Cc Load Effect; Cc Source Effect - Agilent Technologies 6631B Service Manual

CC Load Effect

This test measures the change in output current for a change in load from full scale output voltage to short
circuit.
a. Turn off the supply and connect the output as shown in Figure 2-1a with the DVM connected across the
current monitoring resistor.
b. Turn on the supply and program the current to the full scale current value and the output voltage to the
maximum programmable voltage value.
c. Adjust the load in the CV mode for full scale voltage as indicated on the front panel display. Check that
the CC annunciator of the UUT is on. If it is not, adjust the load so that the output voltage drops
slightly.
d. Record the output current reading (DVM reading/current monitor resistance value in ohms). You may
want to use the average reading program described under "CC Load and Line Regulation".
e. Short the load switch and record the output current reading. The difference in the current readings in
steps (d) and (e) is the load effect and should not exceed the limit specified in the performance test
record chart for the appropriate model under CC LOAD EFFECT.

CC Source Effect

This test measures the change in output current that results when the AC line voltage changes from the
minimum to the maximum value within the specifications.
a. Turn off the supply and connect the ac power line through a variable voltage transformer.
b. Connect the output terminals as shown in Figure 2-1a with the DVM connected across the current
monitoring resistor. Set the transformer to the nominal line voltage.
c. Turn on the supply and program the current to the full scale value and the output voltage to the
maximum programmable value.
d. Adjust the load in the CV mode for full scale voltage as indicated on the front panel display. Check that
the CC annunciator of the UUT is on. If it is not, adjust the load so that the output voltage drops
slightly.
e. Adjust the transformer to the lowest rated line voltage.
f. Record the output current reading (DVM reading/current monitoring resistor in ohms). You may want
to use the average reading program described under "CC Load and Line Regulation".
g. Adjust the transformer to the highest rated line voltage.
h. Record the output current reading again. The difference in the current readings in steps (f) and (h) is the
CC source effect and should not exceed the values listed in the performance test record card under CC
SOURCE EFFECT.
Verification and Performance Tests - 2
19