Re: cockcroft-walton question

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

Original poster: "Ed Phillips by way of Terry Fritz <teslalist-at-qwest-dot-net>" <evp-at-pacbell-dot-net>

Tesla list wrote:
 >
 > Original poster: "Jim Lux by way of Terry Fritz <teslalist-at-qwest-dot-net>" 
<jimlux-at-earthlink-dot-net>

 > Interesting point about effective dividers, though... Consider a big
 > transient propagating back into the CW stack. It will divide evenly if all
 > the caps are the same, but, if you've used the "low ripple" 1,2,3,4 sizes,
 > then the top stage will take the most voltage (because the C is smallest)...
 >
 > With modern switch mode drivers and fast recovery HV diodes where you can
 > raise the pump frequency fairly high, at fairly low cost,  I suspect that
 > the "equal C" approach is far more popular, as it gives you the lowest
 > ripple, for a given output power, for a given cost.
 >
 > The tradeoff analysis might be a bit different in days of yore, where the
 > relative costs of rectifiers and diodes were different.  Certainly, if you
 > had to go out and buy (or build) thermionic rectifiers for each stage, and
 > worry about the filament supplies, etc., minimizing the number of stages,
 > etc. would be very attractive.

	I agree.  I was thinking of voltage multipliers working from 60 Hz,
where capacitor reactance rules performance.  If the frequency is high
enough capacitor size isn't important and they might as well all be the
same.

Ed