Re: MMC

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

Original poster: "Samuel Rosset by way of Terry Fritz <twftesla-at-uswest-dot-net>" <samr-at-bluewin.ch>

Hello Terry, all,

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

> 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).

Thanks for the info! I didn't give you all the information, because in fact
my ballast consist of a 5 ohm resistor in serie with a 15 ohm inductive load
(-at- 50Hz) But if I understood what you wrote, I must model my system with
PSPICE, and find what is the biggest cap value it can charge. If the cap is
too low, I will see a high BPS, and if it is too big and the theoretical BPS
falls below 100and I will see no brakings at all, for the SG braking voltage
will never be reached. The biggest cap value for my system is the one that
will fire at 100BPS Is it right?

I also have another question concerning bleeding resistors across each cap.
How do I choose the value? If it is too low, it will ruin the cap
proprieties, and if it is too high, it will be useless, so what is the
typical value I should use?

regards

Samuel