The Rest of the Story
On Mar 14, 7:53*am, Cecil Moore wrote:
Keith Dysart wrote:
Yes indeed. The reactance looking into the line. But
the reflected wave is not going into the line so this
is not a reactance that it sees.
Part of the reflected wave energy is going into the
reactance along with part of the forward wave energy
when the instantaneous interference between those two
waves is destructive at the source resistor. Anything
else would violate the conservation of energy principle.
That same energy is returned to the source resistor 90
degrees later as constructive interference. Your missing
energy is in the reactance.
Still handwaving. Show the expressions and the numbers
that make it balance. Otherwise, just handwaving.
Now you know why Hecht said
instantaneous power is "of limited utility".
I've known that for quite a while. It is because it is so
difficult to measure with optical signals.
Where the
instantaneous energy is at any point in time is a
complicated mess that you haven't solved.
Not at all. Follow the spreadsheet for a full accounting.
It is the average power that really matters and all the
average reflected power is dissipated in the source
resistor when the reflected wave is 90 degrees out of
phase with the forward wave but under no other conditions.
Averaging is a mathetical operation applied to a function.
In this case a function of time.
The underlying function of time conveys more information than
does just the average which is why just dealing with averages
can lead one astray.
Instantaneous power is completely irrelevant to the
average power data posted on my web page.
Well, it does disprove some of your claims so I can see
why you like to belittle it.
You are
saying that because my pickup has black tires, it
is not a white pickup. My article stands as written
with a disclaimer about any importance being attached
to instantaneous power.
See previous comment.
Walter Maxwell didn't deal with instantaneous powers.
Steven Best didn't deal with instantaneous powers.
To the best of my knowledge, the instantaneous power
straw man was invented by you for the purpose of
muddying the waters.
Your instantaneous power analysis is also incorrect
because you completely ignored the instantaneous
power in the system reactance. You have completely
ignored the role of destructive and constructive
interference. You cannot possibly understand where
the energy goes until you understand interference.
I observe that you have not provided any expansion
based on either reactance or interference that accounts
for the differences.
Most probably because it is not possible.
We have reached the end of the discussion road and
hashed it to death. If we are still in disagreement,
we are just going to have to agree to disagree.
Are you really going to let me be the last man standing
this time?
We shall see.
...Keith
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