Re: Is toroid a Faraday cage?

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

Original poster: "Dave Larkin by way of Terry Fritz <twftesla-at-qwest-dot-net>" <teslaman15-at-hotmail-dot-com>

Antonio, Dave, All,

There is a large and easily observable increase in the drag on the belt of a 
Van De Graaff generator as the terminal voltage increases.  A large ~1MV 
generator I had the privilege of operating a while back showed a ~200% 
increase in drive motor current draw from start-up to full charge.  On badly 
designed or 'overdriven' generators one sometimes sees sparks between the 
belt and the sphere at the point where the belt enters the sphere, 
testifying to the high electric field gradient in that area.

Jolyon,

Your concept of 'infinite electrical suction' seems to be something of a 
misconception.  There can be no _electric field gradient_ inside of a hollow 
conductor, that is a very different thing from there being no charge.

-Dave-


>From: "Tesla list" <tesla-at-pupman-dot-com>
>To: tesla-at-pupman-dot-com
>Subject: Re: Is toroid a Faraday cage?
>Date: Wed, 12 Jun 2002 21:34:31 -0600
>
>Original poster: "Antonio Carlos M. de Queiroz by way of Terry Fritz 
><twftesla-at-qwest-dot-net>" <acmq-at-compuland-dot-com.br>
>
>Tesla list wrote:
> >
> > Original poster: "davep by way of Terry Fritz <twftesla-at-qwest-dot-net>"
><davep-at-quik-dot-com>
>
> >         A pretty question.  Has anyone measured increased
> >         belt drag in a van de Graaf?
> >         (I'm not saying it doesn't happen, just not sure...)
>
>There is surely a drag, as the belt moves charges against the electric
>field, increasing the energy stored at the terminal. This energy comes
>from the mechanical energy spent to move the charges against the field.
>
>Antonio Carlos M. de Queiroz




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