RE: How to Tune a Flat Spiral Coil

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "Steve Greenfield by way of Terry Fritz <twftesla-at-qwest-dot-net>" <alienrelics-at-yahoo-dot-com>

It sounds to me like you are operating it as sort of a
double-ended Tesla coil, then.

So the primary is above, or below the plexi?

Once it arcs through once, though, now it is damaged.
How are you repairing this damage?

Have you thought of trying to ground the center and
wind a new primary of much smaller diameter, near the
center? And then connect three separated smooth pipes
in an interrupted toroid, each to a separate winding?
Now, if you get arcs between those pipes, -that- would
be interesting. But only if you don't have the primary
anywhere near them, or it could just be from one
arcing over and the others arcing to it.

Steve Greenfield


--- Tesla list <tesla-at-pupman-dot-com> wrote:
> Original poster: "David Thomson by way of Terry
> Fritz <twftesla-at-qwest-dot-net>" <dave-at-volantis-dot-org>
> 
> Hi Steve,
> 
> >> Yes, the arcs occurred near the outer windings of
> the secondary.
> >  Ah, you didn't say -that- before. I always got
> the impression that it was
> arcing right through uncut undamaged plexi and hot
> glue.
> 
> It is arcing through the uncut, undamaged Plexiglas
> and hot glue.  It's
> arcing through all of this dielectric to the outer
> windings of the secondary
> coil.  The Plexiglas extends a good 10" beyond the
> outer windings of the
> secondary coil and about 7" beyond the outer
> windings of the primary coil.
> It also extends all the way to the 1/4" bolt in the
> center of the secondary.
> 
> >  Where is it arcing to?
> 
> The arc is a direct line between the inner winding
> of the primary and the
> outer winding of the secondary.
> 
> >  And I thought those three outer ends were
> grounded and the center was the
> high voltage side.
> 
> No.  The secondary is not grounded at all, nor in
> this particular case was
> there anything connected to the center of the coil. 
> The plasma ball had its
> guts removed and there is about a 2" air gap between
> the center of the coil
> and the bottom of the globe.
> 
> Dave
> 
> 
>