User`s guide

Chapter 3 Calibration Procedures
Constant Current (CC) Verifications
58
CC Source Effect (Line Regulation)
This test measures the immediate 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 3-
1 with the digital voltmeter connected across the current monitoring resistor (R
M
).
2 Connect the ac power line through a variable voltage transformer.
3 Turn on the power supply. Select the 8V/20A* or 25V/7A** range, 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 rated value (8.0 V)* or (25.0 V)** and the current to the full
rated value (20.0 A)* or (7.0 A)**.
4 Operate the electronic load in constant voltage mode and set its voltage to
(8.0 V)* or (25.0 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.
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 (2.25 mA)* or (0.95 mA)**.
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.
1 Turn off the power supply and connect the output to be tested as shown in Figure 3-
1 with a load resistor (0.4
Ω)* or (3.5 Ω)** across output terminals. Connect a rms
voltmeter across the load resistor. Use only a resistive load for this test.
2 Turn on the power supply. Select the 8V/20A* or 25V/7A** range, enable the output,
and set the display to the limit mode. When the display is in the limit mode, program
the current to full rated value (20.0 A)* or (7.0 A)** and the voltage to the full rated
value (8.0 V)* or (25.0 V)**.
*For Agilent E3633A Model **For Agilent E3634A Model