Re: which coilform parameters best?

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

Original poster: "Barton B. Anderson by way of Terry Fritz <twftesla-at-qwest-dot-net>" <tesla123-at-pacbell-dot-net>

Hi Boris,

Tesla list wrote:

> Original poster: "boris petkovic by way of Terry Fritz
<twftesla-at-qwest-dot-net>" <petkovic7-at-yahoo-dot-com>
>
> All,
> > Tesla list wrote:
> > > >Bart A 5kva pig can put out 10kva. Pigs are very rugged
units................
> ---
> To be theoretically correct ,I must say, that
> especially in leakage inductance -tank cap resonant
> case with respect to F mains ,a power transformer can
> deliver multirating power levels to TC system.
> Good for TC ,but bad for transformer.
> ---

Very true. Some pigs have died learning to fly. Very infrequent, but it has
happened.

> > Assume a 14.4/347 (5kva) pig is pushed to 10kva with
> > the 0.1uF cap = 10.4ms to charge cap to 20362 Vp.
> >
> > 120 bps = 8.33ms = 19900 cap V = 19.83 joules.
> > 240 bps = 4.17ms = 16900 cap V = 14.28 joules.
> > 480 bps = 2.08ms = 10955 cap V = 6.04 joules.
> >When the cap size gets up there, I think it would be advantageous to go
> > higher, especially if one wants to play with faster breaks.
> ---
> This is relative again.Depends on stray inductance( +
> ballast) and Cp size you deal with.These two make
> possible many combinations as concerns same charging
> frequency of system.There is case where Cp small and L
> large,and case where Cp big and L small giving the
> same charging frequency.

Will we ever see a case where Cp is small in comparison? Maybe in an
extreme case, but I would think
rare.

> Cp small results in higher voltage, than Cp large.

Like you said, it's relative to the inductances. In your case of a small Cp
and large L, current has
changed, and if selected for the same charging rate, the voltage would be
the same as, well as the
time (assuming power factor was unchanged).

> You refer to VA figure ,but what is more important is
> W (real power).If one doesn't care about that, may get
> very poor overall efficiency of charging system
> despite respectable VA levels drawn from mains.

Yes, in keeping with the transformer ratings and to get the point across.
But regardless of
efficiency's, apparent or real power, the affect of the transformer under
the stated conditions still
apply, simply at better or worse efficiency's. Assume if you will, the
previous va numbers were 100%
efficiency (then va=p). Anything less (va < p) will make those numbers even
worse for the metered
power in and strengthen the case for more current.

Maybe what your showing here is that it is also a good idea to attain the
highest power factor
possible on any given charging system. And that, I totally agree.

> Good example is Heise's 1.5 MV TC.He has powered it by
> 200 KVA power transformer,and efficiency has been so
> low that I doubt he has ever delivered more than 60kw
> to TC circuit.

Now there is an extreme case in need of some serious pf correction.

Take care,
Bart