Cecil Moore wrote:
John Popelish wrote:

K7ITM wrote:

What happens to that imbalance in charge? Where does it go? What do
we call something that behaves that way? What's so freakin' special
about that?


The charge briefly piling up and then being sucked out of such an
inductor is the same place charge piles up and is sucked out of parts
of a transmission lines with standing waves on them.


Seems you got sucked in by a myth, John. The forward current is equal
at both ends of the coil.

Now, cut that out! Standing waves have sinusoidal current swings that
vary in amplitude with location. Location includes the two ends of a
coil.

The reflected current is equal at both ends
of the coil.

Smile when you say that.

That takes care of any question of charge imbalance. There
simply isn't any.

Oh poo. At current nodes charge piles up and spreads out, on
alternating half cycles. For one half cycle, the pile is positive,
and for the next it is negative. This is a basic transmission line
concept. If transmission lines had no shunt capacitance, there would
be no place to put this charge. But there is, so it is no problem.
Whether the transmission line is coax, twin line or a slow wave helix
makes little difference. The process is similar. Isn't this what you
have been arguing?

Assume the coil is 90 degrees long and that the forward current is one
amp and the reflected current is one amp.

At one end of the coil, the forward and reflected currents are 180
degrees out of phase. The standing wave current is zero.

At the other end of the coil, the forward and reflected currents
are in phase. The standing wave current is 2 amps.

Okay.

Now do you see why standing wave current is considered not to be flowing?

I see how no current is considered to be flowing. Current is charge
flowing. AC current is charge flowing back and forth.

But I see how two waves going in opposite directions create a standing
wave where the magnitude of the sinusoidal current at different points
along the standing wave have different magnitudes. And that between
the nodes where the amplitude is zero, the phase of the current
variation is constant.