Leakage inductance too high

Hello everyone,
I wound a transformer with ETD29 N87 with Nprimary=52 turns, Nbias=16 turns, Nsecondary=10 turns. When I measured primary inductance I obtain 530uH but the leakage inductance is 291uH. Is it too high?

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waldous says:

Is the transformer properly sized? If it's not, it wouldn't cause a high leakage inductance. How did you wound the winding?

Published: 7 months ago

waldous said:

Is the transformer properly sized? If it's not, it wouldn't cause a high leakage inductance. How did you wound the winding?
celius says:

I think I made a mistake winding the wire around the auxiliary windings, is the way to do it important? I mean, is it important the direction I wound the wire? I have tried to change the cable to a thicker one but I think that doesn't influence.

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celius said:

I think I made a mistake winding the wire around the auxiliary windings, is the way to do it important? I mean, is it important the direction I wound the wire? I have tried to change the cable to a thicker one but I think that doesn't influence.
waldous says:

That wouldn't cause such a high leakage inductance, did you short the other two windings? 

If you want to measure the leakage inductance, you short each of the other windings with a wire, preferably thick and then you measure the inductance across the winding of interest which is open (ie without a short on it). The measurement you get is the leakage inductance of that winding.

In your case, if you are to measure the leakage inductance across the primary, you have to short the secondary with a thick wire and the auxiliary too with a thick wire and measure the inductance across the primary.

If you are to measure the leakage inductance across the secondary, you have to short the primary with a thick wire and the auxiliary with a thick wire and the measure the inductance across the secondary.

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