Re: NST implemented Cockroft-Walton Multiplier

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

Original poster: "by way of Terry Fritz <teslalist-at-qwest-dot-net>" <dhmccauley-at-spacecatlighting-dot-com>

 > >Also, what types of values were you guys typically use for capacitors for
 > >your big cap charging circuits.
 > >I'm currently looking at some TDK 1000pF, 40kV capacitors, and based on
my
 > >charge current, I'll still get about 400-500V
 > >ripple at the marx generator capacitors during charging.  I could reduce
 > >charge current, but that would increase charge time which may or may not
be
 > >desirable.
 >
 >
 > You won't get any ripple at the output, because the marx capacitance acts
 > as a huge filter.  Think of the CW stack, in this situation, as a charge
 > pump that pumps packets of charge up the stack. When the output voltage is
 > low (i.e. marx has low charge), the upper stages of the CW don't do much..
 > as the output voltage rises, the upper stages start to help move the
charge
 > up the stack.


I'm not sure about that.  I have both the CW stack and the marx generator
very accurately modeled in PSPICE and by probing the voltage level on the
last capacitor (output) of
the marx generator, I am getting about 400-500V ripple all the way through
the charging cycle of the marx bank.

I don't have a current limited source (only using a 15kVAC, 60Hz AC source),
but i do have a 20Meg resistor between my CW stack and the input to the Marx
Generator.

Could I be doing something else wrong??

Thanks

Dan