Hi folks,
My first post - I just saw these caps listed on industrial auction site -
not sure if of any use here, but just in case they are:
http://www.go-dove.com/en/auction/view?id=12580057
If anyone is interested, but is hesitant due to collection reasons etc -
let me know, (PM me) as I can bid / collect on your behalf etc as I am
interested in other items there, plus not too far for me
Cheers
Rafal
On 30 October 2017 at 01:16, Terry Oxandale <toxandale@xxxxxxxxxxxxx> wrote:
> Hi Gary,
> I'm using a 6" x 30" secondary with an 8" x 34" toroid (plans are to use
> this with a larger coil in the future, and these are very expensive so I
> chose a single purchase of the larger between the two sizes considered).
> 10Kva pig that is current and voltage adjustable, flat primary with .045uF
> caps using an asynchronous rotary spark gap.
> Per Bert's input (thanks Bert), tuning with the barb has been
> accomplished, which brings me to a question about increasing bang size: Can
> bang size also be increased by decreasing the rpms of the spark gap, by
> allowing a larger charge to take place (using 8-point RSG on a variable DC
> motor)? Interesting thought on the decreased barb length. The current one
> is 1" long, I may go for 1/2" or perhaps 1/4" to see about increasing the
> breakout voltage.
> Anyway, I do have a smaller toroid I'll try (5" by 30" - a large
> cast-aluminum corona ring with an aluminum plate welded in the middle, so
> yes, it is odd, but it appeared to be effective) to get some perspective on
> that.
> Cheers,
> Terry
>
> From: Gary Lau <glau1024@xxxxxxxxx>
> To: Tesla Coil Mailing List <tesla@xxxxxxxxxx>
> Sent: Sunday, October 29, 2017 1:52 PM
> Subject: Re: [TCML] First coil
>
> Hi Terry,
>
> I'm thinking that if the toroid size is too big, it won't break out without
> the barb. Perhaps a few more details of your coil will make for a clearer
> picture. Power source, gap details, cap size, and most importantly, toroid
> size? With toroids, bigger is usually better, at least as far as getting
> the longest possible streamer from a breakout point, but if you're shooting
> for sparks without a breakout point, a smaller toroid may be necessary.
>
> Regards, Gary Lau
> MA, USA
>
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> On Sun, Oct 29, 2017 at 12:25 AM, Bert Hickman <bert@xxxxxxxxxxxxxxxxxxxxx
> >
> wrote:
>
> > Hi Terry,
> >
> > Racing sparks typically occur when energy is being injected into the
> > secondary too quickly. Although this is _usually_ caused by
> > excessively-high coupling, it can also occur when the bang size is too
> > large for the size of your secondary, or if your system is significantly
> > out of tune. To solve the problem(s), you'll need to first insure that
> your
> > system is in tune, that P:S coupling is not excessive, and that your
> toroid
> > is appropriately sized for your system's peak output voltage.
> >
> > 1. Tuning:
> > I'd suggest initially running the system with a breakout point (or barb)
> > during this phase. Reduce the primary spark gap length to reduce maximum
> > bang size. Experiment with primary tap point until you get the maximum
> > secondary spark length at a given variac setting. The system should be
> > smooth running with consistent spark length under continued operation.
> >
> > 2. Coupling:
> > If you don't see any racing sparks, slowly increase the "bang size" by
> > widening the main gap slightly. Don't increase gap length beyond the
> point
> > where the safety gaps begins firing or if you start to see racing sparks.
> > If you see racing sparks, reduce coupling slightly and continue the
> process
> > of increasing the main gap length until you can run at full power with no
> > evidence of racing sparks. You may need to retune the primary a bit by
> > increasing primary inductance slightly (i.e., moving the primary tap
> > outwards 1/8 - 1/4 turn) to compensate for capacitive loading of longer
> > secondary streamers. Any signs of racing sparks mean that you need to
> > further decrease coupling.
> >
> > 3. Final tweaking:
> > Reduce the length of the breakout point/bump to see if the coil can
> > self-break from the toroid as you approach full power without introducing
> > any racing sparks. Further decrease coupling if you see any evidence of
> > racing sparks. Ideally, an appropriately-sized toroid will self-breakout
> > before you reach full power. Failure to self-breakout can occur if the
> > minor toroid diameter is too large (requiring excessively-high breakout
> > voltage) or if the major toroid diameter (and capacitance) is too large,
> > which reduces maximum topload voltage below the point of self-breakout.
> For
> > this case you may need to operate your system with a breakout bump or
> point
> > to insure breakout. Even with an optimal setup, you may still need to
> use a
> > breakout point during humid weather when it's significantly more
> difficult
> > to initiate breakout.
> >
> > Good luck,
> >
> > Bert
> > --
> > Bert Hickman
> > Stoneridge Engineering LLC
> > http://www.capturedlightning.com
> > +1 630-964-2699
> > ***********************************************************************
> > World's source for "Captured Lightning" Lichtenberg Figure sculptures,
> > magnetically "shrunken" coins, and scarce/out of print technical books
> > ***********************************************************************
> >
> >
> > Terry Oxandale wrote:
> >
> >>
> >> It's been a long time since I was more active on this list. I never was
> a
> >> "technical" enthusiast, so being I've had the coil in storage for
> probably
> >> 10 years, and have forgotten more than I remember about coiling. I'd
> like
> >> to
> >> tap the group for some help or advice please.
> >>
> >> My coil appears to operate as I remember it did, as long as I've got a
> >> sharp
> >> pointed barb sticking out the side of the toroid to promote a discharge.
> >> When I remove the barb to get a normal toroial discharge, I get racing
> >> sparks along the secondary, and nothing out of the toroid, all for the
> >> same
> >> power setting as the "barbed" setup (2kva). Thus I separated the
> secondary
> >> from the primary in terms of vertical distance to lower any excessive
> >> coupling (shooting in the dark here), but still racing arcs along the
> >> secondary.
> >>
> >> Any ideas on the huge difference (or lack of performance) between
> "barbed"
> >> and "non-barbed? No component changes have been made since a decade ago
> >> when
> >> it all worked great, and both configurations performing equally well.
> >>
> >> Terry
> >>
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> >>
> >>
> >>
> >
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