Re: Grounding Problem???

["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 Ed,

Tesla list wrote:

> Original poster: "by way of Terry Fritz <twftesla-at-qwest-dot-net>"
<Esondrmn-at-aol-dot-com>
>
> In a message dated 1/28/02 9:55:22 PM Pacific Standard Time, tesla-at-pupman-dot-com
> writes:
>
> >
> > Just FYI courtest JavaTC:
> >
> > At 120bps the 5kva pig charges the 0.05uF cap to 97.8% Vp (9.9 joules). The
> > cap
> > requires 10.37ms to fully charge and electrode alignment occurs every
> > 8.333ms. The
> > %Vp is based on the charge rate curve which is why it's nearing 100%.
> >
> > At 240bps, the cap charges to 83% Vp  (7.14 joules). Still requires 10.37ms
> > but now
> > electrodes align every 4.16ms.
> >
> > There is higher energy at the lower bps (energy should not been the same
> > between the
> > two cases).
> >
> > Take care,
> > Bart
> > --
> > Barton B. Anderson
> > www.classictesla-dot-com
>
> Bart,
>
> Good explanation.  I agree, and the performance of the coil seems to
agree.  It
> runs fine at 240 bps and acts like it is overpowered (for the existing
> coupling) at 120 bps.
>
> At 240 bps, we are inputting about 30% less power but doing it twice as
often,
> so the average power is higher - correct?

Yes in a sense. There is a lower energy discharge twice as often resulting in a
higher power throughput at the gap.

>  Still, I think John Freau has proved
> that higher power, slower bangs (like at 120 bps) produces better
performance.
>
> Ed Sonderman

John has shown from his experimenting that lower break rates are more
efficient in
that they use overall less power for a given sparklength (up to the
limitations of
coil and ps). The actual bang at the gap where losses are high and if occurring
twice as often may cause twice as much loss, and thus, it takes more wall
power to
achieve the same sparklength (up to the limitations of the coil).

The gap itself may be more efficient at higher energy levels, but the coil
has to be
able to handle it. I think there are a number of dynamics involved to
define a given
coils limitations. For example, I would separate cap energy from power
throughput at
the gap as two separate limits becoming non-linear as a function of the gap
and coil
behavier.

My old coil performed better at 240bps with a 0.06uF where 120bps caused
similar
behavier as yours, but as I dropped the cap size to 0.04uF, 120bps had no
problems.
Cp at 0.06uF and a slower rate allows a great deal more energy at the cap.
To lower
the bang, I could either increase the breakrate or lower the cap size as
governed by
the transformer current. BTW, the 0.04uF performed well at 240bps, but took
more
wall power for the same sparklength.

Take care,
Bart