A-7
e.
Record output voltage across Rs and convert it to
current by dividing this voltage by Rs.
f.
Adjust autotransformer to the high line voltage (127
Vac for nominal 115 Vac, 110 Vac for nominal 100
Vac, and 253 Vac for nominal 230 Vac).
g.
When the reading settles, record the voltage across
Rs again and convert it current. Check that the two
recorded readings differ less than 0.01% of output
current plus 250
µ
A.
PARD(Ripple and Noise)
Definition : The residual ac current which is superimposed
on the dc output current of a power supply. Constant current
PARD is specified as the root-mean-square(rms) output cur-
rent in a frequency range of 20 Hz to 20 MHz with the supply
in CC operation.
PARD(RMS) Measurement
Test Parameter:
Measured Variable: Output Current(rms)
Expected Results: E3614A: Less than 5 mA rms
E3615A: Less than 2 mA rms
E3616A: Less than 500
µ
A rms
E3617A: Less than 500
µ
A rms
Test Procedure:
a.
Connect the test equipment as shown in Figure A-8.
b.
Turn the supply's power on and turn VOLTAGE con-
trol fully clockwise.
c.
Turn up output current to the full rated value. Check
that the CC indicator remains lighted. Reduce CUR-
RENT control if not lighted.
d.
Record rms voltage across Rs and convert it to cur-
rent by dividing this voltage by Rs.
e.
Check that the rms noise current is less than 5 mA
rms for E3614A, 2 mA rms for E3615A and 500
µ
A
rms for E3616A and E3617A respectively.
Figure A-8. CC PARD RMS Measurement Test Setup
CC Drift (Stability)
Definition: The change in output current for the first 8 hours fol-
lowing a 30-minute warm-up with constant input line voltage,
constant load resistance and constant ambient temperature.
Test Parameter:
Measured Variable: Output Current
Expected Results: Less than 0.1% plus 10 mA
Test Procedure:
a.
Connect the DVM across Rs in Figure A-4. Operate
the electronic load in constant voltage mode and set
its voltage to the full rated value of the power supply.
b.
Turn the supply's power on and turn VOLTAGE con-
trol fully clockwise.
c.
Turn up output current to the full rated value.
d.
After a 30-minute warm-up, note the voltage on DVM
and convert it to current by dividing this voltage by Rs.
e.
The converted output current should deviate less than
0.1% plus 10 mA from the current obtained in step d
over a period of 8 hours.
ADJUSTMENT AND CALIBRATION
PROCEDURE
Adjustment and calibration may be required after perfor-
mance testing, troubleshooting, or repair and replacement.
Perform those adjustments that affect the operation of the
faulty circuit and no others. To remove the top cover, refer to
"Line Voltage Option Conversion" paragraph.
Maintenance described herein is performed with
power supplied to the supply, and protective covers
removed. Such maintenance should be performed
only service-trained personnel who are aware of the
hazards involved (for example, fire and electrical
shock). Where maintenance can be performed with-
out power applied, the power should be removed.
Figure A-9. Calibration Test Setup
