Agilent Technologies E3620A Operating And Service Manual page 78

TYPE
Oscilloscope
RMS Voltmeter
Multimeter
Electronic Load
Resistive Loads (R )
L
Current Sampling
Resistor (Shunt)
Variable Voltage
Auto Transformer
Line Voltage Option Conversion
To convert the supply from one line voltage option to another,
the following three steps are necessary:
a. After making certain that the line cord is disconnected
from a source of power, remove the top cover from the
supply and set the two sections of the line voltage selec-
tor switch for the desired line voltage (see Figure A-3).
b. Check the rating of the installed fuse and replace it with
the correct value, if necessary. For Option OE3, use a
slow-blow 1 amp fuse. For standard and Option OE9, use
a slow-blow 2 amp fuse.
c. Mark the instrument clearly with a tag or label indicating
the correct line voltage to be used.
Figure A-3. Line Voltage Selector (set for 115 Vac)
PERFORMANCE TESTS
The following paragraphs provide test procedures for verify-
ing the power supply's compliance with the specifications of
Table 1. Proceed to the troubleshooting procedures if you
observe any out of specification performance.
Table A-1. Test Equipment Required
REQUIRED CHARACTERISTICS
Sensitivity : 100 μV
Bandwidth : 20 MHz/100 MHz
True rms, 20 MHz bandwidth
Sensitivity : 1 mV
Accuracy : 5%
Resolution : 100 nV
Accuracy : 0.0035%
Voltage Range : 240 Vdc
Current Range : 10 Adc
Open and short switches
Transient on/off
25 Ω 5% 100 W
0.1 Ω 0.1% 3 W
Range : 85-130 and 200-260 Volts
USE
Display transient response and ripple
and noise waveforms.
Measure rms ripple and noise
voltage.
Measure dc voltages.
Measure load and line regulation.
Measure ripple and noise.
Measure output current.
Vary ac input.
Before applying power to the supply, make certain
that its line voltage selector switch (S1) is set for the
line voltage to be used. (See CAUTION notice in
operating section for additional information on S1.)
General Measurement Techniques
Connecting Measuring Devices. To achieve valid results
when measuring load regulation, ripple and noise, and transient
response time of the supply, measuring devices must be con-
nected as close to the output terminals as possible. A measure-
ment made across the load includes the impedance of the leads
to the load. The impedance of the load leads can easily be sev-
eral orders of magnitude greater than the supply impedance and
thus invalidate the measurement. To avoid mutual coupling
effects, each measuring device must be connected directly to
the output terminals by separate pairs of leads.
When performance measurements are made at the front ter-
minals (Figure A-4) the load should be plugged into the front
of the terminals at (B) while the monitoring device is con-
nected to a small lead or bus wire inserted through the hole in
the neck of the binding post at (A). Connecting the measuring
device at (B) would result in a measurement that includes the
resistance of the leads between the output terminals and the
point of connection.
Selecting Load Resistors. Power supply specifications are
checked with a full load resistance connected across the sup-
ply output. The resistance and wattage of the load resis-
tor,therefore, must permit operation of the supply at its rated
output voltage and current. For example, a supply rated at 25
A-3
RECOMMENDED
MODEL
Agilent 54503A
Agilent 34401A
Agilent 6063A