Re: solid state ballasting?? (fwd)

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Original poster: List moderator <mod1@xxxxxxxxxx>



---------- Forwarded message ----------
Date: Sun, 20 May 2007 11:18:37 -0500
From: resonance <resonance@xxxxxxxxxxxx>
To: Tesla list <tesla@xxxxxxxxxx>
Subject: Re: solid state ballasting?? (fwd)



We are in the final stages of "beta testing" on our dual SCR 91 Ampere 
(Irms) variac eliminator.  We rate these to replace a standard dual stack of 
30 Ampere variacs.

A small ballast is still required with a MOT and a PT or pole xmfr requires 
a slightly larger ballast.  We use a gapped core C-core reactor with our 
pole xmfrs.  Airgap is 100 mils.  Total C-core reactor weight is only 32 lbs 
for up to 60 Amp control.

When we finish our testing in the next 30-45 days we hope expensive and 
heavy variacs will soon become a "thing of the past".  Our entire setup 
weighs only 3 lbs and will replace up to 3 stacked 30 Amp 220 VAC variacs. 
Our plan is to have one to replace smaller 10-20 Amp, 120 VAC variacs, a 
second medium size to replace dual stack 60 Amp variacs, and a third unit to 
replace up to 6 stacked 30 Amp variacs.

I hope to offer this as a "kit" in which we would fully stuff the driver 
board, and experimenters would mount the furnished SCRs on the furnished 
heatsinks.  They would supply the cooling fan, mount the parts, and have an 
electronic variac with a 10 turn pot that would eliminate the large, heavy, 
and expensive variacs now used with standard Tesla coil power supplies.

Results so far are very encouraging --- just need to tweak a few resistor 
values and finish our testing.  Hope to have them ready by July.

Dr. Resonance



>
> I think they do make some kind of solid state ballast
> current control for the large high voltage transformers
> in neon bombarder systems. These transformers are
> usually 15 kV to 30 kV at 7.5 kVA up to 25 kVA.
> However, I don't think that they work too well for
> Tesla coil application as the feedback causes them to
> malfunction, but would probably work fine for a JL
> control. I'm sure some of the list members neon gurus
> like Jack King could offer better info on this matter.
> As a matter of fact, I believe I've seen Jack list one
> of these items on ebay in the past so he may be able
> to "fix you right up".
>
> David Rieben