Re: Would this work? (air gap in ballast core)

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: "J. Aaron Holmes" <jaholmes@xxxxxxxxxxxxxxxxxx>


Unfortunately, these cores are definitely *not* in two
separate pieces.  They're also not varnished in the
slightest bit.  On the contrary, actually; they're
soaked with oil, as I've been told is typical of pole
transformer cores (no varnish, just oil).  As I was
removing the cores from the transformer, the inner
laminations had a tendency to try to slide out, and it
took great physical effort to prevent them from doing
so (and to keep from cutting myself on them)!  I'm
definitely not going to cut the holding straps.  If it
comes down to trying to open one of these cores, I'm
just going to start over with something else :)

I guess my main question is this:  Does it matter if I
have a complete gap in all the laminations?  I'm
guessing not.  I have a mill at my disposal which
should make repeatedly drilling tight, consistent
lines of holes pretty easy.  I'm hoping this will make
zeroing in on the proper inductance easy.  If nobody's
tried something like this, guess I'll be the first! :)

aaron

--- Tesla list <tesla@xxxxxxxxxx> wrote:
> Original poster: Ed Phillips <evp@xxxxxxxxxxx>
>
> You certainly need an air gap, but don't be so sure
> that those
> laminations will fly apart if you cut the bonding
> strap.  All of the C
> cores I've seen have the laminations varnished
> together, with the faces
> ground and polished for good fit.  They come in two
> separate pieces.
>
> Ed
>
>
>