Chapter 3 Calibration Procedures
Constant Current (CC) Verifications
56
CC Load Regulation
This t est mea sur es t he c han ge in o utp ut cu rr ent r esu lti ng f rom a ch ang e in the
load from full-scale output voltage to short circuit.
1Turn off the power s upply and conne ct the output to t ested as shown in Figure
3-1 with the digital voltmeter connected across the 0.19 current monitoring
resistor (RM).
2Turn 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 voltage to the maximum programmable value and the current to the full-
scale value (see Table 3-2).
3Opera te th e ele ctro nic l oad i n con stan t vol tage mode and s et it s vol tage to th e
full scale value of the output to be tested (see Table 3-2). Check that the CC
annunciator is on. If it is not, adjust the load so that the output voltage drops
slightly. Record the current reading by dividing the voltage reading on the
digital voltmeter by the resistance of the current monitoring resistor.
4Operate the electronic load in short (input short) mode. Record the current
reading again by dividing the voltage reading on the digital voltmeter by the
resistance of the current monitoring resistor. The difference between the
current readings in step (3) and (4) is the load regulation current. The
difference of the readings should be within the limit specified below for each
output tested.
5Repeat steps (1) through (4) for the remaining outputs.
Output Difference
+6V 0.75 mA
+25V 0.35 mA
-25V 0.35 mA