Agilent Technologies E3646A, User Manual, Page: 185 / 211

Appendix Service Information
Constant Voltage (CV) Verifications
185
Service
Information
4 Operate the electronic load in open mode (input off). Record the output voltage
reading on the digital voltmeter immediately. The difference between the digital
voltmeter readings in steps (3) and (4) is the CV load regulation. The difference of
the readings during the immediate change should be within the limit of (5 mV)* or
(9 mV)**.
5 Repeat steps (1) through (4) for the other output.
CV Source effect (Line Regulation)
This test measures the immediate change in output voltage that results from a change
in ac line voltage from the minimum value (10% below the nominal input voltage) to
maximum value (10% above the nominal input voltage).
1 Turn off the power supply and connect a digital voltmeter between the (+) and (-)
terminals of the output to be tested as shown in Figure A-1.
2 Connect the ac power line through a variable voltage transformer.
3 Turn on the power supply. Select the output to be tested and 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 current to the maximum programmable value and
the voltage to full rated value (20.0 V)
†
.
4 Operate the electronic load in constant current mode and set its current to
(1.5 A)
†
. Check that the
CV
annunciator remains lit. If not lit, adjust the load so that
the output current drops slightly until the
CV
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 reading
on the digital voltmeter.
6 Adjust the transformer to high line voltage (127 Vac for nominal 115 Vac, 110 Vac
for nominal 100 Vac, or 253 Vac for nominal 230 Vac). Record the voltage reading
on the digital voltmeter immediately. The difference between the digital voltmeter
readings in steps (5) and (6) is the CV line regulation. The difference of the readings
during the immediate change should be within the limit of (5 mV)* or (9 mV)**.
7 Repeat steps (1) through (6) for the other output.
*For E3646A/48A models. **For E3647A/49A models.
†
For E3646A model, and see
Table A-3
for other models
.