Keysight E3631A, Service Manual

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3 Calibration Procedures
70 Keysight E3631A Service Guide
CC Line Regulation
This test measures the immediate change in output current that results from a
change in ac line voltage from the minimum value (10% below the nominal input
voltage) to the maximum value (10% above nominal voltage).
1 Turn off the power supply and connect the output to be tested as shown in
Figure 3-1 with the digital voltmeter connected across the current monitoring
resistor (RM).
2 Connect the ac power line through a variable voltage transformer.
3 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 ).
4 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 remains lit. If not lit, adjust the load so that the output voltage
drops slightly until the CC annunciator lights.
5 Adjust the transformer to low line voltage limit (104 Vac for nominal 115 Vac,
90 Vac for nominal 100 Vac, or 207 Vac for nominal 230 Vac). Record the
output current reading by dividing the voltage reading on the digital voltmeter
by the resistance of the current monitoring resistor.
6 Adjust the transformer to 10% above the nominal line voltage (110 Vac for a
100 Vac nominal input, 127 Vac for a 115 Vac nominal input or 253 Vac for a
230 Vac nominal input). Record the current reading immediately 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 (5)
and (6) 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.
Output Difference
+6V Output 0.75 mA
+25V Output 0.35 mA
-25V Output 0.35 mA