Re:

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

Original poster: Bart Anderson <classi6-at-classictesla-dot-com> 

Hi Chris,

Are you sure you want to run a 200nF cap size? That's on the huge side for 
a 4.5" coil. Have you looked at the number of turns required on the primary 
when using a cap of this size? Also, the cap energy is going to be way up 
there for a coil this size. I run between 20nF and 80nF on my 10KVA pig. 
David Rieben runs 85nF on his. These are just a couple higher powered coils 
for reference. BTW, these are roughly 13" diameter coils. What made you 
consider a 200nF cap? Was it the transformer output current?

Take care,
Bart

> > Original poster: "Chris the great" <downnessisgoingup-at-hotmail-dot-com>
> >
> > I have done some work on my coil since I have last posted, and I have
>found
> > my problem.  I think my tank cap is WAY to small for my MOT power source,
> > which will soon be a 4 MOT stack.  I have calculated (from
> > http://home.earthlink-dot-net/~electronxlc/tccalc.html) that my tank capacitor
> > should be 200nF at 8kV, 650mA, not 13nF.
> > I would like to make sure that this is indeed a good tank cap size, so I
> > don't go and make a huge poly capacitor for nothing (actually 3 in
> > parallel).  Or would another type of capacitor be easier to
>transport/make,
> > or cheaper, or better?
> >
> > Needless to say I will need a very large topload, I was thinking about a
>40
> > inch toroid on top of a 24 inch toroid, for a total secondary capacitance
> > of 77.6pF, with an inductance of 19.6mH.
> > My primary inductance will be very small, however I have found that a
>lower
> > primary inductance produces brighter sparks that are slighly longer.  I
> > will have 2 series static sucker gaps, until I can get a rotary gap.  More
> > on my coil here
> > http://hot-streamer-dot-com/chris/4inchcoil.html
> >
> > Are these good values for my 4.5 inch coil?  I expect a major increase in
> > performace over my 12 inches of spark so far, but will they be around
> > optimum values?
> >
> > Thanks!
> > Chris
> >
> >
>
>
>
>