Re: Bottle Caps, part III

To: "'Tesla List'" <tesla-at-poodle.pupman-dot-com>
Subject: Re: Bottle Caps, part III
From: Tesla List <tesla-at-stic-dot-net>
Date: Thu, 13 Nov 1997 21:35:08 -0600
Approved: tesla-at-stic-dot-net

From:	Esondrmn-at-aol-dot-com [SMTP:Esondrmn-at-aol-dot-com]
Sent:	Thursday, November 13, 1997 1:25 PM
To:	tesla-at-pupman-dot-com
Subject:	Re: Bottle Caps, part III

In a message dated 97-11-13 12:23:41 EST, you write:

<< So, if I'm using a 15kv/30ma neon xfmr at 50Hz and fixed series
 gaps, how much capacitance do I really need?  What would it hurt to
 "over cap" the system a little?  It seems like a little too much
 capacitance is better than not enough.  A slightly oversize cap will
 drop the maximum voltage a little.  So what?  This is easily
 corrected for simply by closing the spark gaps a little. The reduced
 operating voltage translates into less stress on both the neon
 secondary windings and the caps.  Sounds like a "win-win" deal. Is
 there a flaw in my reasoning here?

 Greg
  >>
Greg,

The amount of capacitance you need depends primarily on the secondary
resonant frequency with top load.  Once the secondary is decided on, design a
large flat spiral primary with about 12 to 14 turns.  Now calculate the
capacitor needed to resonate with this primary at the resonant frequency of
the secondary.  This will result in a smaller sized capacitor.  I see many
folks who are  overly concerned about sizing the cap to the transformer.  I
design the coil first, using a large primary which will yield a small value
cap (smaller sized caps are cheaper and easier to build) then usually apply
power in ever increasing increments until I reach the limit of the system.

Ed Sonderman