Agilent Technologies E3646A, User Manual, Page: 192 / 211

Appendix Service Information
Constant Current (CC) Verifications
192
6 Adjust the transformer to 10% above the nominal line voltage (127 Vac for a 115 Vac
nominal input, 110 Vac for a 100 Vac nominal input or 253 Vac for a 230 Vac nominal
input). Record the current reading again immediately 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 (5) and (6) is the load regulation
current. The difference of the readings during the immediate change should be within
the limit of:
7 Repeat steps (1) through (6) for the other output.
CC PARD (Ripple and Noise)
Periodic and random deviations (PARD) in the output (ripple and noise) combine to
produce a residual ac current, as well, as an ac voltage superimposed on the dc output.
CC PARD is specified as the rms output current in a frequency range 20 Hz to 20
MHz with the power supply in constant current operation.
N o t e : For better measurement result, it is recommended to make the connection between
the BNC receptacle and the output terminals shorter as much as possible, and to use
the recommended split ferrites with the cable (BNC to BNC) as shown above.
E3646A E3647A E3648A E3649A
0.55 mA 0.33 mA 0.75 mA 0.39 mA
BNC Cable
Input
RMS voltmeter
RMS voltmeter
(Front Panel Connections) (Rear Panel Connections)
Current
Monitoring
Resistor
BNC
Receptacle
Current
Monitoring
Resistor
Split
Ferrites
Input