Re: Suggestion on Power Supply?

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

Original poster: "Terry Fritz" <teslalist-at-qwest-dot-net>

Hi Christoph,

At 07:45 PM 5/6/2003 +0200, you wrote:
>Hi!
>
>this thread really brought up new insight into the topic to me, but araised
>one further question.

It's sort of messy stuff.  But it is real important so it is worth figuring 
out.


>I'm using a 30nF tank cap with a 200BPS async rotary ( BTW for those who
>remember, I just cant get that damn thing to sync....probably I removed too
>much material from the rotor but works not too bad this way )
>
>referring to that formula from richie burnetts homepage:
>http://www.richieburnett.co.uk/rotary.html
>
>P = 0.5 x BPS x C x Vē

0.5 x 200 x 30e-9 x 10000^2 = 300 Watts

Not that a sync gap can always fire at a say a 10000 volt peak every 
time.  Where an async gap may fire at any voltage.  This reduces the power 
by 1/2 on average with an async gap.  So in the above equation if the peak 
voltage of the transformer where 10000 volts,  you would only get 150 watts 
on average out of the coil with an async gap.  You might be far better off 
with a static gap firing like crazy.  But the RMS currents will be pretty 
high and much harder on the cap.

Note that a say 15000Vrms transformer has a peak output voltage of 15000 x 
SQRT(2) = 21213.2 volts.  You multiply the RMS voltage by 1.4142... to get 
peak volts.


>Is it right that I can only get a power throughput of ca 450 Watt at 10KV
>that way? Or am I messing up the units and it should be 4500Watt?
>
>from the reading of my amp-meter it should be something like 450Watt.
>My power supply should be able to deliver around 10 to 20 times more, but I
>think with that cap and 200 BPS I can't put more power through the system.
>Just wanted to be sure before messing around with my rotary......

You have a pretty big system to be running less than power than a little 
6/30 NST :-p  You need a higher BPS and more caps.  A quick fix is to go to 
a static gap, but watch the cap heating.

Cheers,

         Terry



>I know my lack of math knowledge must really hurt, but please help me anyway
>;-)
>
>Thanks in advance.
>
>Christoph