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Re: Cap problems (fwd)
---------- Forwarded message ----------
Date: Thu, 27 Feb 1997 07:36:17 -1200
From: Ken Smith <ksmith-at-ihug.co.nz>
To: Tesla List <mod1-at-pupman-dot-com>
Subject: Re: Cap problems (fwd)
At 22:48 25/02/97 -0700, you wrote:>>Hi,
>Well I dont have any al flashing either, so I used cooking foil instead.
>
>My cap is 0.03uF with 40 mils of poly between the plates and works very
>well
>on 11KV. Coaxial design.
>
>When constructing the cap using foil it is very important to ensure a
>good
>connection along the entire length of the foil if self inducance and
>resistive losses are to be reduced. The way I achieved this is to allow
>the edge of the foil plates to extend beyond the poly down the length
>before
>rolling. After rolling the foil forms two terminals at each end.
>
>I roll my cap around a lenght of copper water pipe which has been
>insulated over nearly all its lenght except for the ends (wrap poly
>around the pipe and stick down with tape). One foil end can then be
>clamped down to make contact with the bare end of the pipe using a
>hose pipe clip. The other end clamped down using a second hose pipe
>clip, but clamp down on a insulated section of the pipe.
>Connection straps can be slipped under the clip before tightening.
>The whole thing is then put into a length of PVC pipe caped at one end.
>
>Fill with oil and pump down to extract any trapped air.
>
Julian,
Thanks for that - it was the insight I needed. The copper pipe
centre is the key. My problem with using al foil has been the delicacy of
the stuff when it comes to forming terminals. Using the pipe up the centre
as the 2nd terminal will do the trick. Did you find you need any special
insulation on that - or just a few turns of tape ?
Anyway. I will pop out to the supermarket this morning and have a go at
that. Thanks again...
Ken
Ken Smith
Weymouth
Auckland
http://homepages.ihug.co.nz/~ksmith
ksmith-at-ihug.co.nz