Re: Bottle Capacitor Questions

Albert, there is some general info on my site, www.electrophile.8m-dot-com,
on constructing salt water caps, as they are often called. Most people
use glass bottles, the thicker-walled the better. I've had good results
with champagne bottles. I keep losing ones made with thinner glass. Some
folks have tried PET(mylar) or PE(polyethylene) bottles, and while the
mylar is generaly a bad material to use (heats up from rf loss), PE is
great. For calculating values it gets tricky, since there are no
accurate, easy ways of measuring surface area and dialectric thickness. 
You are running with a 15/60 NST? I would expect this to need about ten
wine bottles. I've almost always just experiemented with different values
when using SW caps, till i find a good match. THe best way would be to
purchase a cheap DMM with a capacitance meter in it (~50$, at SEARS?). 
There is no real need to "test" the caps in the way you mentioned in your
other post. If one is bad, then the whole system won't fire. If you feel
the need to know before hand, rig up a way to test continuity using DC
current. They will act as an open circuit to that.
good sw cap=big bottle, thick glass(if you can find PE, USE IT), salt
water for both plates(inside and out), 1/2" of mineral oil topping off
both the water outside and the water inside.

-Grayson Dietrich
"The Electrophile"

On Wed, 18 Aug 1999 16:45:48 -0600 Tesla List <tesla-at-pupman-dot-com> writes:
> Original Poster: "Albert Race" <race-at-dgms-dot-com> 
> Well, I'm working on the tank capacitance for the primary circuit, 
> and it
> looks as though I am going to be making my own. Haven't done this 
> before, so
> this is going to be a good thing. I was wondering if there is anyone 
> out
> there that has any information on creating these "Bottle Capacitors"
> Regarding the dielectric constants for the different types of
> glass/oil/material being used  and basically any information needed 
> to
> calculate the total capacitance for each bottle.. Also. information
> regarding voltage breakdown would be good to have as well. Also, 
> what is the
> best way to test one of these buggers anyways? Any/all information 
> will be
> greatly appreciated....
> Sincerely,
> Albert

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