On 5/18/2011 4:05 PM, Cecil Moore wrote:
On May 18, 2:33 pm, wrote:
Could you please explain why the lumped circuit approach used by many
people across the world presupposes faster than light propagation (as
I can't)?

http://hamwaves.com/antennas/inductance/corum.pdf

"The failure of any lumped element circuit model to describe the real
world lies at its core inherent *presupposition*: the speed of light
is assumed infinite in the wave equation."

"Lumped element circuit theory assumes that there are no wave
interference phenomena present, that is - the currents entering and
leaving the circuit element's terminals are identical."

http://www.classictesla.com/download...ed_failure.pdf

"In fact, lumped-element circuit theory inherently employs the
cosmological presupposition that the speed of light is infinite, as
every EE sophomore should know."

"Lumped circuit theory fails because it's a theory whose
presuppositions are inadequate. Every EE in the world was warned of
this in their first sophomore circuits course."

Give me some time and I will compose an example based on EZNEC results
for a lumped inductor vs a helical inductor of equal inductance. The
results are nowhere near the same.
--
73, Cecil, w5dxp.com


I'm not speaking for Wim, but I think we are both saying the following:

* You have a known load
* You have a transmission line with known characteristics
* Is is possible to use a Smith chart to get the impedance at the input
to the transmission line.
* We now know the load applied to the transmitter.

All we need to know we get from the chart. We admit that reflections are
responsible for the impedance transformation from load to line input.
But, we don't need to know anything about the reflection details, energy
content of the line, nor how light would like it.

So, we are saying that the load at the line input can be viewed as a
lumped circuit. So now we have a transmitter loaded with a lumped
circuit for further analysis.

That's all. It's simple.

John