Standing-Wave Current vs Traveling-Wave Current
On Dec 28, 9:56*am, Cecil Moore wrote:
Keith Dysart wrote:
The cuts changed nothing about the conditions in the circuit.
This reminds me of the guru who asserted that he could
replace his 50 ohm antenna with a 50 ohm resistor
without changing the conditions.
And yet the claim is made that before the cuts there are no
reflections and after the cut there are a bunch. And yet the
conditions in the circuit are EXACTLY the same.
No, conditions are not exactly the same. Before the
cut, there were no reflections. After the cut, there
are reflections. Conditions have changed. I'll bet
the change in the natural noise pattern, which exists
in every system, could be detected at the time of
the cut.
It is good that you agree that the voltage, current
and power distributions are exactly the same, with
and without the cuts. These are the conditions to
which I refer.
It is no different than a connected capacitor and inductor
which will ring for ever given the appropriate initial
conditions.
If we are talking about things that can happen only in your
mind, why stop with irrelevant ringing assertions? Why not
assert that you can leap tall buildings at a single bound
(in your mind)?
I suppose this non-sequitor means that you agree that
an ideal section of transmission line, just like an
ideal inductor and capacitor, will store energy forever
if provided with the appropriate initial conditions,
but do not wish to admit it.
An intriguing thought experiment is to take several
of these sections with stored energy (with the proper
phase relationship) and connect them together. Do
the reflections present at the ends of the short
sections suddenly disappear when the sections
are connected to form a longer line? Are the
reflections now only occurring at the ends of
the longer section?
...Keith
|