Actuator Simulator

TM 11-6625-646-15

As the actuator-simulator is used in the SAS bench test

voltage, chopped, converted to a nominal sine wave,

set, two of the stages on the card are not operational

amplified, and fed back to the SAS amplifier as a

and are not described:

simulated feedback signal (para 1-18 through 1-25).

This simulated feedback signal is also rectified on the

a. Demodulator CR613, CR614

actuator-simulator card and connected through relay

b. Output emitter-follower Q607

contacts to the metering circuit output at pins 20 and 23

of receptacle J63.

1-20. In addition to the two unused stages, certain

resistors and input and output wiring options are not

d. The open or closed loop metering circuit output

used and are not described. In the following stage

of the actuator-simulator card from pins 20 and 23 of

analyses circuit and component functions are described

receptacle J63 is routed to YAW AXIS meter M2.

to cover the operation of the circuit board when it is

e. The feedback signal of the actuator-simulator

used to simulate an extensible link.

card from pin 25 of receptacle J63 is routed to pins L

and N (strapped) of receptacle J60. From this point, the

1-21. Phase Inverter

signal is routed to the feedback (cancellation) circuits of

(fig. 1-2)

the SAS amplifier.

In the unity-gain phase inverter, the output of the SAS

amplifier channel is converted to a dc , signal voltage

f. The 2.5-volt ac feedback resistor excitation

whose polarity is determined by the direction of the

voltage from the SAS amplifier channel is connected to

differential current output of the channel. Dc signal

pins M and P of receptacle J60. From pins M and P the

voltage from the phase inverter is chopped and fed to

excitation voltage is connected to the reference voltage

the two-stage preamplifier. The phase inverter stage

input of the actuator-simulator card at pins 8 and 9 of

includes a regulated - 20-volt dc supply.

receptacle J63. On the actuator-simulator card, the

excitation voltage is used to phase relate the operation

a. The phase inverter is essentially a bridge circuit;

of the chopper stage to the operation of the SAS

resistors R613 and R615 are the two fixed elements.

amplifier channel (para 1-22). The excitation voltage is

The input network consisting of resistors R605, R606,

also connected to the ac metering circuits through the

and R608 and transistor Q601 shunted by resistors

YAW FEEDBACK POT.

EXCITATION position of

R609 and R610 are the two dynamic elements. The

FUNCTION switch S7. (para 1-32).

adjustment of balance resistor R609 establishes the

output of the phase inverter at zero volt when the output

of the SAS amplifier channel is not differential.

b. The load resistors of the phase inverter present

to the SAS amplifier channel a load equivalent to the

torque motor (solenoid) of the extensible link. The

output of the channel is connected through pins 2 and 5

of the card connector to load resistors R605 and R606

which simulate the windings of the link solenoid. Link

operating voltage (approximately 15 volts dc) from the

SAS amplifier is connected through pin 3 of the card

connector to the junction of the load resistors.

1-18. Actuator Simulator

c. When a correction signal is present in the SAS

amplifier channel, the differential current output of the

1-19. (fig. 1-2). The actuator simulator is a plug-in

SAS amplifier causes voltage changes, which are equal

printed-wiring circuit board (card) designed to simulate a

and opposite, at the ends of the load resistors.

SAS extensible link as well as certain other actuators.