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Re: rolled caps (fwd)
---------- Forwarded message ----------
Date: Wed, 22 Apr 1998 06:56:23 -0500
From: Bert Hickman <bert.hickman-at-aquila-dot-com>
To: Tesla List <tesla-at-pupman-dot-com>
Subject: Re: rolled caps
Tesla List wrote:
>
> ----------
> From: D.C. Cox [SMTP:DR.RESONANCE-at-next-wave-dot-net]
> Sent: Monday, April 20, 1998 9:04 AM
> To: Tesla List
> Subject: Re: rolled caps
>
> to: Kevin
>
> The two equations are equivalent -- the units conversion factor of 10^7
> just makes them look different.
>
> Regarding your rolled up caps -- when you roll the caps very tightly you
> compress the dielectric thus reducing it to 1/2 its normal thickness. A
> 1/2 appears in the demoninator which goes "upstairs" to appear as a 2 x
> the final value. If you use 1/2 the unstressed thickness as the "d" in
> your equation you will get the right values on the first calculation
> without multiplication being necessary.
>
> DR.RESONANCE-at-next-wave-dot-net
>
> ----------
<SNIP>
D.C. and all,
I suspect it has more to do with the fact that you actually have a
foil-dielectric-foil-dielectric-foil sandwich, so that when the cap is
rolled it won't short out. The number of foil layers ("N") is 3 so so
that the N-1 factor becomes 2 for rolled caps.
-- Bert --