Appendix Service Information
Constant Voltage (CV) Verifications
173
Service
Information
Load Transient Response Time
This test measures the time for the output voltage to recover to within 15 mV
of nominal output voltage following a load change from full load to half load,
or half load to full load.
1 Turn off the power supply and connect the output to be tested as shown in
Figure A-1 with an oscilloscope. Operate the electronic load in constant
current mode.
2 Turn on the power supply. Select the high voltage range (20V/1.5A)
†
, enable
the output, and set the display to the limit mode. When the display is in the
limit mode, program the current to the full scale rated value (1.5 A)
†
and the
voltage to the full scale rated value (20.0 V)
†
.
3 Set the electronic load to transient operation mode between one half of the
output’s full rated value and the output’s full rated value at a 1 kHz rate with
50% duty cycle.
4 Set the oscilloscope for ac coupling, internal sync, and lock on either the
positive or negative load transient.
5 Adjust the oscilloscope to display transients as shown in Figure A-4. Note that
the pulse width (t2 - t1) of the transients at 15 mV from the base line is no more
than 50
msec for the output.
Figure A-4 Transient Response Time
†
For E3640A model, and see Table A-3
for other models
