Caps: Stacked vs Rolled

           Caps: Stacked vs Rolled
           Thu, 10 Apr 1997 08:22:15 +0000
           Chris Gardner <gchristo-at-clt.mindspring-dot-com>
           Tesla List <tesla-at-pupman-dot-com>

First off - I have set aside the DC coil project until I complete the
556 cascade controll circuit. I am now using a 10kv furnace trans with a
small quick and dirty cap which I think works pretty well for the 15
minutes of careful craftsmanship that went into it. I can only run the
unit at about 30 on the big-ol-variac, but its a start and tons o fun
with purple glowing from the cap and a 2 inch sparc. 

I am now determined to manufacture a serious capacitor and would like to
post my current design thoughts and would ask if this seems sound;

I have read some comentary that smaller caps in par. discharge quicker
that larger caps (Fr. McGahee), My interpretation of this is that the
same plate area will discharge quicker when divided into a greater
number of smaller units, this is the first reason I have decided to go
with a stacked design. The second is flexibility, I think a stacked
design lends itself to an adjustable set up.

I intend to obtain several sheets of .05 copper, and have these sheared
to 5" x 6.5", then take these to a machine shop buddy of mine (arent
they great?) and have him stack-em, clamp-em and rabbit out 1.5" x 4.1"
or so with an eighth inch round on that inside corner. This should leave
me with 25sq inches per plate face. Im thinking about 30 plates.
These would be alternated and placed in a custom plexi box. For
dielectric Ill be using 3 or 4 sheets of polyetheline between each
plate. I havent settled on a thickness yet (hey, I'm still designing)
But all will be mounted and clamped, filled with a good transformer oil
and topped off with a half inch of parafin. (Do these things get hot?
Ive seen no mention of running temps for caps) 
The tabs will then be fixed so that two buss bars can be attached to a
variable number of plates.

I am a strong believer in versatility and already have 4 secondaries of
varying sizes im playing with. 

As they say there is nothing new under the sun, and Im sure this has
been tried. Am I doomed or does this seem a good path to pursue?