Re: New cap. design
On Wed, 15 May 1996 21:32:25 -0600, Tesla List
<tesla-at-poodle.pupman-dot-com>, you wrote:
>>From i_hopley-at-wintermute.co.ukWed May 15 21:30:46 1996
>Date: Thu, 16 May 1996 00:09:12 +0100
>From: Ian Hopley <i_hopley-at-wintermute.co.uk>
>Subject: New cap. design
>Now my problem is this, i was origionally basing my cap. On the assumption
>of arround 1KV working voltage per pair of plates on 20 x 0.2 mfd caps in
>series. Each cap. Comprising 67 plates. giving me a final cap. Value of
>0.01mfd -at- 20KV working. But on the results of my experiments it appears that
>the film is capable of withstanding much higher voltages than was first
> If the breakdown voltage question cannot be answered then i shall do
>another destructive test, submerged in oil (the cap, not me (:-) ) and if
>so what should i assume to be the working voltage i.e. half the breakdown
I may not be the best person to answer your question on what
to do, but I can say what not to do;) Don't underestimate the voltage
you will be using. At least tripple the voltage rating of your cap.
I've blown a single 0.060" polyethylene cap at 15kV, a 3 layer
0.030" polyethylene cap at 15kV, and a 2 layer 0.060" polyethylene cap
at 15kV. Not to mention, 2 bypass caps made from 2 layers of 0.040"
At least in your case you are making your cap from many thin
layers of dielectric instead of a few thick layers. This improves the
E field handling properties of the cap.
Maybe, Richard can respond?