Appendix Service Information
Constant Voltage (CV) Verifications
170
5 Readback the output voltage over the remote interface by sending the
command:
MEAS:VOLT?
6 Record the value displayed on the controller. This value should be within the
limit of (DVM ±5 mV).
7 Program the output voltage to full scale rated value (20 V)
†
by sending the
command:
VOLT 20.0
(E3640A model)
8 Record the output voltage reading on the digital voltmeter (DVM). The reading
should be within the limit of (20 V ± 20 mV)* or (60 V ± 40mV)**.
9 Readback the output voltage over the remote interface by sending the
command:
MEAS:VOLT?
10 Record the value displayed on the controller. This value should be within the
limit of (DVM ± 15 mV)* or (DVM ± 35 mV)**.
CV Load Effect (Load Regulation)
This test measures the change in the output voltage resulting from a change in
the output current from full to no load.
1 Turn off the power supply and connect a digital voltmeter between the (+) and
(-) terminals of the output as shown in Figure A-1.
2 Turn on the power supply. Select the high voltage range (20V/1.5A)
†
, enable
the output, and set the display to the limit mode. When the display is in the
limit mode, program the output current to the full scale rated value (1.5A)
†
and
the voltage to the full rated value (20.0 V)
†
.
3 Operate the electronic load in constant current mode and set its current to the
(1.5 A)
†
. Check that the front panel CV annunciator remains lit. If not lit, adjust
the load so that the output current drops slightly until the
CV annunciator
lights. Record the output voltage reading on the digital voltmeter.
4 Operate the electronic load in open mode (input off). Record the output voltage
reading on the digital voltmeter again. The difference between the digital
voltmeter readings in steps (3) and (4) is the CV load regulation. The difference
of the readings should be within the limit of (5 mV)* or (9 mV)**.
*For E3640A/42A/44A models. **For E3641A/43A/45A models.
†
For E3640A model, and see Table A-3
for other models
