Power Supply Regulation

TB 9-6625-149-50

(6) Adjust oscilloscope controls to display one positive half cycle of square-wave

pattern. If oscilloscope does not display an optimum square wave with rise time less than

20 nanoseconds, perform b below.

b. Adjustments

(1) Remove left-side cover from TI.

NOTE

In the following adjustments, it will be necessary to replace left

side cover on TI after each adjustment to properly note the

effects on waveform.

(2) Adjust H.F. COMP. R475, C475, L457, and L478 (fig. 4) to obtain waveforms

specified in a(6) above for TI current probe amplifier, types 131-1, -2, and -3. (R)

NOTE

L457 affects a wider portion of the front cover, while L478

affects a narrower portion. Ringing, present in the waveform,

will not exceed 2 percent from nominal top of square wave.

(3) Adjust H.F. COMP. R475, C475, L457, L478 (fig. 4) and C468 (not shown) to

obtain waveform specified in a(6) above for TI current probe amplifier, type 131-4. (R)

NOTE

Do not perform power supply check if all other parameters are

within tolerance.

28. Power Supply Regulation

a. Performance Check

(1) Connect ac/dc voltmeter (A2) between -15-volt test point (fig. 6) and chassis

ground. Ac/dc voltmeter will indicate between -13.5 and -16.5 volts.

(2) Vary autotransformer (A3) output between 105 and 125 volts. Ac/dc voltmeter

indication will remain within limits of (1) above.

(3) Adjust transformer for 115 volts ac.

b. Adjustments. No adjustments can be made.