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RE: rolled caps (fwd)
---------- Forwarded message ----------
Date: Tue, 21 Apr 1998 07:47:26 -0700
From: Michael Baumann <baumann-at-proton.llumc.edu>
To: Tesla List <tesla-at-pupman-dot-com>
Subject: RE: rolled caps
*WHOA* Dr. R!
If you'll forgive me, what the heck is that comment about "compressing the
dielectric"?
Methinks you better doublecheck your knowledge base!
The doubling comes from the rolling true, but has nothing to do with
dielectric compression,
but more to do with the physical characteristics of the rolled cap (i.e. the
way the plates and dielectric are positioned with respect to each other.
In other words, our rolled caps are 2 electrode plates, and 2 dielectric
plates,
all of which get used, due to the rolling.
I can say this without fear, as i compress the holy living spit out of my
plate
caps, and I never see a x2 multiplier. After compression in
a vise, I strap with 1/4" lexan bolted across the edges - after comression
is
released I get a drop of about 10%.
Of course, now I need to step out on a limb: If you were to construct a
multiple layer rolled cap, I think you would find that the effective
capacitiance would be represented directly by the number of plates N,
instead of N-1. It just so happens that since rolled caps have N=2
and the normal equation is N-1=1, we have the cap value at 2x what we
expect.
Comments from anyone?
Michael Baumann
> ----------
> 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
>> 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. >