) and (d), won't be minimized.

A simple level shifter lets an IC modulator accept a unipolar input signal

With a single transistor and resistor acting as a controlled current source (see figure), you can shift the operating point of an IC modulator to accept a positive-going modulating signal. The IC, a CA3080E transconductance amplifier (RCA), has its &n input (pin 5) internally clamped near the negative-supply potential. A signal applied through Qi and R3 to pin 5 produces a modulated envelope at the output. Its amplitude is directly proportional to current flowing into the gm input, and the value of R3 determines that current. Since the collector and emitter currents of Qi are equal, current into gm is simply Em/R3.
When Em is at any value below the base-emitter breakdown voltage of Qi, no current is delivered to pin 5, and the output is zero. In a typical modulation application, however, a positive-going modulating signal must produce an output whose carrier amplitude is near zero only when the modulating voltage is zero. So to eliminate this small offset, you can bias Qi's base slightly negative, instead of grounding it as in the figure.
For Q1, choose a general purpose pnp type having a low Icbo· The carrier should be about 1-V pk-pk at the amplifier input. And the network formed by C1, R1 and R2 is designed to interface with CMOS for
70

coupling a high-level signal to the amplifier input. Dale Hileman, Engineering Services Manager,
Sphygmetrics, Inc. , Woodland Hills, CA 90290. CIRCLE No. 312
. .Cl ,____] 0.1µ.F
CARRIER
MODULATING SIGNAL Em
Adding current source Qi, R3 to this modulator allows the circuit to generate a modulated output proportional to a unipolar modulating signal.
E LECTRONIC D ESIGN 5, March I, 1978

<714) 835·2751. <L A.J (213) 933·7256 · Sunnyvale. CA (408) 733-2424 · G11thersbur1. MO (301) 840·9490 ·Houston. (713> 932·1130 · lrvina. TX (214) 296-4444
DATEL !UK> LTD-TEL. ANDOVER (0264) 51055 · OATEL SYSTEMS SARL 620·06·74 · DATELEK SYSTEMS GmbH (089) 77 60 95

·

CIRCLE NUMBIR 31

Ideas for design

Inexpensive circuit monitors voltage conditions in battery-operated equipment

For about a buck, you can build a circuit that lights a warning LED when battery voltage in portable equipment falls outside of design limits. Not only does the circuit (Fig. 1) eliminate expensive and bulky meters; it uses only one IC, an LM2905/3905 precision timer from National (about $0.60 apiece for a 3905) and three stable 1/4-W resistors, in addition to the LED.
A 3905, which operates over the range of 4.5 to 40 V, contains a floating transistor (pins 6 and 7), which can pull a load to ground or supply referenced loads of up to 40 V and 50 mA. Also built-in is a 3.15-V regulator with a 2-V divider, which establishes a trip point between reference and ground. The relationship between the LED activating voltage and external resistors is found from the following equation:

Ra 15k 5

6 LED

-----13 IC LM3905 2

4

8

Re 2.2k

-v

1. This Inexpensive circuit detects low voltage conditions in battery-operated equ ipment, and eliminates the need for expensive and bulky meters.

= 2,

where V is the activating voltage. Assume that the battery in Fig. 1 is a 9-V transistor
type whose voltage must fall to 5 V to light the LED.
You can choose a value for either R,. or R.i. and solve
for the unselected resistor using the equation. Resistor Re is a LED current limiter. Simply by changing the external wiring of the 3905, you can use the same circuit to detect an overvoltage condition (Fig. 2). Note that pin 8 of the IC, grounded in Fig. 1, is tied to pins 1 and 2 in the overvoltage circuit.
Michael Bozoian, Consultant, Consulting Service in Electronics, 702 Fifth St., Ann Arbor, MI 48103.
CIRCLE NO. 313

5

6

I

----1 3 IC

2

LM3905 8

4

7

Re LED 2.2k

2. If you rewire pin 8 of the IC, the circu it of Fig. 1 is able to detect an overvoltage condition .

IFD Winner of October 25, 1977
Tom Gross, T. A. 0. Gross &Associates, Lincoln, MA 01773. His idea "Flyback-Inverter Efficiency Increases when the Transformer Is Loaded Properly" has been voted the Most Valuable of Issue Award.
Vote for the Best Idea in this issue by circling the number of your selection on the Reader Service Card at the back of this issue.

SEND US YOUR IDEAS FOR DESIGN. You may win a grand total of $1050 (cash)! Here's how. Submit your IFD describing a new and important circuit or design technique. the clever use of a new component or test equipment, packaging tips. cost-saving ideas to our Ideas for Design editor. Ideas can only be considered for publication if they are submitted exclusively to ELECTRONIC DESIGN. You will receive $20 for each published idea . $30 more if it is voted best of issue by our readers. The best-of-issue winners become eligible for the Idea of the Year award of $1000.

ELECTRONIC DESIGN cannot assume responsibility for circuits shown nor represent freedom from patent infringement.

72

ELECTRONIC DESIGN 5, March I, 1978

Portable Weather Station

Geophysical Monitor Event-triggered recording to save tape , batteries and for fast computer data-spotting

Oceanographer's Probe
\Jo outside power needed, runs on internal batteries

Log your Analog Data on Digital Tape Cassettes ...

Traffic or Noise Level Logger
Accepts analog or digital (event counter) inputs

Biomedical Data Recorder
Optional 5 mV
differential amplifier for low level detectors.

Pollution and Environmental
Logger
Crystal CMOS clock can command different
scan periods

DATEL'S Dl:2 DATA LOGGER

An Important New Tool -· Choose Datel's
DL -2 Cassette Data Logger for .Jnattended standby rec ording of multi -channel , slowly -varying analog samples. The DL -2 samples up to 64 high level or low level analog channels , digitizes them to 12-bit binary coding and records them on a cassette at 5 samples per second. Also recorded are a one year calendar clock with one second resolution produced by an internal CMOS crystal oscillator. And external digital samples (up to 36 bits) may be recorded at any time. Analog scans are started automatically from a preset front panel scan timer with intervals from one second up to 30 hours.
The all -CMOS electronics of the DL-2 and stepper motor transport consume only one watt while recording and mi crowatts while powered -down between scans. A set of batteries in the front cover will power the DL -2 for a year or longer, recording up to 120,000 samples.

Or external +12VDC or AC power may be used. The DL-2 features a high-quality instrumentation amplifier (down to ±5mV full scale input) and weatherproof housing and connectors suitable for -1 0°C to +60°C environments . (-40° C optional) A companion DL-2R Cassette Reader offers a convenient playback front end to a minicomputer, microprocessor, TTY , CRT terminal or modem telephone coupler.
1020 Turn pike Street, Canton, MA 02021 T EL (617) 828-8000 TWX: 710-348-0135

Santa Ana 17 14 ) 835·2751 (l A I (213) 933 7256 · Sunnyvale CA (408) 733-2424 · Gaithersburg . MD (30 1) 840-9490 ·Houston. (7 13) 932· 1130 ·Irving . TX (214) 256·4 44 4 OVER SEAS DATEL ! UK ) LTD - TEL ANDOVE R (0264) 51055 · DATEL SYSTEMS SARL 620·06·74 · DATELEK SYSTEMSGmbH (089) 77·60·95
CIRCLE NUMBER 32

International teehnolog~

Multiplexer does big job

with simple components

A new multiplexer with a pulse repetition rate of 5 Gbit/s is made of simple components-yet it can be used in high-capacity fiber-optic communications systems in place of complex optical multiplexing techniques currently being developed.
In the multiplexer, developed at the Chalmers University of Technology in Goteborg, Sweden, an oscillator drives a step-recovery diode to produce a lowduty-cycle pulse train. The pulse train is then passed through a power divider and split into a number of microstrip lines, each of which can be individually switched on and off by p-i-n diodes. The switched outputs are passed through microstrip delay lines, then combined by an OR gate (a passive circuit that is the inverse of the power divider).
The delay lines are adjusted so that the delay for the nth channel is tn (n -1) t;n where tPis the period of the input-pulse train. The output is a train of evenly spaced pulses with a pulserepetition frequency equal to n times the input PRF.
Multiplexers have been constructed

AMPL
showing a 5-Gbit/s output PRF and signal-to-distortion ratio of 12 dB. But the Chalmers developers believe that 10-Gbit/s can be achieved and the signal-to-distortion ratio improved using attenuators ahead of the p-i-n diodes.

Backward laser radiation is detectable and usable

The backwards-emitted light of a semiconductor is useful as a signal for the AGC circuitry that stabilizes a laser's output power. But commercial laser diodes are usually packaged so that the backwards-emitted laser light can't be detected by an axially positioned fiber. Now a simple technique, developed by R. Bosch GmbH Geschafts bereich Fernsehanlagen in Darmstadt, W. German, allows the backward laser radiation to be picked up and fed to the AGC system.
A 45° face is formed at the end of a fiber, which is positioned with its axis perpendicular to the laser light, and its sloping end facing away from the laser.

A 10% coupling efficiency, adequate for AGC applications, can be achieved by cutting a plastic fiber with a blade. The coupling efficiency of silica fibers

74

has not yet been measured. But careful polishing of the end faces may achieve coupling efficiencies of 70 to 90%.
Fiber-optic microphone has wide dynamic range
Optical fibers have been used almost exclusively for data-communications applications. But a fiber-optic microphone with a wide dynamic range has been demonstrated at London's University College.
The microphone is the result of investigations of the interaction between coherent light propagating along a fiber and acoustic waves incident on it. In a fiber, small changes in the refractive index phase-modulate light being sent through it. An acoustic wave striking the fiber causes pressure variations that then modulate its refractive index. Because optical wavelengths are small, appreciable phase shifts can be caused by low levels of acoustic power.
Typically, the pressure sensitivity of a single-mode silica or glass fiber is 6 X 10-5 rad/Nm2 where N is in Newtons. In experiments, a fiber 1 km long, wound to occupy a volume of only 10 cm3, detected a pressure change of 10- 6 Nim with 1 mW optical power at the detector converting phase modulation to audio signals. This is some 26 dB below the weakest sound that can be perceived by the human ear. The linear dynamic range is about 180 dB for a 1-m length of optical fiber.
The microphone's sensitivity is increased by increasing the optical power carried by the fiber. With 1W of optical power, the limit for currently available fibers, acoustic powers below the threshold of hearing can be detected by only 30 m of fiber.
Inverter problem solved
Size and weight problems of the isolating transformer used in high power inverters is said to have been overcome by the use of high-frequency transformers in a technique developed by ERA Ltd. in England.
ELECTRONIC DESIGN 5, March I, 1978

complC!!te,
12-Bit Microcircuit Data Acquisition
System
Datel has it...
· z
~
48
:.'\D·\JEL
Ill SYSTEMS.INC.
DATA ACQUISITION SYSTEM HDAS-18
MAOE IN USA

121110 9
< ~ a :i
MUX ADDRESS OUT

6 8 19 16151413

20

>Im' lo 5

< ~a C3 l! a: a: a: a:

~ a: -'

MUX

I~

a:

ADDRESS IN

rlrllr

41 4442
*8 ~8 -~

431817
~~8
: ·~

~ ~

HDAS-16& HDAS-8
..,,. 16 Channels, Single-Ended (HDAS-16) ..,,. 8 Channels, Differential (HDAS-8) ..,,. 12 Bits Resolution ..,,. 50kHz Throughput Rate ..,,. Internal Instrumentation Amplifier ..,,. Three-State Data Outputs ..,,. Military and Commercial
Temperature Range available ..,,. 62-pin Miniature Package ..,,. Priced at $295.00* (1-9)
·u.SA domestic prices only

Datel's HDAS-the first complete 12-bit data acquisition system in a single, miniature package. Using thin-film hybrid fabrication , it challenges modular data acquisition systems on performance and price. Its excellent performance and reliability are also available in versions for full MIL-Spec operation over - 55to + 125C. The HDAS 62-pin package measures only 2.3 x 1.4 x 0.24 inches (58 x 36 x 6 mm) .
1020 TURNPIKE STREET. CANTON . MASS . 02021 TEL (617) 828-8000 / TWX : 710-348-0135 / TELEX : 924461

San ta Ana (714 )835-2751, ( L.A ) (213) 933-7256 · Sunnyvale. CA (408) 733-2424 · Gaithersburg . MD (301 ) 840-9490 · Houston . (7 13)932-1130 · Irv ing . TX (214) 256-4444 OV ERSEAS : DATEL (UK) LTD - TEL: ANDOVER (0264 ) 51055 · DATE L SYSTEMS SARL 620-06-74 · DATELEK SYSTEMS G rnbH (089) 77-60-95

CIRCLE NUMBER 33

Eu CTIWNIC DES IGN 5, M a rch I, 1978

75

r/IA~~~

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oNrEsPeCeON

~e~:s~in

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HPZAIHLAVDALllEC~~~DCRIATIDI

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RCLE CA 91318

CIRCLE NUMBER 35 76

Test WIt h Confldence

and WAulntod:"atlc Coll Mi'cro-Pro ngT. estStatlon
ce11orControll8 d -Coils

:r~'1~1~RES

·TE1S0T00RATES TO

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PE PARTS

UTOMATIC

CY~~:NGE TE~: PACKAGE HA
GO-/ NOQ-GUIOCK NDlES 90%

R HOUR
~l~~lu:~~D-INGFUTEUSYT

TES~~~OING CABLES~TARNOU~F~A~C~TEUSRSERTSESOTFE~~SULATION TESTERS OPES ... COIL & ... MEGOHMMETER

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TESTERS S

~ SLAUGHT
... HAILEY STS . . COMPANY

e 8 ' 405·223-4n3

ARDMOREITOWKXL1 A9H1O()M.8A

7 3401

CIRCLE NUMBER 36

30-6972

ELECTRONIC D ESIGN 5, March I, 1978

New produets

Schottky power diodes run at high junction temperatures

Schottky diodes, the 75HQ series offers 80% less reverse leakage current than its closest competitor, the MBR75 made by Motorola (Phoenix, AZ). The lower leakage minimizes the problem of thermal runaway-one of the major causes of Schottky diode failures.
Another competing diode series, the SD51, is available from TRW (Lawndale, CA). Every diode in this group also handles 75-A loads, but has higher reverse currents and a lower maximum operating junction temperature.
Prices for International Rectifier's 30HQ and 75HQ diodes start at $4.48 for the 30-A, 30-V device and range up to $7.08 for the 75-A, 45-V diode, both in 100-unit quantities. Delivery of samples is from stock, and production quantities require four weeks.

International Rectifier CIRCLE NO. 302

Motorola

CIRCLE NO. 303

TRW

CIRCLE NO. 304

International Rectifier, 233 Kansas Street, El Segundo, CA 90245. Bob Del Vecchio (213) 322-3331. P & A: See text.
Pushing the operating temperatures up and reducing the reverse currents, International Rectifier's families of extended-range Schottky diodes pack more punch into power-supply designs. The diodes can operate at up to 175 C -a 25-C increase over available devices. As a result, you get either more current-handling capability or less heat-sink area.
Typical of the new devices is the 75HQ family, 75-A diodes with reversevoltage capabilities of 30 or 45 V. Reverse currents for the diodes range from 15 mA at a junction temperature of 100 C to 150 mA at a Ti of 150 C. The maximum forward voltage drop for the diodes is as high as 0.9 V at 25 C and a forward current of 150 A (peak), and as low as 0. 74 V at 175 C and 150 A (peak).
The Schottky diodes, since they operate at junction temperatures up to 175 C, permit the ambient temperature of
ELECTRONIC DESIGN S, March I, 1978

the power supply they are used in to rise-typically from 40 to 70 C. Or, ratings can be kept the same but the heat-sink area reduced-by 20 to 40%, according to estimates.
Not only are the 75HQ diodes able to handle the high continuous currents, but they are also sturdy. The maximum peak one-cycle nonrepetitive surge current is 1000 A and the maximum 12t for fusing is 4150 A2S for 5 to 8.3 ms and 2275 A2S for 1.5 ms.
Housed in stud-mount D0-203AB cases (formerly called D0-5), the diodes have a case-to-sink thermal resistance of 0.25 C/W. Mounting torque for the 1-oz devices is 30 lb-in., maximum. All diodes have an operating junction temperature range of -65 to
175 c.
Also available is a 30-A series of high-temperature diodes, the 30HQ family. Reverse currents are less than half those of the 75HQ devices and forward-voltage drops are about the same as the 75HQ units.
Compared to other high-current

Speedy power transistors take high voltage
General Semiconductor Industries, P.O. Box 3078, Tempe, AZ 85281. Jim Williams (602) 968-3101. $4 .95 to $6.00 (100 qty); stock.
Models XGSR7530, XGSR7535 and XGSR7540 feature a VCEO of 300, 350 and 400 V. Each is both current-gain and saturation-voltage rated at 7.5 A. Peak collector current is 15 A. Collector saturation voltage is typically 0.3 V and switching speed is less than 1 µs . Packaging is the T0-3 metal case.
CIRCLE NO. 305
Bridge rectifiers rate 27.5 A, 3-phase
Electronic Devices, 21 Gray Oaks Ave., Yonkers, NY 10710. Dennis Dean (914) 965-4400. Free samples.
A line of 3-phase, full-wave bridge rectifiers is rated at 27.5 A. Peak reverse voltage ratings are 50, 100, 200, 400, 600, 800 and 1000 V. Maximum surge current is 300 A. The bridges are 1.5 X 2 X 0.406 in. and can be mounted on a heat sink or chassis.
CIRCLE NO. 306
77

ICs & SEMICONDUCTORS
Bipolar a/d converter delivers 10-bit output
= ~ til:~~ ~~
15ZT4ilillB9'ou""''
A067110 BIT AOC WITH AUTOMATIC J.$TATE OUTI'\ll'I FOA SINnl F UNE CONTAOt.
Anal,og Devices, Route 1 Industrial Park, P. 0. Box 280, Norwood, MA 02062. Jeff Riskin (617) 329-4700. Stock.
Built using FL technology, the AD571 is a complete, 10-bit analog/digital converter. On a single chip is ad/a converter, voltage reference, clock, comparator, successive approximation register and output buffer. The AD571 performs a complete conversion to 10bit accuracy ± 1/2 LSB with no missing codes in 25 µs. There are three versions available; the J suffix for fully guaranteed 10-bit performance at 25 C (9 bits from 0 to 70 C), the K suffix for a full 10 bits over 0 to 70 C, or the S suffix for -55to+125 C operation. The guaranteed full-scale temperature coefficients of 88, 44, and 40 ppm for each version, respectively, are the total TC errors of all the components in the . circuit.
CIRCLE NO. 307
Transistors switch 1 A and are MIL qualified
Silicon Transistor, Katrina Rd., Chelmsford, MA 01824. Bill Schramm (617} 256-3321. $3.381$4.30; bonded stock.
JAN-2N3740 and JAN-2N3741 silicon power transistors are qualified to MIL-S-19500/441A. They are rated for a VCEO of 60 and 80 V, respectively, and continuous collector current of 1 A. The de gain is 30 to 100 at an le of 250 mA, and the collector-emitter saturation voltage is specified at 0.6 V at 1 A. The devices are in T0-66 cases.
CI RCLE NO. 308
78

High-speed op amp has 15-MHz bandwidth
Texas Ins trumenti;, P. 0. Box 5012, MIS 308 (Attn: LM318), Dallas, TX 75222. Dale Pippenger (214) 238-3527. $1.64 to $10.08 (100 qty); stock.
The LM318 high-speed operational amplifier has a typical small-signal bandwidth of 15 MHz and a slew rate of 50 VIµs min. The op amp has internal unity-gain frequency compensation. External compensation may be added for optimum performance. Supply voltage can range from ±5 V to ±20
v.
CIRCLE NO. 309
Three-terminal regulator adjusts from -1.2 to -37V
National Semiconductor, 2900 Semiconductor Dr., Santa Clara, CA 95051. Dave Whetstone (408) 737-5856. $2.80 to $13.60 (100 qty); stock to 4 wks.
Negative three-terminal adjustable regulators, the LM137 series, are 1.5A devices. The regulators have internal current limiting, thermal shutdown and safe-area compensation. The output voltage shifts 0.2% max when a 10W pulse is applied for 10 ms. Ripple rejection is 75 dB and rms output noise is 0.003% of the output voltage up to 10 kHz. The series covers output voltage from -1.2 to -37 Vin T0-3, T0-5, T0-220 and T0-202 cases.
CIRCLE NO. 3 10
Dual op-amps have high input impedance
RCA Solid State, Route 202, Somerville, NJ 08876. (201) 685-6423. $0.55 (chip) to $1. 73 (100 qty); stock.
The CA3240 and CA3240A dual op amps have gate-protected MOSFET transistors in the input circuit for high input impedance (1.5 x 1012 n), low input current (10 pA at ± 15 V) and high-speed. The op amps have, respectively: max input offset voltages of 15 mV and 5 mV, input offset currents of 30 pA and 20 pA and max input currents of 50 pA and 40 pA. The de supply voltage can range from 4 to 36 V and the common-mode input voltage can swing to 0.5 V below the negative supply rail. Package options are 8-lead or 14-lead plastic DIPs.
CIRCLE NO. 320

Programmable circuit multiplexes 8 lines
Raytheon Semiconductor, 350 Ellis St., Mountain View, CA 94040. (415) 968-9211. $4.25 (100 qty); stock.
The field programmable multiplexer (PMUX), Type 29693, contains four 8line-to-1-line multiplexers with common select and input lines and 10 electrically programmable inputs. The 20-pin device has 10 buffered inputs and four outputs. The 10 input lines form a matrix with 32-bit lines. At each junction of the horizontal inputs with the vertical bit lines, there is a diodefuse combination connecting the two. The bit lines are then routed to four one-of-eight multiplexers controlled by three "select" inputs. The select lines determine which multiplexer inputs are connected to the three-state output drivers.
CIRCLE NO. 321
64-k ROM features 200-ns access time
Mostek, 1215 W. Crosby Rd., Carrollton, TX 75006. Derrell Coker (214) 242-0444. See text; 6 wks.
The MK 36000 64-k ROM operates at a 200-ns access time and requires only 200-mW active power (max) and 25mW standby power. The device operates from a single +5-V power supply with 10% tolerance. Other system features include full TTL-compatible inputs and outputs. The three-state output can drive two TTL loads and 100 pF. The price for the plastic package is $49.00 in 500 quantity with a $1000 refundable masking charge.
CIRCLE NO. 322
ELECTRONIC DESIGN 5, March I, 1978

Don't waste money and ruin PROMs. Move up to
a first-rate programmer.

What defines a tirstrate programmer?
A first-rate programmer is easy to use, safe (U.L. listed}, reliab le , backed with a long-term warranty, and flexible enough to handle advances in PROM technology, a combination you get only with a Pro-Log programmer.
Our systems take the mistakes out ot programming.
Our Series 90 PROM Programmer walks you through tile programming process so tllere's less chance for misprogramming . Separate sockets for master and copy PROMs make it impossible to accidentally destroy a valuable master.
Vendor-approved programming, lull portability, free 2-year warranty.
Using vendor-approved PROM personality modules , Pro-Log's field-proven programmers prog ram every major MOS and bipolar PROM . They also program generic PROM families and do gang programming .

A first-rate programmer is economical, too.
A complete Series 90 consists of a master control unit, a PROM personality module, and options. An M900 master control unit costs only $1,800. An M920 PROM Duplicator master control unit costs only $1, 145. Single PROM personality modules cost from $325 to $450. Generic modules start at $350 . Gang modules which program 8 PROMs simultaneously are $895. All modules come U.L. listed and fit both the M900 and the M920. Options include CMOS RAM buffer (to 4K bytes), RS-232 (terminal or modem) interface, TTY, parallel interfaces, paper tape reader,

They weigh less than 20 pounds so they go where you need them . And they're backed by the longest warranty in the industry, 2 full years parts and labor.

U.L. listed erase light, checksum option, and Auto-baud .*
Find out what else a truly first-rate programmer has to otter.
Call or write for a free pamphlet giving you comparison checkpoints. Pro-Log Corporation, 2411 Garden Road, Monterey, CA 93940. Phone (408) 3724593 .

·Trademark. Pro-Log Corporation.

Microprocessors at your fingertips.

CIRCLE NUMBER 38

E1t l T RONI C D ESIG 5, March I, 1978

79

MICRO/ MINI COMPUTING
System monitor keeps track of microcomputer performance

Motorola Microsystems, 3102 N. 56th St., Phoenix, AZ 85018. Wes Patterson (602) 244-6815. P&A: See text.
Although system monitors are routinely used to analyze the performance of large computer systems, they cost too much for most microcomputer applications. But for just $1045 Motorola's System Performance Monitor gives the micro user the monitor ing capability of units costing several thousand dollars.
Connecting directly to a microcom puter's address bus, the SPM periodically samples the µC system's address lines, and accumulates the results to produce a map of memory addresses with corresponding frequencies of reference. Samples collected in the program-storage region may be used to correlate processor activity with specific program segments. One result is that software bottlenecks can be identified and quantitative information provided about the performance limits they impose. Or, critical program segments may be identified for reorganization or optimization. Or, if a high-level language is being used for software development, certain subroutines may be identified for recoding in assembly language.
An autonomous single-board microcomputer system, the SPM measures 5.75 X 9.75 in. and is physically and logically bus-compatible with Motoro-
80

la's EXORciser µP development system and the Micromodule series of OEM microcomputer boards. Jumpers enable the SPM to adapt logically to other microcomputer bus structures, with physical adaptation left to the user.
As seen from the bus, t he SPM is a passive device; it doesn't disturb the measured system. During operation, 12 address bits from the monitored bus are latched and sampled by the SPM approximately 6000 times per second. Data from each sample accum ulate in one of 256 4-byte counters. Bus observations may be run for almost a week without losing data. Samples may be collected within a specified memory region of 4, 16 or 64 kbytes. Experiments over smaller regions produce greater detail in the results.
Samples collected in the datastorage region of memory may provide such additional useful information as the efficiency of a particular buffermanagement algorithm. Since 1/0 in the M6800 µP is memory-mapped, the SPM can also collect information about 1/0 activity. In addition, processor utilization may be derived from bus-utilization information collected by the SPM. This can be used to project maximum system capacity, or to quantify improvements over previous measurements.
(continued on page 84)

Call your nearest ISC sales representative
Alabama (also Mississippi): W. A . Brown Inst. Inc. Huntsville 205/ 883-8660 Arizona (also Nevada): The T horson Co. Phoenix 602/ 956-5300 Californ ia : T h e T horson Co. Los Angeles 213/476-124 1 Goleta 805/ 964-8751 Mountain View 415/964-9300 San Diego 7 14 /292-8525 lrvi ne 714/55 7-4460 Colorado (also Utah, Wyoming) : The Thorson Co. Denver303/ 759-0809 Florida : W. A . Brown Inst. Inc Ft. Lauderdale 305/ 776-4800 Melbourne 305/723-0766 Orlando 305/ 425-5505 Valparaiso 904/ 678-7932 Georgia: W. A . Brown Inst. Inc. Atlanta 404/ 939-1674 Illinois (N .) (also Ind i ana , Wisconsin) : Resource Data Sys. Northbrook 312/564-5440 Kansas (also W. M i ssouri, Nebraska): Inland A ssoc. Shawnee M ission 913/362-2366 Louisiana: W. A . B row n Inst. Inc . M andeville 504/626-9 701 Maryland (also D .C. , Virginia): Bartlett Assoc . Bethesda 301 / 656-3061 Massachusetts (also Maine, N. Hampshire, Rhode Island, Vermont): Bartlett Assoc. Framingham 617/ 879-7530 M ichigan : WKM Assoc M adison Heights 313/ 588-2300 Minnesota: Cost Reduction Services Minneapoli!! 612/ 822-2 119 M i ssou ri (E .J (also S . I llinois, Iowa): Inland Assoc. St. Louis314/ 821-37'42 New Mexico: T he Thorson Co. Albuquerque 505/ 265-5655 New York (also Connecticut, New Jersey): Bartlett Assoc. White Plains 914/ 949-64 76 North Carolina: W. A . B rown Inst. Inc. Durham 919/682-2383 Oh io (also Kentucky ): W KM Assoc . Cleveland 216/ 267-0445 Dayton 513/ 434-7500 Oklahoma: Data Marketin g A ssoc. Oklahoma City 405/528-6071 Pennsylva nia (E .J (also Delaware) : Bartlett Assoc. Wayne 215/ 688-7325 Pennsylvania (W.J (also West Virginia) : WKM Assoc. Pittsburgh 412/892-2953 South Carolina : W. A. B rown Inst. Inc. Columbia 803/798-3 297 Tennessee: McCoin Elec. Equip. Co. Knoxville 615/ 588-2417 Texas (also Arkansas) :
Data M arketi ng Assoc. Austin 512/ 451-5174 Dal las 214/ 661-0300 H ousto n 713/ 780-2511 San Anto nio 5 12 / 828 -0937 Washington (also Idaho, Montana, Oregon): The Thorson Co. Bellevue 206/ 455-9 180 European Export Sales: Tec hexport. Inc . Cambridge . MA 617/ 661-9424 England: Techex . Ltd. Bournemouth 0202-293-115 France: Peritec Rueil 749-40-37 Switzerland : lntertest. AG Bern 031-224481 West Germany: COT GmbH Altheim 6691-255 Australia: Anderson Digital Equip. Mt. Waverly, V ictoria 03-543-2077 Canada: Cantec Rep.. Inc. Milton. Ont. 416/ 624-9696 Ottawa. Ont. 613/ 255-0363 Pierrefonds, Que . 514/620-3121 Canada : Datamex . Ltd . (D ist ri b utor) Dorval . Que. 514/ 636-9774 Toronto, Ont. 416/ 787-1208 Vancouver. B .C . 604/684-6750 Fa r East: Computers International Los Angeles. CA 213/ 382-1107
·lntelllgent Systems Corp.a
faECTRON 1c DESIG 5, March l, 1978

There mn'· ·process ..... siderable savings over the separate

·rol sys·em ~n ·he mdus·ry option cost. Look at some of the ad-

·hm our lmecolor 800IG vanced lntecolor 8001 G features :

can·· ~mprove. because

· Expanded hardware and software graphics

color commun~ca·es fas·er. · 48 lines by 80 characters with two dif-

Bailey Meter, Taylor Instruments , Dow ferent character heights · Eight foreground

Chemica l, International Paper, ACCO Bristol, PPG Industri es come from a lon g list of industry leaders who have integrated our lnteco lor 8001 color data termi nal into their systemssophisticated systems that demand

colors, plus eight background colors for additional definition · Character and line insert and delete· Page roll-up · 64 Standard Instrument Society of America characters · Plotting capability on a 160 by 192 matrix· Expanded keyboard with cursor and color controls · 19" display

critical control. Now we can bring you

A 25" unit with the same standard

the lntecolor8001G, the same precision features is available at slightly extra cost.

terminal with a special color graph ics

We guarantee delivery of your

package as a standard feature, at con- lntecolor 8001 G eva luat ion unit for

E1 1CT RON 1c DcSIG 5, March I, 1978

CIRCLE NUMBER 39

$1 .925* (cash-with-order) within 30 days or your money back. The same $1 ,925 price goes for orders of 100 units or more. Get the jump on your competition without outspending your rnmpetit ion . Get the lntecolor 800lG.
Intelligent Systems corp.4P
5965 Peac htree Corners East Norcross. Georgia 30071
Telephone 404-449-5961TWX81(}-766-1581
Color commun~ca·es fas·er.
·u.s.domestic price.
81

iati n You Need

At Centralab we are concerned with the same things you are - performance, reliability, on-time delivery. But any ceramic disc capacitor supplier can say that. We go that critical step further; we give you a choice of leads to help you cut your manufacturing costs.
Our standard leads include stand-off types to prevent solder damage; snap-in types to avoid fall-out during assembly; short leads for low profile; long leads for those hard-toreach placements.

We'll go even further. On minimum OEM order, we'll make any lead configuration (under 3V2n) you need. Just tell us your manufacturing problem; we'll give you a costeffective answer.
And don't forget our tape-and-reel packaging for automatic insertion.
Cost savings in use. That's the competitive
edge you get from Centralab. The Centralab Edge.

-~
CENTRALAB/USCC
Electronics · GLOBE- UNION INC.
7158 Merchant Ave., El Paso, TX 79915 C915l 779-3961
CIRCLE NUMBER 8

PMI

monoli c 10-bit DACS.
Good news! Two new ten-bit digital-to-analog converters from the folks who know how to make them monolithically. And each is completely "complete'.' Includes internal reference and output op amp. They are fast {1.5 µsec settling time), with voltage outputs, yet consume only 350mW (max) over the entire military temp range (-55°C to +125°C).
DAC-05: Sign-magnitude coding (sign-plus-ten-bits).
DAC-06: Two's complement coding.
Both DACs are available now specified over the full temp range. Off the shelf to MIL STD-883A Level B. Reliability is enhanced by 100% burn-in, hermetic packaging for all parts, PMI's famous triple passivation, low noise process and no laser trimming.

Data sheets are ready. Parts are on the
shelf. Write, wire or phone. Precision Monolithics, Inc., 1500 Space Park

PiM I

Drive, Santa Clara, CA 95050.

(408) 246-9222. TWX: 910-338-0528.

®

CIRCLE NUMBER 9

OPTICAL SWITCHES
Designing-in switches? Call Spectronics. We can show you a better way.
All Spectronics optical switches are manufactured using our high-technology infrared process, assuring highest reliability. Our broad line is increasingly utilized for such applications as speed control, position and level sensing, and card reading, replacing traditional mechanical switches for these important functions. Interchangeability is no problem - our switches are direct replacements for such popular devices as the H13A1 , A2. ; H1381 , 82; MCA 8, 81 and MCT 8 and 81. Spectronics opto switches
are TTL compatible and feature switching speeds ranging from 1Oto 750 µsecs.
For more details and delivery information, contact Commercial Component Division , 830 E. Arapaho Road, Richardson, Texas 75081, (214) 234-4271.
CIRCLE NUMBER 41

MICRO/MINI COMPUTING (continued from page 80)
A control-console keyboard is used to initialize the starting memory address and memory block size for each measurement experiment. Results are retrieved via console printer or CRT and reported both as a percentage of samples occurring in each memory segment within the measured region and as a histogram. Bus utilization is reported as busy bus cycles, which are sampled as a percentage of the total cycles sampled.
Since the console isn't needed except to initialize the SPM and to retrieve results, the EXORciser console device may be shared for this function. A serial RS-232 interface is included with the SPM, and a current-loop interface adapter is available as an option.
Delivery of the board is from stock.
CIRCLE NO. 301
Thrifty disc drive holds 143 kbytes

-~

. y~~ -

t-.~r.fs ta·~ . . _e~r~eiAnd~ tM! ~. :

- weT~ putting out the widest and -

!lest selection of stock model monolithic filters you'll find at any radio get-together. From s to 180

NUTS TO NOISE!

MHz. over 60 tasty models at 10.1

and 21.4 MHz. Plus two can't-put-

them-down monolithic crystal

discriminators. Nuts to high prices too! we'll give you macadamia

quality at peanut prices.

Plezo Technology Inc.

2525 Shader Road, or1ando, Fl 32804

The standard In monollthlc crystal filters

(3051 298-2000

CIRCLE NUMBER 37 84

Micropolis, 7959 Deering Ave., Canoga Park, CA 91304 . (213} 703-1121. $695.
The 1041 series of disc drives includes software, S-100 bus compatible controller and 143-kbyte capacity. Model 1041 packages a drive, enclosure, cabling and connectors, disc operating system and disc-extended Basic for integration into any 8080A or Z80 microcomputer. Model 1042 adds a power supply and de regulators for desktop use. The drives are hard-sectored into 16 sectors, each 256 bytes long; total tracks per surface is 35. Both offer transfer rates of 250 kbits/s at an average rotational latency time of 100 ms. Access time, track to track, is 30 ms and recording density is 5162 bits/in.
CIRCLE NO. 323
ELECTRONIC DESIGN 5, March I, 1978

Full-function computer fits on desk top

IBM, P.O. Box C-1645, Atlanta, GA 30801. Bill Shaffer (404} 231-3201. $9875 to $32,925.
The IBM 5110 is a desktop computer that houses a central processing unit, a typewriter-like keyboard with a 10key calculator pad and a 1024-character display screen. Main memory holds 16 k, 32 k, 48 k or 64 kbytes of data, depending on the unit selected. The computer is available in two models. Offering either magnetic tape or diskette storage, the Model 1 stores 204 kbytes per tape cartridge or 1.2 Mbytes on a single diskette. The Model 2 allows diskette storage only. Up to two IBM 5114 diskette units, each housing a maximum of two diskette drives, can be attached to the 5110 for an on-line diskette capacity of 4.8 Mbytes.
CIRCLE NO. 324

You probably already have a lot of good reasons for moving your plant or expanding your operation. And they're all great reasons for moving to Palm coast lndustrlal Park. LOCATION - Florida's growing Northeast coast just one hour south of Jacksonville. SAVINCS - Lower state and local taxes, including a total tax on industrial property of 10.BB?mills. Lower housing and labor cost, too.

LABOR - Apopulation of 725,000 within a reasonable
commuting distance.
TRAuNs S1PcrOoRssTtAhTeIOpNrop- er1t·y95wainthd
available access to air, rail and trucking.
CORPORATE COMMITMENT-
IIT community Development corporation is ready to assist you
in every step of your move. LIFESTYLE - The bright,
warm Florida climate.
There's even more good reasons. Write us and we'll send you all the details, or call
Dave Irving toll free at 1·800·874·1828 (in ~lorida
1·904·445·341 i collectl.

Memory module contains more than 1 Mbyte
EMM Commercial Memory Products, 12621 Chadron Ave., Hawthorne, CA !HMSO (213) 644-9881 . $0.10/bit
The Megabyte Module memory is configured as 1,114,112 X 8 (8,912,896 bits), which is 524,288 bits in excess of 1 Mbyte. The additional 64-kbyte capacity allows the use of various error checking methods while maintaining a 1-Mbyte capacity for data. The memory is a random-access, two-wire, 1-1/2D core memory, packaged on a single pluggable PC card. An available chassis can take up to four modules, two 110 cards, and a power supply within 17-1/2 in. of vertical rack space. The memory module operates at 2 µs in the read/restore and clear/write modes with an access time of 1.2 µs.
CIRCLE NO. 325
ELECTRONIC DESIGN 5, March I, 1978

ITT community Development corp ration

-----P~l{RtC·o1f_____ _

I I

1nol

AL PARK '""" I

I

I For more Information wrtte Mr. David Irving, ITT community Development Corporation, Executive Offlees, Palm coast, R. 32037 or cal tOll free at 1-800-874-1828 Un AOrlda 1-904-445-3411 COiiect>.

I I I

PLEASE SEND ME MORE CREAT REASONS FOR MOVINC TO PALM COAST.

I

Pll'( company Is engaged In o manufacturing, o distribution, o other, and we are o moving, o expanding.

NAME

nru _ _ _ __

COMPANY NAME _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _~

I I

I

I ADDRESS - - - - - - - - - - - - - - - - CITY _ _ _ _ ZIP _ _

~--------C-IRCL-E N-UMB-ER-42 --------~ 85

MICRO / MINI COMPUTING
Low-end computer uses PDP-8 processor
Di,gital Equipment, Maynard, MA 01754. Joe Nahil (603) 884-5101. .$12,600; 8 wks.
The Datasystem 308 uses a PDP-8 video data processor and is for data processing that requires a single termi-

nal. A typical system consists of a video date processor with 32 kbytes of memory, dual floppy-disc file system, and a minidesk. The 308 uses the COS-310 operating system whose program includes DIBOL, a business-oriented language. COS-310 files and the DIBOL language permit the user to transfer programs and data to larger systems by appropriate media.
CIRCLE NO. 326

Bulk magnetic eraser is hand held

Standard Grigsby§ rotary switches have printed circuit and solderless terminals that will not bend or twist

Printcraft Systems, 11-17 Beach St., New York, NY 10013. Don Hubbinett (212) 966-0001. $22.50.
The UL-approved hand-held bulk tape/ card eraser electronically restores magnetic cards, cassettes, discs and reel-to-reel recording tapes to "like new" blank recording condition. The process can be performed off line in quantity for either general reuse or for information security. The eraser guards against one program from running into a previously recorded program should a stop code be missed.
CIRCLE NO. 327

Personal computer usesZ80 CPU

our exclusive rigid construction provides you with savings by eliminating
costly assembly operations

"YES" - Save the valuable time wasted on straightening the P.C. terminals of rotary switches!
Our exclusive printed circuit "T' terminals are ruggedly designed to
allow EASY insertion of our rotary switches into any P.C. board pattern.
If you wire your rotary switches with wire-wrap or other solderless
techniques, try a terminal that won't
bend or twist .. . Standard Grigsby's
NEW solderless "T' terminal. Send for Free "Yes" button and
literature.

IJj standard grigsby, im!.

920 Rathbone Avenue · Aurora, Illinois 60507 (312) 844-4300

CIRCLE NUMBER 43
86

Realistic Con trols, 404 W. 35 S t., Davenport, IA 52086. (800) 553-1 863. $2495.
REX, a total microcomputer system, is full y assembled with a Z80 CPU, 24-k RAM, video output, keyboard, microfloppy-disc drive, cabinet, power supply and optional extended-disc Basic and ANSI Fortran IV. The system includes an S-100 motherboard, up to 64 k of RAM (24 k standard), bootstrap and monitor PROM and power-fail and vectored-interrupt circuitry.
CIRCLE NO. 32 8
ELECTRON IC DESIG 5, March 1, 1978

Intel delivers a better 22-pin 4K RAM
fur people who are never quite satisfied.

For some people "good enough" is never quite good enough. In 1972 we introduced the industry's first 22-pin 4K RAM, the 2107. But we weren't content to stop there. So we follo ed with the 2107A. Then in 1975 the 2107B. Now, introducing the 2107C. Compare it with any 4K dynamic RAM. The results are sure to put a smile on your face.
The 2107C delivers a new standard of performance . Access time: 150 ns. Power consumption: 40% lower than the TMS 4060 or our own 2107B. Current spikes: significantly lower than competitor's parts means less system noise with the
2107C. Supply tolerance: ±10% in all· power supplies gives you the widest system operating margins available
anywh re.

Best of all , the 2107C is already in volume production and available in both hermetic and plastic packages. Plan now to upgrade your systems now using our 2107B or any of its second

sources. For a complimentary P2107C evaluation sample and data sheet,

Maximum Access lime Maximum Read/Write Cycle Maximum loo Average Power Supply Tolerance

2101c-1 150 ns 380 ns 35 mA ±10%

2101c-2 200 ns 400 ns 33 mA ±10%

2101c 250 ns 430 ns 30 mA ±10%

contact your Intel sales office. To order, contact Almac/Stroum, Component Specialties, Cramer, Hamilton/Avnet, Harvey Electronics, Industrial Components, Pioneer, Sheridan, Wyle/ Elmar, Wyle/Liberty, L.A. Varah, Zentronics. Or write us. Intel

Corporation, 3065 Bowers Avenue, Santa Clara, CA 95051.

·

In Europe, Telex 24814, Brussels.

n Jap~, Telex 28426, Tokyo.

COMPONENTS
Solid-state chopper comes in T0-5 case

Large indicator lights are attention grabbers

Low-profile heat sink fits T0-3 and T0-66

Solid State Electronics, 15321 Rayen St., Sepulveda, CA 91343. Ed Politi (213) 894-2271. $89 (100 qty); 1 to 3 wks.
The NS8000A is a transformerisolated solid-state chopper built with stabilized integrated silicon semiconductors in a T0-5 type enclosure. The max chopped current is 10 mA and the total device dissipation in free air is 0.5 W (2 W at 25-C case temp). The chopping frequency (limited by an internal transformer) ranges from 50 kHz to 1.5 MHz.
CIRCLE NO. 329

Industri,al Devices, 7 Hudson Ave., Edgewater, NJ 07020. (201) 224-4 700. Free samples.
Large attention-getting panel indicator lights, Omni-Glow 2600, have built-in, round metal bezels that retain a lens. High dome-shaped, or lowprofile flat or rounded lenses can be used. The indicators fit into a 7/8-in. diameter panel opening or in a keyed D-mounting hole. Either snap-fit or speednut mounting may be used. Lamps for the indicators are either standard or high-brightness neons or rugged wire-lead incandescents.
CIRCLE NO. 330

Aavid Engineering, 30 Cook Court, Laconia, NH 03246. (603) 524-4443. Free samples.
Heat sinks that feature a universal hole pattern, part numbers 5060 and 5061, also accommodate T0-3 and T0-66 case-style devices. The heat sinks are 0.375-in. high and fit PC boards spaced 0.5-in. between board centers. Both types come with black anodized finish.
CIRCLE NO. 331

VICTORY SELECTIVITY

THERMISTORS
Sel ect ivity, not just a word but a reality at VECO. SensiChips ~ thick films, beads and probes in a wide variety of sizes and resistances. Try us, you'll like VECO quality and prices.
~ ~ VICTORY ENGINEERING CORP. V1c1ory Rd . Spnngheld , N J 07061 TWX 710·983·4430 Tel 201-379-5900

Rogan knobs look better and are built better,

CIRCLE NUMBER 45 88

and we'll prove it with a free sample.
After you receive our catalog, send us a note outlining your specific requirement and the quantity involved.
Or furnish us with our cqmpetitor's part number and we will cross-reference it.
Our samples and quotation will be returned promptly.
3455 Woodhead Drive, Northbrook, Illinois 60062 (312) 498-2300 CIRCLE NUMBER 46
CIRCLE NUMBER 47 ~

Intel delivers the only 16-pin 4K RAM
that~ sure to keep you smiling.

You may or may not think of your memory system as a

masterpiece. But one thing is certain, once you've reached

volume production you're going to be reluctant to make major

changes. That's why it is so frustrating to find that a supplier

has painted you into a comer by deciding to stop delivering

the part you want. Or by trying to switch you to a newer,

non-compatible part.

Smile. Our 2104A 16-pin 4K RAM is the answer. It's a

direct replacement for both the older 4096 metal gate and

newer 4027 silicon gate parts. The 2104A keeps your produc-

tion line moving without expensive re-design. Plug it in

and you're ready to go.

The 2104A is best for your new

- designs, too. We've been delivering this

part Ut volume since July, 1976. So you

8"

Intel to deliver the quantity

Delivery is not the only reason to specify the 2104A. There's

not a 16-pin 4K RAM anywhere with lower power consumption.

And because the 2104A has significantly lower current spikes

than other 16-pin 4K RAMs, there's less systern noise. What it all
means is that when you

2104A-1 2104A-2

Maximum Access
lime 150 ns 200 ns

Maximum Maximum Read/Write loo
Cycle Allerage 320 ns 35 mA 320 ns 32 mA

design your next system, 2104A-3 250 ns 375 ns 30 mA

it makes sense to design 2104A-4 300 ns 42? ns 30 mA

it using our 2104A.

2104A

350 ns

500 ns 30 mA

You can order the 2104A from distributor stock. Contact:

Almac/Stroum, Component Specialties, Cramer, Hamilton/

Avnet, Harvey Electronics, Industrial Components, Pioneer,

Sheridan, Wyle/Elmar, Wyle/Liberty, L.A. Varah, Zentronics.

Or write Intel Corp., 3065 Bowers Ave., Santa Clara, CA 95051.

IqEur pe. Tel~)~J Brussels. In Japan JtYlllJlj·p~·'j

COMPONENTS

Thermistor in glass bulb is indirectly heated
Fenwall E lectronics, 63 Fountain St. , F ramingh am, MA 01701. (61 7) 872-8841 .
Thermistor K365 has a heating element and thermistor bead enclosed in a glass bulb. It is unaffected by changes in ambient conditions. When power is applied directly to the thermistor bead, temperature increases 1 C/0.015 W. Power of 0.04 mW to the heater indirectly heats the thermistor bead 1 C and changes the thermistor resistance, typically, from 50 to 15 k!l
CIRCLE NO. 332

As you can plainly

see, our new air variable

capacitor is nearly as small as many sub-miniature ceramic

great stability. Q is t
1000 at 100 MHz. T

+ 1s

trimmers. It also features the =45 PPM/°C. And it's

same mounting configuration available in maximum

which means you can use it in capacities of 3, 6.5, 12.7, and

many of the same applications 19.0 pF in either vertical or

But small size isn't the only horizontal tuning PC and

reason for buying our new stripline mounting versions.

Micro T'" capacitor. Because What's more, it gives you all

it's air variable, it offers you this for a very small price.

E. F. Johnson Company/Dept. E.D., Waseca, MN 56093

D Please send me technical

D Please send me samples.

information on sub-miniature

You can call me at

air variable capacitors.

Name·~~~~~~~~~~~~~~~~~~~~~~~ Firm~~~~~~~~~~~~~~~~~~~~~~~~
Address.~~~~~~~~~~~~~~~~~~~~~~~
City_ _ _ _ _ _ _ _ _ _ _ _State_ _ _ _ _ _ __

00 :JOHNSON Zip~~~~~~~~~~
For fast service, contact your local Johnson Distributor.
CIRCLE NUMBER 48
90

RCD networks save board space
TRW Capacitors, 301 West "O" St., Ogallal,a, NE 6.91 53. (308) 284-3611. 8 to 10 wks.
Resistor-capacitor-diode (RCD) networks save both circuit-board space and design time. The networks come packaged in axial-lead molded-plastic cases. Diodes have reverse-breakdown voltages of 1000 V with less than 50 mA of leakage current and max forwardvoltages of 1.1Vat1 A. Resistors, rated from 1/ 4 to 1/2 W, have values from
100 to 800 n. And metallized-Mylar
capacitors have voltage ratings from 100 to 400 V and capacitances from 0.22 µF to 1 µF.
CIRCLE NO. 333
Slim DPM features 3-1/2 digit display
Fairchild Ins truments & Con trols, 1725 Technology Dr., San Jose, CA 95110. John Hatch (415) 962-2521. $33.
Model 30 3-1/2-digit DPM is a flat pack that operates on only 0.75 W at 5 V de. With the display blanked, power is reduced to 0.05 W. The meter is available in a full-scale range of ± 1.999 V with a resolution of 0.0005%. Higher ranges are obtained by the use of external resistor-divider networks. Accuracy is ±0.1% of reading, ± 1 digit. The display is 0.5 in. high. The unit fits NEMA and DIN standard 0.44 X 3.59in. panel cuts.
CIRCLE NO. 334
E LECTRONIC DESIGN 5, March I, 1978

MODULES & SUBASSEMBLIES Dual line amp has equalizer option

Analog interface board handles many functions

Cassette transport has accurate speed
MFE, Keewaydin Dr., Salem, NH 03079. Jim Saret (603) 893-1921. $560; 4 to 6 wks.
The Model 450B digital-cassette transport has a speed-control system that provides long-term speed accuracy at the heads without the use of a prerecorded digital clock track. The transport is fully ANSl/ECMA compatible, allowing full interchange of cassette tapes with any other compatible system. Two data tracks are available allowing data storage up to 5.9 Mbits (720 kbytes) per cassette. Read/write speeds from 10 to 40 in/s are available providing data transfer rates up to 32 kbits/s using the bi-phase level encoding standard. Search speeds up to 80 in/s can be used.
CIRCLE NO. 335

Plantronics Kentrox, 14335 N. W. Science Park Dr. , Portland, OR 97229. (503) 643-1681. $155 (amplifier), $47 (equalizer); stock.
The Model 3300 dual line amplifier takes an optional line-amplitude equalizer that provides transmit and receive equalization in four-wire applications with DIP switches to select equalization. The amplifier has a power regulator and 70-dB power-supplynoise rejection. Simplex leads are provided. A switch selects 150, 600 and 1200-0 input and output impedances. A visual indication of gain is provided.
CIRCLE NO. 336

Vector Graphic, 790 Hampshire Rd., Westlake Village, CA 91361. Lore Harp (805) 497-6853. $115; stock.
The multifunction analog interface board interfaces a µP with potentiometers, joysticks or voltage sources. An 8-bit digital port with latch strobe is used as a keyboard-input port. Tonepulse generators also can be used to produce sounds for games or keyboard audio feedback . Also included are four aid inputs, MWRITE logic and poweron jump capability for computers lacking a front panel.
CIRCLE NO. 337

Pancake Resolvers
Custom-designed for complex applications.

Our special-design resolvers are today performing on missiles, aircraft, submarines, radar and satellite systems.
Our pancakes, in sizes 16 through 134 and in single and dual speed configurations, are among the most reliable and accurate resolvers available. As are our standard resolvers.
We deal in difficult, custom applications, using engineer-to-engineer contact with detailed technical interchanges to assure smooth production, delivery and absolute performance.
As a result, American Electronics, Inc. has been, for over 15 years, one of the leading suppliers of custom resolvers.
Call or write for our free data package with complete 20-page technical work on resolvers, including outline and performance details.

AEI

AMERICAN ELECTRONICS, INC.
® ELECTRO-MECHANICAL INSTRUMENTS DIVISION

1600 VALENCIA DRIVE, FULLERTON, CA 92631 TELEPHONE (714) 871-3020

CIRCLE NUMBER 49
ELECTRONIC D ESIGN 5, March I, 1978

·-----------------
I I I I I I I I I I I

I

I

II Solid state electronic MICRO-BUZZER from

I

CITIZEN : High reliability, competitively

I

I priced with immediate delivery.

I

I

A complete range: SMB 1.5, 6, 12, 24, voe

I

I

RMB 3, 6, 12, 24, voe IMB (Intermittent) 6, 12, voe

: ~~z!1A~ ~Na-me ________ :

I CORPORATION 1710 - 22nd St.

Company

I I

I I

Santa Monica,

Address

I CA 90404

I Toll Free (800) 421-6516 ""'c""it-y- - - - - -s=1-,a1-.- - - -

I In Calif. (213) 829-3541 TWX : (910) 343-6450

Zip

Phone

I

·----------------- CIRCLE NUMBER 50 91

PACKAGING & MATERIALS
Adhesive tacks wires and terminates coils

DIP sockets provide up to 64 pins

Solderless wire terminal gives firm tool grip

Loctite, N Mountain Rd., Neioington, CT 06111. (203) 278-1280.
A wire-tacking adhesive system called the Tak Pak simplifies circuitboard engineering changes and lowers coil production costs with its instantcuring adhesive. Wires are tacked to circuit boards by first priming the bond area with wire-tacking accelerator. A drop of clear, thick wire-tacking adhesive is then applied to the wire. The material cures within 15 s. When terminating coil wires, adhesive is first applied to the wire. The accelerator is then applied and the drop cures in less than 5 s.
CIRCLE NO. 338

Excel Products, 401 Joyce Kilmer Ave., New Brunswick, NJ 08903. (201) 249-6600.
Low-profile 800 Series DIP sockets include from 4 to 64 pins per socket. The bodies are Valox or FR4 glass epoxy, UL recognized and 94V-O rated. With a height of 0.116 in., the sockets' pins come with 1, 2 or 3-level wrappedwire posts, PC posts or bifurcated pins. Pins are plated with gold over nickel or tin plate, all to MIL specs.
CIRCLE NO. 340
Thick-film kit screens resistors and conductors

Teledyne Ansonia, 1 Riverside Dr., Ansonia, CT 06410. Bob Sobolewski (203) 735-9311. Free samples.
Funnel-Crimp wire terminals have knurled barrels that give positive grips for holding when crimping and handling. An internal funnel guides the wire into the barrel and positions stripped wire for crimping. A built-in tool stop (sharp shoulder) eliminates mis-crimping. Tongue type terminals include rings, spades, flanged spades, locking spades, hooks and male/female disconnects. Color coding in red, blue and yellow identifies wire capacities from 22 to 10 AWG.
CIRCLE NO. 342
PC connectors designed for wave soldering

Flat sockets offer 42 to 62 pins for DIPs

Oi,rcuit Assembly, 3169 Red Hill Ave., Costa Mesa, CA 92626. Dick Foringer (714) 540-5490.
DIP sockets with 42, 52 and 64 pins fit calculator and microprocessor chips. The sockets provide four staggered rows of pins on 0.5-in. centers. A low-profile, open-design insulator body reduces component height.
CIRCLE NO. 339
92

Methode Development, 744 7 W Wilson Ave., Chicago, IL 60656. (312) 867-9600. $200; stock.
A polymer thick-film evaluation kit permits experimentation with screenprinting resistors and conductors on PC boards. The technology eliminates many discrete components and can be used for multilayer or crossover conductors, or to eliminate circuit soldering or plating. Twelve 2-oz samples of resistor, conductor, insulator and solvent compounds, plus several samples of circuits and PC boards are included in the kit. One ounce of material will cover up to 500 in.2·
CIRCLE NO. 341

Viking Industries, 21001 Nordhoff St., Chatsworth, CA 91311. (213) 341-4330. See text; stock to 6 wks.
Type NK and NL PC connectors, for wave soldering, have round-contact tails instead of the square tails commonly used for wrapping. The round tails fit into smaller holes than the square tails and allow for more uniform solder joints. Contacts come on 0.1, 0.125 and 0.156-in. centers with two tail lengths. For standard wave soldering, a 0.2-in. tail is used. For the Raychem Solderpak system, a 0.25-in. tail is available. Pricing for a standard 40-position connector (3VH40/9JNK5) is $3.63 in 500 to 999 quantity.
CIRCLE NO. 343
ELECTRONIC DESIGN 5, March I, 1978

Aluminum heat sink mounts vertically

Strain relief installs without tools

Alarm prevents theft or removal of equipment

·

Tran-Tee, P.O. Box 1044, Columbus, .NE 68601 . ClijJ Schroeder (402) 564 -274 . 0.095; 5 wks.
The Series MlllO aluminum heat sink is for vertical mounting where space is limited. Dimensions above the circuit board are 1.25 high, 0.84 wide a nd 0.235-in. thick. Transistors mount by the use of a 0.14-in. diameter hole or a push-on clip. The heat sink takes plastic encapsulated transistors with T0-220, T0 -202 or A2 cases.
CIRCLE NO. 344

Weckesser, 4444 W. Irving Park Rd., Chicago, IL 60641. (312) 282-8626.
Nylon Straincheck bushings don't crimp or torture wire or cable and it can be installed without tools. The cable is laid in the bushing section, the bushing and cable inserted into the chassis and the locking member is pushed in over the cable into the open portion of the hole until it locks. The bushings fit type SC-J cable in 18/2, 16/2, 18/3 and 16/3 gauges.
CIRCLE NO. 345

Stajer, PO.Box 1171, Lowell, MA 01853. (617) 458-3871. Prom $48.
Equipment Guard alarm systems protect all types of electrical equipment against theft or removal by detecting a cut or unplugged line cord. Slave units enable the user to expand the system. The alarm is useful in laboratories to ensure that important experiments are not interrupted by the unauthorized removal of test equipment.
CIRCLE NO. 346

CIRCLE NUMBER 51

ELECTRONI C DESIGN 5, March I, 1978

93

INSTRUMENTATION
Frequency synthesizer resolves 0.001-Hz

XV recorders use capacitance feedback

Multimeters feature LCD readouts

Rockland Systems, 230 W. Nyack Rd. , West Nyack, NY 10994. David Kohn (914) 623-6666. $3440; 4 to 6 wks.
The Model 5100-13 frequency synthesizer has a frequency range from de to 3 MHz with 0.001-Hz resolution across the entire range. The instrument provides absolute phase continuity in switching, fast switching (1.5-µs max programming delay), short-term stability of ±1 X l0·6/°C and spectral purity of -70 dB spurious, -55 dB harmonic.
CIRCLE NO. 347

Houston Instrument, 1 Houston Square, Austin, TX 78753. Jim Bell (512) 837-2820. $895 to $1275.
The Type 100 Omnigraphic XY recorders use capacitance feedback transducers rather than slidewires or potentiometers in the servo positioners. Specifications include an accuracy of ±0.2%, linearity of ±0.1%, slew speed of 20 in.ls, common-mode noise rejection of 140 dB, critical damping and sensitivity of 1 mV/in. The general-purpose versions include a switch for change from English to metric scaling, 11-position attenuators for the X and Y inputs and a zero check.
CIRCLE NO. 348

Non Linear Systems, P.O. Box N, Del Mar, CA 92014. (714) 755-1134. $99.50/$125.
Two digital multimeters, LM-300 (3digits) and LM-350 (3V2-digits) provide LCD numeric readouts for best viewing in bright sunlight. The meters measure ac and de voltage, resistance, and ac and de current. Options include a leather carrying case, a tilt stand case, a panel-mount flange, a 45-kV probe, an rms probe, rechargeable batteries and charger unit.
CIRCLE NO. 349

Noll BREAKAWAY I WIRING DUCT

Exclusive "breakaway" sidewalls set

a new mark in wiring duct utility.

Interior scoring along the bottoms of

both sidewalls facilitates removal of

wall segments for junctioning, etc.-

with no reduction of bending strength

in the critical direction toward the duct

centerline. No awkward cuts required.

Snip. Snip. Pop! Available in all stan-

MEETS ALL

dard styles and sizes.

J.l.C. STANDARDS

@Approved

Pat. Pend.

Write for free samples.

~ TAYLOR ELECTRIC, INC.

DIV OF TAYLOR INDUSTRIES INC

P 0 BOX 729 MARBLE FALLS TEXAS 78654

CIRCLE NUMBER 52 94

Sealectro ''Press-Fit~ Teflon Terminals

The standard of the industry...one-piece Teflon insulated terminals, completely assembled and ready to install. Biggest selection of feedthrus, standoffs, receptacles, jacks, probes, plugs available anywhere ... and available in all EIA colors. Virgin Teflon bushings and precision machined lugs for high shock and vibration resistance, temperature range, and high electrical and mechanical performance. Simply center terminal over prepared chassis hole... Press-Fit...that's it! Available from nationwide network of stocking distributors. Send for new catalog.

, . - - - - , ,. CIRCUIT COMPONENTS DIVISION
SEALECTRD

CORPORATION

MAMARONECK, N.V. 101543

PHONE 9M 898·S800 TWX 7IO· S6«Mt10

SUIKtllWnt

1<&011'IHl~r·11·4 , S111l1 2\S, 5-n111111 OIU t1 '1·U.1 21l l HO Ill\

too oi. Ito! lll ollflfhf" ··· · h·ll 11, 11111~\1 111 'i'it·. ( I

!·ISi HS-1212

lt1l«lrlllt , Put···ll'. Mants , h1t.a'

Sultclr1Sl . Z.ntlnhUi1tll·h1IHhl llHlf1o11ltnt·"'· " 1111ct

CIRCUIT COMPONENTS · R F COMPONENTS · PROGRAMMING OEVtCES

CIRCLE NUMBER 53

ELECTRONIC DESIGN 5, March l, 1978

Bodine's PM drive family grows-
New 32D permanent magnet Control Motors and 320-SF right angle gearmotors, perfectly matched with Bodine speed/torque controls. Continuous duty ratings of 1/ 121 l/ 10 and 1/s Hp at 2500 Rpm. See your Bodine Distributor or write for Cat. CDC-PM.
New 32-frame
PMmotors and gearmotors!

ADE (After Delivery Economies) make Bodine a better fhp buy
Bodine Electric Company, 2500 W. Bradley Place, Chicago, IL 60618. CIRCLE NUMBER 54

You've been looking for a more reliable solid·state relay.
Justlookat this one.
A unique combination of dv/dt snubber, fusible-link protection in the trigger circuit, plus an overdesigned triac-all combine to protect against catastrophic system failure should the triac fail to turn on .
Either zero-voltage or non-zero-voltage switching, both types rated for maximum ac load currents of SA or 1OA. Any control voltage from 3 to 32V de; all models compatible with TTL, DTL, CMOS logic. Solderpin, quick-on, or screw terminals.
Call (609-882-4800) or write for further information. Heinemann Electric Company, Brunswick Pike, Trenton, NJ 08602.
HE!lNEMANN
We keep you out of trouble.

0 Heinemann 6961

CIRCLE NUMBER 55 CIRCLE NUMBER 56 ...

Thermal shock failures
Superior peel strength Superior line definition Many overplate combinations

Sim;+ Additive Subtractive

No

Yes

No

No

No

Yes

Yes

Yes

No

Yes

No

No

Yes

Yes

No

Yes

No

Yes

Litton

A CED CIRCUITRY

4811 West Kearney · Springfield, Missouri 65803 · Telephone 417-862-0751 · TWX 910-775-4705 TOTAL CAPABILITY· Conventional and Semi-Additive Plated-Thru-Hole ·Multilayer· Backpanels ·Print and Etch
CIRCLE NUMBER 57

DATA PROCESSING
Dumb terminal is CRT/printer combo
Lear Siegler/EID, 714 N. Brookhurst St., Anaheim, CA 92803. John Pagliaro
(BOO) 854 -3805. $3890.
The Dumb Connection peripheral package (ADM-3A video terminal, the Model 210 ballistic printer and interconnecting cable) gives the user the flexibility of both a video terminal and a 180-char/s receive-only serial printer. The ADM-3A has 59 data entry keys, a 24-line, 12-in. screen and 1920 char. Switches offer a choice of eleven baud rates (975 to 19,200 baud) and an RS-232 or 20-mA current-loop interface. The Model 210 prints bidirectionally at rates of 75 lines/min for 132 characters or 120 lines/min for 80-char lines.
CIRCLE NO. 356
Data modems operate at 2400 bits/s
Racal-Milgo, 8600 N. W. 41 St., Miami, FL 33166. R. Nathanson (305) 592-8600. $1092 to $1275; 2 wks.
The 24-LSI Mark II modem operates at 2400 bits/sand provides pushbutton test features. Included are internal error test, receive test, and analog and digital loopback tests. Nine LEDs provide continuous indication of key EIA interface signals and modem status. The modems are compatible with ICC 2200/24 and 24-LSI modems, and Western Electric 201B and 201C data sets. The modems allow full-duplex operation over four-wire point-to-point and multipoint dedicated lines, and direct operation over two-wire dial-up lines.
CIRCLE NO. 357
98

Paper-tape reader/punch is whisper-quiet
Data Specialties, 3455 Commercial, Northbrook, IL 60062. (31 2) 564-1800. $2335; 6 wks.
The SRP-3075 whisper-quiet papertape reader/punch with parallel or serial interface punches at speeds up to 75 char/s, and reads up to 300 char/s. The unit punches Mylar, Mylar laminates, oiled, unoiled, rolled and folded tapes without readjustment or modification.
CIRCLE NO. 358
Data terminal uses gas-discharge display
Computerwise, 4006 E. 137 Terrace, Grandview, MO 64030. (816) 765-3330. $995; stock.
The Transactor III data terminal includes a single-line 32-char gas-discharge display and a 53-key TTY-style keyboard. The terminal connects to any computer with an RS-232 or 20-mA current-loop interface or to a communications line through a modem. Switches select the operating mode, including 110 to 9600 baud speeds, full or half duplex, even/odd/no parity, and the station address. The standard unit supports ASCII-coded data. EBCDIC is available as an option.
CIRCLE NO. 359
Video display divides into separate areas
Human Designed Systems, 3700 Market St., Philadelphia, PA 19104. (215) 382-5000. $1260 (50 qty).
The Concept 100 CRT terminal handles several different functions simultaneously by allowing the user to divide the display memory into any number of separate rectangular "windows," which can be treated as separate displays. The terminal handles forms control, text editing, line-drawing graphics, multiple pages of display memory and multiple character sets. Up to 19 user-programmable function keys are provided.
CIRCLE NO. 360

Video terminal displays 1920 char/page

Datamedia, 7300 N. Crescent Blvd., Pennsauken, NJ 08110. Bob Sullivan (609) 665-2382. $1520 (100 qty).
The Elite 3025A is a buffered TTYcompatible CRT terminal with a singlepage video memory that displays 1920 alphanumeric characters in a 24-line, 80-char format. Operating modes include local edit, batch, batch modified and transparent. The terminal is asynchronous and compatible with 103 and 202-type modems. Fifteen baud rates, up to 9600, are keyboard selectable.
CIRCLE NO. 361
Small plasma display mounts on desk

.....

·

Pichler Associates, 410 Great Rd. , Littleton, MA 01460. Pete Martin (617) 486-8948. $1450; stock to 12 wks.
The DPA64 alphanumeric plasma display is a small desk-mountable, PROM-operated unit that is easy to read in high ambient light over a 120° viewing angle. Plug-compatible with most minicomputers and modems through a 20-mA current-loop or RS232C interface, the UL-listed unit handles up to 9600 baud. A self-refreshing RAM buffers up to 128 char. Changing the PROM produces code and character-font changes. The unit displays up to four 16-char lines of 0.3in. high 5 X 7 dot matrix characters.
The DPA64 measures 6.5 X 7.5 x 8.5
!Il.
CIRCLE NO. 362
ELECTRONIC DESIGN 5, March I, 1978

POWER SOURCES
Rack-mounting supplies adjust over wide range

Switcher models get UL recognition
ACDC Electronics, 401 Jones Rd., Oceanside, CA 92054. (714) 757-1880. $620 to $720; stock.
The JF Series of fan-cool ed switching-regulated power supplies boast UL component recognition under standard 478 for electronic data-processing equipment. The switchers generate almost 2 W per in3· Three ver-

sions are available: JF120 (5 V, 120 A); J F150 (5 V, 150 A); J F102 (either 5.2 V, 16 to 80 A or 2.2 V, 0 to 50 A). Regu lation of all models is 0. 1% ±5 mV for either a no-load to full-load change or for a ±10% input-voltage change. Ripple is 10-mV rms max or 50-mV pkpk max. Output voltage returns to wit hin 1% in less than 100 µs fo llowing a 50% load step. The package for all three unit s is 5 X 8 X 101/2 in.
CIRCLE NO. 365

A copian, Easton, PA 18042. Tom Skopal (215) 258-5441 . $300 to $370; 1 wk.
Rack-mounting power supplies provide output-voltage ranges between 0 to 6 and 0 to 50 V de and output current to 16 A. The output voltage and current limit-point adjusts continuously from zero to maximum ratings, either by means of the built-in controls or with external programming resistances. Options include metering, overvoltage protection and 210 to 250-V-ac input. Line and load regulations are ±0.005% or 2 mV and ripple is 0.25 mV rms. Height of the units are 3.5 and 5.25in.
CIRCLE NO. 363
UL-recognized switchers have one to seven outputs

LH Research, 1821 Langley A ve., Irvine, CA 92714. Wally Nuss lock (714) 546-5279. $0.65/W.
Eight single and multiple-output switching-power-supply models in the MM Series are recognized under UL 478. The number of outputs produced by various units ranges from one through seven. Total power for a ll outputs is either 375 or 750-W, depending on the model.
CIRCLE NO. 364
ELECTRON IC D ES IGN 5, March I, 1978

±15Vsupplies were common ltl ) industry standard DAC80 an<! models and built more of these popular~Wi!M Now, MOS memories and µP's demand .t1:2V sr.ipp Ill design problems we've set the standard once ag81n- · Wfffi ADCBOZ models that cover the ±11 .4 to ±16.0V and +SV supply
Everything else stays the same: ±12V DAC80: 12-bit resolution , ±1 /2 LSB max linearity, .:30 ppm/°C max gain drift and 300 nsec settling time to +0.01% FSA. Price:(100's) $19.50. ±12V ADC80: 10 and 12 bits, 25 µsec max conversion time, ±1/ 2 LSB nonlinearity, internal reference, clock and comparator. Price: (100's) $49.50. Ca ll-write for specs on a ful l line of data conversion products, inc luding 8to 16- bit hybrid DAC's . BURR-BROWN, P.O. Box 11400, International Airport Industrial Park, Tucson , Arizon a 85734, Phone: (602) 746-1 11 1.
BURR-BROWN
IEIEll
Putting Technology To Work For You
CIRCLE NUMBER 58
99

New literature
1/20 and 1/10 hp motors
Specifications and schematics on a series of motors and gear motors with input horsepower ranging from 1/50 to 1/10 are shown in a brochure. Molon Motor & Coil, Rolling Meadows, IL
CIRCLE NO. 366
Circuit breakers
Photographs, dimensional drawings, delay curves, specifications of a snapaction magnetic circuit breaker are given in a four-page bulletin. Airpax Electronics, Cambridge, MD
CIRCLE NO. 367
Industrial control µC
The IP300 industrial-control-microcomputer system is described in a brochure. The publication discusses operational advantages, hardware features and system software of the IP300. The pamphlet contains a configuration summary listing standard systems, options, and both digital and analog 1/0 modules. Digital Equipment Corp., Communication Services, Northboro, MA
CIRCLE NO. 368
Silicon photodetectors
A 24-page electro-optic-components catalog reviews the physical and electrical properties of silicon photodetectors, providing basic information on structure, response, sensitivity limits, temperature effects and equivalent operating circuits. Centronic, Mountainside, NJ
CIRCLE NO. 369 100

PC board laminates
Copper-clad laminates for printedcircuit boards are described in a foldout brochure. The illustrated six-page brochure contains a comprehensive, easy-to-read table that lists applications and technical specifications for each of the many laminate grades and compositions available. Westinghouse Electric, Micarta Div., Hampton, SC
CIRCLE NO. 370
Op amps
Data sheets on 18 operational amplifiers and 22 fast analog-function modules plus a microcomputer are included in a 92-page catalog. A selection guide indexes op-amp modules by slewing rate, by gain-bandwidth at XlOO, and by settling time to 0.1%. Optical Electronics, Tucson, AZ
CIRCLE NO. 371
Pressure transducers
Two bulletins describe 0 to 5-V-dc isolated-output signal, bonded straingauge pressure transducers. Teledyne Taber, North Tonawanda, NY
CIRCLE NO. 372
UL standards
"Catalog of Standards for Safety" is an easy and quick reference guide to UL's 396 published standards. Underwriters Laboratories, Northbrook, IL
CIRCLE NO. 373
Magnetics
The use of custom magnetics in modern circuits and application information on wideband, rectifier, and pulse transformers and inductors are discussed in a 14-page booklet. Polyphase Instrument, Bridgeport, PA
CIRCLE NO. 374
GP and power relays
Specifications, characteristics, wiring diagrams and dimensional drawings for more than 1200 stock and special relays are included, as well as socket information, in a 56-page catalog. A relay selection chart guides the user to the proper relay class which fits his particular requirements. Magnecraft, Chicago, IL
CIRCLE NO. 375

Signal processors
A brochure describing the new SPS-61 and SPS-81 programmable digital signal processors features a unique set of comparisons that clearly explain the difference between array processing and real-time signal processing. Signal Processing Systems, Waltham MA
CIRCLE NO. 376
Semiconductors
"Integrated Circuits Reference Book 1978," Vol. 1: Analog Circuits ($29.50) and Vol. 2: Digital Circuits ($29.50) lists details of all ICs, with a PRO ELECTRON type number, which are available on the market. It is an upto-date reference source of ICs made in Western Europe. "Semiconductor Reference Book 1978" ($35.00) is a revised and updated Fifth Edition listing the technical characteristics of every semiconductor device made in Western Europe with a PRO ELECTRON type number, which is on the market. Both books include an explanation of the PRO ELECTRON code, a list of the symbols used and a glossary in English, French and German. Scholium International, Flushing, NY
CIRCLE NO. 377
Rf coaxial connectors
A 36-page catalog features the SMA series of rf coaxial connectors. ITT Cannon Electric, Santa Ana, CA
CIRCLE NO. 378
Digital cassette recorders
Descriptions, specifications and application information on low-power recorders for data logging, data loggers with crystal-controlled clocks, universal readers, incremental and continuous read/write cassette systems, OEM incremental transports and ANSI-compatible high-speed continuous recorders are covered in 16 illustrated pages. Block diagrams, outline drawings and timing sequences are also included. Memodyne, Newton Upper Falls, MA
CIRCLE NO. 379
Connectors
Cinch Nu-Lok environment-resistant coaxial cable connectors that meet MIL-C-25516 are fully described in a 16-page catalog. TRW Cinch Connectors, Elk Grove Village, IL
CIRCLE NO. 380
EL ECTRONIC DESIGN 5, March I, 1978

Bulletin
board

Raytheon Data Systems Co. has doubled the main memory of its PTS-100 programmable terminal systems and increased the number of operator stations those systems can support.
CIRCLE NO. 381

Longer shelf life, high reliability, and no degradation in power output over operating life are among the advantages of a new hard seal construction technique now being offered on Hughes Aircraft Co.'s line ofheliumneon lasers.
CIRCLE NO. 382
Intel's Microcomputer Components Div.'s 6-MHz 8748 single-chip microcomputer, which was priced at $275 in single-unit quantity and $150 in 100unit quantity, is now priced at $75 and $48, respectively.
CIRCLE NO. 383
Blank cards for programming Hewlett-Packard's HP-67 and 97 calculators are now available at a reduced price-$195 (1000 qty).
CIRCLE NO. 384
Data General has added comprepensive data communications capabilities to its microNOVA family, giving users the ability to implement asynchronous and synchronous protocols and run Data General's RJE80 (IBM 2780/ 3780) and IBM HASP II emulation packages on a microcomputer system.
CIRCLE NO. 385
Elco's Series 6307, 6064, 6007 and 6308 card-edge connectors are now U.L. approved.
CIRCLE NO. 386
Opcoa's OP· 004 series stud-mount GaP LED panel lamps come with 6in. insulated leads and provide a variety of indicator functions in equipment requiring LEDs with long lead lengths. The typical luminous intensity at a forward current of 15 mA is 2 med with viewing angles of 60° and 120°. These units come in red, green, and yellow.
CIRCLE NO. 387
ELECT RON IC D ESIGN 5, March I, 1978

Rockwell MOS/LSI TouchTonedetection can get you into more products.
CRC-8030, Rockwell's MOS/LSI digital Touch Tone®detector, can open up new markets for your products by providing a low cost, high performance solution for dual tone multi-frequency (DTMF) detection.
A product ofCollins high-technologytelecommunications experience coupled with Rockwell's extensive MOS/ LSI production capability, CRC-8030 has been in quantity production for over a year. Besides traditional telephony systems, it can be used in a growing number of applications including computer signaling and control systems.
CRC-8030reducescosts versus conventional systems (in some cases as much as one fifth the cost) and offers the size and reliability benefits of MOS/ LSI. You get: detection in 22-39 MS; on-chip oscillator operating at 3 .579545 MHz color burst crystal frequency; binary or 2 -of-8 coded outputs; operation with single or dual power supply.
The CRC-8030 performs the key critical functions of DTMF detection. To implement a complete DTMF receiver, a number of front-end band-split filters are available. And, if you need DTMF-to-dial pulse conversion, use the CRC-8030 in conjunction with Rockwell's MOS/LSI Binary-to-Dial Pulse Dialer, the CRC-8001.
For more information on telecommunications devices and applications services, contact your nearest Hamilton/ Avnet distributor. Or use the coupon below.
Touch Tone is a registe,..ed trademark of AT & T.

Get the full story.

ED-3/1

Microelectronic Devices Rockwell International P.O. Box 3669, Anaheim, CA 92803 Attn : Marketing Services D/727 RCSS · (714) 632-3698

I want informatio n on D CRC·8030 D CRC-8001 D Send it by mail D Have a salesman call me.

Name

Title _ _ _ _ _ _ _ _ _ _ __

Company _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _~

Address _ _ _ _ _ _ _ _ _ _ _ _ _ _ City _ _ _ _ _ _ _ _ _ __

'!' State _______ Zip Code ____ Telephone _________ Rockwell International

...where science gets down to business

IOI

Applieation notes
Power supplies
Power-supply decoupling, preloading and input-transient-suppression methods are treated tutorially in the latest issue of WATTS UP. The 12-page journal includes descriptions of significant new ac/dc and de/de power supplies, plus recent technical literature. Semiconductor Circuits, Haverhill, MA
CIRCLE NO. 388
Capacitance-type switching
A capacitance-switching technique that employs standard microcircuits is described in a 16-page designer's guide. Included are curves and nomographs. American Microsystems, Santa Clara,
(;A CIRCLE NO. 389

Spectrum analyzers
The advantages and potential that can be obtained by interfacing a spectrum analyzer to the computational power and analysis of a computer are discussed in a four-page application note. Marconi Instruments, Northvale, NJ
CIRCLE NO. 390
Soldering problems
"Common Production Soldering Problems: Causes and Cures" details the problems encountered in hand, dip or wave soldering. For each problem a complete visual description is provided for quick identification. Multicore Solders, Westbury, NY
CIRCLE NO. 39 1
V/f and f/v converters
Twenty-five applications on both v/f and f/v converters are given in an application note. Teledyne Semi.conductor, Mountain View, CA
CIRCLE NO. 392

Microcircuit packaging
An "Encyclopedia of Hybrid Microcircuit Packaging," a 74-page booklet, contains nearly 300 subjects, from "A.I.D." to "zymurgy," and 170 illustrations. Qualified persons in the hybrid-microcircuit industry may obtain complimentary copies of the encyclopedia. Isotronics, New Bedford, MA
CIRCLE NO. 393
X-Y recorder
The most important features required in a full-capability X-Y recorder are described in a 4-page data sheet. Using the Model 7015B X-Y recorder as an example, the brochure discusses the importance of the internal time base, matched input filters, remote pen lift, TTL-level remote control, autogrip chart hold and paper-alignment guides as well as construction features and product support. Hewlett-Packard, Palo Alto, CA
CIRCLE NO. 394

odds·on choice NEW! From · CAPllOL - k-

There's no need to gamble with selectlvlty that stays put

when you specify Murata piezoelectric ceramic filters.

Whether your appllcatlon Is AM, TV, FM-stereo or CB, we

have Just the 455 KHz, 10.7 MHz or 4.5 MHz filter to do the

Job. What's more, we have a variety of ladder type con-

- -=---=------ figurations specifically designed for critical communlca· tlons requirements. Write for

R .... ' . ._.IAll.,j_.,___

._.a._
-~!..~

complete technical and appllca· tlon Information to: Murata Cor· poratlon of America, 1148 Franklin Road, S.E., Marietta,

CORPORATION Georgia 30067. Phone: 404·

OF AMERICA 952-9777.

first In ceramics

CIRCLE NUMBER 59 102

MODEL MLA
LEVER SWITCH
A panel- mount switch with one- piece molded cam and handle. It extends onl y 15/s" beh ind panel. Extremel y smooth operation with positive detent action .
COMPLETE SPECIFICATIONS IN NEW BROCHURE

CAPlrOL

The Capitol Machine &SwitchCo.
87 Newtown Road, Danbury, CT06810 203- 744- 3300

CIRCLE NUMBER 60
ELECTRONIC D ESIGN 5, March I, 1978

quickod1

New and current products for the electronic designer presented by their manufacturers.

Electronic oesiun

MINIATURE CERAMIC TRIMMER CAPACI· TORS 9371 series of ceramic trimmer ca -
pacitors are compact, economical and rugged. They' are 50% smaller than other trimmers of this type yet provide high ca pacitance values. Available in 4 capaci-
tance ranges, 1.5 to 4, 3 .0 to 10, 3 .5 to
18 and 5.0 to 25 pf with Q's > 300 at
10 MHz. They have an overall diameter of .225" with .215" above board height. JOHANSON MANUFACTURING CORPORATION , Rockaway Valley Road, Boonton, N.J. 07005 201-334-2676

TRIMMER CAPACITORS

181

FIGARO GAS SENSOR TGS is a gas sen· sitive semiconductor. When combustible gas is absorbed on the sensor surface, a marked decrease of electrical resistance occurs. Major features of the sensor in· elude high sensitivity, long term reliability and low cost. The applications are: GAS· LEAK ALARM, AUTOMATIC FAN CON·
TROL, FIRE ALARM, ALCOHOL DETEC· TOR, etc. Figaro Engineering Inc., North
America Office-3303 Habor Boulevard, Suite D·8, Costa Mesa, Calif. 92626 Tel:
(714) 751-4103 Telex: 678396

GAS SENSOR

184

~
YOU'LL GET IT THE DAY BEFORE YOU ORDER IT as soon as we perfect a time· travel machine. Meanwhile 3 working days is typical turn-around for rack-mounting chassis units, card cages, desk-top & floor-standing cabinets, mini-consoles, subassembly housings. Circle our number or phone Techmar, 213·478·0046, and stand away from the door!

ENCLOSURES

182

HARDWARE MATHBOARD-RAM SAYER!! performs logarithmic & trigonometric
functions, e', y\ multiply, add, divide,
subtract, etc., etc., 8 digit mantissa, 2 digit exponent, very fast (comparable with

in-system software) Compatible with M6800 Microprocessor KITS AVAILABLE AT

$72.80, $252. $555. A · Board, software, full instructions B · 'A' and all compo· nents, unassembled C · Assembled, inst. manual, sftwr. pkg. WOODTRON LTD., PO. BOX 4067, STATION "C", CALGARY, AL·

BERTA, CANADA.

HARDWARE MATHBOARD

185

. D., . ~ ' h i.""~"'"

,,~
-.-u! ... _

l'NCH·O TO LtNlAI DCCONVlllU

" . ..

..... .·II" ·
.... 11 ·

. ,, · JO·

Syne;~ro to Linear DC Converter: Infinite Resolution. Full (± 180°) or Limited Angle DC Output (±90°), ±6 or ± 15 minute accuracy at input rates up to 1440° /sec., 60 or 400 Hz input. Custom Output scaling available. Module 2.6" x 3.1" x .82" H. Price from $350 in quantity. Other
CCC Products are Synchro to Digital, Digital or DC to Synchro, Solid State C.T.'s or CDX's, and Absolute Encoders. Send for Free Catalog & Application Notes. Computer Conversions Corp., East Northport,

N.Y. 11731-(516-261-3300).

SYNCHRO TO LINEAR DC

183

Ultrasonic Pulse Generators drive piezo· electric transducers. The plug-in modules simplify ultrasonic system design. High energy outputs available up to 350 volts into 50 ohms, with 10 nsec risetime. Modules contain pulse rep rate clock variable to 10 kHz, or the output pulse may be triggered externally. External sync output pulse coincident with main bang. Trigger, sync TIL-compatible. MetroTek, Inc. (509) 946·0684

ULTRASONIC PULSE MODULES

186

ELECTRONIC DESIGNS function is:
· To aid progress in the electronics manufacturing industry by promoting good design. · To give the electronic design engineer concepts and ideas that make his job easier and more productive. · To provide a central source of timely electronics information. · To promote communication among members of the electronics engineering community.
Want a subscription? ELECTRONIC DESIGN is circulated free of charge to those individuals in the United States and Western Europe who functi on in design and development engineering in companies that in· corporate electronics in their end product and government or military agencies in· volved in electronics activities. For a free subscription, use the application form bound in the magazine or write for an application form.
If you do not qualify, paid subscription rates are as follows: $30.00 per year (26 issues) U.S./Canada/Mexico, $40.00 per year (26 issues) all other countries. Single copies are $2.50 U.S. and all other countries. The Gold Book (27th issue) may be purchased for $30.00 U.S./Canada/Mexico, and $40.00 all other countries.
If you change your address, send us an old mailing label and your new address; there is generally a postcard for this in the magazine. You will have to requalify to continue receiving ELECTRONIC DESIGN free.
The accuracy policy of ELECTRONIC DESIGN is : · To make diligent efforts to ensure the accuracy of editorial matter. · To publish prompt corrections whenever inaccuracies are brought to our attention. Corrections appear in "Across the Desk." · To encourage our readers as responsible members of our business community to report to us misleading or fraudulent ad· vertisi ng. · To refuse any advertisement deemed to be misleading or fraudulent.
Individual article reprints and microfilm copies of complete annual volumes are available. Reprints cost $6.00 each, prepaid ($.50 for each additional copy of the same article), no matter how long the article. Microfilmed volumes cost $23 for 1976 (Vol. 24); $30 for 1973-75 (Vols. 21-23), varied prices for 1952-72 (Vols. 1-20). Prices may change. For further details and to place orders, contact Customer Services Dept. University Micro· films, 300 N. Zeeb Rd., Ann Arbor, MI 48106. (313) 761-4700.
Want to contact us? If you have any com· ments or wish to submit a manuscript or article outline, address your correspondence to:
Editor ELECTRONIC DESIGN 50 Essex St. Rochelle Park, NJ 07662

quick ad1

New and current products for the electronic designer presented by their manufacturers.

Free New catalog contains over 34,500 quality power supplies from the world's largest manufacturer, Power/Mate· Corp. Power Supplies for every application including submodulars, open frame, vari-
rated, encapsulated, laboratory & system. All units UL approved and meet most
military and commercial specs for industrial and computer uses. Power/Mate Corp., 514 S. River St., Hackensack, NJ 07601 (201) 343-6294

POWER SUPPLIES

187

HIGH STABILITY LOW COST QUARTZ CRYSTAL for µ.-processor and clock oscil lator. Accuracy is ±0.002% at 25°C, Fre-
quency change over -10 to + 55°C is
within ±20ppm. 1.000, 1.8432, 2.000,
2.097152, 2.4576, 3 .2768, 4 .0000, 5.0000, 5,0688, 5.1850, 5.7143, 6.5536, 10.0000, 18.0000, 18.4320, 20.0000,
22 .1184 lmmed . Dlvy. $1.85 ea . 10 MHz up in HC-18/u; (Min. 100 pcs.) Q·MATIC CORP., 3194-D Airport Loop Dr., Costa
Mesa, CA 92626, (714) 545-8233, Telex 678389

CRYSTAL

190

METHODE BUS BARS REPLACE MAZE OF COSTLY CABLE HARNESSES in computer, communications, industrial control systems. Fifteen years custom design experience, plus innovations like extra-strength
staked and soldered .025" pins, puts METHODE first in bus bar designs for both military and commercial applications . . . FREE Design Guide or call our Cus-
tomer Engineering Service Dept., Methode Manufacturing Corp., 1700 Hicks Road,
Rolling Meadows, IL. 60008. (312) 392·
3500.

BUS BARS

193

Paladin Corporation introduces the first truly easy-to-use, efficient, coaxial wire
stripper. The Paladin Coaxial Stripper will strip every coax wire with an O.D. be· tween .14 & .30 inches. Its compact body (3.5 in.) and light weight (1 Oz.) allow for use in areas which previously prevented post-stripping coax wires. The tool has removable cassette blades which are rated for up to 10,000 strips. PALADIN CORP., 2680 Valencia Circle, Thousand Oaks, CA 91360, (805) 492-2853

COAXIAL WIRE STRIPPER

188

MAGNETIC SHIELDING Take advanta ge of Eagle 's 23-year background in shield de· sign and production . Custom and stand · ard models . Full service includes desi gn, en gineering, fabrication. heat treatin g, finishin g, testin g. Also wide selection of sheet and foil so you can form your own shields . For helpful design and cost data, request Bulletin E·77 . Eagle Ma gnetic Co., Inc ., Box 24283 , Indianapolis , IN
46224 , 317·297-1030.

MAGNETIC SHIELDING

191

VARIAC® AUTOTRANSFORMERS There are hundreds of Variac continuously ad· justable autotransformer mode Is for smooth control of ac voltage to regulate light, heat, power, current, motion and speed. Metered, ganged, motor-driven, remote-controlled, high frequency single and three-phase models with optional overload protection, ball-bearings and microswitches. Ask us about your special application requirements. GenRad, 300 Baker Ave., Concord, MA 01742, 617· 369-8770.

GEN RAD

194

?...L r---· t--"' H . II ORILL
_r._. -i-. . . . . . .
11 Ll CUllDE MSS
~! ,. · ---

NEW 3-LEAD TRANSISTOR SOCKETS from Methode have an extended funnel -shaped lead-in which eliminates the need for tran-
sistor lead preforming or trimming. Also, ideally suited for automatic insertion of transistors into the socket. Contacts are reliable dual leaf cantilever type of phosphor bronze with tin plating. Insulation is flame retardant polyester rated 94VO. Methode Electronics, Inc., 1700 Hicks Rd., Rolling Meadows, IL 60008. (312)
392-3500.

3-LEAD TRANSISTOR SOCKETS

189

NO ETCH BREADBOARDS . . . WIREWRAP BREADBOARDS with isolated pad

drill-mill construction. Quickly duplicate any etched board ; build circuits from full-

size artwork. Add components to and/or change circuitry of previously etched

boards. Complete freedom in wire-wrap design/layout. Ideal for high frequency ground plane construction. A kit of three

IP6003C with # 60 carbide drills, $30.00 ($12 .50 ea.) . A. F. Stahler Company, P.O.

354, Cupertino, CA 95014 (408) 252-

4219.

NO ETCH BREADBOARDS

192

CGH Metal Glaze Resistors from TRW op· erate in high ambient temperatures with excellent high voltage load stability. These
thick film resistors are particularly suited for precision high voltage and high im· pedance applications such as voltage multipliers, X-ray equipment, and high voltage power supplies where precision
tolerances and TCs are required. TRWI
IRC Resistors, an operation of TRW Elec· tronic Components, 401 N. Broad St., Phila ., Pa . 19108. (215) 922-8900.

CGH HIGH VOLTAGE

195

MINl/BUS:ID BY ROGERS, low-cost, low· inductance, high capacitance printed cir· cuit board bus bars for noise reducing voltage distribution, are available in a variety of ready-to-ship designs. Prototype kits are also available from stock. Call or write Mini/Bus product specialist for a complete list. Rogers Corporation, Chandler, AZ 85224. Phone: (602) 963-4584. (EUROPE: Mektron NV, Gent, Belgium; JAPAN: Nippon Mektron, Tokyo.)

BUS BARS

196

UNIVERSAL JUNCTION UNIT . . . for three devices, RS232C or current loop.
... Six switches provide all 63 interconnects that are possible between three 1-0 devices. LED's indicate data flow. . . . . . . Designed to provide circuit com· patibility and easy data routing between different manufacturer's devices. . . . . . . $350 (1-4) from DIGITAL LABORA· TORIES, 600 Pleasant St., Watertown, MA 02172 (617) 924-1680

3 PORT RS232 & 20 MA LOOP

197

FAST, RELIABLE DISCHARGE PRINTER DC-1606B/DC-2106D prints 16 or 21 column alphanumerics in a 5 x 7 dot matrix format. Its MTBF is 5.5 million lines on a 2.25" paper costing less than a half a cent a foot. 3.8" H x 5.4" W x 5.5" D, it is as low as $99 in 100 quan· tity. Interface electronics and power supply available. HYCOM, 16841 Armstrong Ave, Irvine, CA 92714 714/557-5252.

DISCHARGE PRINTER

200

.,DDRMEYER

DORMEYER COACH'S NEW 12-PAGE CAT· ALOG ON COMMERCIAL USE TRANS· FORMERS offers quick reference application help. A wide variety of channel frame and bracket mount open coil 120/30 VAC transformers; Universal Mount control units with 5, 10, 12, 20, 40 and 55 VA ratings are described. Electrical data, load curves and mounting data is given

on these U/L and CSA listed or recognized transformers. Dormeyer Industries,
Dept. QA 3418 N. Milwaukee Avenue, Chicago, IL 60641, (312) 283-4000.

TRANSFORMER CATALOG

201

TIMECO INC.
tltftooH··
MAIUFICTUR£RS Of PRECISION
~-COlfllCllll[YJC[.$
!~
- 1 ~ ~--~ ~
···I·· _____ ! ..-.._

Free 16 Page Catalog from Timeco, Inc. describes line of Time Delay Relays and other timing devices. Included are On Delay, Off Delay, Interval (one-shot) and Repeat Cycle units. Units are available for DC Voltage from 12 to 120 and AC
from 12 to 220. Also AC/DC units as well as 50 Cycles. Time Ranges from .02 Seconds to 16 Minutes. All Units are Guaranteed for 1 Year and over 150,000 are in service.

TIME DELAY RELAY CATALOG

202

Free 1978 Catalog of Recorder Products.
Complete description of all Memodyne incremental and continuous digital cassette recorders, data loggers, transports, universal readers and high speed record ·
ing system with illustrations, block dia· grams, mechanical dimensions and timing sequences are contained in this new catalog. Accessories, supplies, cassettes
and a price list are also included. Write for your free copy! Memodyne Corpora· tion, 385 Elliot Street, Newton Upper Falls, MA 02164 (617) 527-6600

FREE RECORDER CATALOG

203

Electronic Design
Advertising Sales Staff Susan G. Apolant Sales Coordinator
Rochelle Park, NJ 07662 Robert W. Gascoigne Thomas P. Barth Stan Tessler Constance McKinley 50 Essex St. (201) 843-0550 TWX: 710-990-5071 (HAYDENPUB ROPK)
Philadelphia Thomas P. Barth (201) 843-0550
Boston 02178 Gene Pritchard P.O. Box 379 Belmont, MA 02178 (617) 489-2340
Chicago 60611 Thomas P. Kavooras Berry Conner, Jr. 200 East Ontario (312) 337-0588
Cleveland Thomas P. Kavooras (312) 337-0588
Los Angeles 90045
Stanley I. Ehrenclou Burt Underwood 8939 Sepulveda Blvd . (213) 641-6544
Texas Burt Underwood (213) 641-6544
San Francisco Robert A. Lukas 465 S. Mathilda, Suite 302 Sunnyvale, CA 94086 (408) 736-6667
England Constance McKinley 50 Essex St. Rochelle Park, N.J. 07662 Phone: (201) 843-0550
Europe Sanders, W. J. M. Raadhuisstraat 24 Graft-De Ryp, Holland Phone: 02997-1303 Telegrams: Eu radtea m-Amsterdam Telex: 13039-SIPAS
G. Nebut Promotion Presse Internationale 7 ter Cour des Petites Ecuries 75010 Paris, France Telephone: 5231917, 1918, 1919
Dieter Wollenberg Erikastrasse 8 D-8011 Baldham/Muenchen Germany Telephone: 0 8106/4541
Tokyo Haruki Hirayama EMS, Inc. 5th Floor, Lila Bldg. , 4-9-8 Roppongi Minato-ku, Tokyo, Japan Phone: 402-4556
·-·w Cable: EMSINCPERIOD, Tokyo
~ABP

ALL THE INFORMATION ON MICROPROCESSOR SELECTION AND SOFTWARE IN ONE CONVENIENT SOURCE!
· First appeared in Electronic Design Magazine!
· Over 30 manufacturers represented!

The manual includes a complete data page for each microprocessor or family of processors, with a complete description of the processor, its family of support circuits, architecture, available software, and the unit's instruction set.

------------------------ MICROPROCESSOR DATA MANUAL Edited by Dave Bursky
Send to: HAYDEN BOOK COMPANY, INC.

Other sections include:
· the pitfalls to avoid when choosing a specific model;
· micro fundamentals
I and a glossary of

50 Essex Street, Rochelle Park, N.J. 07662

I terms;

Please send me MICROPROCESSOR DATA MANUAL (#5114-X,

I · a report on floppy-disc

$7.95) on 15-day examination. At the end of that time, I will send payment, plus postage and handl ing , or return the book and owe nothing.

I I I

·

drives; background information on micro

I selection and software.

I Firm _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ __

I

Address_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ __ I Make your micro

City/State/Zip_______ _ _ _ _ _ _ _ _ _ _ I decisions easier! Order

1a-oos I your copy today!

SAVE MONEY! If you send cash with order, publisher pays postage and handling. Same return guarantee. Price subject to change without notice. Offer good in U.S.A. and Canada only.
106

: [JJ
·------------------Eu:CTRO 1c D ES IGN 5, Ma rch I, 1978

Electronic Design recruitment and classified ads

PLACE YOUR AD AT ONLY $55 PER COLUMN INCH IN

Eleclronlc Design

- GET A REPEAT AD FREE!
With our 2 for 1 plan, your net cost in Electronic Design is only $27.50 per column inch, lowest among all the national newspapers and electronics media . You get a total of 165,418 exposures to EDEM engineers and engineering managers (not counting 11 ,668 more among general or corporate managers) at only 33¢ per thousand! You can 't beat the price. You can't beat the coverage and you can't beat the quality.

YOU REACH ENGINEERS WITH TITLES LIKE THESE:

· Chief Engineer · Development Engineer · Design Engineer · Project Engineer · Electronic Engineer · Engineer-Supervisor · Section Leader · Staff Engineer · Systems Engineer · Test Engineer · Standards Engineer · Master Engineer

EleclronlcDeslgn RECRUITMENT ADVERTISING RATES

15% commission to recognized agencies supplying offset film negatives. 2% 10 days , net 30 days. Four column makeup. Column width 1-314" x 10".

SPACE
One column inch 2 col. in. 1/1 6 page (1 /4 col.) 118 page (1 /2 col.) 1/4 page (1 col.)
1/2 page (2 cols.)
3/4 page (3 cols.) 1 page

DIMENSIONS

Wide

Deep

1-314" x 1"

1-314" x 2"

1-314" x 2-112"

1-3/4" x 5"

1-3/4" x 10" Vert.

3-1 /2" x 5" Hor.

3-1 /2" x 10" Vert.

7"

x 5" Hor.

5-1/4" x 10"

7"

x 10"

COST
$55. $110. $130. $275. $550.
$1100.
$1650. $2200.

NOTE: EACH RECRUITMENT AD YOU PLACE WILL BE REPEATED FREE OF CHARGE!

LATE CLOSING DATES

Electronic Design is mailed every two weeks. Because of its timeliness. personnel recruitment · dvertising closes only two weeks before each issue's mailing date.

Issue Date

Recruitment Closing Date

Malling Date

Mar.15 Mar. 29 Apr. 12 Apr. 26 May 10 May 24 June 7

Feb. 17 Mar. 3 Mar. 17 Mar. 31 Apr. 14 Apr. 28 May 12

Mar. 3 Mar. 17 Mar. 31 Apr . 14 Apr . 28 May 12 May 26

HOW TO PLACE YOUR AD
CALL THE RECRUITMENT HOT LINE 201·843·0550
Camera-ready film (right reading negatives, emulsion side down) or cameraready mechanicals must be received by deadline . Or. if you wish us to set your ad (typesetting is free) simply pick up the phone and call our RECRUITMENT HOT LINE - (201) 843-0550. Ask for:
Constance McKinley
RECRUITMENT ADVERTISING MANAGER ELECTRONIC DESIGN
50 Essex Street. Rochelle Park. New Jersey 07662

ELECTRICAL ENGINEERS

ANALOG Engineers to design test stands and associated electrical/electronic controls and data acquistion systems. Experience in solid state closed loop analog control systems.

DIGITAL Engineers to design the hardware. and software of digital computer based equipment used in the testing of high speed rotating machinery and mechanical actuating equipment. Experience in Assembly and Fortran programming of mini-computers is required .

ANALOG/DIGITAL Engineers to design control circuits for turbine systems and other high speed machinery. Must have experience in both analog and digital control circuit design .
Sundstrand Corporation's Advanced Technology Group designs, manufactures and markets a variety of aircraft accessory products. Sundstrand offers an excellent benefits package including an extensive medical and dental plan. We are located in Rockford, Illinois , providing for easy access to Chicago and to the recreational areas of southern Wisconsin .

Send resumes to:

SUNDSTRAND CORPORATION Peter L. Arthurs 4751 Harrison Avenue Rockford, IL 61101
An Equal Opportunity Employer. M/ F

Eu CTRON 1c D ESIG 5, March I, 1978

107

MANAGER
APPLICATIO!'WS El'WGll'WEERll'WG to 825,000
Our cltcnl Is a leader in the commercial electronics field and one of the most dynamic and successful among the 1000 lnrA"est Industrial corporations. They seek n marketing minded multi-project, state of the art cn~lncer to direct an application engineering group. This is an exceptional career opportunity for a BSEE to broaden an en~l nccrlng career through association with sales markellng and project manugemcnt responstbllfllcs. Our client Is un cquul opportunity cmploycr-'.\t / F uncl pnys all employment expenses . Reply In conrtclcncc to P . Lu11tn~cr.
'~f'J. W. Willard Associates, Inc. (agency!
One Lincoln Center Syracuse, New York 13202 (315) 422·5111
POWER SUPPLY ENGINEERS
Junior and Senior Level Relocation to Dallas, Texas Area
Heavy experience with DC to DC, linear, and high frequency switchers. Openings on all levels with a rapidly ... growing high technology company. Send resume or contact
REACOR, INC.
718 Lingco Drive, Richardson, Tex. 75081 or call (214) 231-7218
SYSTEMS PROGRAMMERS
· Assembler Language · New Systems development · Business applications · Requires 1-4 years' experience
with major operating systems · Competitive salaries. benefits · Maryland countryside location Principals only, please. All inquiries confidential.
Mr. W.T. Myers Director of Personnel Management Executive Plaza IV Hunt Valley , Maryland 21031 301 / 667-9211
An Equal Opportunity Employer M/ F
ln*ESIQMt:
DISPLAY DATA CORPORATION
HOW TO PLACE YOUR AD CALL THE RECRUITMENT
HOT LINE 201 ·843·0550
108

"' SYSTEMS ENGINEERING:
FIRST IN TRUE 32-BIT MINIS
FIRST IN REAL TIME SOLUTIONS
FIRST IN CAREER OPPORTUNITY
ALLIN FORT LAUDERDALE

We're putting more bytes to work in a real time environment than anyone else 1n the industry. For almost 2 decades. we've bred

a family of pacesetting systems. culminating in the first true 32-bit

super m1n1 . not a bridge -the -gap system from 16 bit architecture.

but a true 32-bit machine with richer instruction sets and larger

directly addressable memory.

This kind of presence means opportunity is here . now .along

with the resources to really make a name for yourself. If being on

the cutting edge of technology. surrounded by year round warmth

and swaying palms sounds inviting . consider the many ways avail-

able for you to grow at Systems Engineering.

We welcome the professional who 1s highly motivated in the

.

direction of creativity. fresh conceptuahzation. and imaginative problem-solving in state-of-the-art design and software development of small to medium real time systems

~I' CONTRACT ADMINISTRATOR Senior Level . With Program
~ Management Capability. We require experience , ability and effectiveness ~ at all levels of management in negotiating , drafting . enforcing , and ~ administering fixed-price government and industrial contracts and ~ knowledge of ASPR , and computer systems . Background is essential in ~ either legal, business , or engineering areas. Some travel.

PROJECT ENGINEERS BSEE andexperiencewithjobcosting of
custom computer systems.

PROJECT LEADER BSEE and minimum of four years experience
as Group Leader involved in job costing for custom computer systems.

MICROPROGRAM MER Minimum of one year design experience in
FIRMWARE design. Work involves state-of-the-art advanced concepts .

SENIOR ENGINEERS (DIGITAL) Four years experience 1n
LOGIC DESIGN. Microprocessor or CPU experience highly desirable. Work involves Custom Systems Group.

SOFTWARE TECHNICAL INSTRUCTOR Twoormoreyears
teaching computer software courses in industry or academia. Must have knowledge of ASSEMBLY and FORTRAN language.

~l~!~u~~k~~~~~~ 12t~Wla~~u~!Y~o~!~!i~!'!~Js~~s~
background in FORTRAN . Real Time and inter-CPU COMMUNICATIONS and Data Base experience preferred.

~!~f~~r~~x~~r:!~~o~ JR~a1!i~~o~ ~n~ ~~pl~~l~:~r~;~e~~:
As semblers and FORTRAN required .

MTS PROGRAMMER (CUSTOMER SERVICE) Minimum
of three years in ASSEMBLY and FORTRAN LANGUAGE . Programming background in Real -ti me and applications environments. Customer contact experience desired. Some travel.

TECHNICIANS DIGITAL 1/ 0 and CPU experience desirable. Will
work closely with digital design engineers. Two years experience in troubleshooting..and testing preferred.

DESIGNER Three to ten years experience 1n electro-mechanical
design for a computer manufacturer.

SYSTEMS offers top start1nq salaries. relocation to beautiful Fort Lauderdale, a full-range benefits program including dental insurance. savings/ retirement plan and 100% tuition refund. and the opportunity to work and advance your career in a stable and stimulating professional environment. For immediate and confidential cons1derat1on. please forward resume or detailed letter of information, including current annual compensation to:
MR. FRED BRILLANTE, Dept. ED

ENGINEERING LABORATORIES
8901 W..t Sunrise Blvd., Fort LauderUle, Floria 33313
EQual °""""""''Y Employe< ...../ femolo
Constance McKinley
RECRUITMENT ADVERTISING MANAGER l!LECTRONIC DESIGN
50 EHex Street, Rochelle Park, New Jersey 07662
faEcTRo 1c DESIG 5, March I, 1978

have a
gripe?
let ;iis know
about it! We'll help you put pressure on any company that makes promises in its ads .. . then fails to deliver. Electronic Design refuses to run advertisements deemed to be misleading or fraudulent. ACCURACY is everybody's business. So if you have a gripe about a misstatement or inaccuracy in either editorial or advertising material in Electronic Design ... tell us about it. We'll do everything we can to find out what happened and see that it's corrected . Notify ... George Rostky Editor-in-Chief Electronic Design 50 Essex Street Rochelle Park, New Jersey 07662
110

How Much
Are You
Worth?
INCOME ~OUTGO
In most parts of the country the climate has not been good this winter but the climate has never been betterfor Engineers, Technical , Scientific and Manufacturing people desiring a change. Do you want more money, better location or better growth potential?
If you are looking for a change, look to IPA to assist you . One hundred and thirty-five agencies with offices from coast to coast are at your disposal.
All positions are Employer Fee Paid . No cost to you ever'
If you are looking for more than your present
position offers, send your resume. salary requirements, position objectives and relocation preference to:
Inter-City Personnel Associates, Inc. P.O. Box 1296 Charlotte, N.C. 28231
'The buck doesn't stop here: it starts here"
Research Engineers
Leading Southwest research and development organization has immediate openings for: Senior Instrumentation Engineer - MSEE plus 5 yrs. experience in design and development of analog and digital solid state circuitry and systems . Desirable prior experience should include project supervision , minicomputer interface design, microprocessors and instrumentation development. Senior Electronics Engineer - MSEE or Ph .D. plus 5 yrs . experience in digital communication systems design and testing. Assignments will involve point-of-sale terminal polling strategies and equipment, simulation of digital communication network and systems and error rate prediction . Senior Electronics Engineer - BSEE plus 7 yrs. experience in automatic test equipment using minicomputers and microprocessors. Assignments will include development of automatic test equipment for machinery and electronics. Electronic Engineers - BSEE plus education background or experience in microprocessors systems design , automatic test equipment or digital communications. Wide variety of challenging project assignment. Electrical Engineer - BSEE plus 3-5 years experience with electrical power equipment in offshore/ underwater environments. All positions located in sunny San Antonio. Salary based on qualifications. Excellent benefits. Send resume. with references, in complete confidence to:
Director of Personnel
Southwest Research Institute
P.O. Drawer 28510 San Antonio, Texas 78284
EL ECT RO NIC D ESIGN 5, March I , 1978

Power Supply Ir----------------------------~
I

I I

Designers

I

EFFORTLESS ...
If you 're ready to move on with your career, it can be a lot easier than you expect.

I Explore the rewards and satisfaction of working on new and : exciting communications and experimental satellite programs.
I GOES - NASA's Weather/ Environmental Satellite Program

We are the members of

GM S-2 - Japan's Newest Weather Satellite Program

SBS - Privately Owned U.S. Commercial System

who work extensively with electronics industry leaders. The companies we service have many openings and pay for us to search you out.
Send your resume to the office nearest you. Then sit back and relax while we do the work.

ANIK-C - Canada's Latest National Communications System
Join the Hughes tea m of S pace & Co mmun icat io ns Enginee rs who a re desig ning high voltage (5 to IO KV), space qua li fie d high efficiency power supplies for T WTs. Operati o ns wit h mult iple co llect or T WTs (as loads) prese nt interesti ng des ign challenges.
Experience with series a nd switching regula t o rs, T WM co nverters a nd DC- D C converters a nd BS o r M S in EE a re des ired .

BURTON PERSONNEL SERVICE 300 Walker Bu ilding 120 Boylst on Street Boston, Massachusetts 02116
(61 7) 482-1950
ANDERSON-TAYLOR P.O. Box 21 Exton. Pennsylvania 19341
(21 5) 363-1600
PETER A. KECHIK & ASSOCIATES. INC. 1420 Renaissance Drive Park Ridg e. Ill inois 60068
(312) 298-1148
STAFF DYNAMICS. U.E. 26 Six th Street Stam ford . Connecticut 06905
(203) 324-6191
CAREER SPECIALISTS. INC. 4b00 El Camino Rea l, Su ite 206 Lo s Altos. Ca lifornia 94022
(4 15) 94 1-3200
BRENTWOOD PERSONNEL ASSOCIATES Electronics Division 1280 Route 46 Parsippany , New Jersey 07054
(201) 335-8700
190 associates internationally

For immediate co nsid erat io n please ca ll (co ll ect): Mr. G. Kema ni s, Asst. Mgr.

C o mmunicat ions La bs, a t (2 13) 648-873 1 or se nd yo ur res ume t o: Professio na l

Empl oyment , Dept. 4 1-20, P.O. Box 929 19. Los A nge les , CA 90009.

r------------------1

I

I

I I

l HUGHES:

I I

t

t

L------------------~
HUGHES AIRCRAFT COMPANY

·----------------------------· I Engineering

ENGINEERS SYSTEMS ANALYSTS/

Specialists

"A Professional Approach to Your Career Growth"

A re you at a career impasse? A re your abilities being stretc hed to the fullest? If not , take a positive ap proac h and tal k to the

specialists at Gray Kimball Associates. Our nationwide roster of bl ue-chip c lients have co me to re ly on us in rec ruiting to p-

echelon engineering tale nt . All fees/ expenses p aid by our c lients .

Challenging positions available nationwide include:

RF Engineers
Signal Processing

Digital/Analog Engineers

Phase Lock Loop

.

Spread Spectrum Analysis

Secure Communication

Micro p rocessors Display Systems EW System$

PROGRAMMERS

Nat1o nw1de Profess io nal Fee Pa id Pos1t1ons Salary Range to 35 K Call Collect o r sen d resume to K. Schargus o r
S Nemser fo r immediate attention .

Software/ Hardware

An alog/ Digital

Wea pon Systems

Microprocessors

Sonar/ Radar

Instrument at ion

Electro optics

Test Engi neering

Electro nic Design

Mechanical Design

AMERICAN PERSONNEL SERVICE

240 Slate Street

New London, Conn. 06320 203-442-0395

r
KEEP

Software Engrs/
Programmers
Real-Time Mini-Computer

Reliability/ Maintainability
Engineers

Electronic Design's
GOLD BOOK

Now is the time to arrange a confidential interview with
Lou Basso (516) 799-5400
· GR:1~ y~~B;~~n ~S~QCl~TES INC.
660 Sway , Massapequa , N.Y. 11758 O ur clients are equal oppo rtunity em pl oyers

HANDY
When

You Call

\.

~

ELi:cTRONic D ES IGN 5, March t. 1978

111

semi Advertiser's inde#
CU.STOM

CMOS LSI
· Reduce Your Circuit to a Single Chip with One of Our 14 Master· slices.
· Fast Turn Around - Prototypes in 4 to 6 Weeks.
· Development Cost - As Low As $ 2, 150.
· Quantities from 200 to 200,000 Pieces with Volume Prices as Low as $1.50 Each.
Call
Orhan Tozun or Joe Puhich (408) 735-9370
Or Send for New Brochure:
International Microcircuits, Inc. 3004 Lawrence Expressway Santa Clara, CA. 95051
CIRCLE NUMBER 61

HEWLETT-PACKARD

Model

YourC011 Model

Your Cost

sm ~~ ~:C2~!~1:i::!11 ~~~Ci~P611p1r

~ ~~ ~~~~~~~~H~~ltfH~;r

S596.95 15495

HP 92 Bond Tr·d·r-F1n.nce-Pnnter 496 95 HP 2SC Sc1ent 11t11ns me mory

127 95

HP 25 Sc1ent.-prog11mm1bl1

99.SO HP 27 Comb Bus.-Sc11nce-S111.

138.95

HP 90 R/E-Bus-fin ·200 yr c1l1nd1r 234 95 HP 91 Pnn1er Sc11nt· HP 45 s pecs

HP 21 Sc11n1. slide rule

63 95 HP 10 hind held P1r-mem., small

HP user hb.sohll boolr.1 l4Cl)euh

9.50 HP 22 RI C Busin111-fin1nc1

....25995
139.95

HPeccessonH 1td1scountpnce1
Berween 211naend 3131171, buy one HP-67 or 97, gel S105 worth ol software frH . Buy one

HP·l9C or Z9C. get S37 50 of software frH

We 1111n HP t11nct11sed d11ler Eich unit comes complete with ch1rger, benenes, CHt, manu1ls Ont v11r gu111nt1t by Hewlttt·P1ct1rd Wt will bea t 1nv dt1I. Try us

"'''' TEXASL~~!RUMENTS~

Tl 59 960 prog sttp-100 mt ms S214 95

PC JOOApnnterlorTISS.51-56-52 146.95 Model

Your Cost

~~140A~~11~~:· ~~:~dl~;:.~:;theses ~: ~ ~~.~c:.::~.~l~~·,!~l~;l:~·:~:~:. ':~:~

SR 51-2 Super Shdt Rule-Conv,

48 95 Tl 1750 Thin, will. LCD 2M Hrs, mtm. 17.95

D1t1 Chp pencd thin , LCD 1000 H11 2195 MBA 8 u11ness·Fin1nc1·St1t1

Tll&l:lln11an1Rtpll'(ctlcs

25.95 L1ttl1 Prol lort.1d1Sy1.lup

6U5 12 95

Tl 2550-3 8us1ness·M1morv Tl 5040 Pnnte1·D11pl1v·Memorv Tl 5050M AC-DC printer. memory Tl 1050 Mtm pe1ctnl-1qu111 rool
llbrtntslorT1591ndTl5B
~: ~: :::: :;:: :~p~~=s=~

25 95 Da11-M1n 18111 Pron t duc.

21 .95

'8 95 Tl 5015 P11n111·G,.nd Tot1l·P1rc1n1 64.95

83 95 Tl 5100 Dtsk· D1grt1I, mtm -p11c1nt 43 95

1295 Tl 1025 Memory-Ptrctnl·+ I-

10.95

29.00 TI01g1111Watchts5 1unc1. trom

9.95

~ ~ ~:~·~::.w~Jt.~lO.~a'd:i,~~!~~~

·AH styles

9.9Sup

We1r11Tllr1nch111dd11l1r1ndc1rryTl1ccesson111t d11countpnc11

Wt wtll bt1l 1ny dt1I Try us All Tl ctlculators 111 gu1r1n1eed by TlltH ·n11rum1nts, Inc.

SPECIALS

Mod ti

YourCost Model

Your Cost

Nortlco #185D1cta11n11 unit Norelco #BID1c111Jnqunrt Norelco #l86T11nscnb1ng unit

99.95 Sony KV-214\ R Color Rtmott 21"

619.95

~:~:= ~:~h8~~:Recorder

:~:~

Norelco #NT·lntwdict1ting unit Norelco #97d1Ctal111gor t11nsc No11lca #9Bd1C1at1ngortran1c. NortlcoM1mC11stttt1 Cr11g#2625elect.noteboat
Cr11g #2706Ad1c1111ng f1tan1c

164 00
29100
~ ~
149.00 119.95

Rc:AStltct1vi11on 3M dryphotocopym1ch1nt #l49
rcB~~~c~~~~~~·:.::1~:1ch

819.95 7995
11~:~

A11n co mput TV g1 m1f27 wa r g1mes 1" .95 Phont Mllt-Codt AP ho ne·

SonylCV-120tColorTnnitron12"

309 95 Record A tall-Ans SV'ttms

ctM us

SonylCV-1512 Colorl11n1tron15" SonvKV·IS4JR Color Rematt1S"
SonvKV·l14 lR Colo1 Remo11 17" SonvKV·1921Color l nn1tron 19" Sonv KV-1941R Colar Rtmolt 19"

359 95
: ,,;; 44 9.95 529 95

Chnsmaster II, compul
~:.T~n,~~~d~t~Ct~~'.?1~
Unittta, tlc. pnnt ctlu. Atan p1nb1H TV 111mt

199.95
199.95 e1 llu1
74.95

SonvKV-2101Colorlnmtran21"

559.95

Wo ...,-, ,,-,,-,- _.,,,-,.-~-,-m-,.h-C-,.,-,-,-_.-m.-,-,-4,.-,- ~C- ommod0<0-

APF-Un111ta- Canon- C1110-Sh1rp-Panason1c- S1nyo-81tly--JVCHV G~n-Kosmos-Victor-S1ncl11r-P t1rlcord1r-M1dta al1nn-3MMic1om1-Uovds- 801het---ftockwtll-Sentry Sifts- Walton Gvm tqu1pt --JICA--Ztn1th-Sony-A111t-Phont M111-R1cord A C1ll·Cod1 A Phone ind manv more Over 20,000 um1s. !Try COFFE E PLUS 11 SI 79 per
ont pound can by tht c111 al 24 cans. F1t1qht prtp11d. Good stll t r I

Pnces 111 lob LA. Goods s11b1tC1 10 1vadao~1ty Ast for our t1mou1 e1t1log. Wew1Ubeat1nypncts1flhecompet1t1onh11thegood1on h1nd
AddS3.00lor1h1ppmgh1ndheldc1lcul1tors CA rt11dentsa dd 6%11lt1 t1a.

CIRCLE NUMBER 62 112

AFS Precision Tools ......... . ..... . 104 AMP, Incorporated . . ......... . . . .. 10, 11 Ad vanced Micro Devices............. 4,5 Allen Bradley Co............. . . . .... 16 American Electronics................. 91 Analog Devices, Inc.. . . .. .... . . . .. 12, 13
Bodine Co ., The . . . . . . . . . . . . . . . . . . . . . 95 Bourns, Inc., Trimpot Products
Di vision ... . .......... .. . . ... Cover II Burr-Brown Research Corporation . . . . . 99 Burroughs Corporation ............... 67
Capitol Machine & Switch Co., Inc., The........ . ........... ... . . 102
Centralab/ USCC. ... . . . ....... . .. . . . 82 Citizen America Corpora tion .......... 91 Computer Conversion s Corp .. . . . . . . . 103 Continenta l Specialties Corpor-
ation. . . . . . . . . . . . . . . . . . . . . . . Cover Ill
Dale Electronics, Inc . . . . . . . . . . . . . . 38,39 Data General Corporation ......... 14, I5 Data 1/ 0 Corporation ....... . ....... 18 Datel Systems, Inc. . . . . .. . . .. . .. 71 ,73,75 Deltrol Controls . . . . . . . . . . . . . . . . . . . . . 95 Digital Laboratories.... . . .. . . ... . . . . 105 Dormeyer Industries, Inc .. . .. .. . . ... 105
Eag le Magnetics, Inc ................ 104 *Electronic Design................ 95,96 Essex Group, Sub . of United Tech-
nologies. . . . . . . . . . . . . . . . . . . . . . . . . . . 93
Fairchild Semiconductor, Components Group ........................... . 53
Fairchild System s Technology, A Division of Fairchild Ca mera a nd Instrument Corporation .......................... 16A-B
Figaro Engineering, In c..... .. .... ... 103
Gen Rad ...................... . .. . . 104 *Gold Book, The. . . . . . . . . . . . . . . . . . . . 97
Hayden Book Co........... . . . . . . . . 106 Heinem ann Electric Company ........ . 95 Hewlett-Packard . . . . .. . . . .. . . .. .... . 1,52 Hycom ............ . ............... 105
ITT Community Development Corp ... 85 Intel Co rpo ration .............. . .... 8,9 Intel Memory Systems. . . .. .... . .. . 87,89 Intelligent Systems, Inc ........... . 80,8 1 Intern ational Microcircuits, Inc . .. . ... 11 2
Jo han son Manufacturing Corp.. .. . . . . 103 John son Company, E.F ......... . ... . 90
Kepco, Inc......................... . 30 Keysto ne Carbon Company...... . .. .. 28
Litton Advanced Circuitry. . . . . . . . . 96,97
* Mektron .... . ........ . ....... . . . . .. 16

Memodyne Corporation .. ... . . . . . . .. 105 Methode Manufacturing Co .... . .... . 104 MetroTek , Inc ..... . . . . . . . . . . . . . . . . . 103 Micro Devices Div. of
Emerson Electronic . . . . . . . . . . . . . . . . 62 Miller-Stephenson Chemical Co., The . . . 6 Murata..... . ....... ... ... .. . . ..... 102
Ol ympi a Sales Company, Inc .. . .... . 112 Optron, Inc. . . . . . . . . . . . . . . . . . . . . . . . . . 7
Paladin Corporation ... .. ... . .. . .. 76,104 *Philips Electronic Components and
Materi a ls . . . . . . . . . . . . . . . . . . . . . . . . . 93 Piezo Technology, Inc ....... . .... . ... 84 Power/ Mate Corp ... . ... . . . . . . . . . . . 104 Precision Mono lithics, Incorporated . . . . 83 Pro-Log Corporation . .. ..... .. ....... 79
Q-M ati c Corporation .. . ... ... .. .. ... 104
RCA Solid State Di vision ...... Cover IV Rockwell Intern ationa l. . . ....... .. .. IOI Roga n Corporation . . . . . . . . . . . . . . . . . . 88 Rogers C orpo ra tion .. . ... . ... . ...... 105
Sa lon Intern a tiona l des Composa nts Electroniques. . . . . . . . . . . . . . . . . . . . . . 76
Sea lectro Co rporation . . . . . . . . . . . . . . . . 94 Semtech Corporation . . . . . . . . . . . . . . . . . 21 · sfernice. . . . . . . . . . . . . . . . . . . . . . . . . . . . 92 Signeti cs Co rporati on...... . . . . . . . . . . 25 Slaughter Co . . . . . . . . . . . . . . . . . . . . . . . . 76 Spectronics, Incorpo rated .......... 27,84 Sp rague Electric Compa ny..... .. .. . .. 29 Stand ard Grigsby, Inc ........ . . . .. . .. 86 Struthers-Dunn , Inc.. . . . . . . . . . . . . . . . . 17
TDK Electroni cs ... ...... . .... . .. . ... 34 TRW/ IR C Resistors, an operation of
TRW Electronic Components...... 104 T ay lor Industries, Inc...... . ......... 94 Techmar Omniclosure.. . ... .. .. . .... 103 Tektronix, Inc. . . . . . . . . . . . . . . . . . . . 33,35 Teledyne Rel ays, A Teledyne
Company.............. . ........... 2 Teledyne Semiconductor .... . . . . . . . . . . 36 Tex as In struments, Incorporated ....... 63 Timeco, Inc. . . . . . . . . . . . . . . . . . . . . . . . 105 Triplett Corporation .. . . . . . . . . . . . . . . . 69
Victory Engineering Corp.. . . . . . . . . . . . 88
Western Digita l Corporation . . . . ... . . . 18 Woodtron , Ltd . . . . . . . . . . . . . . . . . . . . . 103
· Adverti sers in non-U .S. edition
RECRUITMENT
Displ ay Data. . . . . . . . . . . . . . . . . . . . . . . 108 Gray, Kimball Associ ates .. . .... . .... 111 Hughes..... . . . . . . . . . . . . . . . . . . . 109, 111 Intercity.. . . . . . . . . . . . . . . . . . . . . . . . . . 110 N atio na l Personnel Associates... . . . .. 111 So uth west Resea rch Institute. . . . . . . . . 110 Sunstra nd . . . . . . . . . . . . . . . . . . . . . . . . . . I07 Systems Engineering Labs...... . . . . . I08
E LECTRONI C DESIG N 5, March I, 1978

Hobbyist or professional , there are probably a lot of circuits you build just for the fun of it. And a lot you 'd like to build , but never get around to.
One reason is the cost of parts. Parts you buy for one project, but can 't re-use ... because you haven't time to take them carefully apart. Or because of heat and mechanical damage that occur when you do.
Now, there's an easier way that can save you big money on parts and hours on every project, as well : Proto-Board" Solderless Breadboards.
Now, assembling , testing and modifying circuits is as easy as pushing in - or pulling out -a lead . IC's, LED 's, transistors , resistors , capacitors ... virtually every kind of component .. connect and interconnect instantly via long-life, nickelsilver contacts. No special patch cords or jumpers needed - just

NO. OF

14-PIN OIP SUGG.

MOOEL TIE-POINTS CAPACITY LIST ·

PB -6

630

6

$15.95

PB-100 760

10

19.95

PB-101 940

10

29.95

PB-102 1240 PB-103 2250

12

39.95

24

59 .95

PB-104 3060

32

79.95

PB-203 2250

24

80.00

PB-203A 2250

24 129.95

OTHER FEATURES
Kit - 10-minute assembly
Kit - with larger capac ity
8 distribut ion buses. higher capacity
Large capacity. moderate price
Even larger capacity: only 2.7t per tie-point
Largest capacity: lowest price per tie-point
Bu ilt-in 1%-regulated 5V. 1Alowripple pawer supply
As above plus separate '2 -amp +1 5Vand - 15V internally adjust able regulated outputs

·M anufacturers suggested list Pri ces and soec1f1cat1ons sub1ect 10 c hang e without notice

lengths of ordinary #22-30 AWG solid hookup wire .
Circuits go together as quickly as you can think them up. And parts are re-usable, so as your " junk box" builds , you build more and more projects for less and less money.
Before you invest in your next project, invest in a CSC breadboard .
Ordertoday. Call 203-624-3103 (East Coast) or 415-421-887 2 (West Coast): 9 a.m.-5 p.m. local time. Major credit cards accepted . Or see your CSC dealer. Prices
= $ = slightly higher outside USA. CONTINENTAL SPECIALTIES CORPORATION
70 Fulton Terrace, Box 1942, New Haven, CT 06509 203-624-3103 TWX 710-465-1227
WEST COAST: 351 California St., San Francisco, CA 94104, 415-421 -8872 TWX 910-372-7992 GREAT BRITAIN: CSC UK LTD.
Spur Road , North Feltham Trading Estate, Feltham, Middlesex, England.
01 -890-8782 lnt'I Telex : 851-881 -3669
., 1978, Continental Special1ies Corporat ion

Ready with megarad CMOS to newMIL38510 specs.

RCA will take orders ~iPfri[.'l" '."--

for 23 megarad-hard

CMOS circuits to

MIL-M-38510 Class·-*

S specifications. We're

ready to deliver 106 radiation hard-

ness because we've had so much

experience in supplying CMOS

hardened to 10~

After shipping hundreds of

thousands of parts to 105 Rads,

megarad was a natural step up for

us. Many of our Rad-Hard CMOS

05704 05604

circuits are now in satellites. Voya-

gers 1 and 2, for example, which are well into space.

When you use RCA Rad-Hard CMOS, you can have added confi-

dence because every single wafer processed for Rad-Hard is sample

tested on one of our two in-house cobalt sources.

In addition to the 23 MIL types, we can produce any RCA COS/MOS

logic circuits processed to megarad hardness.

Let us send you "Radiation Guidelines" plus two other papers on test

results and recent advances in Rad-Hard CMOS. For immediate informa-

tion, call (201) 685-6625.

Or write RCA Solid State headquarters in Somerville, NJ; Sunt>ury-

on-Thames, Middlesex, England; Quickborn 2085, W. Germany; Ste.

Anne-de-Bellevue, Quebec, Canada; Sao Paulo, Brazil; Tokyo, Japan.

When you say CMOS, say RCA first.
CIRCLE NUMBER 232

RCll