Re: Sonderman Testing (fwd)
---------- Forwarded message ----------
Date: Mon, 29 Sep 1997 08:00:28 +1200
From: Malcolm Watts <MALCOLM-at-directorate.wnp.ac.nz>
Subject: Re: Sonderman Testing (fwd)
A few comments......
> From: Esondrmn-at-aol-dot-com
> To: tesla-at-pupman-dot-com
> Subject: Sonderman Testing
> Last night I finally got my coil fired up again. Changes since last testing
> were replacing all the contacts on the rotary and eliminating the static gap
> in series with the rotary. The spark gap across the capacitor is set down to
> 5/8". This is my 6" coil with a .025mfd C.P. cap, powered by a 14.4 kva pig.
> The first project was to find the best tune at low power. I had a ground
> wire set up maybe 3.0 feet from the toroid and a wire laying on the edge of
> the toroid pointing at the ground wire target. The welder was set at
> minimum. It again wouldn't run worth a damn with the resistor bank in
> parallel with the welder so I unplugged it, now using only the welder for
> ballasting. I noticed immediately that I had much more consistent firing of
> the rotary spark gap. It started to fire at maybe 25% of full variac power.
The welder is resonating with your primary cap I would say.
> Now I opened up the safety gap across the capacitor to about 1.0". I was
> very surprised to find out that I could only open up the variac to maybe 60%
> of full power before the safety gap across the cap started firing again. It
> must be in tune, why is the safety gap firing????
See my musings from last week. I have every intention of cracking
this problem. That doesn't mean an easy solution will be necessarily
forthcoming though. I think you are taking a serious risk with your
cap running with a gap this wide.
> I turned the variac down a small amount where it would run without firing the
> safety gap. Increasing the primary current produces hotter sparks up to a
> point then at full current, the spark length falls off noticeably. This is
I read that as inadequate quench for that input current. I wonder
whether the extra resistance in your old wiring was doing the job?
> Increasing the rotary gap speed causes hotter sparks for a while and then
> falls off past a certain point. This is unlike my past experience where this
> coil was hungry for power and would continue to produce better sparks as I
> increased the rotor speed - as fast as I dared turn it up.
> I could certainly use some help here. This coil used to produce 80"
> discharges and now I can't seem to get past about 36" to 40". Something is
> not right and I can't find it. If the primary and secondary are in tune, why
> can't I apply full voltage? I have the rotary gap across the high voltage
> mains, should I swap it with the cap and put the cap across the mains and let
> the rotary act as a safety gap for the cap - and remove the existing safety
> gap across the cap - as Peter E. suggested the other day? I really can't
> afford to blow up any more capacitors. By the way, the main safety gaps
> connected near the output of the pig, with the center post grounded, never
> did fire in any of these tests. It never has fired very often in the past
> unless I was getting secondary hits down into the primary.
I can't really be of any more help without being able to get "hands-
on" with the problem sorry.