TM 5-6115-400-35
normal diode will indicate very low
resistance in one direction and extremely
high in the other. If the diode is shorted,
tor. The output of the transformer
very low resistance will ;be indicated in
provides a signal that is applied to
both directions. An open diode will read
transformer T1, thus affecting the
infinite in both directions.
controls to transistor Q1 and
d. Disassembly.
Disassemble the voltage
adjusting the generator excitation in
regulator assembly as shown in figure 126.
the right direction to minimize cross
current circulation.
e. Cleaning. Clean all parts with a clean cloth
dampened with an approval cleaning solvent and dry
b. Removal. Refer to figures 121 and 123 to
thoroughly.
remove the voltage regulator.
f. Inspection and Repair.
c. Bench testing.
(1) Inspect the resistors and transistors for
(1) Test all transistors and capacitors using
damaged terminals, defective insulation,
suitable transistors and capacitor test
and other visible damage.
equipment.
(2) Inspect the capacitors for broken leads or
(2) Test all resistors using an ohmmeter.
cracked cases.
The three thru-bolt mounted resistors
(3) Inspect the transformers and chokes for
should measure within 10 percent of their
cracks, breaks, broken terminals, and
rated values. All resistors soldered to the
evidence of overheating.
panel boards should measure within 10
percent of their rated values.
(4) Inspect the chassis for cracks, breaks,
and other damage.
Inspect threaded
(3) Test chokes and transformers for
parts for defective threads.
continuity using an ohmmeter. Test the
chokes and transformers for grounds by
(5) Repair or replace defective parts as
testing between one lead of each winding
necessary.
and the core with a multimeter. Test each
g. Testing.
transformer for shorted windings by
(1) Check for voltage regulation.
testing between one lead of the secondary
(2) Check for Steady-State variations.
winding and one lead of the primary
(3) Check for Transient Performance.
winding.
(4) Test the diodes for shorts or opens using
the voltage regulator.
an ohmmeter. When testing the diodes,
connect the leads of the ohmmeter in
voltage regulator.
such a way as to isolate the diodes from
other diodes and surrounding circuitry. A
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