Original poster: G Hunter <dogbrain_39560@xxxxxxxxx>
Hi Chip,
The transformer / cap matching formulas often break
down when pole pigs are involved for precisely the
reasons you've just illuminated. An optimal cap for
7200vac at 2 amps is just too big. It's not a big
deal. Smaller-than-resonant caps are the norm at such
power levels. Start off with about 50nF and
incrementally add capacitance until you get decent
sparks. Maxwell Labs 30nF 30KV plastic caps go for
about $100 apiece on e-bay these days. Try one or two
of those to start with.
Cheers,
Greg
--- Tesla list <tesla@xxxxxxxxxx> wrote:
> Original poster: "Chip Ford" <chipford@xxxxxxxxxxxx>
>
> Ok...there are many kinds of transformers out there.
> Seems that the
> really BIG coils use a pole pig. Such as "The green
> monster". His is
> a 15kva @ 14400 volts. Using the math KVA = ((VOLTS
> X AMPS) / 1000),
> I came up with an amperage of @ 1.042 Amps (15,000
> watts). Since .001
> Amps is equal to 1ma, he has 1042ma. According to my
> calculations,
> the resonant cap is @ .1919 uf. I think he said his
> cap was
> .1uf...close but not real close..Now, I think alot
> of the line
> transformers have a selector switch on them. I think
> they are like
> 7200, 6400, 5600 volts for the ones around here. So,
> if I have 15 kva
> transformer @ 7200 volts, it will have an amperage
> of @ 2 amps
> (2000ma)(15,000 Watts). At this rate, my cap is
> gonna be around .75
> uf. This is really high and from a few calculations
> that I have made,
> A secondary coil 12" 81/2" dia. 48" tall will need
> over 10000 turns
> of #39 awg. wire on it. This pretty much makes this
> transformer
> unusable. Besides that, where is a hobbest ever
> gonna find a cap? Am
> I missing something here? Are my calculations
> incorrect? Am I looking
> at the transformer incorrectly? Please
> comment...Chip Ford
>
>
>