[Prev][Next][Index][Thread]
Re: Yesterday's GNATS meeting (fwd)
---------- Forwarded message ----------
Date: Tue, 28 Apr 1998 22:26:21 -0600 (MDT)
From: Chip Atkinson <chip-at-pupman-dot-com>
To: Tesla List <tesla-at-pupman-dot-com>
Subject: Re: Yesterday's GNATS meeting (fwd)
Ed,
The power system for the 9" coil is 220V, 40A breaker (tapped off the
electric stove wire) into a power cabinet. The power cabinet has 2 28A
220V variacs ganged together. I have one stove element in parallel with
an arc welder (your tip a while back). The output then goes to a 14400V
10KVA pole pig.
Chip
=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
Chip Atkinson
http://www.pupman-dot-com
--- If I can't fix it, I can fix it so it can't be fixed --
=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
On Mon, 27 Apr 1998, Tesla List wrote:
>
>
> ---------- Forwarded message ----------
> Date: Mon, 27 Apr 1998 21:44:07 -0600 (MDT)
> From: Chip Atkinson <chip-at-pupman-dot-com>
> To: tesla-at-pupman-dot-com
> Subject: Yesterday's GNATS meeting
>
> Greetings all,
>
> Yesterday was another meeting of the Greater Niwot Area Tesla Society.
> Mike
> Hollingsworth came over and we fired up my 9" coil for the first time.
>
> This coil has about 1000 turns of 22ga wire around a thickwall pvc pipe.
> I believe that the coil form is 8" diameter pipe, but the o.d. is roughly
> 9". We tried a couple toroids, different capacitor configurations,
> different power levels, different gap settings and the effects of
> different tunings. We also had an oscilloscope running and watched the
> wave forms when the coil was in and out of tune.
>
> We also discovered that there are some situations where you actually get
> better performance when you let the smoke out.
>
> Here are the details. Mike came over and brought some goodies such as
> large magnets and an old variac that I'll have to play with. We decided
> that we'd most like to play with the 9" coil that I had finished but
> never gotten working. I recently acquired three rolled caps and put
> one of these into the circuit in parallel with the existing capacitor.
> The new capacitance total is roughly 0.04 uF (0.025 + 0.017). The
> toroid is one that I had on my 4" coil, a 7x21 or so. We got some
> pretty decent sparks. However, the problem is that I have several
> space problems. I have a garage door that I wish to keep alive, and a
> garage that's suitable for a good 4" coil. Therefore, we had to keep
> the sparks pretty short and directed using a sharpened piece of wire
> on the toroid.
>
> Next we decided to try a series gap in series with the rotary. This
> didn't work too well, and we thought we'd try reducing the gap between
> the stationary and moving electrodes in the rotary so there wouldn't
> be too much total gap to bridge. This didn't help too much either, so
> the stationary and moving electrodes in the rotary so there wouldn't
> be too much total gap to bridge. This didn't help too much either, so
> we started backing out the series gaps until there were none at all.
> Now, with the reduced spacing of the rotary, the coil did much better
> than it had. Out with the stationary for now.
>
> The next idea to try was adding another capacitor to give a total of
> 0.06uF. We didn't notice much if any improvement, but we did notice
> after a few seconds, that some smoke was starting to rise from
> somewhere and there was an orangish colored light coming from the
> rotary gap. An immediate shutdown followed by an investigation
> revealed that the rotary gap was chock full of smoke (the rotary is
> totally enclosed in 1/2" lexan and 1" plexiglas). After letting the
> smoke out of the enclosure and removing an end of the enclosure, the
> coil was back to its previous glory.
>
> The other two things we tried were running the scope and a larger
> toroid. The scope was interesting. With the coil in tune, we could
> see the sort of dual hump damped wave profile. When it was out of
> tune, there were between 4 and 6 humps and a much shallower angle of
> decreasing amplitude. I took pictures and if they turn out, I'll send
> them to someone for scanning and subsequent posting.
>
> The larger toroid probably had a beneficial effect, but I can't say
> for sure because it effectively decreased the distance between any
> grounded object and the coil. I was basically running an RF jacobs
> ladder between a piece of grounded pipe and the toroid.
>
> I guess the next thing is to put the coil outside and really throttle
> it up to see what it's capable of. Next I'll start fiddling with it
> to see how I can increase the output.
>
> Chip
>
>
> =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
> Chip Atkinson
> http://www.pupman-dot-com
> --- If I can't fix it, I can fix it so it can't be fixed --
> =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
>