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TROUBLE
SHOOTING
CHART
(cont'd)
Symptom
Probable
Cause
Remedy
7.
Low output
voltage
Fired
"OV"
Place
power
"ON-OFF"
switch
unadjustable
by volt-
in OFF
position.
To
resume
age
controls
(suffix
operation,
return
switch
"OV"
models
only)
to "ON"
position.
Check
for
shorted
Q101,
Q102
ADJUSTMENT
OF
CALIBRATION
CONTROL
Whenever
parts
are
replaced,
adjust
calibration
control
only when
voltage
in-
dication
is improper
and does not reflect
maximum
ratings.
Adjust
Voltage
Calibration
Control
R2
as
Follows:
1.
Remove
AC
power
input
to the
supply
and
place
power
ON-OFF
switch
in OFF
position.
Zu
Break
seal
on wiper
of R2
from
resistor
housing.
3
Operate
the
power
supply
for
constant
voltage
connected
as
shown
in
fig-
ure
1,
and
no
external
load.
:
^.
Turn
VOLTAGE
ADJ.
control
knobs
fully
clockwise
and,
using
a DC voltmeter
of one
percent
accuracy
or
better,
adjust
R2
to
provide
output
voltage
EO MAX
+ 7%
of Eg MAX
at
25°C
ambient;
where
EO MAX
is
rated
output
voltage
of
the
supply.
Эў
After
adjustment
is
completed,
remove
AC
power
input
to
the
supply
and
reseal
wiper
of R2
to
potentiometer
housing.
PERFORMANCE
CHECKS
Check
the
ripple
and
regulation
of
the
power
supply
using
the
test
connection
diagram
shown
in
figure
4.
Use
suggested
test
equipment
or
equivalent
to
obtain
accurate
results.
Refer
to Specifications
and
Features
for minimum
performance
standards.
Set
the
differential
meter,
DC VTVM
(John
Fluke
Model
801H
or
equivalent)
to
the
selected
power
supply
operating
voltage.
Check
the
power
supply
load
regulation
accuracy
while
switching
from
the load
to no-load
condition.
Long
load
leads
should
be a twisted
pair
to minimize
AC
pick-up.
Use
a Variac
to vary
the
line voltage
from
105-132
or
132-105
volts
AC and
check
the
power-supply
line
regulation
accuracy
on
the VIVM
differential
meter.
Use
a VIVM,
Ballantine
320
or equivalent,
to measure
rms
ripple
voltage
of the
power
supply
DC
output.
Use
oscilloscope
to measure
peak-to-peak
ripple
voltage
of
the
power
supply
DC
output.
10
IM-LL
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