Re: Capacitor check (fwd)
---------- Forwarded message ----------
Date: Thu, 23 Apr 1998 19:48:25 +0100
From: Vivian <V.C.Watts-at-btinternet-dot-com>
To: Tesla List <tesla-at-pupman-dot-com>
Subject: Re: Capacitor check (fwd)
From: Tesla List <tesla-at-pupman-dot-com>
To: tesla-at-pupman-dot-com <tesla-at-pupman-dot-com>
Date: 23 April 1998 19:13
Subject: Capacitor check (fwd)
>---------- Forwarded message ----------
>Date: Thu, 23 Apr 1998 14:48:27 MYT
>From: Sulaiman Abdullah <sulabd-at-hotmail-dot-com>
>Subject: Capacitor check
>I'm about to assemble my flat-plate capacitor, almost all materials
>ready and waiting for your feedback!
>My main question is regarding tracking-length;
>I designed the capacitor (PE and Aluminium) to have 1" space to
>the 'edges' and 2" to the 'ends'.
>I certainly expect 30 kV peak, and I'd value all your opinions
>as to whether this is enough allowance, and would you care to
>'guestimate' what clearance would produce a RELIABLE capacitor
>for 50 kV peak. Assume I'll clean all parts fairly well and
>vacuum out most air-bubbles.
>I asked this question a while ago in a different way, I'm asking
>again because I REALLY don't want to waste a significant ammount
>of my hard-earned cash! Thanks...... Sulaiman
I built my flat-plate capacitor with Polystyrene Sheets 24" * 16".
I originally had, as you have described, 1" space to the 'edges' and
2" to the 'ends'. I ran the TC with a 10Kv 50ma xfmer. After a few runs
the capacitor broke down by tracking at the ends. I was able to dismantle
the capacitor because I made it dry (no glue).
An original prototype I made with varnish sticking the Aluminium and
sheets together had too many bubbles so I scrapped it before even using it.
Using new plastic with the protective cover just being removed and clean
conditions actually produced the capacitance with about two thirds the
of plates of the glued variety.
I now have 2" space on the edges and 4" at the ends. I had obviously to use
more plates to achieve original capacitance of 0.015uf as the area was
No problems since.
Viv Watts UK.