Measurment of Primary inductace of transformer Lp

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Hi friends ,
In PI EXPERT, transformer construction parameter Lp is mentioned as 520 micro henry
, at what test frequency on L.C.R. METER shall i check Lp , 100 Hz or 1khz?
L.C.R. Meter have only these two test frequencies for inductor measurement..
As s.m.p.s designed to operate at 132 khz.

Waiting for advice and explanation .


You should measure the inductance at the switching frequency or at 100 kHz. Another way to measure inductance is using the oscilloscope. Operate the power supply with DC voltage and capture the drain current waveform and then use V = L di /dt to figure out what inductance is giving you the measured di /dt.