Roll ILCA Servo Simulator Circuit

55-4920-430-13

(4) With a positive input at pin 10, one pitch feedback output at pin 32 is 180 out-of-phase with

the input voltage at pin 1. The other pitch feedback signal at the output of U13 pin 2 is -0.5 volt, out-of-

phase in relation to the output at pin 32. Load isolation resistors R18 and R29, fix the output impe-

dance at pins 2 and 32 at about 56 ohms.

NOTE

The outputs of U14 at pin 52 and of U15 at pin 50 are not used.

(5) When relay K2 is energized, integrator U17 is gated and output modulator U16 is discon-

nected. Relay K2 is energized when the 28 vdc hydraulic pressure signal is removed from pin 40 or

when pin 40 is connected to ground at pin 4 by HYD PRESS switch S29. Relay K2 is also energized

when a 28 vdc reset signal is present at pin 15. When pin 13 is connected to ground at pin 4. Self test

relay K1 is energized. This connects the self test input at pins 11 and 12 to the input of the servo simula-

tor. It also disconnects the AFCS computer servo amplifier output from the input of servo simulator

U18.

b. Roll ILCA Servo Simulator Circuit. (See fig. 1-5. )

(1) The impedance of the extensible links servo valve is simulated by resistors R37, R38, R39, and

R41 and amplifier U12, with pin 22 of card A1 grounded through a 200-ohm resistance. This is the

value of the current servo resistors in the servo amplifier. The gain of amplifier U12 from pin 22 to TP3

is -2 vdc/ma.

(2) The output of amplifier U12 is fed to an integrator made up of amplifier U11, resistor R40,

and capacitor C6. The integrator simulates the servo valve of the extensible link zener diodes VR3 and

VR4 simulate the limits extensible link travel. The transfer function of the integrator is -20 vdc/vdc

second. Output is limited to -12.5 to +12.5 volt dc, by VR3 and VR4. Resistor R44 is selected to ex-

tablished the drift of the integrator at zero.

(3) Analog multiplier U10 simulates the extensible link position transducer. The gain of the mul-

tiplier is (X1-X2) (Y1-Y2)

10. When 13-volt ac is applied to pin 1, the voltage at Y1 is fixed at 5-volt

ac by a voltage divider consisting of resistors R49, R50, and R51. Resistors R47 and R48 from a 3:1

voltage divider which fixes the maximum input voltage to the multiplier at about 9-volt dc when integ-

rator output is maximum. Modulator gain from the integrator output to pin 20 is 0.76 x -0.5 vrms/

vdc = 0.38 vrms/vdc. The normal output at pin 20 is 15 vrms/sec-ma. This output is controlled by the

current input at pin 22, which is limited to about 4.75-volt rms or 6.7-volt peak. Resistor R50 is selected

to control the gain of the modulator. Resistor R53 is selected to establish the dc offset of U10 at 0.

(4) With a positive input at pin 22, one roll feedback output at pin 20 is 180 out-of-phase with

the input voltage at pin 1. The other roll feedback signal at the output of U7 pin 45 is -0.5-volt out-of-

phase in relation to the output at pin 20. Load isolation resistors R54 and R65 fix the output impedance

at pins 20 and 45 at about 56 ohms.

NOTE

The outputs of U8 at pin 49 and of U9 at pin 48 are not used.

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