Tim:
Let's say that I admit all that you present.
The fundamental question still stands.,
Why do we insist on producing conductors composed of very expensive
core materials, when we could achieve the same effect, or better, by
coating the core material with a highly conductive skin?
On Fri, 15 Jun 2007 20:48:22 -0500, Tim Daneliuk
wrote:
Tom Watson wrote:
On Fri, 15 Jun 2007 20:26:23 -0500, dpb wrote:
The electric utilities spend a great deal on research and I spent a
sizable fraction of my career in the utilities business working w/ EPRI
(Electric Power Research Institute, a utility-funded R&D organization)
in the I&C and Transmission & Distribution areas and if the concept was
considered very high on the list, it would have received funding for at
least theoretical work. To the best of my knowledge it hasn't.
The problem with those who are educated is that they have been trained
off the obvious.
Their predilection is to assume the veracity of the precedent, without
question.
I'm asking you to revisit the fundamental assumptions.
I'm not sure where you're going with this. Skin Effect is
not an "assumption" - it can be calculated and probably even
measured. From http://en.wikipedia.org/wiki/Skin_effect we
get this (near the end of the article):
In copper, the skin depth at various frequencies is shown below.
frequency depth
60 Hz 8.57 mm
10 kHz 0.66 mm
100 kHz 0.21 mm
1 MHz 66 µm
10 MHz 21 µm
In Engineering Electromagnetics, Hayt points out that in a power station
a bus bar for alternating current at 60 Hz with a radius larger than
1/3rd of an inch (8 mm) is a waste of copper, and in practice bus bars
for heavy AC current are rarely more than 1/2 inch (12 mm) thick except
for mechanical reasons. A possible solution to this problem consists of
using cables with multiple insulated conductors. A thin film of silver
deposited on glass is an excellent conductor at microwave frequencies.
----------------------
Note that multi-wire transmission lines for very high power shortwave
transmitters (and their attendant power supply lines) make use of this
fact today. So .... where are you going, I wonder ...
Regards,
Tom Watson
tjwatson1ATcomcastDOTnet (real email)
http://home.comcast.net/~tjwatson1/