Re: panasonic mmc rating?

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

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

Hi Larry,

Vpeak = Vrms x 1.414

so,

6500 x 1.414 = about 9200 volts.  

For 1600V caps like the Panasonics, you need at least 6 caps per string.  2
strings of 9 is fine.  The current limit for this MMC will be about 4 amps
RMS.  Most MMC problems are casued by too much current not too much
voltage.  MMCs can take lots of "extra" voltage but too much current will
overheat them and poly melts at only 85C.  I get about 2.6 Arms for you
coil so all should be fine.  I trust you will have drain resistors across
the the caps too.

Cheers,

	Terry


At 05:11 AM 9/25/2002 +0000, you wrote:
>I'm building an mmc using panasonic caps from the same group as
>the ones spec'd in the terry filter.  the digikey p/n is p10513-nd.
>I'm building an mmc to replace the single pulse cap that I killed
>in my friends tabletop coil.  its using a 6500v/20ma open frame nst
>and the resonant cap is about 8nf.  the rms output is ....  okay
>my stupid math skills are haunting me...  is the rms output 6500 x 1.41
>or 6500 x 2 x 1.41 ?  the cap i designed is 2 strings of 9 0.033uf 1600v
>caps. giving a rating of 14.4kv at 7.5nf ( i think, the plans are in the 
>other room. )
>
>the question:
>to calc rms output: 6500v x 1.41 = rms output?
>I'd like to overrate the mmc so I would get 6500 x 2 for the target rating.
>
>also planning on making the mmc into a cube of sorts due to size 
>constraints.  if cooling becomes an issue, I will place a small fan on one 
>end of the cube.  the mmc cube will be like this: imagine two strings of 
>caps folded length-wise 2 times.  2 wide by 3 high. about a 3" cube.
>
>larry
>
>
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