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Re: Capacitor charge, were is it?

On 10/28/96 22:25:27 you wrote:
>
>> Subject: Capacitor charge, were is it?
>
>> R. Hull post - All of the charge is held in the dielectric of the 
secondary
>> and not the
>> metallic components.  This is the case in all capacitors.  The plates can
>> never store charge!..  Only conduct it to a point where work can be done
>> electrodynamically.
>> 
>> If this is true we could not have a capacitor with a charge that has no
>> dielectric (vacuum).
>
>
>Richard Hull comments:
>
>AHA!  But the vacuum is a dielectric!!  yessiree...  Space (absolute 
>vacuum is endowed with both a dielectric constant (permittivity) and an 
>inductive nature (permeability) Eo and Uo.
>
>  The multiplacation of the permittivity and permiability of free space 
>yields the reciporical of the square of the speed of light.  This is one 
>of those classic mathematical identities which is true, but has no real 
>physical or causal meaning.  Just a fun identity.
>
>
>However did we come think that the charge was held on the plates when the 
>most no brainer of simple experiments would show it to be otherwise!!!!
>
>Richard Hull
>
>
>
>> We can, however, and the charge must be held on the plates. The energy is
>> stored in the electric field which can only be there if the plates have a
>> different charge from each other.
>
>
>They only have a differing charge due to the work that was performed on 
>the dielectric!  No real work was ever performed on the plates.  The 
>dielectric holds 100% of the charge.  R. Hull
>
>
> I recall a post of an experiment in which
>> a capacitor is charged, then carefully dismantled. The two metal plates
>> were handled, shorted together, then reassembled getting the charged
>> capacitor which can be shorted out yielding a large spark.
>> There must be something going on here that is not obvious.
>
>
>
>Yeah, real emperical experiment from which truths can be unearthed at a 
>core level not often considered in a world where we are told that the 
>"plates" are the thing.  Actually, a good physics school will make all 
>this manifest to advancing students.  They often, upon matriculating, 
>revert back to the plate concept of charge storage, however.  Often, only 
>upon being pressed, will they reflect back to the more theoretical 
>aspects of charge storage.  Richard Hull
>
>
<couple of big snips>
>

This thread is most interesting and stimulating.  The amount of energy 
stored in a capacitor is a function of the relative dielectric constant.  If 
you check the physics or chemistry handbook, you will find that water has 
the highest relative dielectric constant of just about any material.  So, I 
would conclude that for a capacitor of a given geometry, when water is used 
as the dielectric much more energy could be stored.

Why not make water filled caps for a TC rather than oil filled caps?

Phil Gantt

Phil Gantt (pgantt-at-ix-dot-netcom-dot-com)
http://www-dot-netcom-dot-com/~pgantt/intro.html