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Re: Why does top capacitance work? (fwd)
---------- Forwarded message ----------
Date: Sat, 22 Feb 1997 00:41:47 -0800
From: Bert Hickman <bert.hickman-at-aquila-dot-com>
To: Tesla List <mod1-at-poodle.pupman-dot-com>
Subject: Re: Why does top capacitance work? (fwd)
Tesla List wrote:
>
> ---------- Forwarded message ----------
> Date: Wed, 19 Feb 1997 22:18:37 -0700
> From: Tesla List <tesla-at-pupman-dot-com>
> To: testla-at-pupman-dot-com
> Subject: Re: Why does top capacitance work?
>
> Subscriber: lod-at-pacbell-dot-net Wed Feb 19 22:12:10 1997
> Date: Tue, 18 Feb 1997 22:06:31 -0800
> From: lod-at-pacbell-dot-net
> To: tesla-at-pupman-dot-com
> Subject: Re: Why does top capacitance work?
>
> Bert Hickman wrote:
>
> > Greg,
> >
> > You certainly make some compelling points. I agree that the "root" of a
> > streamer, once formed, will act as a weakenned area during subsequent
> > bangs, since it's the area of highest current density and should have
> > the greatest degree of thermal ionization. The advantage a large toroid
> > may provide on higher-impedance coils may come from providing a low
> > impedance energy reserve (i.e., a capacitor to ground) during the time
> > that the streamer is re-propagating along the weakenned path blazed by
> > its predescessor. Adding larger capacitance will provide a
> > proportionately larger reserve of energy once the voltage rises to the
> > point where reignition occurs.
>
> I suppose that could be true, but does the toroid really store a significant
> amount of the secondary energy? What do you suppose the time constants would
> be for the toroid capacitance alone discharging into the streamer? 20pF x 400k?
> A high speed current probe at the toroid may be the only way to find out.
>
<SNIP>
Greg,
I'd contend that considerable energy is being stored in the toroid,
particulary during the instant of maximum secondary voltage. In fact
virtually _all_ of the energy in the secondary:toroid system will be
stored in the electrostatic fields associated with Ct+Cs when peak Vout
is reached. For a system having a relatively large toroid, where toroid
capacitance (Ct) is 2X - 4X the secondary coil self-C (Cs), over 2/3 to
3/4 of the total energy would reside in the toroid.
Safe ccoiling to you!
-- Bert --