Re: poly-alum caps

Subject: poly-alum caps

Ken Says
"Hey coilers,
I just got R.Hulls poly cap video; lotsa detailed instructions. Looks like
with a little elbow grease you can build some good quality caps. My question
is this...with the size of poly and alum he uses they come out to about
.0187 or so (mfd) so I was wonderin', since the coil I'm buildin' with neon
power, needs about .0047 mfd. Can I just vary the size of the materials to
get the needed capacitance? I'm using a 7" dia. 24.5" winding with #22
magnet wire. One 12000V neon -at- 30 milliamps, but will prolly add another or
two later to get up the watts. Any suggestions or ideas will, as always, be
much appreciated.

                                     Ken Cravens

   If you learn by making mistakes, I'm gettin' a FABULOUS education!"

Yes, that is a good idea.  Scale them down to about 55% of the size in the
instructions.  This will get you about .01mfd.  Then build two and use them
in series and you will get aout .005mfd.  These two capacitors in series will
be good for about 20,000 volts.  I built two of these capacitors (at .019mfd)
and blew both of them using them one at a time with 15,000 volt neons.  The
second time I was intentionally trying to keep the voltage down to about 12kv
until my commercial capacitor arrived and it blew anyway.  I am convinced the
.062 poly capacitors can only be safely used at 9 or 10 kv.

Ed Sonderman