"Richard Clark" wrote in message
...
On Sun, 29 Apr 2007 15:36:43 -0500, "amdx" wrote:

This is then a characteristic of the Capacitor called D (dissipation).
Any increase in current tied to loss immediately goes to the bottom
line of resistance - it is a square law relationship, after all.

So your saying yes, the thought experiment would show more loss,
but the loss is in the capacitor. The loss in a capacitor would be
dielectric
and loss in the plates right?

Hi Mike,

Depending upon construction, most assuredly. However, little loss is
found in dielectrics (unless you are using particularly crummy
examples). For bad dielectric, you can expects arcs and sparks
followed by carbon, and then catastrophic heat accumulation. Most
lost is in what is specified in ESR (effective series resistance)
which you have already identified as in the plates, but often more in
the leads and their connections to the plates. To pack in more
capacitance, the trend is for thinner plates for a given package
volume. You can guess where the resistance will rise there when the
circulating currents are see-sawing in that thin metal.

I gave you a little bit of a trick question when I ask,

The loss in a capacitor would be dielectric and loss in the plates right?

In my inductor the interwinding capacitance is made of a dielectric
(some type of insulation and air) and the plates (made by the wire).
The wire has more current because of that interwinding capacitance,
and as you say "loss is by the square".
Is my argument moving you at all?



(let's not get into radiation resistance right now)

Why not? Small loops suffer by comparison, and multi-turn loops even
more so.

I figure it would only confuse the issue.
I was trying to stay away from radiation resistance because my experience
of
the effect Bill ask about has been with small aircore inductors. But on
second thought
even those have Rr.

The smaller, the worse. It is not so much about the size of Rr, but
its relation (ratio) to Ohmic loss. For instance, a 1 meter loop
composed of #40 wire is going to be deaf and dumb at 80M, but you
might have a chance with 10cM hollow pipe with tight connections. Both
exhibit the same Rr, but the wire's Ohmic loss is clearly deadly in
comparison to it, than for the pipe's Ohmic loss. Rr in this band,
for this size, runs on the order of 0.0075 Ohms.

Why does the resistance go up near resonance?

I haven't seen that happen.
Try measureing the Q of an aircore coil close to it's self resonance
(or worse, at self resonance without an additional capacitor)
and then at half that frequency.

However, for the same resistance, as you
approach resonance, the circulating currents climb, and loss is by the
square.

I'm defining circulating currents as those that circulate between turns
and don't necessarily go through the capacitor used to resonate the coil.
Does that fit your definition as used in your paragraph above?

Thanks, Mike