(9) Vary the variac form 105 to 125
(20) Rotate the COARSE ADJ. control
volts ac.
maximum counterclockwise.
(10) The reading on the dc voltmeter
(21) Adjust the dc voltmeter range to
as connected in (6) above shouls not
the 0.5-volt range and center the me-
vary from its original reading by
ter before making the next test.
more than 1 millivolt (-6,0 to 6.1
(22) Adjust control R23 on the outer com-
volts 0.001).
ponent panel until the dc voltmeter
(11) Adjust the variac for an input to
indicates approximately 1 or 2 divi-
sions below zero (negative output
the power supply of 115 volts ac.
(12) Remove the dc voltmeter test leads
voltage) (fig. 5-3).
from R45 and meter M2 and connect
(23) If these requirements cannot be
the leads across the terminals of ca-
met in the first series of adjust-
pacitor- C1 (fig. 5-1).
ments, repeat the procedures given
(13) Adjust the COARSE ADJ. control
in (18) through (22) above.
(24) The required voltage range as
clockwise until the dc voltmeter indi-
cates a voltage from 20 to 21 volts
measured at the output terminals at
dc. (Do not allow the shaft of con-
the end of the test is from -0.02
trol R30 to turn with the variac con-
volt to a maximum of 36 volts dc
trol. If necessary, hold the shaft of
0.3.
R30 steady during this adjustment.)
(25) Rotate the COARSE ADJ. control
(14) Turn POWER switch S1 to OFF and
to its maximum counterclockwise po-
lock the coupling setscrews on the
sition (fig. 2-1).
variac to the R30 shaft.
(26) Change the dc voltmeter range
(15) Turn POWER switch S1 to ON
switch to the 0.5-volt range.
and recheck the voltage ((13)
(27) Rotate the FINE ADJ. control
above) . If necessary, readjust the
through its range. The dc voltage at
shaft coupling to meet the 20- to 21-
the output terminals should go
volt requirement.
through a range of 0.8 volt dc.
(16) Remove the dc voltmeter from
N o t e : A d d t h e m e t e r readings alge-
across C1 and set the range selector
braically to obtain the given range. The
switch to 50 volts.
actual range as indicated on the meter may
(17) Connect the dc voltmeter test leads
seem to give a value of 1 volt; however, a
to the output terminals on the front
manipulation of the signed quantities should
give a 0.8-volt range.
panel of the power supply (fig. 2-1).
(18) Rotate the COARSE ADJ. control
(28) Remove all test equipment and re-
store the equipment to its normal con-
maximum clockwise.
dition.
(19) Adjust control R24 on the outer com-
ponent panel to provide a reading of
35.7 to 36.3 volts dc (fig. 5-3).
5-8
