Control Board Adjustment Locations - HP 3000 III Series Manual

HP 32421A Series III Power Supplies
d. Connect a digital voltmeter between the +16.45V test point on
the control board (figure 9-4) and a common ground point on
the edge of the control board.
Note
Allow the digital voltmeter to warm-up before
taking any measurements.
e. Place control board switch Sl in position 1 (calibrate).
f. Power up the system and allow five minutes for power supply
circuits to stabilize.
g. Refer to table 9-4 and determine the float voltage setting.
h. Adjust potentiometer R35 on the control board (figure 9-4)
for the voltmeter indication determined in the previous
step. This assumes that the battery is almost fully charged.
If it is not, the voltmeter indication will be low and grad-
ually increase as the battery charges. A stable indication
must exist before R35 can be satisfactorily adjusted.
i. Set switch Sl to position 2 (normal).
j. ,Power down the system and disconnect the digital voltmeter.
k. Replace power supply top cover.
1. Install the power supply into the cabinet.
+1645V
°O-3V
123
G
OGND
e:P-
5V
R35
OGND
o
+5.00V
REF.
o
Rl39
D
COMPONENT SIDE
OGND
OGND
012V
O+5V
Figure 9-4. Control Board Adjustment Locations
9-17