Gaps between the Bobbin and the Ferrite Core in a Transformer


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Hi guys

We purchase Transformers (for smt) from some manufacturer (I work in a PCBA line)
We discovered spacing or gaps between the Bobbin and the ferrite core.
"As the ferrite is made by sintering, not by machining, some clearance could appear between the ferrite core and the bobbin."

the manufacturer claim that this is a well known phenomenon and has absolutely no influence on the functionality of the transformer. what do you think?
is there a standard of some kind that defines tolerances for space/gap between a ferrite core and a bobbin in a transformer? Is someone familiar with this phenomena?



There will be some gap. This is to get the positive surface contacts between the ferrite limbs when assembled. Usually the impregnation will prevent the play of the ferrite. Suitable adhesives are also used sometimes.

The manufacturer's claim is ok, but the ferrite play (if any) must be arrested. I am not aware of any standards, but the gap is a design consideration in the bobbin to be suitable for all makes of standard ferrites.
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