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Re: MMC question (SMT cap comment)



At 08:33 PM 6/15/99 +0200, you wrote:
snip...
>Hmm, I have never seen SMD caps with a 500V or higher rating. The
>biggest ones I have seen are rated at 100V and 220nF. These are
>made from polyester and have a dv/dt of 35V/µsec. The test rating
>(for 2s) is 350V/µsec. So, even if we neglect the polyester problem
>(which we really can“t), we would still need a lot of rows to get a
>useable amperage. Another problem might lie in the fact that they are
>"S"MD. The distance between the layers and the end "plates" is
>very small and the surface is "open" to grime and dust. This might
>present a problem with corona and or voltage creepage along the
>surface. If you pot it in something solid (like epoxy) you will never
>be able to rebuild it. If you use an oil bath, then you have one of
>the things I like to avoid around HV: oil ;o). And....... wouldn“t it
>look kind of awkward having an 8" coil with a SMDMMC the size
>of two cigarette packs? ;o)). It might be an interesting idea for
>a µTC, tho. 2-4" sparks from a "cigarette pack and a 9V" {;./\)
>Or how about feeding the output from this into an helium filled
>bag floating above your head (sort of like a halo ;o)).
>
>Coiler greets from germany,
>Reinhard
>
>

We us American Technical Ceramics 3600 volt 470 pF caps at work.  These are
very high Q caps that cost about $5 each.  Far too expensive for Tesla work
but they do exist...  They are about 0.5 x 0.5 x 3/16 inch.

	Terry 


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