Re: additional transformers [rolled caps]

From: 	Peter Electric[SMTP:elekessy-at-macquarie.matra-dot-com.au]
Reply To: 	elekessy-at-macquarie.matra-dot-com.au
Sent: 	Thursday, July 31, 1997 6:15 AM
To: 	Tesla List
Subject: 	Re: additional transformers [rolled caps]

Tesla List wrote:
> From:   richard hull[SMTP:rhull-at-richmond.infi-dot-net]
> Sent:   Wednesday, July 30, 1997 1:27 PM
> To:     Tesla List
> Subject:        Re: additional transformers
> >Just though I'd throw in my two bobs worth after having blown up a few
> >rolled poly caps!
> >
> >All of mine failed at the edges (even being under oil) so I reckon the
> >secret is to put big overlaps between the plastic and the Al plates i.e.
> >at least an inch or more. Also here the thick poly sheet is bloody
> >expensive! so use multiple sheets of 8 mil concreters plastic,
> >preferably the clear stuff but if all else fails use black plastic with
> >engine oil! It ran ok on my coil for more than 3 months.
> >
> >Cheers,
> >
> >Peter E.
> >
> >Peter,
> I recommended leaving a full 2" edge separation metal to edge of dielectric
> in all rolled capacitors!
> Richard Hull, TCBOR

Thanks for the info on that, I will go 2" on my future overlaps. It
seems strange to me that sparks seem to travel much further along the
surface of an insulator, no matter how clean it seems to be. Maybe this
is due to microscopic impurities on the surface of the plastic?

Another little trick that you probably have already figured out is to
insulate the input connections to the plates by rolling a few layers of
poly around them.

Cheers, Peter E.