Voltage Calibration
Set the sense switch to local. Connect the DMM (set to Volts) across the output. Set voltage and
current controls to minimum. Switch output ON (Check LED is on) and check for a reading of
00.00V ± 0.01V on the Volts display and DMM; check the Amps display reads 0.00 ± 0.01A.
Set voltage and current controls to maximum. Adjust VR5 (maximum output volts) for a reading of
20.15V to 20.25V on the DMM. Adjust VR6 (measured output volts) until the Volts display
matches the reading on the external DMM.
Switch output OFF. Adjust VR10 (preset volts) until the Volts display shows the previous reading.
Current Calibration
With output OFF, set voltage to 10.00V and connect the 1kΩ resistor across the output terminals.
With output ON, adjust VR11 until the Amps display shows 0.01. Remove 1kΩ resistor.
Switch output OFF. Set output voltage to nominally 2V. Set current limit control to 0.02A. Connect
the DMM (set to Amps) and load in series across the output. Switch output ON.
Adjust VR8 (offset compensation of current control error amp) for a reading of 0.020A
± .001A on the DMM. Check that the CC LED is ON and display reads 0.02.
Increase voltage controls and current control to maximum. Adjust load until the DMM reads
20.00A ± 0.02A. Adjust VR7 (measured output current) until the Amps display matches the DMM
reading.
Reduce load until the CC LED is ON. Adjust VR4 (maximum output current) until the Amps
display shows 20.2.
Voltage Regulation
Connect + sense to the + output terminal, connect – sense to the – output terminal. Select
Remote Sense.
Connect the DMM (set to Volts) across the sense terminals, no load, output ON.
Adjust voltage controls for a reading of 18.xxxx on the DMM; note exact reading.
Connect load of 9 to 9.9A to the output terminals and adjust VR9 (differential voltage gain) until
the external DMM matches the previous reading.
10