Re: capacitor idea

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

Original poster: "Chris Arnold by way of Terry Fritz <teslalist-at-qwest-dot-net>" <chris_arnold-at-msn-dot-com>

Rodney,

There's also another way to look at this idea.  In very nontechnical terms 
the higher dielectric constant of the material between the two high voltage 
layers does no good if it doesn't have most of the voltage stress across 
it.  The dielectric constant is a ratio of the effectiveness of a given 
dielectric to that of a complete vacuum.  If you are interested in more 
information on this subject there's a good deal of information in the 
following thread started about a month ago dealing with the capacitance of 
a multiple dielectric system.  In it is everything from simple explanations 
to fairly rigorous (as far as e-mail lists go that is) derivations of how 
that behaves.

http://www.pupman-dot-com/listarchives/2003/June/msg00129.html

Hope this helps.

Chris Arnold


>From: "Tesla list" <tesla-at-pupman-dot-com>
>To: tesla-at-pupman-dot-com
>Subject: Re: capacitor idea
>Date: Sun, 10 Aug 2003 20:47:30 -0600
>
>Original poster: "davep by way of Terry Fritz <teslalist-at-qwest-dot-net>" 
><davep-at-quik-dot-com>
>
>
>>Last night I was thinking and I got an idea about using multiple types 
>>dielectrics in a capacitor. ( I'd like to take this moment to say, I'm an 
>>amateur, I have no idea if any of this would work. Just thought it was 
>>worth asking about.)
>>What if you took 2 layers of something with a very high breakdown voltage 
>>(maybe some type of spray on/ paint on high voltage insulation) and 
>>placed a layer something with a high dielectric constant between the 2 
>>high voltage layers?  Could this result in a very small amount of space 
>>between the plates of the capacitor, and a high dielectric constant, 
>>there for a high capacitance and high break down voltage?
>         There is a subtlety here.  The overall voltage
>
>         will divide across the layers in nonobvious
>         ways.
>         If I Recall: the voltage across a given layer
>         depends on the dissipation factor (or is it the
>         dielectric constant?) and the thickness
>         (especially for RF).  Rather than 'just the
>         thickness'.   Put another way: the voltage
>         Will Not end up Conveniently across the high
>         withstand material...
>
>         Compound/composite dielectric systems have been
>         studied, and, sometimes, used in professional
>         work, however their applications are tricky...
>--
>         best
>         dwp