Negative Input test.

TM 55-4920-430-13

(12) Set the YAW switch to OPERATE. Monitor the Feedback No. 2 output on the digital mul-

timeter. Within 1.6 to 2.4 seconds the multimeter shall indicate 1.5 volts ac, out-of-phase. The indica-

tion shall rise to 2.18 to 2.58 volts ac, out-of-phase.

(13) Set the YAW switch to RESET. The multi meter shall indicate less than 0.03 volt ac.

(14) Disconnect the positive lead of the multi meter from receptacle pin J1-BB. Connect it to recep-

tacle pin J1-LL.

(15) Set the YAW switch to OPERATE. Monitor the Feedback No. 2 output on the digital mul-

timeter. Within 1.6 to 2.4 seconds the multi meter shall indicate 1.5 volt ac out-of-phase. The indication

shall rise to 2.18 to 2.58 volt ac, out-of-phase.

(16) Set the YAW switch to RESET. The multimeter shall indicate less than 0.03 volt ac.

(17) Reduce the output of the power supplies to 0.

(18) Disconnect No. 2 power supply.

( 19) Disconnect the multimeter.

(20) Disconnect No. 1 power supply and the decade resistor.

b. Negative Input test.

(1) Set the SERVO SIMULATION YAW switch to OPERATE.

(2) Connect the negative terminal of No. 1 power supply to one side of the decade resistor. Con-

nect the other side of the decade resistor to receptacle pin J1-HH. Connect the positive side of the power

supply to receptacle l-v. Set the decade resistor to 1000 ohms.

(3) Connect the digital multimeter across the decade resistor, positive input of the multimeter to

negative input of the power supply. Set the multi meter to the 2 vdc range.

(4) Adjust the output of No. 1 power supply for 0.100 volt on the digital multimeter.

NOTE

This applies approximately 0.1 milliampere of input current through J1-

JJ .

(5) Disconnect the digital multimeter from No. 1 power supply and the decade resistor.

(6) Connect the digital multimeter, set to read 20-volt ac across receptacle J1-FF (line) and J3-AA.

The digital multimeter shall indicate less than 0.03 VAC.

(7) Connect No. 2 power supply across receptacle pins J3-A (+) and J l-C.

NOTE

When a test includes a requirement that an ac voltage be in-phase or

out-of-phase, oscilloscope channel A must be connected across the

digital multimeter. Oscilloscope channel B must be connected to the ac

source and the oscilloscope external triggered from the ac source.

(8) Adjust the output of No. 2 power supply to +28 volt dc. Monitor the Feedback No. 1 output on

the digital multimeter. Within 1.6 to 2.4 seconds, the multimeter shall indicate 3.0 volt ac in-phase. The

indication shall rise to 4.45 to 5.05 volt ac, in-phase.

(9) Set the YAW switch to RESET. The multimeter shall indicate less than 0.03 volt ac.

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