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Re: Combining several caps
Original poster: "Christopher Boden by way of Terry Fritz <teslalist-at-qwest-dot-net>" <chrisboden-at-hotmail-dot-com>
You may wish to do a little reading at www.thegeekgroup-dot-org/mmc I can
supply you caps, and all the reference material you need to design and
build an MMC array.
Christopher "Duck" Boden Geek#1
President / C.E.O. / Alpha Geek
The Geek Group
Because the Geek shall inherit the Earth!
Never doubt that a small group of thoughtful, committed citizens can change
the world. Indeed, it's the only thing that ever has.
The ability to learn is older - as it is also more widespread - than is the
ability to teach.
- Both from Margaret Mead, 1901 - 1978
>From: "Tesla list" <tesla-at-pupman-dot-com>
>Subject: Re: Combining several caps
>Date: Thu, 30 Jan 2003 16:39:05 -0700
>Original poster: "Ramon van der Hilst by way of Terry Fritz
>Today we've measured the NST, and the secundary RMS voltage is 5640,
>giving a peak voltage of about 8,5 kV. (<I've learned! :D) Actually quite
>strange numbers, as it's not near the 2x4000 it said, yet the peak is
>higher.. might this've happened because we measured at an input of 2 VAC,
>giving an output of 54,8 VAC?
>well anyway, after taking a better look at some sites about MMC's, I've
>been searching around for some polypropylene MKP caps. On a postordersite,
><http://www.conrad-dot-com>www.conrad-dot-com I found Epcos MKP polypropylene caps
>with the following specs:
> 0,15 µF, UN = 630 V=, Ueff = 250 V~, tolerance 5% and 6,0 x 15,0 x 26,5
> mm (width x height x diameter).
>I was thinking about buying 50, 10 extra, and using 40 of them. That would
>give (I've learned again ;-) tnx all!) 0,00375 uF -at- 10 kV, while wintesla
>and tcc both gave 0,0037 uF as needed capacitance (for 5640V, that is RMS).
>I was wondering though, as neither of the programs mentioned it, whether
>you have to fill in the RMS values or the peak values. anyway, are the
>caps right? (if it's peak voltages then we'll adjust the amount of caps to
>the right capacitance... as long as it's still 9kV or more).
> Tesla list <tesla-at-pupman-dot-com> wrote:
>Original poster: "Sean Taylor by way of Terry Fritz "
> > We've acquired a NST (sec. : 8kV, 10mA at 220V, 50Hz) and so WinTesla
> > suggested we use a 4 nF capacitator.
> > What seemed the simplest for us is using 16 (C1) 1nF 2kV caps, placed in 4
> > parallel rows of 4 caps in series.
>SNIP . . .
>Well, there are a couple problems here. First, the 4 caps in series will
>total up to exactly 8 kV, where your NST is an 8 kV NST, and will actually
>put out 11.2 kV on the peaks, plus the ringing in the primary tank circuit
>will repeatedly reach a high voltage as well. You'll need a cap rated for
>at least 12 kV. Second, 4 caps in series, while increasing the voltage
>capability, will decrease the capacitance. Four of your caps in series will
>be 0.25 nF at 8 kV, so 4 strings of 4 will yield 1 nF a! t 8 kV. You're best
>bet for a cap right now would probably be a saltwater cap, easy to make,
>cheap, and variable size. Someone recently posted the Geek Group bucket cap
>link, or you can search for it on google. Good luck!