Hioki 3511-50, Instruction Manual, Page: 64 / 140

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5.2 Supplying DC Bias
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5.2.2 How to Supply a DC Bias Current
CAUTION
In order to avoid electric shock accident, be absolutely sure not to
touch the test terminals while the DC bias is being supplied to them.
Do not short circuit between the clips of the test probes with the DC
bias still being supplied. Doing so may damage the probes or cause
a short circuit accident.
Capacitor
C
↑
Z
Choke coil
CH
3511-50
+
-
DC current
source
Sample to be tested
L
POT
L
CUR
H
POT
H
CUR
+
-
DC Bias Current Circuit
To supply a DC bias, use the optional 9269 DC BIAS CURRENT UNIT.
For details on using the 9269, refer to the Instruction Manual of the 9269.
(Depending on the test frequency, test signal level, and test range, the 9269
cannot be used.)
If the 9269 is not used, refer to the followings.
To supply a DC bias current to a transformer or a choke coil or the like,
construct an external bias circuit as follows. (For details, refer to JIS C-
6435.)
Use a choke coil (CH) which has a large enough impedance with reference
to the sample under test (Z).
Use a capacitor (C) which has a small enough impedance (i.e., a large
enough capacitance) with reference to the sample under test (Z).
Be careful about the polarity when connecting together the probes, the
sample to be tested, and the DC current source.
Be careful not to magnetically saturate the choke coil (CH) with the DC bias
current.
It takes a little time for the DC current which is being supplied to the
sample under test to reach the set value, so you should wait for a certain
stabilization time period (which depends upon the value of the capacitor (C)
before performing testing. Be careful, because if you perform testing before
this stabilization time period has elapsed, the results will not be reliable.