Agilent Technologies 6612B, Service Manual, Page: 16 / 74

2 - Verification and Performance Tests
16
Transient Recovery Time
This test measures the time for the output voltage to recover to within the specified value following a 50% change in
the load current.
tttt
t
v
Loading
Transient
Unloading
Transient
v
t
Figure 2-2. Transient Waveform
a. Turn off the supply and connect the output as in Figure 2-1a with the oscilloscope across the +S and the -S
terminals.
b. Turn on the supply and program the output voltage to the full-scale value and the current to the maximum
programmable value.
c. Set the load to the Constant Current mode and program the load current to 1/2 the power supply full-scale rated
current.
d. Set the electronic load's transient generator frequency to 100 Hz and its duty cycle to 50%.
e. Program the load's transient current level to the supply's full-scale current value and turn the transient generator
on.
f. Adjust the oscilloscope for a waveform similar to that in Figure 2-2.
g. The output voltage should return to within the specified voltage (v) in less than the specified time (t). Check
both loading and unloading transients by triggering on the positive and negative slope.
Constant Current (CC) Tests
CC Setup
Follow the general setup instructions in the Measurement Techniques paragraph and the specific instructions given
in the following paragraphs.
Current Programming and Readback Accuracy
This test verifies that the current programming and readback are within specification.
a. Turn off the supply and connect the current monitoring resistor across the power supply output and the DVM
across the resistor. See "Current Monitoring Resistor" for connection information.
b. Turn on the supply and program the output voltage to 5 V and the current to 20mA (±1mA).
c. Divide the voltage drop (DVM reading) across the current monitoring resistor by its resistance to convert to
amps and record this value (Iout). Also, record the current reading on the front panel display. The readings
should be within the limits specified in the performance test record card for the appropriate model under CC
PROGRAMMING @ 0 AMPS.
d. Program the output current to full-scale .