design for new capacitor

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: "Dr. Adriano Mollica" <adriano.mollica@xxxxxxxxxxx>

Hello list,

i just bought on ebay a certain quantity of douple faces copper fiber glass
plate for very cheap.

i will like to use them to make a capacitor, and i believe that it is
possible.

But i'm worring about the design. infact, every single plate is already  a
little capacitor "as is",  and if  i'm right , the thickness of the
fiberglass will be 1.6 mm, that is very big (this will lead to a high
punture voltage resistance , but low capacity).
So , how should i connect the plates one to another in parallel
cinfiguration trying to avoid any "corona" , and external spark? and so on,
considering that the plates will be in a number of 20-40 and i cannot
overlap them due the double face!!!

Any ideas?

bye bye


----- Original Message -----
From: "Tesla list" <tesla@xxxxxxxxxx>
To: <tesla@xxxxxxxxxx>
Sent: Wednesday, March 01, 2006 5:53 AM
Subject: Re: rolled cap blowew out


> Original poster: Chris Estes <estescc@xxxxxxxxxxxx>
>
>
>
>
> Tesla list wrote:
>
>
>  >Original poster: Adriano.Mollica@xxxxxxxxxxx
>  >
>  >
>  >Hello list,
>  >
>  >after the last attempt to start the TC using lithuanian capacitors,
>  >that used to explod very quick and very often, i made a homemade
>  >rolled polyethylene cap.
>  >The dielectric thickness was 0.4 mm, since 1 mm should resist 60kv, i
>  >thought that 0.4mm should handle about 25kv.
>  >After the rolling up of the materials, i dip the roll into a tube
>  >filled with synthetic engine motor oil, and by a vacuum pump i
>  >removed all the air inside.
>  >
>  >unluckly, after few successful sparks, the capacitor stopped working
>  >and started to make a noise (probably an internal arc).
>  >i'm pretty disappointe 'cause i spend around 40 euros in materials,
>  >and many hours of work!
>  >
>  >how can i built a cheap, reliable, and FAST pulse discharge capacitor?
>  >
>  >i'm thinking about planar caps in air ( at least is the cheapest
>  >dielectric i know.!
>  >
>  >any suggestion?
>  >
>  >how much is the dielectric costant of the air, and its puncture voltage?
>  >37 nF cap wil probably be very large?
>  >thanks!
>  >
>  >
>
> I've just finished an interesting design thats yeilded about 6.7 nf
> with I'm guessing 50 Kv strength. Its a stacked plate cap that uses
> corrugated cardboard and mineral oil for the dielectric. I place 2
> pieces of cardboard between each plate to give about 250 mil (3/4 cm)
> spacing. All the pieces of cardboard are oriented so that when looking
> down on the stack you can see through the corrugation if that makes
> sense. then i place the stack in a container and fill it with oil. The
> orientation of the cardboard lets the air bubbles flow up and out quite
> nicely. The most expensive component is all the oil and, I believe,
> they will have a 'self healing' quality. If theres a puncture, all I
> need to do is shake it around to jostle the oil a bit. The dimensions
> are about 20cm by 35 cm by 35 cm for, as I said, about 6.7 nf. If you
> wanted more farads in less space then you could probably just use one
> layer of cardboard but I just needed about 7 nf for my NST resonant
> condition and wanted to be sure about the dielectric strength. I
> haven't tried this out yet as I'm still building the rest of my coil
> but I can't see any serious flaw in my design so far. Good luck and
> happy coiling.
>
>