M520086-01
4-5
e.
Adjust R87 until the power supply output voltage starts to increase in normal
polarity. Reverse adjustment direction of R87 until output voltage decreases to
zero reading on the DMM. Do not continue adjustment when the output reads
zero volts.
Current Full-Scale Calibration
Full-scale current calibration is accomplished by adjusting R88. The following sequence
is recommended.
a.
Connect an external calibrated current shunt between the power supply
negative output and a resistive load bank capable of full-rated power.
(Optionally, the shunt may be connected between the power supply positive
and negative output bus bars.)
b.
Connect DMM across current shunt sensing terminals.
c.
Connect a DMM between TB1-9(+) and TB1-11(-). Set to 200 millivolt range.
d.
Set front panel voltage control potentiometer fully clockwise.
e.
Apply power to power supply.
f.
Adjust front panel current control for 100 millivolt reading on DMM across TB1-
9 and TB1-11.
g.
Adjust R88 until rated output current flows through external current shunt.
Current Monitor/Parallel Tracking Amplifier Zero Calibration
The Current monitor/parallel tracking amplifier zero is accomplished by adjusting R79.
The following sequence is recommended.
a.
Connect a jumper (short circuit) between TB1-9 and TB1-11.
b.
Connect a resistive load across output terminals.
c.
Connect a DMM between TB1-12(+) and TB1-13(-). Set DMM to DC volts on
0.2 volt scale.
d.
Set front panel voltage and current control potentiometers fully
counterclockwise.
e.
Apply power to power supply
f.
Adjust R79 to 0.00 volts on DMM.
g.
Remove power from power supply.
h.
Remove jumper between TB1-9 and TB1-11.
i.
Remove resistive load from power supply output terminals.
j.
Reconfigure power supply for normal operation.