Re: Combining several caps

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

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
www.thegeekgroup-dot-org
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>
>To: 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 
><teslalist-at-qwest-dot-net>" <enqrypzion-at-yahoo-dot-com>
>
>
>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).
>
>tnx again!
>
>
>
>  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!
>
>Sean Taylor