Primary inductance measurement method for flyback converter

Jitendra Suthar

Hi,

I want to measure primary inductance of flyback converter which is designed through planar transformer.

By measuring primary current flowing through Rsense (refer attached schematic) (Isense),

can we derive L(primary) using V= L*di/dt formula ?

where V= Primary voltage, di = Isense, dt = ON period of swithcing mosfet

Regards,

Jitendra

0 Jitendra Suthar over 5 years ago

0 Mike O' over 5 years ago

Hello Jitendra,

We don't generally derive equations on the e2e. However, you can derive the primary magnetizing inductance based on V, W and P.

Please see below.

V = L*di/dt

W = (L*di^2)/2

P = dW/dt

P/fsw = dW

P/fsw= (L*di^2)/2

L = 2*P/(fs*di^2)

Regards,

Mike

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