Chapter 3 Calibration Procedures
Constant Voltage (CV) Verifications
53
3
CV 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 3-1.
2 Connect the ac power line through a variable voltage transformer.
3 Turn on the power supply and select the desired output to be tested using the meter
and adjust selection key on the front panel. Enable the outputs and set the display to
the limit mode. When the display is in the limit mode, program the current of the
selected output to the maximum programmable value and the voltage to full rated
value (see Table 3-2).
4 Operate the electronic load in constant current mode and set its current to the full rated
value (see Table 3-2) of the output to be tested. 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.
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 autotranformer 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 specified below for
each output tested.
7 Repeat steps (1) through (6) for the remaining outputs.
Output Difference
+6V 2.6 mV
+25V 4.5 mV
-25V 4.5 mV
To Next Page
Loading...
Need help?
General
