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Re: Fw: frequency (fwd)

Trent

BPS with a static gap can go over 120bps at 60Hz mains freq. If the cap is
small - impedance at 60Hz higher than the HV tranformer secondary (ie less than
resonant size), it will charge up to the breakdown voltage of the gap in less
than one half-cycle, and thus you will often get more than one bang. A resonant
cap may also deliver greater than 120bps due to the voltage rise it produces.
Often with a reso cap you turn *down* the input volts to get back to 120 again.
Larger cap sizes will, of course, take longer to charge up and then you can get
lower break rates.

As for rotary gaps, I'm not an expert. All I know is that a sync rotary gives a
much more stable break rate, is generally better quenching and more efficient,
and stresses your components less. You can also adjust the phase of firing.

Alex





Tesla List wrote:

> Original Poster: Tesla List <mod1-at-pupman-dot-com>
>
> >---------- Forwarded message ----------
> >Date: Thu, 15 Apr 1999 12:56:53 -0500
> >From: Marius Grigoriu <compwiz-at-stratos-dot-net>
> >To: Tesla List <tesla-at-pupman-dot-com>
> >Subject: Re: frequency
> >
> >Tesla List wrote:
> >
> >> Original Poster: "Trent" <trent-at-iex-dot-net>
> >>
> >> Hello All,
> >>
> >> Q:  Is it possible to have an input frequency greater than the 60 cycles
> going
> >> to the spark gap/primary, and if so, how?
> >>
> >> Thx,
> >>           AT
> >
> >Again, I am posting to learn, so if I'm wrong, don't get mad :)
> >
> >The whole idea of the spark gap and capacitor is to convert those 60 or 50
> cycles
> >to RF current so it can resonate with the secondary. If you have a current
> source
> >of the right frequency, you should be able to take it directly to the
> primary,
> >skipping the gap.
> >
> >Am I correct in my statments?
> >Marius Grigroiu
> >
>
> Dear Marius et al,
>
>   Hmmm...your question is interesting and somewhat akin to what I am seeking
> to understand; however my aim is NOT to eliminate the spark gap as it is the
> source of the damped wave (DW) oscillations I feel are important in my work.
>
>   I am working with electromedical devices and am attempting to understand
> the relationship between the frequency of the incoming voltage/current
>  typically 60 cps) with regard to the charging of the capacitor and the
> breaks per second (bps) of the spark gap.  It appears that the maximum bps
> with a static gap are limited to 120.
>
>   This limit doesn't appear to apply to a rotary gap.  My questions:  How
> does the use of a rotary gap effect the charging of the capacitor, the break
> down of the gap and the power transfer across the gap, when subject to the
> typical incoming frequency?  Aren't we sacrificing power by increasing the
> bps?  Is it possible, say by using a higher frequency input, to increase the
> charge to the capacitor, thereby increasing the power across the gap,
> resulting in greater effectiveness of the system?
>
>   I'm looking at the possibility of using a 400cps input in an attempt to
> realize greater efficiency from a rotary gap system; any input/feedback is
> welcomed.
>
>   Thanx and best regards,
>                                                   Trent