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Re: Capacitor "tap" in Primary?



Original poster: "Jolyon Vater Cox by way of Terry Fritz <twftesla-at-qwest-dot-net>" <jolyon-at-vatercox.freeserve.co.uk>

Is it possible to get an autotransformer-like step up on a primary of a
spark-gap TC using a capacitor tap -in a manner  similar to that  exhabited
by the tuned circuit of  a Colpitts oscillator (but without the amplifier
and feedback)?

By the way, how does the "Poulsen Principle" work
only it seems strange that adding a capacitor directly across a spark gap
would would do anything to make it run cooler. Are there any good references
to the technique and does anyone know how it works?  Could it be that the 2
nF cap act to remove HF transients that would otherwise heat the gap -a bit
like a snubber across a TRIAC or a Zobel network across a loudspeaker, by
any chance?

Jolyon

----- Original Message -----
From: "Tesla list" <tesla-at-pupman-dot-com>
To: <tesla-at-pupman-dot-com>
Sent: Wednesday, June 26, 2002 7:12 PM
Subject: Re: Capacitor "tap" in Primary?


> Original poster: "D.C. Cox by way of Terry Fritz <twftesla-at-qwest-dot-net>"
<DR.RESONANCE-at-next-wave-dot-net>
>
>
> Spark gap losses can be reduced considerably by connecting a .002 cap
> directly across the spark gap.  This, discovered in the 1930's, is know as
> the Poulson Principle.  It was a neat trick used by early radio spark gap
> pioneers.
>
> Regards,
>
> Dr. Resonance
>
>
>
>
> ----- Original Message -----
> From: "Tesla list" <tesla-at-pupman-dot-com>
> To: <tesla-at-pupman-dot-com>
> Sent: Wednesday, June 26, 2002 7:25 AM
> Subject: Capacitor "tap" in Primary?
>
>
> > Original poster: "Jolyon Vater Cox by way of Terry Fritz
> <twftesla-at-qwest-dot-net>" <jolyon-at-vatercox.freeserve.co.uk>
> >
> >
> > Capacitor "tap" in primary?
> >
> > Has anyone had experience of using a capacitor tap instead of a tapped
> inductor
> > in the primary tank circuit of a Tesla coil -with the spark gap
connected
> > directly across one or other of the capacitors?
> >
> > The reason? To allow the charging of a high value capacitor to a
> relatively low
> > sparking voltage with a relatively high current in order to reduce the
> recharge
> > time between firing of the gap. The second capacitor would be of equal
to
> or
> > smaller value than the first so that at resonance the RF voltage across
> the
> > ends of the primary would be higher that the voltage across the gap.
> >
> > The system might be compared with a pi-tank or the tuned circuit of a
> Colpitts
> > oscillator (without the associated parts).
> >
> > Would this work or would energy simply be wasted in the spark gap?
> >
> >
> >
> >
>
>
>
>