Agilent Technologies E3620A Manual De Funcionamiento Y Servicio página 80

Load Regulation (Load Effect)
Definition: The immediate change,
output voltage resulting from a change in load resistance from open
circuit to the value that yields maximum rated output current (or vice
versa).
To check the load regulation:
a. Connect the test equipment across the output of the V1 sup-
ply as shown in Figure A-7. Operate the electronic load in
constant current mode and set its current to 1.000 A. Input
off the electronic load.
b. Turn on the supply. Push the V1 METER switch in and adjust its
voltage to 25.0 volts. Then input on the electronic load.
c. Record the voltage indicated on the DVM.
d. Operate the electronic load in open (input off) mode and
recheck the DVM indication immediately. The readings'
difference during the immediate change should be within
0.01% plus 2 mV of the reading in step (c).
e. Repeat steps (a) through (d) for the V2 supply.
Figure A-7. Basic Test Setup
Line Regulation (Source Effect)
Definition: The immediate change,
output voltage resulting from a change in ac input voltage from a
minimum to a maximum value (±10% of nominal voltage).
To check the line regulation:
a. Connect a variable autotransformer between the input
power source and the power supply line plug.
b. Connect the test equipment across the output of the V1 supply as
shown in Figure A-7. Operate the electronic load in constant current
mode and set its current to 1.000 A. Input off the electronic load.
c. Adjust the autotransformer for a low line input (-10% of nominal
voltage).
d. Turn on the power. Push the V1 METER switch in and
adjust the output of the supply to 25.0 volts, then input on
the electronic load. Record the DVM indication.
e. Adjust the autotransformer for high line voltage input (+10%
of nominal voltage) and recheck the DVM indication immedi-
ately. The readings' difference during the immediate change
should be within 0.01% plus 2 mV of the reading in step (d).
f. Repeat steps (b) through (e) for the V2 supply.
Ripple and Noise(Normal Mode Voltage)
Definition: Ripple and noise are measured in the rms or peak-
to-peak value over a 20 Hz to 20 MHz bandwidth. Fluctuations
below the lower frequency limit are treated as drift.
• E , in the static value of dc
OUT
• E , in the static value of dc
OUT
RMS Measurement
The rms measurement is not an ideal representation of the
noise, since fairly high output noise spikes of short duration
could be present in the ripple and not appreciably increase
the rms value.
To measure the ripple and noise of the rms value on each
output supply output:
a. Connect the test equipment across the output of the V1
supply as shown in Figure A-8.
b. Turn on the supply and push the V1 METER switch in.
c. Adjust the output of the V1 supply to 25.0 volts.
d. Check that the rms noise voltage at the true rms voltme-
ter is less than 0.35 mV.
e. Repeat steps (a) through (d) for the V2 supply.
Figure A-8. Ripple and Noise rms Measurement Test
Peak-to-Peak Measurement
The peak-to-peak measurement is particularly important for
applications where noise spikes could be detrimental to a
sensitive load, such as logic circuitry.
To measure the ripple and noise of the peak-to-peak value on
each output supply output:
a. Connect the test equipment across the output of the V1
supply as shown in Figure A-8, but replace the true rms
voltmeter with the oscilloscope.
b. Turn on the supply and push the V1 METER switch in.
c. Adjust the output of the V1 supply to 25.0 volts.
d. Set the oscilloscope to AC mode and bandwidth to 20 MHz.
e. Check that the peak-to-peak noise is less than 1.5 mV.
f. Repeat steps (a) through (e) for the V2 supply.
Common Mode Current (CMI)
Definition : Common mode current is that ac current compo-
nent which exists between any or all supply or output lines
and chassis ground.
To measure the common mode current:
a. Connect the full load for the V1 output terminal.
b. Connect a 100 kΩ resistor(R
in parallel between V1 - terminal and chassis ground.
A-5
Setup
) and a 2200 pF capacitor
S