Re: capacitance formula

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "Jim Lux by way of Terry Fritz <teslalist-at-qwest-dot-net>" <jimlux-at-earthlink-dot-net>

At 08:33 AM 6/4/2003 -0600, you wrote:
>Original poster: "Ray von Postel by way of Terry Fritz 
><teslalist-at-qwest-dot-net>" <vonpostel-at-comcast-dot-net>
>As I read the question it related to the capacitance.  That has nothing to 
>do with the voltage.
>
>>In practice,  you would also use equalizing resistors across each capacitor
>>to equalize the voltage across the capacitors.
>
>Yes, but there are only two plates in this capacitor. Physically there is 
>only one capacitor. It consists of two plates separated by two different 
>dielectrics.
>Ray
>
>
>
>>The Captain
>>
>> > >I've been wondering what the capacitance between two conductive plates
>> > >separated by some distance that is filled with both a sheet of plastic
>> > >and some oil, where the plastic and oil have different dialectric
>> > >constants, and the thickness of each is different.

Consider that there is an infinitesimally thin virtual capacitor plate 
between the two dielectrics. As far as the fields go, it's the same. And, 
yes, the dielectric with the lower epsilon (dielectric constant) will have 
the lower capacitance and the higher voltage stress.  This is exactly the 
phenomenon that makes air bubbles in a dielectric evil.