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Re: Toroid Design .



Tesla List wrote:
> 
> Original Poster: Ed Phillips <evp-at-pacbell-dot-net>
> 
> "Ed -
> 
>   Isn't the  charge zero on the inside of the upper terminal during VDG
> operation? How can there be an "up hill" effect for the charge on the
> belt?
> I would consider it a "down hill" effect.
> 
>   The work to put the charge (100% eff) on the outside of the terminal
> is
> 
>      W = Q x V   joules per coulomb
> 
>   Have you found an equation to relate this work to the motor that would
> indicate the motor slows down as the voltage on the outside of the
> terminal
> increases?
> 
>   John Couture"
> 
>         Yep, the charge on the INSIDE of the upper terminal IS zero, but the
> VOLTAGE on the outside isn't!!!  Here is an analogy which at least hints
> at what is happening.  As the belt moves "up" (toward the upper
> terminal) you are moving LIKE charges to it; since like charges repel,
> it takes work to move them "up", and that work is stored as additional
> charge on the upper terminal.  As the voltage on the terminal increases,
> the "hill" is getting higher and the repulsion is getting greater, hence
> the greater load on the motor.  By the way, I built a small hand-cranked
> VDG once, and it was possible to see the belt "back away" from a
> highly-charged upper terminal when the crank was released.
> 
>         My eyes are on the blink at the moment, so don't feel like
sitting down
> at the desk and figuring, but shouldn't be much work to figure out the
> actual work being done.  Will give it a try when I'm doing better.
> 
> Ed

Note added 12/31/98:

	For a really neat animated illustration of charge transfer in a VDG
look at:

		http://www.pelletron-dot-com/charging.htm

Ed