Keysight E3631A, Service Manual

Page: 71 / 131

Calibration Procedures 3
Keysight E3631A Service Guide 69
CC Load Regulation
This test measures the immediate change in output current resulting from a
change in the load from full rated output voltage to short circuit.
1 Turn off the power supply and connect the output to tested as shown in Figure
3-1 with the digital voltmeter connected across the 0.1 W current monitoring
resistor (R
M
).
2 Turn on the power supply and select the desired output to be tested using the
meter and adjust selection key on the front panel. Enable the outputs and set
the display to the limit mode. When the display is in the limit mode, program
the voltage to the maximum programmable value and the current to the full
rated value (see Table 3-2 ).
3 Operate the electronic load in constant voltage mode and set its voltage to the
full rated value of the output to be tested (see Table 3-2 ). Check that the CC
annunciator is on. If it is not, adjust the load so that the output voltage drops
slightly. Record the current reading by dividing the voltage reading on the
digital voltmeter by the resistance of the current monitoring resistor.
4 Operate the electronic load in short (input short) mode. Record the current
reading within two seconds by dividing the voltage reading on the digital
voltmeter by the resistance of the current monitoring resistor. The difference
between the current readings in step (3) and (4) is the load regulation current.
The difference of the readings during the immediate change should be within
the limit specified below for each output tested.
5 Repeat steps (1) through (4) for the remaining outputs.
Output Difference
+6V Output 0.75 mA
+25V Output 0.35 mA
-25V Output 0.35 mA