Re: newbie question - spark gap and toroid

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "ho \[shu\] huang" <shuhuang-at-singnet-dot-com.sg> 

Ok Doc,

Will heed your advice..thanks a lot!

Shu

At 05:51 PM 11/1/2004 -0700, you wrote:

>Original poster: "Dr. Resonance" <resonance-at-jvlnet-dot-com>
>
>A 14 x 3 inch toroid would work best for a 30 mA NST.  We carry them in
>stock if you need one.
>
>Aluminum will limit your peak primary current somewhat but not too critical.
>If you want the brightest sparks, then use copper on the pri SG.
>
>At 30 mA you might find best performance with no blower at all.  Try it with
>your setup to see what works the best.
>
>Dr. Resonance
>
> >  >
> >  > I've got my tesla coil to work but I've got a couple
> >  > of quick questions for
> >  > you pros out there: -
> >  >
> >  > 1. My SG spark gap's made from aluminium curtain
> >  > rail, not copper pipe. The
> >  > rail is flat, so it's easier to mount. Does it
> >  > matter? My coil works, but
> >  > I'm not sure if aluminium hinders performance in any
> >  > way.
> >  >
> >  > 2. Does it matter that air isn't blown directly at
> >  > the sparks? Do the
> >  > sparks require a lot of air to be "quenched", or
> >  > will a bit of moving air
> >  > be enough? In other words, is more wind better?
> >  >
> >  > My spark gap (pic here:
> >  > http://web.singnet-dot-com.sg/~shuhuang/spark_gap3.jpg
> >  > ) sparks at the ends of the rails, which is sort of
> >  > shielded by the 10mm
> >  > thick plastic support. I can easily reconfigure it
> >  > so that the sparks get
> >  > most of the breeze from the fan, but I'm wondering
> >  > if it's worth the
> >  > effort. The fans blow, rather than suck, BTW.
> >  >
> >  > 3. I used 2 aluminium wok covers joined together
> >  >
> > (http://web.singnet-dot-com.sg/~shuhuang/tesla_coil_lab.jpg
> >  >  > ), ~210mm wide and
> >  > 320mm in diameter, as a toroid but I suspect a
> >  > traditioanl toroid might
> >  > work better. Believe it or not, I'm actually having
> >  > a hard time flexible
> >  > drainage pipe. It's apparently not used very often
> >  > any more...where I live
> >  > (SIngapore) anyway. I came across the pool float
> >  > toroid design on a
> >  > webpage, and I've found one on sale cheap. It's 23"
> >  > in diameter and 8"
> >  > thick. Is that too big a toroid for my 15kV 30mA,
> >  > 90mm 900 turns AWG 24
> >  > wire secondary coil, set up?
> >  >
> >  > thanks!
> >  >
> >  > Shu
> >
> >
> > Shu,
> >
> > Nice photos. Thanks for sharing.
> >
> > I don't know about aluminum for spark gap electrodes.
> > I've heard aluminum soon gets full of pits and holes
> > until it looks like a sponge. I have no first-hand
> > experience with it however. I've always used copper or
> > brass electrodes. On the other hand, it sure is a
> > nice-looking spark gap you built there--very neat and
> > professional. I think I'd go with the reality test--if
> > the spark gap works well, don't worry about the
> > aluminum.
> >
> > Moving air can have a profound effect on spark gap
> > performance. Try blowing a jet of compressed air
> > through the thing and see see what happens. If forced
> > air gives noticeable improvement, then you'll have to
> > do something about your air flow.
> >
> > I think a 23" X 8" toroid is too big for a 15kv/30ma
> > NST system. Child-size 20" x 5" vinyl pool toys are
> > common in the US. See if you can find one of those.
> >
> > Actually, the Wok covers make a pretty neat-looking
> > terminal. People use all kinds of crazy stuff for top
> > loads. Why not Wok covers? The important thing is that
> > it woks well, um, I mean works well.
> >
> >
> >
> >
> > =====
> > Gregory R. Hunter
> >
> > http:\\hot-streamer-dot-com/greg
> >
> >
> >
> >