Technical data

Service and Maintenance 8
Constant Voltage (CV) Verifications
E364xA User’s and Service Guide 189
CV load effect (load regulation)
This test measures the immediate 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 8- 1.
2 Turn on the power supply. Select the high voltage range
(20 V/1.5 A)
[1]
, 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 maximum
programmable value and the voltage to the full- scale rated
value (20.0 V)
[1]
.
3 Operate the electronic load in the constant current mode
and set its current to 1.5 A
[1]
. 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 up. Record the output voltage reading
on the digital voltmeter.
4 Operate the electronic load in the 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
[2]
or 9 mV
[3]
.
[1] For the E3640A model. For other models, refer to Tabl e 8 -5 .
[2] For the E3640A/E3642A/E3644A model.
[3] For the E3641A/E3643A/E3645A model.