Re: AC vs DC and Toroid Question

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

Original poster: "Mark Broker by way of Terry Fritz <teslalist-at-qwest-dot-net>" <mbroker-at-thegeekgroup-dot-org>

The resonant value capacitor for a 7.5/240 setup is .085uF.  The LTR 
capacitor for use with a static gap is around .12uF.  Using a 120BPS 
triggered static gap or a 120BPS syncronous RSG would charge a .15uF cap 
fully with ease.  The largest possible capacitor that could be used with a 
120BPS triggered 7.5/240 setup is .22uF (9 strings of 6 large "Geek Caps" ;) ).

240mA of current can charge a .15uF cap to ~10.5kV once per half cycle 
utilizing the inductive kick effect from the NSTs.  It takes far more 
current to charge the cap to the typical ~21kV for a PDT-driven coil.

Regards,

Mark Broker
Chief Engineer, The Geek Group

On Fri, 06 Jun 2003 15:28:31 -0600, Tesla list <tesla-at-pupman-dot-com> wrote:

>Original poster: "Dr. Resonance by way of Terry Fritz 
><teslalist-at-qwest-dot-net>" <resonance-at-jvlnet-dot-com>
>
>
>The 240 mA will be no where near enough drive current to keep your cap
>charged.  We use 14 kVA to drive a 0.15 MFD cap.  Your alternative would be
>a much lower rep rate but your output spark length will suffer considerably.
>
>With this large coil you might consider a pole pig and external reactor for
>the correct power input.
>
>On a 12 inch dia. sec. you need a 34 x 8.5 inch toroid for effective match.
>
>The sec. coil should be elevated above the plane of the primary coil approx
>4.5 inches for correct coupling for max. spark output.
>
>Dr. Resonance
>
>Resonance Research Corporation
>E11870 Shadylane Rd.
>Baraboo   WI   53913
> >  >
> >  > I have a relatively large secondary coil-about 2500 ft., 12.5" dia, 50"
> > high.
> >  >   Have a small (14 dia duct pipe toroid but planning a larger one.
> >  >
> >  > I have several questions, please:
> >  >
> >  > 1)  Given a .15 mfd primary capacitor, a rotary spark gap, and a set of
> > four
> >  > 120v/7500v neon transformers in parallel producing 240 ma together,
>would
> >  > there be a performance difference (1) operating the system AC versus
>(2)
> >  > rectifying the current to produce DC, and slowing the spark gap down to
> >  > allow the
> >  > capacitor to charge fully between firing ?
> >