Technical data

8 Service and Maintenance
Constant Voltage (CV) Verifications
190 E364xA User’s and Service Guide
CV source effect (line regulation)
This test measures the immediate change in the output
voltage that results from a change in the AC line voltage
from the minimum value (10% below the nominal input
voltage) to the 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 8- 1.
2 Connect the AC power line through a variable voltage
transformer.
3 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 current to the maximum programmable value
and the voltage to the full- scale rated value (20.0 V)
[1]
.
4 Operate the electronic load in the constant current mode
and set its current to 1.5 A
[1]
. 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 up.
5 Adjust the transformer to the 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 the 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
[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.