HP E3610A Operating And Service Manual page 9

current to the full rated value of power supply.
b. Connect the unit to the ac power line through a variable
autotransformer which is set for low line voltage(104 Vac for
115 Vac).
c. Turn the unit's power on and turn CURRENT control fully
clockwise.
d. Turn up output voltage to the full rated value as read on the
digital voltmeter.
e. Record the output voltage at the digital voltmeter.
f. Adjust autotransformer to high line voltage) 127 Vac for
115 Vac).
g. When the reading settles, record the output voltage again.
Check that the two recorded readings differ no more than
0 . 0 1 % of output voltage plus 2 mV.
Load Transient Recovery Time
d. Set the electronic load to transient operation mode between
one half of unit's full rated value and unit's full rated value at
a 1 KHz rate with 5 0 % duty cycle.
e. Set the oscilloscope for ac coupling, internal sync and lock on
either the positive or negative load transient.
f. Adjust the oscilloscope to display transients as in Figure A-3.
g. Check that the pulse width of the transients at 10 mV from
the base line is no more than 50 usee as shown.
PARD(Ripple and Noise)
Definition: Periodic ar>d random deviation(PARD) in the unit's output
ripple and noise combine to produce a residual ac voltage superim-
posed on the dc output voltage. Constant voltage PARD is specified
as the root-mean-square(rms) or peak-to-peak(pp) output voltage in
a frequency range of 10 Hz to 10 MHz.
Definition : This is the time for the output voltage to return to within
a specified band around its voltage following a step change in load.
Test Paramater:
Measured Variable: Output Voltage Transients
Expected Results: Less than 50 usee (at 10 mV from base line)
Test Procedure:
a. Connect the test equipment as shown in Figure A-2, but
replace the DVM with the oscilloscope. Operate the electronic
load in constant current mode.
b. Turn the unit's power on and turn CURRENT control fully
clockwise.
c. Turn up output voltage to the full rated value.
PARD(RMS) Measurement
Test Parameter:
Measured Variable: Output Voltage(rms)
Expected Results: Less than 200 uV rms
Test Procedure:
a. Connect the test equipment as shown in Figure A-4.
b. Turn the unit's power on and turn CURRENT control fully
clockwise.
c. Turn up output voltage to the full rated value. Check that the
unit's CV indicator remains lighted. Reduce VOLTAGE control
if not lighted.
d. Check that the rms noise voltage at the true rms voltmeter is
no more than 200 uV.
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Figure A - 3 . Load Transient Recovery W a v e f o r m
A-3