Voltech AT360, User Manual

Page: 416 / 470

T
ESTS AND
T
EST
C
ONDITIONS
P
AGE
7-118 V
OLTECH
AT
I
U
SER
M
ANUAL
7.1.31 LPBX – I
NDUCTANCE WITH
E
XTERNAL
B
IAS
(P
ARALLEL
C
IRCUIT
)
DC Bias Measure
Range
Test
Voltage
Test
Frequency
Basic
Accuracy
0.1A to
250A
1nH 1MH 1mV to 5V 20Hz to 3MHz 0.2% @ Q>10
This test requires the use of one or more Voltech DC1000 Precision DC Bias
Current Sources. Contact your Voltech sales office for details.
The inductance of a transformer winding while an external bias current is
flowing through it may be tested using series or parallel equivalent circuit
models. Initially the DC bias current is set up and allowed to stabilize. An AC
voltage is applied across the selected winding; the voltage across and current
through the winding are then measured using harmonic analysis. The
measured voltage is divided by the current to obtain a complex impedance and
the inductance is calculated.
On selecting ‘LPBX Inductance with External Bias (Parallel Circuit) from the
‘Available Tests’ window, a dialogue box will be displayed.