Re: Why does top capacitance work?

To: tesla-at-pupman-dot-com
Subject: Re: Why does top capacitance work?
From: Greg Leyh <lod-at-pacbell-dot-net>
Date: Thu, 13 Feb 1997 22:26:05 -0800
Subscriber: lod-at-pacbell-dot-net Sat Feb 15 14:25:24 1997

Bert wrote:

> Steve,
> 
> It turns out that adding capacitance to the top actually reduces the
> maximum output voltage that the coil can generate! However, adding a
> toroid-shaped top-load can prevent the secondary from starting to
> break-out with corona/streamers until a higher voltage is reached. This
[snip]

> -- Bert H --

Bert,

Doesn't this apply only to the very first gap firing, when the power is
first applied?  After that, the first streamer would adversely compromise
the holdoff voltage of the toroid, acting electrically as a long needle 
that projects from the toroid.  The subsequent gap firings appear to only
build upon the initial streamer, unless the gap rate is so low that the 
ions start to re-combine between gap firings.  This results in a large
number of small streamers.

I am still mystified as to why a large toroid makes a difference.  My 
favorite explanation is that the addition of a huge toroid forces the
operator of the TC to add capacitance to the primary, for tuning purposes.
More capacitance increases the thruput power, which is always better.

-GL