RE: Capacitor design and Toroids

>Hi All
>I have started building a REAL coil. 8"dia 26" long secondary and would
>like any feedback to keep the project on track.
>Has any one used Kapton for the dielectric of a capacitor?
>This stuff seems incredible with specs like..
>dielectric strength of 7000V/mil
>dielectric constant of 3.5
>and dissipation factor of 0.003 at 1KHz?
>Also I thought I would make a toroid ~ 4" x 12". My question is if
>the center needs to be removed or can it be shaped like a
>fat disk, (that is a 4" thick disk with rounded edges?)
>Dave Huffman


Have you checked the price on Kapton?  I think it may be prohibitively
expensive.  It is a great material for capacitors.

I am sure the toroid you described would work fine.  Most home built toroids
are circular on the outside and flat in the center because it is the easiest
way to make them.  Your 12" toroid will be ok for getting the system up and
running but with an 8" dia. secondary, you will want a much larger toroid -
like 30" or 40" or larger.  I am presently using a 40" toroid on my 6"
secondary at 5 to 8 kva.

It sounds like you have the job most of us would like.

Ed Sonderman

How tail is this setup?  Should I measure the discharge electrode at the outer edge or the center of the curved edge? I can't imagine what it looks like.
Dave Huffman