Re: Suggestion on Power Supply?

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

Original poster: "Jeremy Scott by way of Terry Fritz <teslalist-at-qwest-dot-net>" <supertux1-at-yahoo-dot-com>

Pete,

I was doing the calculations based on exactly that,
limiting the pig so it does not put out more than
it's rating. The maximum limit for me is 7200VA
because my 240V circuit is only rated for 30A.

I am aware that pole pigs can and will infact try
to draw whatever they need to accomodate the load,
even if that load is a huge capacitor, but I think
pigs are dangerous enough even at their rated power.

If I wanted to really push it: (and bought enough
PFC caps...)

7200VA = 14400V / .5A

(14400V / .5A) * C * 5
Time it takes to charge .03uF to 20362V = 4.32ms
This is close enough to 4.16ms, possible BPS = 240

Same power level per gap firing, so same spark length
calculated. Just now twice as many firings :) (longer
sparks perhaps -- air is ionized twice as fast...)

OR -- lets double up the capacitance:

Time it takes to charge .06uF to 20362V = 8.6ms
Close enough to 8.3 for 120BPS

Capacitor energy: 12.44 Joules
Dump it all in the tank in 1.72ms:

7200W = 12.44J / .00172s

1.7 * SQRT (7200) = 144 = 12 foot arc

And so on... the only real limitation with a pig is
what my house circuit will handle. This assumes I've
got the coil correctly built with a massively thick
primary for low resistance, optimal toroid, optimal
coupling, efficient gap etc...

The secondary coil windings are only 25.5" long by
6.625" in diameter, so I honestly think 12 foot sparks
may be out of the question.



















--- Tesla list <tesla-at-pupman-dot-com> wrote:
 > Original poster: "Terry Fritz" <teslalist-at-qwest-dot-net>
 >
 > Jeremy,
 >         there is nothing about that pole pig that
 > will prevent it from
 > delivering more than .3472A, if you put a low
 > resistance or large capacitance
 > across its output it just puts out that much more
 > current. The current (or
 > VA) rating is to avoid overheating it if you run it
 > at that load for ever.
 > If you run it for a small time you can go over its
 > rating, way over.
 >
 > This is why people use ballast on the input side of
 > a pig, to prevent from
 > over currenting it when the output is shorted - like
 > when the sparkgap is
 > conducting if you connect your power accross the gap
 > as is common.
 >
 > This is in distinction to NSTs which contain
 > magnetic shunts inside to
 > prevent over-currenting the output even if the
 > output is a direct short
 > circuit.
 >
 > -Pete Lawrence.
 >
 >
 >  >
 >  >Sorry Terry, I just don't see how I can use a
 > 153nF
 >  >capacitor with a 5000VA pole pig:
 >  >
 >  >5000VA = 14400V/.3472A
 >  >
 >
 >


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