Re: Sonderman Testing
---------- Forwarded message ----------
Date: Mon, 29 Sep 1997 19:33:01 -0400 (EDT)
Subject: Re: Sonderman Testing (fwd)
In a message dated 97-09-28 17:31:27 EDT, you write:
<< 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
> 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
> the rotary spark gap. It started to fire at maybe 25% of full variac
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
> of full power before the safety gap across the cap started firing again.
> 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
> safety gap. Increasing the primary current produces hotter sparks up to a
> point then at full current, the spark length falls off noticeably. This
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
> 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
> not right and I can't find it. If the primary and secondary are in tune,
> 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
> the rotary act as a safety gap for the cap - and remove the existing
> 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.
Thanks for the response. How wide of a gap do you think I can use on the
capacitor safety gap and not risk killing it? If you say maybe 1/2" and
let's assume I find the current problem and fix it, would this safety gap
across the cap never fire during normal running if the coil is in tune? At
what distance would you expect it to fire during norman running?
You said maybe the extra resistance of the old primary interconnect wiring
was helping the gap to quench. I also had a three gap static gap in series
with the rotary in the old configuration. This whole problem did start when
I rewired the primary with copper instead of two pieces of RG213 in parallel.
I am stubborn and have been fighting this problem for many months now. I
would like to think I (we) could resolve it with the current design but I am
about ready to rebuild the primary interconnect wiring and put it back like
it used to be.
Thanks again for the comments, Ed Sonderman