4122, 4212 Datasheet 4122ce
User Manual: 4122ce
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MODELS 4122CE, 4212CE
DC BRUSH SERVO AMPLIFIERS
Copley Controls, 20 Dan Road, Canton, MA 02021 Tel: 781-828-8090 Fax:781-828-6547
Web: http://www.copleycontrols.com Page 1 of 1
FEATURES
• CE Compliance to
89/336/EEC
• Underwriters Laboratories
Recognized Component
to UL 508C
• Only one potentiometer!
• Component socket configures
amp completely
• Flexibility! Internal 40-pin
socket configures amp with no
soldering
• Separate current limits:
Continuous, peak, and peak-
time
• No integrator windup
when disabled
• Fault protections:
Short-circuits from output to
output, output to gnd
Over/under voltage
Over temperature
Self-reset or latch-off modes
• 3kHz Bandwidth
• Wide load inductance range:
0.2-40 mH.
• Surface mount technology
construction, lower part count.
APPLICATIONS
• X-Y stages
• Robotics
• Automated assembly machinery
• Magnetic bearings
THE OEM ADVANTAGE
• Conservative design for high
MTBF
• No soldering required to change
header parts.
• Custom configurations
available (contact factory)
No-pots, custom headers
PRODUCT DESCRIPTION
These amplifiers are variants of the
popular 4xx2 series DC brush motor
amplifiers that feature compliance with
European Community directive
89/336/EEC, also known as “CE”.
Models 4122CE and 4212CE are third-
generation amplifiers for dc brush motors
from Copley Controls Corp. Built using
surface-mount technology, these amplifiers
offer plug and play operation in a very
small package. All models take industry
standard ±10V control signals as input, and
operate motors in torque mode, or velocity
mode using analog brush tachometers.
Velocity loops using brush-tachometer
feedback are used for open-loop speed
controls, or in position control loops
requiring improved regulation at low
speeds.
Model 4122CE operates from +22 to
+90VDC unregulated power supplies, and
outputs 10A continuous, 20A peak.
Model 4212CE operates from +22 to
+125VDC power supplies, and outputs 6A
continuous, and 12A peak.
The active logic-level of the amplifier
Enable input is jumper selectable to GND
or +5V to interface with different control
cards. /Pos and /Neg enable inputs remain
ground active for fail-safe operation.
Mosfet H-bridge output stage delivers
power in four-quadrants for bi-directional
acceleration and deceleration of motors.
An internal solderless socket holds 17
components that configure the various gain
and current limit settings to customize the
amplifiers for a wide range of loads and
applications.
Header components permit compensation
over a wide range of load inductances to
maximize bandwidth with different motors.
Individual peak and continuous current
limits allow high acceleration without
sacrificing protection against continuous
overloads. Peak current time limit is
settable to match amplifier to motor
thermal or commutation limits.
All models are protected against output
short circuits ( output to output and output
to ground ) and heatplate overtemperature.
With the /Reset input open, output shorts
or heatplate overtemperature will latch off
the amplifier until power is cycled off & on,
or until the /Reset input is grounded.
For self-reset from such conditions, wire
/Reset to ground and the amplifier will
reset every 200ms.
A bicolor led speeds diagnostics during
set-up, or for fault isolation after the unit is
in service.
MODEL POWER I-CONT I-PEAK
4122CE
+22 to +90 VDC
10 20
4212CE
+22 to +125 VDC
6 12
MODELS 4122CE, 4212CE
DC BRUSH SERVO AMPLIFIERS
Copley Controls, 20 Dan Road, Canton, MA 02021 Tel: 781-828-8090 Fax:781-828-6547
Web: http://www.copleycontrols.com Page 2 of 2
TECHNICAL SPECIFICATIONS Test conditions: 25°C ambient, Load = 200µH. in series with 1 Ω., +HV = maximum normal value
MODEL 4122CE 4212CE
OUTPUT POWER
Peak power ±20A @ ±80V ±12A @ ±120V
Peak time 1 sec unipolar from 0A, 2 secs. after polarity reversal
Continuous power ±10A @ ±80V ±6A @ ±120V
OUTPUT VOLTAGE ±Vout = ±HV*(0.97) - (Ro)*(Io)
Ro = 0.2 Ro = 0.1
LOAD INDUCTANCE Selectable with components on header socket: 200 µH to 40mH
BANDWIDTH Current mode: 3kHz with 200µH load at maximum supply voltage, varies with load inductance and RH15, CH16 & CH17 values
PWM SWITCHING FREQUENCY 25kHz
REFERENCE INPUT Differential, 94K between inputs, ±20V maximum
GAINS
Input differential amplifier 1:1 (Volt / Volt)
PWM transconductance stage Ipeak / 6V ( I peak = peak rated output current; 6V measured at Current Ref J2-9 )
LOGIC INPUTS
Input voltage range 0 to +24V
Logic threshold voltage ( LO to HI transition ) 2.5V ( Schmitt trigger inputs with hysteresis )
/Enable ( Internal jumper JP1 reverses logic ) LO enables amplifier, HI disables
( Default function with JP-1 on pins 2-3. For +5V enable and GND inhibit, move JP1 to pins 1-2 )
Time delay on Enable 0.9 ms after Enable true to amplifier ON, <1ms to disable
/POS enable, /NEG enable Gnd enables positive or negative output currents. +5V or open inhibits (<1ms delay)
( Setting of JP-1 has no effect on ground-active level of /POS and /NEG enable inputs )
/Reset LO resets latching fault condition, ground for self-reset every 200 ms.
Input resistance 10K pull-up to +5V, R-C filters to internal logic
POTENTIOMETER
Balance Use to set output current or rpm to zero. RH1 = 10 MΩ for Balance function, RH1 = 100kΩ for Test function
LOGIC OUTPUT
+Fault ( /Normal ) HI = Overtemp OR output short OR power NOT-OK, OR NOT-Enabled; LO = Operating normally AND enabled
HI output voltage +5V ( 3.3kΩ pullup resistor to +5V ) +50V maximum
LO output voltage <0.5V typical, 1.25V @ 250mA max, Ro = 5Ω ( mosfet on resistance )
INDICATOR (LED)
Normal Green: ON = Amplifier Enabled AND Normal ( power OK, no output shorts, no overtemp )
Red = Fault ( NOT Normal, see +Fault output above )
ANALOG MONITOR OUTPUTS
Current Ref ( current demand signal to pwm stage ) ±6V @ demands ±Ipeak
Current Monitor ( motor or load current ) ±6V @ ±Ipeak (1kΩ, 33nF R-C filter)
DC POWER OUTPUTS ±15VDC each output in series with 10kΩ
PROTECTIVE FEATURES ( Note 1 )
Output short circuit (output to output, output to ground) Latches unit OFF
Overtemperature Latches unit OFF at 70°C on heatplate
Undervoltage shutdown @ <20V <20V
Overvoltage shutdown @ >92VDC >129VDC
POWER REQUIREMENTS
DC power (+HV) Transformer isolated from power mains +22 to +90VDC +22 to +125VDC
Watts minimum 2.5W 2.7W
Watts @ Icont 25W 41W
THERMAL REQUIREMENTS
Storage temperature range: -30 to +85°C; operating temperature range: 0 to 70°C baseplate temperature
MECHANICAL
Amplifier case size 4.3 x 3.0 x 1.0 in. (109 x 76.2 x 25.4 mm.)
Weight 0.43 lb (0.2 kg.)
CONNECTORS
J1 (Power & motor): 5 position compression-connector; Phoenix MKDS 3; maximum wire gauge AWG 12 ( 4 mm2 solid or 2.5 mm2 stranded ) wire.
J2 (Signal): 16-position 0.1” centers housing ( Molex: 22-01-3167 ) with AWG 30-22 crimp contacts ( Molex 08-50-0114 , 16 required )
NOTES
1. Latching faults disable amplifier until power is cycled off-on, or /Reset input is grounded. Non-latching faults re-enable amplifier when fault condition is
removed. Overtemperature and short-circuits are latching faults, under or overvoltage faults are non-latching. If /Reset input is grounded, amplifier will auto-
reset from latching faults every 200ms.
MODELS 4122CE, 4212CE
DC BRUSH SERVO AMPLIFIERS
FUNCTIONAL DIAGRAM
NEG
ENABLE
POS
ENABLE *
-
+-
+
RH7
RH6 CH8
RH10 CH11
100PF
REF AMP
Gv = 1
RH3
RH4 CH5
RH2
AUX
TACH (-)
REF(+)
REF(-)
RH1
CURRENT LIMIT
SECTION
Gv = +HV
10
PWM
MOSFET
"H"
BRIDGE
STAGE
GND
GND
MOT OR +
MOT OR -
+HV
-
+
CH17 RH15
CH16
47K
47K
PEAK
CONT
PEAK
RH13
RH12
CH14
Voltage gain =
1
TI ME
1K
33NF
1K
33NF
CURRENT
MON IT OR
CURRENT
REF
1K
OUT P UT
CURRENT
SENSE
+HV
DC / DC
CONVERTER
-15
+15
GND
+FAULT
+5V
CONTROL
LOGIC
STATUS
&
GND
MOTO
R
A
UXILIAR
DC
SERVO
PREAMP
CW
TACH
REF LEAD
INTEGRATOR
CURRENT
ERROR
AMP
LED
GREEN =
NORMAL
RED =
+15V
-15V
BALANCE
50K
CASE GROUND
NOT
TO CIRCUIT GROUND
CASE MAY BE
GROUNDED
MOMENTARY SWITCH CLOSURE RESETS
WIRE RESET TO GROUND FOR SELF-
RESET
+5
+15
-15
POWER GROUND AND SIGNAL GROUNDS ARE
J2 SIGNAL CONNECTOR
J1 MOTOR & POWER
CONNECTOR
-
+
-+
VOLTAGE
GAIN
+/-6V for
+/-Ipeak
+/-6V at
+/-Ipeak
60.4 K
100 K
10 MEG
4.8 kHz FILTER
4.8 kHz FILTER
100 K
100 K
RESET
10k
10k
INTEGRATOR RESET
SWITCHES
TURN ON WHEN AMP IS
FOR SHIELDING
16
6
7
4
5
9
8
1
3
15
14
13
2
11
12
1
2
3
4
5
VALUE DEPENDS ON
SEE "ARMATURE INDUCTANCE"
GND
+15V
-15V
CH9 (OPEN)
*JP1
10
-
+
123
* JP1: PINS 2-3 FOR /ENABLE AT
PINS 1-2 FOR /INHIBIT AT
0.47U
4.7MEG
182K
NOTE:
DEFAULT VALUE OF CH11 IS 0
FOR T ORQUE MODE
OPERATION
FOR VELOCITY MODE ( BRUSH
REPLACE CH11 WITH
CURRENT
CURRENT
*
*
+/-80V Max
+/-80V Max
TYPICAL CONNECTIONS
+HV
GND
+
1
2
3
4
5
J1
J1
MOTOR
ENCODER
+
4
5
J2
10
13
12
11
GND
ENABLE
POS ENABLE
NEG ENABLE
REF+
REF-
TORQUE MODE
Note: JP1 on pins 2-3 ( default )
1
2
J1
J1
J2
MOTOR
TACH
+
+
7
6
4
5
J2
10
GND
13
12
11
ENABLE
POS ENABLE
NEG ENABLE
REF+
REF-
VELOCITY MODE ENCODER
+HV
GND
+
3
4
5
Note: JP1 on pins 2-3 ( default )
Notes
1. All amplifier grounds are common (J1-3, J1-4, J2-2, J2-7, and J2-10 )
Amplifier grounds are isolated from case & heatplate..
2. Jumper JP1 default position is on pins 2-3 for ground active /Enable input ( J2-11 )
For /Inhibit function at J2-11 ( +5V enables ), move JP1 to pins 1-2
3. For best noise immunity, use twisted shielded pair cable for reference and tachometer inputs.
Twist motor and power cables and shield to reduce radiated electrical noise from pwm outputs.
Copley Controls, 20 Dan Road, Canton, MA 02021 Tel: 781-828-8090 Fax:781-828-6547
Web: http://www.copleycontrols.com Page 3 of 3
MODELS 4122CE, 4212CE
DC BRUSH SERVO AMPLIFIERS
Copley Controls, 20 Dan Road, Canton, MA 02021 Tel: 781-828-8090 Fax:781-828-6547
Web: http://www.copleycontrols.com Page 4 of 4
CONNECTORS AND PINOUTS
J1: MOTOR & POWER CONNECTIONS
Pin Signal Remarks
1 Motor (+) Amplifier output to motor (+) winding
2 Motor (-) Amplifier output to motor (-) winding
3 GND Power supply return. Connect to system ground at this pin.
4 GND Power supply return. Connect to system ground at this pin.
5 +HV +HV DC power supply input
J2: AMPLIFIER BOARD CONNECTIONS
Pin Signal Remarks
1 +15V +15V in series with 10kΩ
2 Gnd Signal ground
3 -15V -15V in series with 10kΩ
4 Ref (+) Differential input positive terminal for Reference voltage
5 Ref (-) Differential input negative terminal for Reference voltage
6 Tach (-) Negative terminal of brush tachometer
7 Gnd / Tach (+) Signal ground, or positive terminal of brush tachometer
8 Curr Mon Output current monitor: ±6V output at ±peak output current
9 Curr Ref Current demand signal to PWM stage: ±6V demands ±peak current
10 Gnd Signal ground
11 /Enable Amplifier enable input: enables or inhibits PWM switching at outputs
Default: Gnd enables amplifier, open or +5V inhibits ( JP1 @ 2-3 )
For controllers that output +5V to enable amplifier, move internal
jumper JP1 to pins 1-2 ( Gnd will inhibit, +5V or open will enable )
12 /Pos Enab Gnd to enable output current in one polarity, open or +5V to inhibit
Typically used with grounded, normally closed limit switches.
13 /Neg Enab Gnd to enable output current in opposite polarity, open or +5V to
inhibit. Typically used with grounded, normally closed limit switches.
14 /Normal Current-sinking when amplifier enabled and operating normally.
Goes to +5V when amplifier disabled or fault condition exists.
15 /Reset Ground to reset overtemp or output short circuit latching faults.
For automatic reset of faults every 200mS, ground permanently.
16 Aux Single-ended auxiliary input.
BALANCE POTENTIOMETER
Default position: centered. Functions to bring output current ( in torque mode ) or output velocity ( in tachometer mode ) to zero
with reference input voltage at zero, or control system output at zero. Normal range is ±1% of full scale with 10Meg resistor in
header location RH1. To use the pot as a wide range set-point adjustment, install a 150kΩ resistor at RH1. Now, full CW or CCW
will have the effect of a ±10V signal at the reference inputs.
STATUS LED
Dual color, red/green.
Color +HV /Enable Short Overtemp
Green Normal Active None Normal
Red Too low or too high X X X
X Inhibited X X
X X Output short X
X X X Too hot
Note 1, 5 2, 5 3, 5 4, 5
Notes:
1. +HV normal >20V and <92V for model 4122CE, >20V and <129V for model 4212CE
2. /Enable is ground-active for JP1 on pins 2-3 ( default ). To reverse function, switch JP1 to pins 1-2.
3. Shorts detected by overcurrent circuit are between outputs, or from outputs to ground.
4. Overtemperature faults occur when heatplate temperature is >70°C
5. +HV and /Enable cause momentary amplifier shutdown, operation is restored when +HV is within normal limits and /Enable input is active.
Output shorts, and overtemperature faults latch-off amplifier. Thus amplifier will remain off until power is cycled on/off, or /Reset input is grounded
momentarily. If /Reset input is wired to ground, output short and overtemperature faults will self-reset every 200ms.
MODELS 4122CE, 4212CE
DC BRUSH SERVO AMPLIFIERS
Copley Controls, 20 Dan Road, Canton, MA 02021 Tel: 781-828-8090 Fax:781-828-6547
COMPONENT HEADER
RH3
REFERENCE INPUT SCALING
RH2
RH1
PREAMP HI-FREQUENCY ROLL-OFF
RH6
TACH INPUT SCALING
CH5
RH4
REF INPUT LEAD RESISTOR
RH7
CH8
TACH INPUT LEAD NETWORK
BALANCE RANGE
CH9
RH10
CH11
AUX INPUT
CH14
RH15
PEAK CURRENT LIMIT
CH16
CONTINUOUS CURRENT LIMIT
CH17
PEAK TIME LIMIT
RH12
RH13
PREAMP DC GAIN & INTEGRATOR
LOAD INDUCTANCE COMPENSATION
60.4K
100K
10MEG
100K
COMPONENTS LABELLED "SEL"
ARE NOT INSTALLED AT FACTORY
REF INPUT LEAD CAPACITOR
100K
JP1
(SEE CHART FOR VALUES)
0.47UF
4.7 MEG
182K
(SEL)
(SEL)
(O OHM)
(SEL)
(SEL)
(SEL)
USER SHOULD SELECT VALUES AS REQUIRED
12
3
1
16
J2
J1
1
5
NO PARTS INSTALLED
IN THESE LOCATIONS
ARMATURE INDUCTANCE
Model 4122 CE
4212 CE
Load (mH) RH 15
CH17
CH16
RH15
CH17
CH16
0.2 to 0.5 80.6
k
2.2 nF
390 pF
69.8
k
2.2 nF
390 pF
0.6 to 1.7 200
k
680 pF
220 pF
100
k
1 nF
330 pF
1.8 to 4.8 402
k
680 pF
180 pF
301
k
470 pF
100 pF
5 to 14 806
k
680 pF
150 pF
698
k
330 pF
82 pF
15 to 45 1.5M
470 pF
100 pF
1.21M
220 pF
82 pF
Note: Values in bold & italics are factory installed standard. Values shown are for 90V (4122CE ) and 125V (4122CE). At
lower supply voltages RH15 may be increased and CH17 decreased.
PEAK CURRENT LIMIT (AMP) CONTINUOUS CURRENT LIMIT (AMP)
4122CE 4212CE RH12 (Ω)
4122CE
4212CE
RH13 (Ω)
20 12
182
k
10
6
4.7Me
g
16.7 10 56
k
7.4
4.4
7.15Me
g
13.3 8 30
k
5.7
3.4
10Me
g
10 6 18
k
6.7 4 9.1
k
3.3 2 3.9
k
Web: http://www.copleycontrols.com Page 5 of 5
PEAK CURRENT TIME-LIMIT (SEC)
Tpea
k
CH14 (μF)
1 0.47
0.8 0.33
0.5 0.22
0.3 0.15
0.2 0.10
0.1 .047
Notes on Current Limits:
1. Values in bold & italics are factory installed standard.
2. Peak times double after polarity reversal.
3. Peak current limit should be set greater than continuous current limit.
If Ipeak < Icont then peak overrides continuous limit and Icont = Ipeak.
Minimum setting for peak current is 0% of peak rating.
4. Continuous current sense is for average current. Symmetrical waveforms with zero
average value may cause overtemperature shutdown of amplifier or motor damage
due to high I2R losses.
5. Times shown are for 100% step from 0A with default value of RH13 ( 4.7 Meg ).
When changing RH13, peak times will change. Set RH13 for continuous current
limit first, then pick CH14 based on waveforms at Curr Ref ( J2-9 ).
MODELS 4122CE, 4212CE
DC BRUSH SERVO AMPLIFIERS
Copley Controls, 20 Dan Road, Canton, MA 02021 Tel: 781-828-8090 Fax:781-828-6547
Web: http://www.copleycontrols.com Page 6 of 6
APPLICATION INFORMATION
IMPORTANT! ALWAYS REMOVE POWER WHEN CHANGING
HEADER PARTS!!
OPERATING MODES
These amplifiers operate as either open-loop current sources, or
feedback devices using analog tachometers.
As open-loop current sources, the ±10V at the reference inputs
produce current in the load, typically a motor. The motor acts as
a transducer, and converts current into torque, the twisting force
at the motor shaft. This is called torque mode. It is used most
frequently in systems that have controllers taking feedback from
an encoder on the motor shaft. The computer calculates both
position and velocity from the encoder signal, processes them in
a digital filter, and outputs a signal to the motor causing it to
accelerate or decelerate.
As a feedback amplifier, a signal is generated by an analog brush
tachometer mounted on the motor. This is a generator that
produces an analog signal that has a polarity and amplitude
proportional to the motor speed. The amplifier subtracts the tach
signal from the reference signal, and amplifies the difference
between them. This is called velocity mode, because the
amplifier changes the motor current ( torque ) so that the motor
velocity is proportional to the reference signal.
TORQUE MODE OPERATION
Torque mode is the default configuration. For input voltages of
±10V, the amplifier will output its peak rated current.
In torque mode, motor current is held constant, and motor speed,
or velocity changes as the load changes.
In torque mode the gain of the servo preamplifier is simply 0.6
and scales the ±10V from the reference signal down to the ±6V
that drives the PWM stage.
The servo preamplifier integrator function is disabled, and the low
gain is constant over a wide range of frequencies. Thus we
sometimes call this flat-gain mode.
VELOCITY MODE OPERATION
The difference between the reference and tachometer signals is
amplified and used to change the torque on the motor. Ideally,
the difference between the command and feedback signals would
be zero, so in velocity mode operation the servo preamplifier
must have much higher gain than when in torque mode.
In addition, the gain must change over a range of frequencies.
For “stiffness” that corrects for steady-state changes, the
amplifier uses an integrator. For fast response the loop gain of
the servo preamplifier must be tailored to the characteristics of
the motor and tachometer. To control oscillations from the
tachometer, the gain of the preamplifier must roll-off, or decrease
at higher frequencies.
In velocity mode, motor speed is held constant, while motor
current changes in response to changes in the load.
THE PARTS OF THE AMPLIFIER
DIFFERENTIAL AMPLIFIER
The reference signal ( the command signal from the control
system ) is sensed by a differential amplifier. This acts like a
voltmeter with two probes, measuring a voltage between two
points. Current flowing in the amplifier power wiring causes
voltage drops in the wires resistance. This in turn can produce a
voltage at the amplifier ground that is different than the control
system ground. If this voltage is added to the output of the control
system, it can produce oscillation, or inconsistent operation. To
eliminate this effect, you should always use both reference
inputs.
Connect the Ref(+) input to the output of the controller card, and
the Ref(-) input to ground at the control card. Now, the differential
amplifier will measure the control signal at the control card and
will reject any noise that exists between amplifier and control
system grounds.
THE SERVO PREAMPLIFIER
This section processes the reference signal and any feedback
signals, and generates an internal current reference signal that
controls the PWM stage to produce output currents. It is here that
the reference signal and tachometer signals are compared, and
the difference signal produced and amplified.
Three components on the header control the behavior of the
servo preamp. The chart below lists the default torque-mode and
starting-point values for velocity mode operation:
Part
Torque Velocity
CH9
out 220pF
RH10
60.4
k
680
k
CH11
short 4.7nF
CH9 controls the high-frequency roll-off.
RH10 controls the loop gain, and thus the step-response
of the amplifier.
CH11 ( along with RH7 ) forms the integrator that gives the
stiffness at a standstill, or speed regulation while running.
CURRENT LIMITING
This stage takes the output of the servo preamplifier, and
processes it before sending it to the PWM stage. The amplitude
of the signal is first clamped to produce peak current limiting. This
signal then goes to the continuous current-limit circuit where
these functions are produced. Finally, the current-limited signal is
outputted to the PWM stage as the current-reference signal. This
signal is quite useful in that the current limit action can be seen
here and measured without connecting a motor, thus protecting it
from overload during initial setup.
PWM STAGE
The voltage at the output of the current limit stage is called the
current reference. This signal becomes the demand signal that
controls the PWM stage. Here the current demand is converted
into a current in the motor. This current can be measured at the
current monitor, which shows the response of the motor to the
current demand signal. By operating as a current source, the
PWM stage is able to achieve faster response from the motor
than if was acting only as a variable voltage.
The current error amplifier compares the current reference with
the current monitor, and adjusts the output voltage such that the
demanded current flows in the motor. The gain of this amplifier is
controlled by RH15, CH16, and CH17, which are used to
compensate the amplifier for the motors’ inductance.
MODELS 4122CE, 4212CE
DC BRUSH SERVO AMPLIFIERS
Copley Controls, 20 Dan Road, Canton, MA 02021 Tel: 781-828-8090 Fax:781-828-6547
Web: http://www.copleycontrols.com Page 7 of 7
INSTALLING THE AMPLIFIER
Select the header components for current limits first as this will
protect the motor during later procedures. Using the Current Ref
signal will allow you to view the effect of component changes on
the current demand signal without loading the motor until the
adjustments are complete. The effects of the current limits can
best be seen by inputting a reference signal of ±10V as a square
wave of about 1/4 Hz. This way there will be enough time at
peaks to observe the peak time ( which will twice the unipolar
time after reversals ) and to see the continuous current value
after the peak time occurs.
PEAK CURRENT LIMIT
Amplifiers are shipped with 182kΩ installed in RH12. This
delivers the amplifiers peak rated current. For lower settings use
values from the table.
CONTINUOUS CURRENT LIMIT
Choose RH13 based on the motor manufacturers specification
for your motor. Table values give basic settings. This setting
keeps the motor within its thermal limits. Note that this limit
measures average current and will not work on symmetrical
waveforms such as might occur during system oscillation. Use an
external thermal circuit breaker for protection from such
overcurrent faults.
PEAK-TIME LIMIT
Header component CH14 controls the length of time for which the
amplifier will output peak current. When peak currents that are
less than the amplifiers peak rated current, this time will increase,
eventually becoming infinite as you reach the continuous current.
After a polarity reversal, the peak time will be twice that of a
unipolar current change.
GROUNDING & POWER SUPPLIES
Connect positive terminal of power supply to J1-5, negative
terminal to J1-4. For best results do not ground power supply, but
ground each amplifier with heavy wire from J1-3 to equipment
‘star’ ground point.
If power supply is >1m. from amplifiers, add local filter capacitor
near amplifiers (250μF minimum per amplifier).
/ENABLE INPUT
With internal jumper JP-1 on pins 2-3 ( default position ), the
/Enable input ( J2-11 ) must be grounded for the amplifier to
operate. For operation with cards that output +5V to enable the
amplifier, move the jumper on JP-1 to pins 1-2. This will reverse
the /Enable input active level so that grounding the input will
inhibit the amplifier, and +5V (or open) will enable.
Note: There is a 0.9ms delay /between Enable TRUE and
amplifier ON.
/POS & /NEG ENABLE INPUTS
These inputs are always ground active, open circuit or +5V will
inhibit. In service these would be grounded through normally-
closed limit switches. When a motion axis enters the limit, torque
will be inhibited to prevent further travel into the limit, but torque
will be available to back-out of the limit switch. Because torque is
still available in one direction, the Normal led stays ON, and the
Normal output signal remains true.
Delay on /Pos and /Neg enables is <1ms.
TORQUE MODE SETUP
1) Select RH12, RH13, and CH14 for motor current-limits.
2) Select RH15, CH16, and CH17 on header for armature
inductance.
3) Ground /Enable, /Pos Enable, and /Neg Enable inputs to
J2-10. ( Assumes default setting of JP-1 to pins 2-3 )
4) Connect amplifier to transformer-isolated DC power supply.
5) Adjust value of RH10 if necessary to change
transconductance.
VELOCITY MODE SETUP
Begin with the default components in positions RH10 & CH11.
This will give a lower loop gain, and the integrator will be
disabled. After loop gain has been adjusted as described below,
the integrator is setup for best stiffness and response.
1) With the default components in RH10 & CH11, perform
torque mode setup steps 1,2,3, and 4. This will prepare the
amplifier to drive the motor within its current limits and
compensate the PWM stage for motor inductance.
2) From the motor/tachometer datasheet, find the tachometer
gradient. Typically this will be 3 or 7 volts per krpm ( volts per
thousand revolutions per minute ). Multiply this number by the
maximum speed ( in krpm ) that you want to achieve at the
±10V reference input. For example, suppose that you have a
7 v/krpm tachometer and want to operate at 3000 rpm ( 3
krpm ) at ±10V input. Multiply the 7 v/krpm by 3 krpm to get
21V. Divide this number by your reference voltage ( 10V in
this case ) and get 2.1. Now multiply the value of the
reference input resistor, RH7 by this number. Use the default
value of 100k times 2.1 to get 210kΩ. A close production
value resistor would be 220kΩ. Install this at location RH3 to
scale the tachometer input.
3) Connect the motor to the Motor (+) and (-) output of the
amplifier at J1-1, and J1-2. With the motor disconnected from
the load, connect up the tachometer to the tach inputs at J2-6
& J2-7. Turn on the amplifier and spin the motor gently. If it
runs away at high speed, turn off the amplifier and reverse
the connections to the tachometer only. Power up again and
the loop should now be stable and motionless ( save for a
small balance adjustment ) at 0 reference input.
4) Apply a small step input voltage to the reference inputs. A 2V
peak-to-peak square wave of 2Hz is a good start. Observe
the signal at the tachometer input ( J2-6 ). If the signal
overshoots and undershoots for more than one cycle, then
reduce the value of RH10 by 30-50% and try again. If the
response is slow without any overshoot, increase RH10 by
the same amount and re-try. Optimal gain will show a fast
response with no overshoot, or a small amount that settles
back without appreciable undershoot. If there is tachometer
resonance ( high pitched squealing ) after this adjustment,
install a 330 pF capacitor at CH9 and increase value in steps
of 3X until oscillation disappears. Re-test step response.
5) Install a 10 nF capacitor at CH11. Test again with square
wave input, or gently twist shaft with no input. Best choice of
CH11 will give good stiffness at the motor shaft when tested
by turning, and will show some overshoot ( perhaps 10% ) to
a step input without ringing. As CH11 is decreased, stiffness
will increase but overshoot will increase, too. If too small,
CH11 will produce violent oscillation. Disable amplifier
immediately and change to a larger value.
MODELS 4122CE, 4212CE
DC BRUSH SERVO AMPLIFIERS
OUTLINE DIMENSIONS
Dimensions in inches (mm.)
3.00
4.30
4.00
2.00
0.56
0.625 1.00
0.16
ORDERING GUIDE
Model 4122CE 20A peak, 10A continuous, +22 to +90VDC brush motor amplifier
Model 4212CE 12A peak, 6A continuous, +22 to 125VDC brush motor amplifier
Copley Controls, 20 Dan Road, Canton, MA 02021, US
A
Tel: 781-828-8090
Fax: 781-828-6547
Web: htt
p
://www.co
p
le
y
controls.com
Rev C,06//07/2010
