Re: TESLA COIL REVISED

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

Original poster: "Trans-world" <jaro-at-surfside-dot-net> 

Please see below.

-----Original Message-----
Date: Tuesday, January 06, 2004 7:32 PM
From: dhmccauley-at-spacecatlighting-dot-com
Subject: Re: TESLA COIL REVISED
 >
 >Jaro,
 >
 >You have a number of errors in your statements.
 >
 >Firstly, the classic tesla coil's output voltage is created through
the
 >resonant rise of voltage on the secondary coil.

That's what I used to think until I joined this group. But most people
here claim that the output voltage is to be determined by the L2/L1
ratio (in a classic TC). If it was due to resonant rise, then you could
greatly increase output voltage by using a THICK wire to increase the
coil's Q. So you guys better get this straight, it CAN'T BE BOTH.

 >And it is, as you stated have a ideal gain related to the sqrt (Ls/Lp)
or
 >sqrt (Cp/Cs).
 >
 >Secondly, your statements regarding solid state tesla coils are
incorrect as
 >well.  A 50-turn secondary on a solid state
 >tesla coil would yield extremely poor results.  I have built a large
number
 >of solid state tesla coils (>20) and have experimented with
 >many different sizes of secondaries, number of primary turns and
secondary
 >turns.  I've also built solid state tesla coils ranging in
 >frequencies from about 45kHz up to 10MHz+.  Best performance always
occurred
 >with a secondary with about 1000-1200 turns.

That is not logical. It conflicts both with what Tesla said, and what
math shows. As I've shown in the previous email, a 50-turn secondary
(at 3.5MHz)doesn't have a higher impedance/reactance than a 1000-turn
coil at 100kHz. In fact its impedance is lower, because 50 turns of a
thick wire has about 200 times lower resistance than a 1000-turn coil
of thin wire. So the voltage output of the 50-turn coil should be at
least as high as from the 1000-turn coil.

If you know anything about RESONANCE, you should understand that if you
feed a coil at its resonant frequency, its voltage WILL KEEP RISING, as
high as the resistance losses will alow it. The power you pump into
such a coil will be transformed into VOLTAGE and HEAT. There's nothing
else, except leakage to ground which only occurs at very high voltages
and which can be improved by better insulation. Now that may not work
for classic TC, but it definitely is the case for solid state TC's.

 >For longest output arcs, frequency ranges of 45kHz to 250kHz seemed to
work
 >best and for cleanest CW brush-like discharges for
 >audio modulation started at about 300kHz (still considerable corona
noise)
 >and at about 3MHz became completely silent.

Are you saying that only the 50-turn CW coil became silent, or any TC
coil does at that frequency?

 >Beyond 5MHz,
 >magical things start occuring with the output arc and the brush like
 >discharge starts becoming more and more like a candle flame, although
I
 >haven't
 >been able to build a reliable solid state coil to operate at
frequencies
 >above 3MHz just yet.

So how can you criticize my 3.5 MHz 50-turn solid state coil design
when you only have experience with classic TC's at high frequencies? I
respect your experience, but if you can't build a reliable solid state
coil at 3+ MHz frequencies, maybe you should talk to people who have
new ideas, instead of trying to put them down.

 >
 >As others suggested before, instead of throwing around all this theory
and
 >ideas, I would suggest as well that you start building some coils for
 >yourself and
 >see the results firsthand.

Why? Einstein didn't build a single cyclotron to prove his theories
either, does that invalidate his ideas? But I do plan to do some
building, it's just that I have a lot of other projects to do first.

Jaro

 >
 >Dan
 >
 >
 >
 >> Now, since the output voltage of CLASSIC TC depends on the L2/L1
ratio
 >> instead of a resonant rise, this design wouldn't be good for classic
TC
 >> because the output voltage would be rather low. BUT, it WOULD be
 >> perfect for a SOLID-STATE Tesla coil, because this coil produces
 >> RESONANT RISE (as you yourself mentioned).
 >>
 >> So now that we know that a 50-turn secondary doesn't have higher
losses
 >> than a 1000-turn one, even though it resonates at much higher
frequency
 >> (several MHz), we can see that the 50-turn secondary is a superior
 >> design when used in SOLID-STATE Tesla Coils.
 >>
 >> And that's because while the output voltage of 1000-turn coils is
 >> limited by the L2/L1 ratio, the 50-turn solid-state TC has no such
 >> limitations, and will build up the output voltage to ANY LEVEL that
the
 >> insulation will allow.
 >>
 >> Of course the higher frequency will result in shorter sparks, so
this
 >> coil would be more for people who want to experiment with very high
 >> frequencies and perhaps experience beams or walls of light
(brush-like
 >> discharge), instead of the sparks. And that brush-like discharge
would
 >> probably be more plasma-like than the usual low-frequency sparks.
 >>
 >> Jaro
 >>
 >>  >
 >>  >Regards, Gary Lau
 >>  >MA, USA
 >>  ><snip>
 >>  >
 >>  >
 >>  >---
 >>