Re: The Tabletop Tesla Coil Showdown - OFFICIAL RULES and WEBSITE

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

Original poster: "Nicholas Field by way of Terry Fritz <twftesla-at-qwest-dot-net>" <nick.field-at-hvfx.co.uk>

Hi both Johns, All,

First off I'm greatly enjoying this thread and if I get a spare moment might
put up an entry myself.

The question of duty cycle is a difficult one.  I think perhaps the
qualifying factor should be that the output spark appear 'continuous' to the
eye (probably 15-25pps).  Otherwise the competition could get rather
meaningless.

I _could_ charge up a big reservoir cap from a multiplier driven by a 4/20
transformer, then dump all zillion joules into Thor's tank circuit in a
short burst and claim 18 feet from a 4/20 neon.  However I doubt many people
would feel that was in the 'spirit' of the contest!  The reservoir cap
approach also has the effect of taking a lot of the skill out of the contest
and handing the trophy to the guy with the biggest cap bank (eg. Greg Leyh,
who has more than his fair share of coiling trophies already!).

For those interested in the ultra low duty cycle end of things I think Dale
Hall built a solar powered TC that would charge up over a long period then
let rip with a few long sparks, I used to have his URL but now it comes up
dead.

Safe Coiling,
Nick
_______________
Nick Field, HVFX
www.hvfx.co.uk


> Original poster: "by way of Terry Fritz <twftesla-at-qwest-dot-net>"
<FutureT-at-aol-dot-com>
>
> In a message dated 10/7/02 7:23:58 PM Eastern Daylight Time,
tesla-at-pupman-dot-com
> writes:
>
>
> >
> > John F. -
> >
> > Let the contestant use any rep rate he desires. Now that would be a real
TC
> > challenge. Low rep rates would give more spark only up to a certain
point.
> > When that point is reached the losses would start to be greater than the
> > input and the spark length would remain the same or start to decrease in
> > length. This happens often with coilers who add input watts to their
coil
> > but beyond a certain point the spark length remains the same length much
to
> > the chagrin of the coiler.
>
>
>
> John C,
>
> A very low rep rate coil simply stores energy for a long period
> of time and releases it quickly.  Such a set up can give terrific
> spark lengths for a given input power, but not for a given
> instantaneous input power of course.  Losses are not much of
> an issue here.  We're probably talking about different kinds of
> systems.  In one setup which I called the "DC Disruptive Pulsed
> Compound Storage Tesla Coil", I was able to get 56" sparks using
> only 460 watts.  It gave about 4 spark trains per second, and the
> spark did not appear to be continuous.
>
>
> >
> > A contest with these rules means that a coiler would have to build
dozens of
> > coils of different configurations and inputs to find the optimum Tesla
coil
> > that would have the greatest spark length percentage over your equation.
My
> > estimate would be that the winner of this type of contest would have a
coil
> > that has less than 1000 watts input. I base this on spark data from the
> > List. For example many 1000 watt coils give sparks over 4.5 ft,
>
>
>
> Many coils that are claimed to be 1000 watt coils, actually draw
> a lot more than 1000 watts.  Folks use a 1000 watt NST, and
> therefore call it a 1000 watt coil.  But NST's can draw much more than
> their rated input powers, esp if powered by a 140 V output variac.
>
> but there
>
> >
> > are no coils under 10 KW input giving sparks over 14.2 ft. Larger coils
are
> > even less spark efficient.
>
>
>
> See my comment above....
>
> Note that pole type transformers have an output
>
> >
> > capability of over 10 times their nameplate rating when shorted. This
means
> > that the watt input for a certain random spark length would have to be
an
> > instantaneous type wattage. This type of metering is never done for pole
> > type or similar transformers.
>
>
>
> The watt input for a pole type TC system tends to remain
> reasonably steady, although there can be surges especially
> using async gaps.  It's not customary to try to gauge the exact
> wattage at the time the spark occurs.  An average input wattage
> is usually considered to be acceptable.  One can eliminate
> surging by using a sync gap.  Using a sync gap, the wattage
> stays steady, from spark to spark.  This would satisfy your
> desire to equate spark length with input wattage.
>
> John F.
>
>
> >
> > John Couture
>
>
>
>