HP 6296A - Page 34

•
•
•
Type
Resistor
Capacitor
Decade
Resistance
Box
POWtR SUPPLY
UNDER
TEST
LOAD
Required
Recommended
Characteristics
Use
Model
Value:
See
Paragraph 5-47.
Calibrate programming
current
----------------
:t:O.
1
%.
l/2
watt.
500µ.f, 50
wvdc
Measure impedance.
----------------
Range:
0-SOOK.
Measure programming
----------------
Accuracy:
0.
1%
plus
l
ohm
coefficients.
Make-before-break
contacts.
NOTE
A
satisfactory
substitute
for a differential
voltmeter
is
to
arrange
a reference voltage source
and
null
detector
as
shown in Figure
S-3.
The reference
voltage source
is
adjusted
so
that
the
voltage
differ-
ence
between
the
supply
being measured and
the
reference
voltage
will
have the required
resolution
for the measurement being made. The voltage
differ-
ence
will
be
a function of the null
detector
that
is
used,
Examples
of
satisfactory
null
detectors
are:
S
419
A
null
detector,
a
DC
coupled
oscilloscope
utilizing
differential
input,
or
a
SO
mv
meter
move-
ment
with
a
100
division
scale.
For the
latter,
a
2
mv
change
in voltage
will
result
in
a meter
deflec-
tion
of four
divisions.
CAUTION
Care
must
be
exercised
when using
an
electronic
null
detector
in which
one
input terminal
is
grounded
to
avoid ground loops
and
circulating
currents.
NllU.
"DETECTOR
REfUENCt
VOLTAGE
SOURCE
0
S-10
PERFORMANCE
TEST
5-11 The following
test
can
be
used
as
an
in-
coming
inspection
check
and
appropriate
portions
of
the
test
can
be
repeated
either
to
check
the
operation
of
the
instrument
after
repairs
or
for
periodic maintenance
tests.
The
tests
are
per
fonned
using
a
115-VAC
60
cps.,
single
phase
in-
put power source.
If
the
correct
result
is
not
ob-
tained
for a
particular
check,
do
not
adjust
any
controls; proceed
to
troubleshooting
(Paragraph
5-28)
•
Figure
5-3.
Differential
Voltmeter
Substitute,
Test
Setup
S-3