Keysight 1143A, User'S And Service Manual

Page: 30 / 56

To adjust power supply current limits
This procedure sets the current limit of the supplies to approximately
330 mA for each supply.
Equipment Required
Equipment Critical Specification Recommended
Model/Part
Digital Multimeter Better than 0.1% accuracy 3458A
Resistor 50
Ω
, 10 W, 1% 0811-3707
Use the adjustment locator on page 28 to find the test points and adjustments.
1
Connect the DVM between TP5 (ground) and TP1 (+17.3V).
2 Connect the 50-
Ω
resistor between TP5 and TP1.
3
Adjust R60 (Positive Current Threshold) for a reading of
+
16.7V
±
300 mV.
4 Connect the DVM between TP5 (ground) and TP2 (
−
17.3V).
5
Disconnect the 50-
Ω
resistor from TP1 and connect it to TP2
(between TP5 and TP2).
6
Adjust R61 (Negative Current Threshold) for a reading of
−
16.7V
±
300
mV (
−
16.4 to
−
17.0 V).
If the supplies cannot be adjusted into tolerance, go to the "Troubleshooting and
Repair" section of this chapter.
Service
Making Adjustments
30