From: "Malcolm Watts"
Date: Mon, 13 May 2002 17:06:55 +1200
Subject: Re: [TSSP] Topload breakout potentials
Hi Paul,
Here in brief are the details:
> Yes. I don't think I have the details of Malcolm's coil. It would
> be a good idea to go through all four of these coils and make an
> accurate model of each, and to confirm a few things with some
> measurements so that we know for sure that the model is representing
> the tuning of each coil properly.
Secondary Fr 130kHz approx
Ds = 9.9"
Hs = 47" with 1 turn of 3/8" copper above it adding another inch.
Spacewound with 0.56mm Cu, approx 980 turns. The thickness given does
not include polyesterimide insulation. Wound by bifilar winding two
lengths of the same wire and removing one after winding completion.
Ls about 45mH
Cs (bare) about 19.3pF
NOt that heavily varnished. Maybe to about 1/3 of the thickness of
the wire.
Topload is positioned about 1/4" above the top of the copper pipe
turn. I'll get to its geometry in a minute.
Primary:
Cp about 0.1uF MMC shunted with 4.6666 recur overall.
15 parallel strings consisting of 7 series'd 47nF (nom) each.
Coil: Helix
Hp about 4"
Dp about 26"
4 turns 3/8" copper pipe
Lp around 16uH
Bottom turn of primary roughly at some height as bottom turn of
secondary.
Gap normally set to fire about 8kV, maybe a bit more.
Rep rate as seen on the scope varies between 100 and 200 BPS in
somewhat erratic fashion. It requires extremely fine tuning of both
airflow through the gap and gap width setting to produce its best
which is somewhat over five feet with the available transformer.
Topload: A roughly oblate spheroid, 24" in diameter and 10.5" thick.
ROC somewhat undefinable due to the rough surface. A mean cross-
section would put it at somewhere between 3 and 4" minimum. It was
made by gluing polystyrene foam blocks together, shaping with a
serated breadknife and then covering with Al foil stuck with contact
adhesive.
Any ohter details reqd., let me know.
Cheers,
Malcolm
Maintainer Paul Nicholson, paul@abelian.demon.co.uk.