Re: Geek group caps, I think I made a mistake?

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

Original poster: "Jolyon Vater Cox by way of Terry Fritz <twftesla-at-qwest-dot-net>" <jolyon-at-vatercox.freeserve.co.uk>

By calculation a 1.5uF capacitor connected across an AC supply with
frequency of 60Hz  has a reactance of 1/(2 x pi x 60 x 1.5 x 10^-6) which
equals 1768 Ohms.

Now I might be wrong here- but from my understanding of Ohm's law
by V=IR and assuming a maximum current of 30 mA (remembering that NSTs are
current limited)
the max voltage across the capacitor will be 30 x 10^3 x 1768 = 53
volts -not enough to fire a spark gap but at least your capacitors should
not be damaged!

They should of course be wired in series, not in parallel, in order to work
properly
to give 1.5nF rather than 1.5uF
then the reactance will be roughly 176839 Ohms which with 30mA flowing
through it (V=IR again)
gives a voltage of 5305V -rather low admittedly but might just fire a gap if
it were small enough.

It would probably be better to find another NST and put that in parallel
with the existing one for 60mA which by V=IR will give a voltage of 10610V
across the cap -leading to easier gap firing. Otherwise you could rectify
the AC from the transformer to DC and use  that to charge the cap in a DC
powered TC setup.

Jolyon

----- Original Message -----
From: "Tesla list" <tesla-at-pupman-dot-com>
To: <tesla-at-pupman-dot-com>
Sent: Saturday, November 16, 2002 4:04 AM
Subject: Re: Geek group caps, I think I made a mistake?


 > Original poster: "by way of Terry Fritz <twftesla-at-qwest-dot-net>"
<dhmccauley-at-spacecatlighting-dot-com>
 >
 > Just curious to why you would run 10 in parallel.  That would give about
 > 1.5uF which is way to high for a 15/30 type NST.
 > Also, if you actually powered 10 of these in parallel with a 15/30 NST you
 > most certaintly just destroyed all of them.
 >
 > 10 of them in series would give you about 0.015uF which is a good resonant
 > size for a 15/60mA NST.
 >
 > Dan
 >
 >
 >
 >
 >
 >  > Original poster: "by way of Terry Fritz <twftesla-at-qwest-dot-net>"
 > <PLUGHzz-at-aol-dot-com>
 >  >
 >  > the caps I recieved are 2000 VDC .15mf , the ac current goes right
through
 >  > them.
 >  > im using an 15/30 nst can I make these work somehow? I tried 10 in
 > parallel
 >  >
 >  > Hellllp
 >  > Thanks
 >  > Danny L. Ray II
 >  >
 >  >
 >  >
 >  >
 >
 >
 >