Performing measurements
R&S
®
LCX Series
66
User Manual 1179.2260.02 ─ 02
To determine the mutual inductance, the R&S
LCX calculates the parameters
based on:
V
s
= voltage in secondary circuit
R
s
= resistance of secondary circuit
I
s
= current in secondary circuit
I
p
= current in primary circuit
L
s
= inductance of secondary circuit
M = mutual inductance
Hence, if you have no current in the secondary circuit (I
s
= 0):
You can derive the mutual inductance, which can also be negative:
Measuring the leakage inductance of a transformer
This example refers to a measurement of a transformer with the test fixture (R&S
LCX-
Z5). You can also use only the included standard cables for inductance measurements
without the test adapter.
To measure the leakage inductance, the short circuit measurement principle as used
for a conventional inductance is suitable:
1. To select the transformer measurement (DUT component type), press the
[Transformer] key.
2. To select the parameters for measurement results display:
a) Select the measurement pair softkey in the upper left corner, to open the selec-
tion editor.
b) Select "M-
Θ
d" (inductance, phase angle).
3. Short-circuit the secondary winding of the sample transformer.
L CUR
short
secondary
primary
H CUR
H POT
L POT
Figure 7-3: Leakage inductance measurement
The measured values of the primary circuit correspond to the leakage inductance.
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