TM 11-6625-2958-14&P

SECTION V

MAINTENANCE

5-1INTRODUCTION

5-2 Upon receipt of the power supply, the performance check (Paragraph 5-5)should be made. This check is suitable for incoming inspection. If a fault is detected in the power supply while making the performance check or during normal opera- tion, proceed to the troubleshooting procedures (Paragraph 5-51). After troubleshooting and repair (Paragraph 5-71),perform any necessary adjustments and calibrations (Pare graph 5-73). Before

returning the power supply to normal operation, repeat the performance check to ensure that the fault has been properly corrected and that no other faults exist. Before performing any maintenance checks, turn on the power supply and allow a half-hour warm-up.

5-3TEST EQUIPMENT REQUIRED

5-4 Table 5-1lists the test equipment required to perform the various procedures described in this section.

Table 5-1.Test Equipment Required

 

TYPE

 

 

 

REQUIRED

 

 

USE

 

RECOMMENDED

 

 

 

 

CHARACTERISTICS

 

 

 

MODEL

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Differential

 

Sensitivity: 1mV full scale (min.)

 

Measure

dc

voltages;

3420A/B (See

 

 

Voltmeter

I

Input impedance: 10M Ω (rein.)

 

calibration

procedures.

Note on Page 5-2)

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Oscilloscope

 

Sensitivity and bandwidth;

 

Measure

ripple;

display

140A with 1423A

 

 

 

 

100µV/cm and 400KHz for all

 

transient

recovery

wave-

time base and

 

 

 

 

measurements except noise spike;

 

form; measure noise

1400A vertical

 

 

 

 

5mV sensitivity and 20 MHz band-

 

spikes.

 

 

 

plug-in; 1402A

 

 

 

 

width for noise spike measure-

 

 

 

 

 

plug-in for spike

 

 

 

 

ment.

 

 

 

 

 

 

 

 

 

measurement.

 

 

 

 

 

 

 

 

 

 

Variable

 

Range: 207-253Vac. Recommend-

 

Vary ac input for line

- - - -

 

 

Voltage

 

ed minimum output current: 12A,

 

regulation

measurement.

 

 

 

Transformer

 

6259B; 22A, 6261B and 6268B;

 

 

 

 

 

 

 

 

 

 

24A,

6260B: 36A,

6269B.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

AC Voltmeter

 

Sensitivity: 1mV full scale de-

 

Measure ac voltages and

403B

 

 

 

 

flection (min). Accuracy: 2%.

 

ripple.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

DC Voltmeter

 

Sensitivity: 1mV full scale de-

 

Measure

dc

voltages.

412A

 

 

 

I

flection (rein). Accuracy: 1%.

 

 

 

 

 

I

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Repetitive

 

Switching rate: 60-400Hz

 

Measure

transient

re-

See Figure 5-5.

 

 

Load Stitch

I

Rise

time:

2µsec.

 

 

I

covery time.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Resistive

 

Values: see

Figures

5-2and 5-5.

 

Power supply load

 

- - - -

 

 

Loads

I

 

 

 

 

 

 

resistors.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Current

 

Values: see

Figure

5-8.

 

Measure

output current;

A4R123; : A4R123A-

 

 

Sampling

 

 

 

 

 

 

 

calibrate

ammeter.

A4R123B,

 

 

Resistors

 

 

 

 

 

 

 

 

 

 

 

6260B only; see

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Replaceable Parts

 

 

 

I

 

 

 

 

 

I

 

 

 

 

Table.