Technical data

78 U8001A/U8002A User’s and Service Guide

5Service Guide

CC Load Effect (Load Regulation)

This test measures the immediate change in output current

resulting from a change in the load from full rated output

voltage to short circuit.

Procedures:

1 Power off the power supply and connect the output to be

tested as shown in Figure 5- 7(B) with the DMM

connected across the 0.01

Ω current monitoring resistor

2 Power on the power supply.

3 When the power supply is in limit mode, program the

output voltage to maximum programmable value and

output current to full rated value, i.e. 3 A for U8001A and

5A for U8002A.

4 Enable the output.

5 Operate the electronic load in constant voltage mode and

set its voltage to 30 V. Ensure that the power supply is in

CC mode. If not, adjust the electronic load so that the

voltage drops slightly until the power supply is in CC

mode.

6 Record the current reading by dividing the voltage reading

on the DMM by the resistance of the current monitoring

resistor.

7 Within a few seconds after step 6, operate the electronic

load in short mode and record the current reading by

dividing the voltage reading on the DMM by the resistance

of the current monitoring resistor.

8 Compare the reading obtained in steps 6 and 7. The

difference should be within the limit of:

• U8001A: 2.6 mA

• U8002A: 3 mA