Re: A 20 kV DC tank supply

tesla-at-pupman-dot-com on 08.12.98 11:26:05

To:   tesla-at-pupman-dot-com
cc:    (bcc: Marco Denicolai/MARTIS)
Subject:  Re: A 20 kV DC tank supply

Original Poster: "Steve Young" <youngs-at-konnections-dot-com>

>As to how to transfer energy to your primary capacitor from your
>capacitor, consider using an H-Bridge configuration, depicted below.
>Robertson  uses such an arrangement, apparently with good success.  You
>contact him directly for more information, schematics, etc.

+ ----|------------------|-------------------|
      |                  o                   o
      |                gap A1              gap B2
      | 30 uf            o  pri C   pri L    o
     ===                 |----||---OOOOOO----|
      | 20 KV            o                   o
      | filter         gap B1              gap A2
      | cap              o                   o
- ----|------------------|-------------------|

>Gaps A1 and A2 simultaneously fire, then Gaps B1 and B2 fire, repeating ad
>finitum.  This can be done with a (more complicated) RSG, or you could
>consider using triggered spark gaps.  The H-bridge avoids a spark gap
>directly across the flywheel cap.

Some questions:

- why to invert to charging polarity of priC and priL ? Same polarity would
work as well.

- doesn't the 30 uF cap and the tank supply impedance get involved in
creating losses and shifting the original resonance frequency during bangs?

More, an analysis of this circuit seems quite difficult to me. Very much
depends on how much the priC gets discharged at each bang... If it remains
charged (as sure it does) the pulses get asymmetric (e.g. odd bangs at a
higher voltage than even bangs)...

Anybody explained the idea behind this circuit?