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h.
Record voltage indicated on DVM.
i.
Adjust autotransformer for high line voltage.
j.
Reading on DVM should not differ from reading of
step h by more than 30/A/.
5-49
PARD {Ripple and Noise).
Definition: The residual ac current superimposed on the
do output of a regulated power supply. Ripple and noise
measurement may be made at any input ac line voltage com¬
bined with any dc output voltage and load current within the
supply's rating.
5 50
Most of the instructions pertaining to pickup prob¬
lems associated with constant voltage ripple and noise
measurement also apply to the measurement of constant-
current ripple and noise. Figure 5-8 shows two test setups that
can be used when measuring the ripple and noise of a
constant current supply. F.fiber test setup can be used depend ¬
ing on the availability of an appropriate monitoring resistor.
5-51
The current monitoring resistor (Rf\/|> in Figure 5-8
can be constructed of parallel-connected resistors. It must
have very low inductance to prevent the high frequency com¬
ponents of CC ripple from causing a misleading voltage drop.
A current probe/amplifier combination such as Tektronix
P6302 probe and AM503 amplifier can be used for the current-
monitoring transformer (T1) in Figure 5-8B.
5-52
To check the ripple and noise, proceed as follows:
a.
Connect oscilloscope or rms voltmeter as shown in
Figure 5-8.
b.
Turn on supply and turn up output voltage. Adjust
output current and Rp until front panel meters indicate
10 A and approximately 20 V. If unit switches to CV
mode, use OUTPUT ADJUST controls to increase CV
limit so that unit remains in CC mode.
c.
The oberved ripple and noise should be less than 0.5
mV rms (5 mA rms).
S-53
TR 0 U B LES H OOTIN G
5-54
Introduction
5-55
The following paragraphs describe use of self tests
which the 6034A can perform to verif y the operation of many
of
its
circuits,
signature
analysis,
and
the
detailed
troubleshooting trees. Also described is an optional service
package. The procedures described in these paragraphs are
designed to help a technician identify and locate any faults in
the 6034A as rapidly as possible. A good understanding of the
principles of operation is particularly helpful, and it is recom¬
mended that Section IV of this manual be reviewed before at-
POWER SUPPLY
RMS VOLTMETER
OR OSCILLOSCOPE
RMS VOLTMETER
POWER SUPPLY
OR OSCILLOSCOPE
Figure 5-8.
Constant-Current Ripple and Noise Measurement Test Setup
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