Re: Directions for tesla coil research

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

Original poster: "Shaun Epp by way of Terry Fritz <twftesla-at-qwest-dot-net>" <scepp-at-mts-dot-net>

Question about increasing Q, See below,

----- Original Message -----
From: "Tesla list" <tesla-at-pupman-dot-com>
To: <tesla-at-pupman-dot-com>
Sent: Sunday, May 05, 2002 6:44 PM
Subject: Re: Directions for tesla coil research


> Original poster: "Ed Phillips by way of Terry Fritz <twftesla-at-qwest-dot-net>"
<evp-at-pacbell-dot-net>
>
> Tesla list wrote:
> >
> > Original poster: "Malcolm Watts by way of Terry Fritz
> <twftesla-at-qwest-dot-net>" <m.j.watts-at-massey.ac.nz>
> >
> > HI Paul, Jim,
> >
> > On 3 May 2002, at 10:41, Tesla list wrote:
> >
> > > Original poster: "Paul Nicholson by way of Terry Fritz
> > <twftesla-at-qwest-dot-net>" <paul-at-abelian.demon.co.uk>
> > >
> > > Jim's comments cut to the heart of the matter:  The question is,
> > > what is the relative significance of topload voltage and topload
> > > charge in determining streamer performance?
> >
> > Absolutely agree. It's been a hobby horse of mine for quite a while
> > now. For one of my coils, increasing Ctop by an effective 100% (Ctot
> > increased from about 26pF to 33pF or so) resulted in a 25% increase
> > in reach with the same primary energy and breakrate. However,
> > unloaded primary Q was also increased by 50% as a result of retuning
> > so the Ctop factor did not sit alone. Given half a chance (like a
> > suitable test room), I'd like to boost Ctop further and check for
> > further improvement. Maybe in the semester break in June.
> >
> > Regards,
> > malcolm
>
> I've long suspected that the beneficial effect of big topload
> capacitance is to reduce the L/C ratio of the secondary, thereby
> lowering the resonant frequency and increasing the Q for the same
> streamer loading.  Result is there should be more energy stored before
> breakout, and coupling should be easier to adjust.
>
> Ed
>

How does a bigger top load increase Q.    if Q = Xl / R      and     Xl  =
2 * pi * f * l.

from these equations, one would assume that if frequency goes down, due to a
shift in resonant frequency, then Q decrease because Xl decrease.  I know
I'm missing something important here, right?

Shaun Epp