Re: My Coil: Problems? (fwd)
---------- Forwarded message ----------
Date: Sun, 28 Sep 1997 15:46:05 -0400
From: Thomas McGahee <tom_mcgahee-at-sigmais-dot-com>
To: Tesla List <tesla-at-pupman-dot-com>
Subject: Re: My Coil: Problems?
> ---------- Forwarded message ----------
> Date: Sat, 27 Sep 1997 19:50:38 -0400
> From: Tom Heiber <theiber-at-lonet.ca>
> To: Tesla List <tesla-at-pupman-dot-com>
> Subject: My Coil: Problems?
> Hey, I am back. I was away for a while but now I'm back at coiling.
> Anyways, I'll get straigth to the point. I have a medium size neon
> The Neon xfrmr is a 12Kv -at- 60mA (Jefferson) . Anyway I tried to add
> xfrmer so i bought one. A different company though since I couldn't
> Jefferson, This one is a Allanson. Anyhow. Both xfrmers are 12Kv -at-
> The Jefferson indicates 720VA on the plate while the Allanson shows
> can that be? Mathematically it should be 720, right?
When used for luminous tube service the actual RUNNING voltage drops
considerably below the max 12KV voltage rating. The transformer is a
current limited device, and will deliver the rated current into a
dead short. Note that the transformer in question does NOT deliver 30
ma AT 12KV, but an open circuit voltage of 12KV, and a closed circuit
current of 30 ma. The 360VA rating is probably more "correct", in
that the unit will most likely be able to supply the full 30 ma at a
voltage of 6KV. The 720VA rating was arrived at by multiplying the
max voltage times the max current. But, as most engineers will tell
you, it is rare that you will get a unit that can supply EVERYTHING
at its max rating. Now, a pole pig is a different animal, and can
usually more than live up to its labelled rating set. A 10KVA pole
pig really IS 10KVA.
By the way, if a neon transformer is operated with a properly chosen
value of HV cap, then it can be operated in a 60 HZ resonance mode
and even deliver MORE than its "rated" VA.
Don't worry about the discrepancies in labelling on your
transformers. If the KV and ma ratings are the same, then treat that
as equals. Sometimes there is a slight voltage difference between
different manufacturers, but not enough to be concerned about.
> I have decided to connect them together in parallel. Making note of
> the polarities so the xformers work in phase.
> However It altered my coil operation drastically.
> First of all. The sound the spark gap makes it TOTALY different.
> 1 xfrmer (4 gaps, series) it sounded a high pitched steady tone,
loud. Now on 2
> xfrmrs it sounds kinda choppy. The freq. of the sound also lowered
> because of the choppines). I have not altered the capacitance nor
> tap. Yet I see a small increase in output. Before I had 2 xfrmrs. I
was able to
> concentrate all of the coil's output (torroided) on a breakout
point. Now I get
> sparks all around the torroid and the breakout point. When I remove
> breakout point I see a lot of discharge from higher secondary
windings to lower
> I'd appreciate any input on these.
> Tom Heiber
Sounds like you are out of tune. Play with the primary tap. When you
hit tune all the other symptoms should disappear.
Adding more trannies could also mean that now you have more available
current than your cap can handle. You may want to increase the size
of the cap accordingly. And re-tune, of course!!
Hope this helps.