Service and Maintenance 8
E364xA User’s and Service Guide 209
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 Table 8-5.
[2] For the E3640A/E3642A/E3644A model.
[3] For the E3641A/E3643A/E3645A model.