Technical data

Service Guide 5
U8001A/U8002A User’s and Service Guide 79
CC Source Effect (Line Regulation)
This test measures the change in output current that results
from a change in AC line voltage from the minimum value to
the maximum value.
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 current monitoring resistor (R
M
).
2 Connect the AC power line through an AC voltage source.
Adjust the AC voltage source to provide nominal input
voltage to the power supply.
3 Power on the power supply.
4 When the display is in the limit mode, program the
output voltage to maximum programmable value and
output current to full rated value, i.e. 3 A for U8001A and
5 A for U8002A.
5 Enable the output.
6 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
output voltage drops slightly until the power supply is in
CC mode.
7 Adjust the AC voltage source to low line voltage limit.
Record the output current reading by dividing the voltage
reading on the DMM by the resistance of the current
monitoring resistor.
8 Within a few seconds after step 7, adjust the AC voltage
source to high line voltage limit and record the output
current reading by dividing the voltage reading on the
DMM by the resistance of the current monitoring resistor.