Figure 6-1. Connections for final testing.

Figure 6-1.

Connections for final testing.

e. Rotate the FINE ADJ. control (fig. 2-1)

Regulated Reference Supply Test

6-5.

extremely counterclockwise.

Connect the equipment and set the controls

The

f. Turn the POWER switch to ON.

outlined in paragraph 6-4.

pilot lamp should light.

a. Set up the dc voltmeter as a conventional

g. Adjust potentiometer R44 (located on

vtvm. Refer to paragraphs 11 and 12, TM 11-

outer component board in figure 5-3) until the

6625-438-10. Set the input range switch to 50

dc voltmeter reads between 6.0 to 6.1 volts dc.

volts (VOLTS RANGE switch).

h. Observe the indication on the ac voltme-

b. Set up the ac voltmeter as described in

ter. The maximum allowable ripple should be

Set the

paragraph 14, TM 11-6625-320-12.

50 microvolts (measured at the low end of the

VOLTS-DB range switch to the 0.001-volt

meter scale).

range for this test.

i. Rotate the variac to provide a variation

Note:

Be careful to shield the meter test leads to

in the ac input voltage from 105 to 125 volts

prevent stray pickup from circuits adjacent to the hot

ac.

lead.

Note: Connect Multimeter TS-352/U as an ac volt-

c. Connect the dc voltmeter and the ac volt-

meter across the output terminals of the test variac

meter test leads across capacitor C16 as shown

to perform the procedures above.

in figures 5-4 and 6-2. (Refer to figures 4-3

j. Note the voltage reading on the dc volt-

and 7-3 for the schematic location of the test

meter as the variac is turned. The voltage

point.)

should vary not more than 1 millivolt dc from

d. Rotate the COARSE ADJ. control on the

its original value which was meassured in g

front panel of the power supp]y extremely

above.

counterclockwise.

k. The ripple voltage measured on the ac

N o t e : The shafts of T1 and control resistor R30

voltmeter should remain at the 50-microvolt

are ganged by the adjustable coupling (fig, 5-1) Dur-

level.

ing this procedure, the shaft coupling must be secured

against slipage.

6-2