N122-001 Series Servoamplifier with Oscillator ... - Moog Inc

N122-001 Series
Servoamplifier with
Oscillator/Demodulator
DESCRIPTION
The N122-001 Servoamplifier with Oscillator/Demodulator is
specifically designed for use with systems that have threestage
servovalves using LVDT's as spool position feedback
sensors. The card contains the excitation/demodulation
necessary to close the inner loop of the servovalve spool,
while providing PID control for the outer loop servoamplifier
section. The card can be reconfigured, by jumper selection,
for closed-loop position control systems that use LVDT's as
position sensors and two-stage servovalves.
Features
• Closed-loop control of three-stage servovalves with LVDT
position sensors.
• Outer loop PID control-jumper selectable, independent
gain potentiometers.
• Current limiter (rate limit control possible).
• Inner loop gain potentiometer.
• Convenient front panel test points and potentiometers for
easy field calibration.
Adjustments
P1 Trim: Changes authority of signal on terminal 7. Turn CW to
reduce authority. Adjust to provide scaling of input at terminal 7.
P2 Bias: Changes bias voltage at input (summing) stage. Turn CW for
positive input bias voltage. Adjust for desired offset between
command and feedback.
P3 P-Gain: Changes proportional gain of input (summing) stage.
Turn CW to increase gain. Adjust for system stability.
P4 I-Gain: Changes integral gain if jumper I is on. Turn CW to
increase gain. Adjust for system stability.
P5 D-Filter Frequency: Changes corner frequency of low-pass filter
on differentiator. Turn CW to increase frequency. Adjust to reduce
excessive noise.
P6 D- Gain: Changes derivative gain if jumper D is on. Turn CW to
decrease gain. Adjust to add phase lead.
P7 Dither Frequency: Turn CW to increase frequency. Adjust for a
frequency appropriate for system dynamics.
P8 Dither Amplitude: Turn CW to increase amplitude. Adjust for
desired dither current amplitude, typically ± 10% of rated current.
Note: jumper DITHER must be on.
P9 Current Limit: Adjust maximum output current. Turn CW to
increase.
P10 Inner Loop Gain: Adjust inner loop gain if three-stage valve is
being used. Turn CW to increase gain. Adjust for stable operation.
Jumper 7 off for three-stage valve operation. Jumper 7 on for unity
gain on inner loop.
P11 Exciter Frequency: Changes frequency of excitation voltage at
terminal 19. Turn CW to increase frequency. Adjust for desired
excitation frequency.
P12 Demodulator Phase: Adjusts sample and hold timing to primary
oscillator. Adjusts for maximum output at terminal 9. Turn CW for
lead, turn CCW for lag. Set full CCW for operation ≤ 3 kHz.
P13 Exciter Amplitude: Changes amplitude of excitation voltage at
terminal 19. Turn CW to increase amplitude. Adjust for desired
excitation amplitude.
P14 Demodulator Span: Changes span of dc output at terminal 9.
Turn CW to increase gain. Adjust for desired scale factor (volts/inch).
P15 Demodulator Zero: Changes offset of dc output at terminal 9.
Turn CW to shift output in the negative direction. Adjust for zero Vdc
at desired transducer position.

TECHNICAL DATA
N-
SPECIFICATIONS
Servoamplifier
Servovalve Drive: ± 100 mA into 100Ω
Proportional Gain: 5 to 300 mA/V
Integral Gain: 8 to 4000 mA/V-sec
Differential Gain: 0.04 to 4 mA-sec/V
Inner Loop Gain: 10 to 200 mA/V
Exciter
Frequency:
Amplitude:
Stability:
100 to 2500 Hz
2 to 11 Vpp
≤ 250 ppm amplitude/°C
Demodulator
Ripple:
Linearity:
Stability:
Gain:
Frequency
Response:
Temperature
Range:
Form Factor:
Weight:
< 40 mV p-p at the excitation frequency
≤ ± 0.2% at 1.2 kHz
± 250 ppm gain/°C; ± 0.01 mV/°C
1 to 10 Vdc/V p-p typical, varies with
transducer characteristics
Linear from 0 to 180° as a function of
excitation frequency
0°C to 50°C (32°F to 122°F)
Eurocard 100 x 160 mm, 7HP, 3 U
0.5 lb.
SCHEMATIC
Notes:
P ... P3 GAIN ADJ JMPR1 ON/OFF
I ... P4 GAIN ADJ JMPR2 ON/OFF
D ... P6 GAIN ADJ JMPR3 ON/OFF
... P5 FILTER ADJ
INNER LOOP
GAIN ADJUST
P10
CURRENT
LIMITER
P9 ADJUSTMENT
1. Indicates test
points located on front
panel.
2. CAUTION: Perform
adjustments with
hydraulic system off.
Before applying power
to any cards, disconnect
the servovalves. They
should not be connected
until current limit has
been set.
3. An “extender card”
is highly recommended
to gain access to test
points and adjustments
while cards are
powered-up within a
eurocard rack assembly.
(Moog ref P/N A81750-1)
4 Operating points on
ends of ‘LVDT” coils will
become increasingly
non-linear and should
be avoided. An
operating range over
the ± span of the LVDT
core adjustment must be
made to achieve
optimum linear
performance results.
PCB TEST POINT
TP1
TP2
TP3
TP4
TP5
FRONT PANEL
VIN1
VIN2
VIN3
VP
ISV
FEEDBACK
COMMAND
INNER LOOP
FEEDBACK
NC
NO
COMMON
ACTIVE LOW
ACTIVE HIGH
BUFFERED
DEMODULATED
OUTPUT
DEMODULATOR
OUTPUT
VIN1 VIN2
1
P1
2
-
COMMAND TRIM
3
+
4
12
13
14
15
16
8
9
JUMPER
MUST BE
CONNECTED
VIN3
-
+24 V
BUFFER
DIFFERENCE
AMPLIFIER
P2
SYSTEM BIAS
K1
RELAY
K1
(RED LED)
20
24
26
29
28
VDEM
P
I
D
OSCILLATOR
P11 FREQUENCY ADJ
P13 AMPLITUDE ADJ
SAMPLING PULSE
P12 PHASE ADJ
DEMODULATOR
P14 SPAN ADJ
P15 ZERO ADJ
+24V @ 15 mA
POWER GROUND
-24V @ SERVOVALVE CURRENT
+15VREF @ 70 mA
+15V @ 70 mA
JMPR7
INNER LOOP
SUM & GAIN
P10
DITHER
P7 FREQUENCY
P8 AMPLITUDE
JMPR4 ON/OFF
CURRENT
OR VOLTAGE
JUMPERS
19
21
P12 FULL CCW FOR OPERATION < 3 KHZ
VSEC
VOSC
17
18
4
ISV
6
7
LVDT
SERVOVALVE
TJWhite / Register / 250
Moog is a registered trademark of Moog Inc. and its subsidiaries. All trademarks as indicated herein are the
property of Moog Inc. and its subsidiaries. ©Moog Inc. 2003. All rights reserved. All changes are reserved.
TP6
VOSC
22
SIGNAL GROUND
TP7
TP8
VSEC
VDEM
30
31
-15V @ 70 mA
-15VREF @ 70 mA
© Moog Inc., Industrial Controls Division • USA: +1-716-655-3000 • Germany: +49-7031-622-0 • Japan: +81-463-55-3615
For the location nearest you, contact www.moog.com/worldwide. For complete disclaimers, see www.moog.com/disclaimers
N122-001 Servoamplifier CDL6187 RevD 500-217 02/04