Re: MMC voltage ratings

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

Original poster: "Barton B. Anderson by way of Terry Fritz <twftesla-at-qwest-dot-net>" <tesla123-at-pacbell-dot-net>

Hi Johanthan, Terry, All,

I can speak for JavaMMC. I put in the numbers immediately after I read Terry's
reply and JavaMMC says the reliability is "very good". Jahanthan's problem
is not
knowing the thermal dissipation factor for this cap,  which is 22 C/watts. With
JavaMMC, you enter the lead length. In this case, the lead length input
would be
about 58mm. This is something I tried with the MMC design and I think it was a
bad idea because know one knows what the heck to enter into the input box
and it
directly affects reliability.

I'll work on this and see if I can revamp JavaMMC. As a matter of fact,
I've been
wanting to pull JavaMMC off the website until I can make it worth using. I
think
I will unless someone has a knee-jerk reaction (I can't imagine that). For now,
I'd recommend the tables at the other sites which were posted.

Take care,
Bart
--
Barton B. Anderson
http://www.classictesla-dot-com
Tesla list wrote:

> Original poster: "Terry Fritz" <twftesla-at-qwest-dot-net>
>
> Hi Johanthan,
>
> A 15kV transformer has a peak voltage of 21kV.  10 2000 volt caps give 20kV
> which is close enough since MMC caps can easily be pushed somewhat beyond
> their ratings without worry.
>
> As Mark's chart at:
>
> http://hot-streamer-dot-com/temp/MMCcapSales.gif
>
> Shows, 2 strings are fine.  The current is about 12 amps which is just at
> what they can take without worry.  More info is at:
>
> http://hot-streamer-dot-com/TeslaCoils/MMCInfo/GeekCaps/GeekCaps.htm
>
> I can't speak to the JAVA MMC calculator but is should work.  I can't find
> the URL or I would try it.
>
> Cheers,
>
>         Terry
>
> At 08:47 AM 11/20/2001 -0800, you wrote:
> >Hi All,
> >
> >I am making my MMC, and am a little unsure of whether I have an adequate
> >voltage rating. The Geek site says this is ok, and the Java MMC calculator
> >says the reliability is bad. I must be doing something wrong, as it says all
> >my designs are bad, even when I put silly numbers of caps in a string. Could
> >y'all weigh in on this one? I want to make a good one that lasts. My specs:
> >
> >PSU: 15/120, static gap, desired tank cap around .03uf (LTR)
> >
> >I have 22 caps, .15uf/2000VDC. The Geek site says 2 strings of 10 will be
> >ok, this would be .03uf/20kv. Does this have an adequate safety margin?
> >
> >I could go closer to resonant and get 8 more
> >caps, and have 2 strings of 15 for .02uf/30kv. Is .02 close enough to .0212
> >(the value listed as resonant) to be resonant?
> >
> >Once again, as always, thanks much.
> >
> >Jonathan Peakall