[sdiy] Gapped vs. Ungapped Transformers?

[harrybissell]

Hi Tim

an ungapped transformer has a complete magnetic flux path through the
core...
very efficient but saturates easily.

Gapping the core (a small gap) allows flux to 'leak' out.. allowing the
tranformer
to work almost as well at low currents, and able to survive higher
currents as well.
The transformer coils work like an iron core at low levels and (sort of)
more like
an air core at high levels...

Gapped cores are hard(er) to saturate.  DC will saturate a
transformer... even faster
with an ungapped core.

H^) harry

Tim Curtis wrote:

> Hi Everyone -
>
> I've got a transformer question...
>
> What does it mean when transformers are "gapped" or "ungapped"?  I'm
> wondering about an audio output transformer.  There are two of them
> listed at exactly the same specs but one is marked "gapped" and the
> other marked "ungapped - no d.c."
>
> Anybody care to share their insights?  I'm not a transformer person.
>
> Thanks,
>
> Tim