Re: Displacement Current Revisited


Personally, I find this discussion very relevant; but then again
I'm not the EE type this list seems well populated by.

I was actually looking for the Id equation, myself; Thank You

If I am applying the concept correctly, (no guarantee of that)
the equation implies phase shifted Id coaxial to I(real).

However, dE/dt is max as E crosses zero.
So I and Id are coherent.
However this applies only to the inductor,
in the situation of the TC toroid there must be (IMHO)
a longitudinal Id to ground plane as well as a radial
Id from space charge.

But the only one that would
conceivably not have a coherent I(real)
would be the last one.
Does anybody know if this is where
free air streamers arise from?
Or am I just oversimplifying?

Bryan Kaufman

Tesla List wrote:

> Original Poster: "John H. Couture" <COUTUREJH-at-worldnet.att-dot-net>
>   Greg, Terry, All -
>   Nothing apparently has happened to the notion that "displacement" currents
> are still considered to be caused by the changing E field. Cook gives the
> equation:
>     Id = (eo)(dE/dt)
>   Id = Displacement current density
>   (eo)(dE/dt) = per Maxwell's equations
>   Cook also says that "Maxwell's equations are grounded in experiments".
>   He also writes "we must be cautious, for phenomena presently unknown could
> well require modification of these equations in the future".
>   Does anyone know of new experiments that would have changed Maxwell's
> equations? How would this affect the electrical fields around Tesla coils?
>   This still leaves the question for coilers of how to measure the near and
> far electrical fields around a Tesla coil. Apparently this is also a
> question for radio engineers regarding radio transmitter antennas. The field
> strength meters are not capable of measuring the near fields. Terman says
> the near fields do exist and are stronger than the E fields near an antenna
> (Tesla coil). Obviously radio engineers would be more interested in the far
> fields than the near fields.
>   Is it correct that Malcolm's LED's were energized by the far fields and
> Bart's lamps were energized by the near fields. How can you prove this?
>   To my knowledge the above issues have not already been hashed out.
>   Is the above too theoretical, not proper, or of little interest for this
> List?
>   John Couture
> -----------------------------------