Re: MMC

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

Original poster: "Terry Fritz" <twftesla-at-uswest-dot-net>

Hi Samuel,

At 09:27 PM 1/8/2001 +0100, you wrote: 
>
> Hello all,
>  
> Before I buy the caps for my new MMC, I'd like to ask you some question, for
> I don't want to make the same mistakes (I'll stay away from WIMA MKP 10, for
> their rated dv/dt was only 250 v/us, when I was asking for 800 v/us from
> every caps!) Someone on the list recommanded me to use WIMA FKP 1. Does
> anyone use them?


The Wima FKP1 series is perfect!

>
>  
> How can I choose a cap value. I am using a PT, and therefore not caring much
> about resonant charging? I have a 220V wallplug -at- 10 amps and a 16 kV PT.
> From the 2200VA I can draw from the house plug, 500W are lost in the
> resistive ballast. I was thinking to use the conservation of energy :
> (2200-500)=0.5*BPS*C*(16000)^2 but I am not please with that for the
> following reason :
> I am assuming a cos(phi)=1, which is not accurate, 
> I am using a static gap, so how can I be sure the of its firing voltage (that
> I assumed to be equal to 16KV), and same thing with the BPS, with a static
> gap, it is hard to know!


For a 60Hz line at 120 BPS I get 72nF.  I modeled the system and found that
72nF would charge at 120BPS for a firing voltage of 22.6kV which is 16kV x
SQRT(2).  This incudes your 5 ohm ballast.

http://hot-streamer-dot-com/temp/samuel.gif

1/2 x C x V^2 x BPS = 2200 watts throughput.  

You used 16000 volts but that is an RMS value and you want to fire the gap near
the peak at 16000 x SRT(2).

>
> I read somewhere that with a static gap, one should use 
> LTR C <= 1.5* C resonant : Why? Where does this formula come from?



LTR stuff is for NSTs.  It is found by MicroSim analysis as at:

http://hot-streamer-dot-com/TeslaCoils/Misc/NSTStudy/NSTStudy.htm

Is is possible to make LTR PT an PIG systems but no good solid data exists for
that.


Cheers,
        
        Terry


>
>  
> Thank in advance
>  
> Samuel