[sdiy] Gapped vs. Ungapped Transformers?

Tue Mar 11 17:15:21 CET 2003

JH wrote:

>I thought by using a gap you're getting a combination of both
>materials, air and your core material, thus creating a core
>that has lower Mu than an ungaped core would have, but also
>increasing the maximum allowed H field before the the core
>(of combined materials) saturates.
>But I've never heard this to be dependent on the signal level.
>Why should it (as long as nothing saturates) ?
>JH.

Hmmm... Good point. However my experience with tranformers is in
resistance welding supplies (usually 60 - 400 KVA) so we play in a different league.  We are interested in power transfer, not signal
integrity... so we run on the edge of saturation (very non linear)

for audio you would not go there. You are correct for audio that you would never even approach saturation... but it is precisly at that
point where the difference becomes obvious.

So when I said it was dependent on 'signal levels' I meant signal
levels that take you to (or beyond) the knee of the hysteresis curve.
I admit that would be a bad thing in an audio design   ;^P

(otoh some people want a lot of distortion...)

H^) harry