Negative Input Test - TM-55-4920-430-130122

TM 55-4920-430-13

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 externally triggered from the ac source.

(9) 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 volts ac out-of-

phase. The indication shall rise to 4.45 to 5.05 volts ac out-of-phase.

(10) Set the PITCH switch to RESET. The digital multimeter shall indicate less than .03 vat.

(11) Disconnect the positive lead of the multimeter from receptacle pin J1-W. Connect it to recep-

tacle pin J1-L.

(12) Set the PITCH switch to OPERATE. Monitor the Feedback No. 2 output on the multimeter.

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

rise to 2.18 to 2.58 volts ac out-of-phase.

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

( 14) Disconnect the positive lead of the digital multimeter, from receptacle pin J l-L. Connect it to

receptacle pin J l-N.

(15) Set the PITCH switch to OPERATE. Monitor Feedback No. 3 output voltage on the 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.

(16) Set the PITCH switch to RESET. The multimeter shall indicate less than .03 volt ac.

(17) Reduce the output of the power supply No. 2 to 0 volt.

(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 PITCH 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-JJ. Connect the positive side of the power

supply to receptacle pin J1-PP. Set the decade resistor to 1000 ohms.

(3) Connect the digital multi meter across the decade resistor, positive lead of the multimeter to

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

(4) Adjust the output of No. 1 power supply for -0.10 volt on the digital multimeter.

NOTE

This applies approximately 0.1 milliampere of input current through J1 -

JJ.

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