Agilent Technologies E364XA Series, User Manual

Page: 188 / 220

Appendix Service Information
Constant Current (CC) Verifications
187
Ser
vice
In
for
mat
ion
3
Set the voltage of the electronic load to (8.0 V)
†
to operate it in constant voltage
mode since a voltage drop occurs on the load wires. Check that the CC
annunciator is on. If it is not, adjust the load so that the output voltage drops
slightly. Record the current reading by dividing the voltage reading on the
digital voltmeter by the resistance of the current monitoring resistor.
4 Operate the electronic load in short (input short) mode. Record the current
reading again by dividing the voltage reading on the digital voltmeter by the
resistance of the current monitoring resistor. The difference between the
current readings in step (3) and (4) is the load regulation current. The
difference of the readings should be within the limit of:
5 Repeat steps (1) through (4) for the other output.
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 (10% below the nominal input voltage)
to the maximum value (10% above nominal voltage).
1 Turn off the power supply and connect the output to be tested as shown in
Figure A-1 with the digital voltmeter connected across the current monitoring
resistor (R
M1
).
2 Connect the ac power line through a variable voltage transformer.
3 Turn on the power supply. Select the low voltage range (8V/3A)
†
, enable the
output, and set the display to the limit mode. When the display is in the limit
mode, program the voltage to the full scale rated value (8.0 V)
†
and the current
to the full scale rated value (3 A)
†
.
4 Operate the electronic load in constant voltage mode and set its voltage to
(8.0 V)
†
. Check that the CC annunciator remains lit. If not lit, adjust the load
so that the output voltage drops slightly until the
CC
annunciator lights.
5 Adjust the transformer to low line voltage limit (104 Vac for nominal 115 Vac,
90 Vac for nominal 100 Vac, or 207 Vac for nominal 230 Vac). Record the output
current reading by dividing the voltage reading on the digital voltmeter by the
resistance of the current monitoring resistor.
E3646A E3647A E3648A E3649A
0.55 mA 0.33 mA 0.75 mA 0.39 mA
†
For E3646A model, and see
Table A-3 for other models