Re: newbie question - spark gap and toroid

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

Original poster: "Gregory Hunter" <tesla_39560-at-yahoo-dot-com> 

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