Voltech AT3600 User Manual page 295

V AT3600 U
OLTECH SER
1.9. LL
W
Leakage inductance is important in many applications. One example is flyback
designs for high frequency switched mode power supplies, where the leakage
inductance must be less than a specified critical value for proper operation.
M
Leakage inductance is tested by measuring the inductance of a 'primary' winding
when one or more 'secondary' windings are shorted out. In performing the calculation
at the end of the test to extract the inductance value from the measured winding
impedance, the tester uses a series equivalent circuit.
In making the measurement, the tester automatically compensates for the impedance
of the wiring, the connections and the relays in the shorting path.
Leakage inductance can be measured using a test current in the range 20µA to
100mA at a frequency of 20Hz to 1MHz.
You may choose a suitable test current and frequency based on the expected value of
the leakage inductance using the following table:
T T C
ESTS AND EST ONDITIONS
M
ANUAL
LLO- L
OR
U
HERE SED
C
EASUREMENT
Leakage Inductance range
100nH →
→
1uH
→
10uH
→
100uH
→
1mH
→
10mH
→
100mH
→
1H
The Test Conditions for Leakage Inductance Measurement
I
EAKAGE
ONDITIONS
Frequency
1uH
10uH
100uH
1mH
10mH
100mH
1H
10H
VPN 98 - 024
T
NDUCTANCE
Preferred test signal
Current
300kHz 50mA
100kHz 20mA
30kHz 10mA
10kHz
1kHz
100Hz
100Hz
50Hz
500µA
T
RANSFORMER ESTS
5mA
5mA
5mA
1mA
P 7.1.15.
AGE