Re: TC efficiency, was Math help...

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

Original poster: "Sundog by way of Terry Fritz <twftesla-at-qwest-dot-net>" <sundog-at-timeship-dot-net>

Hi All, Peter

 I've built a *slew* of 2.5 (2" pvc), and 3" coils.  My record was was a 37"
arc from a 2.5x13" coil wound with 26ga wire.  I ran it on a 9/60, 120bps
SRSG ,and a 13nf MMC (3 strings of 13 i believe).  IMHO it's more impressive
to crank every bit of performance out of a tiny coil.  The little 2" coils
at 2kva input (from the pig, same tank cap, really high breakrate on a DC
RSG) would throw 3-4 20" streamers at a time before flashing over (they
*always* died, despite creepage discs and baffles. )  The output was just
freakishly intense for such a tiny coil.  With only a few hundred feet of
wire on 'em, it wasn't too bad to toast them.

Many of the same principles I applied to my big 10" coil, and so far I've
been impressed with the coil.  I still have another .1uf of capacitance to
get worked in there (yes, you read that right, it's .2uf total).  it's a
space to run it and store it issue.

But all kindsa sparks are fun! :)

Shad
----- Original Message -----
From: Tesla list <tesla-at-pupman-dot-com>
To: <tesla-at-pupman-dot-com>
Sent: Thursday, July 12, 2001 9:01 PM
Subject: RE: TC efficiency, was Math help...


> Original poster: "Peter Lawrence by way of Terry Fritz
<twftesla-at-qwest-dot-net>" <Peter.Lawrence-at-Sun-dot-com>
>
> John Couture,
>              I've built half a dozen 3.5 x 12 inch TCs, all with different
> wire diameters (500 to 2000 turns) and many primaries (5 to 25 turns),
> and many Caps, and many Toroids, and many spark gaps.
>
> The best I've gotten is about 12" (maybe 14") streamers from a 9/30 NST.
> J Freau's calculation of 1.7 * sqrt(watts)  =>  28", so I'm off by a
> factor of two.
>
> As far as I can tell J Freau's formula only applies to 6x24" and larger
coils.
>
> I'll admit that I still have to try blown and synchronous-rotary gaps
though.
>
> And I'll have to admit that streamer length is not the same as
"efficiency"
> the way you are talking about it...
>
> YMMV,
>
> -Peter Lawrence.
>
>
>
> >
> >John, All -
> >
> >Do you or anyone else have tests with calcs to prove that large TC's are
> >more efficient than small ones?
> >
> >Normally with electrical devices the larger the more efficient. However,
> >Tesla coils are not normal electrical devices. I believe this is why a
clear
> >understanding of the differences between magnetic and electric circuits
is
> >so important. These two types of circuits are often combined incorrectly
> >when discussing Tesla coils.
> >
> >Efficiency and energy transfer involves losses, Ohms law, etc, in
electric
> >circuits. Magnetic circuits have a different set of rules. The energy
> >transfer between the Tesla coil primary and secondary coils is a magnetic
> >circuit transfer and there are no magnetic flux losses. This is Faraday's
> >action or voltage at a distance with no conductors. Electric circuits
> >require conductors. Note that Hertz and Maxwell went way beyond the above
> >concepts using Hertzian waves with no conductors.
> >
> >John Couture
> >
> >---------------------------
> >
> >
> >
> >
>
>
>
>