Transformer design and construction

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pablo_wamco
Transformer design and construction

Hi, I designed a LED driver with PIExpert and I bought the transformer from RTS; this circuit works fine, but when I tried to make the transformer for my self it doesn´t works; it´s appears that doesn´t maintain output voltage while input voltage varies with constant load; I use same materials as sample´s transformer (I disassemble your transformer and reuse copper foil and ferrite core), but it doesn´t works too.

Can you give me some help please?

I send attached result of design from PIExpert.

Thanks for your response.

File

PI-Cochrane
Possible reasons

The circuit and the right transformer have been verified already. So definietly something wrong happens when you built the transformer. I guess either the direction is not correct, or the insulation has been damaged. PLS wind a new transformer with right direction first. Worng direction usually happens when we wind a transformer by ourseleves.

 

 

pablo_wamco
Transformer design and construction (2)

Transformer it´s winded in the right direction and insulation it´s right too. Any other idea?

PI-Cochrane
somethign must be wrong

The design has been verified already. Could you test a good tranformer to make sure that the board is ok? If the board is ok, then something must be wrong in the transformer.

pablo_wamco
Transformer construction and design

I test both transformers in the same board, one works fine while other not. What happens if leakeage inductance is slightly superior than recommended value of the original design?

PI-Cochrane
transformer with higher leakage

The higher leakage inductance results in higher voltage stress of TOPSWITCH and lower efficiency. But the board should work. Definitely you should work on the transformer.