Re: Multi-Rolled Cap

To: tesla-at-poodle.pupman-dot-com
Subject: Re: Multi-Rolled Cap
From: Tesla List <tesla-at-stic-dot-net>
Date: Sun, 25 May 1997 22:13:14 -0500
Approved: tesla-at-stic-dot-net

Subject:  Re: Multi-Rolled Cap
  Date:   24 May 97 05:29:33 EDT
  From:   Alan Sharp <100624.504-at-CompuServe.COM>
    To:  "INTERNET:tesla-at-pupman-dot-com" <tesla-at-pupman-dot-com>

>> I have been following the posts on
>> building caps and I understand the
>> advantages of putting caps in series.
>> 
>> Let me represent 4 caps in series as
>> 
>> -----||---||---||---||-----
>> 
>> This is equivalent to:
>> 
>> ----|||||------
>> 
>> That is why not make a sandwich of 5 plates
>> of Al foil seperated by polythene sheets.
>> No connections are made to the 3 inner plates.
>> This would be very dificult in a rolled cap,
>> because of the number of layers. But easier
>> in a flat cap. 

>This is routinely done since the turn of the century in virtually 100%
>of
>all flat plate type mica condensers.  I have constructed several
>polystyrene
>caps like this for use at 5KVAC.  Works great.

>Richard Hull, TCBOR

Thanks, Tom, Richard, Robert for your comments. Tom's right if you have
single sheets of polythene seperated by conducting sheets then
effectively all the imperfections are in line - ZAP. (This is also a
problen for caps in series). I was staggering the layers to reduce
the electrical gradient between the layers. 

If I build it then I may use 3 thin layers of poly between each foil
plate. But I'm hoping my surplus caps will hold.

Have fun,

Alan Sharp.