The Rest of the Story
 

On Mar 26, 9:35*pm, Cecil Moore wrote:
Keith Dysart wrote:
Or perhaps the element you have identified does not have
the appropriate energy flow function? (It doesn't.)

Please prove your assertion.

So you are having difficulty doing the math to justify
your hypothesis.

This requires that the sum of the flows out of the
elements providing energy equals the sum of the flows
into the elements receiving the energy.

True for energy. Not true for power.

Ummmmm. Conservation of energy requires that the total
quantity of energy in the system not change. This requires
that the sum of the changes of the quantity of energy in
each element be zero. A change in energy quantity is a
flow. The energy flows must sum to zero. Energy flow is
power. The powers must sum to 0 to satisfy conservation
of energy.

And we are still waiting for the energy flow function
for the element that you claim is doing the storing
of the energy.

If you cannot understand the reference I gave you,
I don't know what to tell you.

You could simply do the derivation for an example that
demonstrates your hypothesis.

Does it detect energy? Are you sure?
Or is it voltage that it detects? Or current?

Please provide proof that voltage or current can
exist without energy.

I realize now that you were probably thinking of a TDR
that sent a pulse (I was thinking of one that sent a
step). My assertion is that when
Ptotal = Pfor - Pref
the idea that Pfor and Pref describe actual energy
flows is very dubious. Ptotal always describes an
energy flow.

When Pfor is 0, then Pref is equal to Ptotal and since
Ptotal is always describing an energy flow, Pref does
in this case as well. Similarly when Pref is 0.

-------

And now, since you are having trouble computing the
energy flows into the various elements here they are
again, for the circuit in the example of Fig 1-1, 100 Vrms
sinusoidal source, 50 ohm source resistor, 45 degrees of
50 ohm line, 12.5 ohm load, after the reflection returns...

The power flow into the line is
Pg(t) = 32 + 68cos(2wt)
and along with
Ps(t) = 100 + 116.6190379cos(2wt-30.96375653)
Prs(t) = 68 + 68cos(2wt-61.92751306)
energy is nicely conserved because
Ps(t) = Prs(t) + Pg(t)

The load presented by the line has a resistive and a
reactive component, so we can separate the power into
two parts
Pg.resis(t) = 32 + 32cos(2wt-61.92751306)
Pg.react(t) = 0 + 60cos(2wt+28.07248694)
which, for confirmation, nicely sums to Pg(t) above.

Now as I recall, your claim was that the total power
dissipated in the source resistor would be the power
dissipated before the reflection returned plus the
power imputed to be in the reflected wave plus the
power stored in and returned from some other element
in the circuit.
Prs(t) = 50 + 50cos(2wt)
+ Pr.g(t)
+ Pstorage
= 50 + 50cos(2wt)
+ 18 - 18cos(2wt)
+ Pstorage
Pstorage = 68 + 68cos(2wt-61.92751306)
- 50 - 50cos(2wt)
- 18 + 18cos(2wt)
= 0 + 36cos(2wt-90)
which is not the power function of the reactive
component of the line input impedance, Pg.reac(t),
computed above. So the energy is not being stored
in the reactive component of the line input
impedance.

...Keith

The Rest of the Story
 

On Mar 26, 9:51*pm, Cecil Moore wrote:
Keith Dysart wrote:
In other posts, you have suggested that this would be
a constructive interference energy and that there would
be an equal destructive interference energy to provide
it. If you still claim this, where is this destructive
interference happening?

I have said a source can match any destructive interference
by supplying less power and match any constructive interference
by supplying more power. If you have to falsify what I have
said to try to win the argument, you have already lost.
Since you have ample sources available in your example, my
assertion about interference far removed from any source
doesn't apply - but you know that.

I had not realized that you had these alternate sources for
the interference energies, not having seen that in your papers.

But it is one way to sidestep the issue; different rules for
the expectations of superposition and interference in different
scenarios.

I am surprised then, for the example of Fig 1-1 with 12.5 ohms,
that you don't just say "There is a source nearby, that *must*
be where the unaccounted energy comes from", and leave it at
that.

...Keith

The Rest of the Story
 

On Thu, 27 Mar 2008 11:49:03 GMT
Cecil Moore wrote:

Roger Sparks wrote:
The bottom line in a nutshell? I'll try.

Thanks Roger, good stuff and much appreciated.
My digesting of your spread sheets is about to
be interrupted by surgery.

Thanks for the kind words. Sorry to hear about your surgery. I hope it goes well and you have a quick recovery.

During those times, the power applied to
the transmission line is much HIGHER because the reflected wave reflects
from the load and source, and merges/adds to the forward wave from the
source.)

May I suggest that you use the word "redistributed"
instead of "reflected" as does the FSU web page at:

http://micro.magnet.fsu.edu/primer/j...ons/index.html

Clip

I think "redistributed" would be the word if the discontinuity included a resistance. "Reflection" is the historical word for wave reversal and implies a "mirror image", which is not the same as the forward image.

I hope the surgery does not take you away from the discussion for long.

--
73, Roger, W7WKB

The Rest of the Story
 

Keith Dysart wrote:
So you are having difficulty doing the math to justify
your hypothesis.

Actually no, the math is not difficult. I'm pre-
occupied with something else and think it's just
time to agree with Hecht that instantaneous power
is "of limited utility".

Have you taken a look at Roger's spreadsheets?

Conservation of energy requires that the total
quantity of energy in the system not change.

:-) Isn't the whole purpose of a transmitting
antenna to radiate energy away from the antenna
system? And that radiation continues to be "lost"
from the system space for some time after the
source power is removed?

Wouldn't you have to define the "system" as the
entire universe for your statement to be true?

The powers must sum to 0 to satisfy conservation
of energy.

That may be true, but there's still no conservation
of instantaneous power principle. A hot resistor
continues to radiate heat long after any power
source is removed.

You could simply do the derivation for an example that
demonstrates your hypothesis.

Already done on my web page. My only actual hypothesis
concerns average power. I've wasted too much time
bantering about something that Hecht says is "of
limited utility".

the idea that Pfor and Pref describe actual energy
flows is very dubious.

Again, look yourself in the mirror and tell yourself
that what you are seeing contains no energy. The
theory that some EM waves contain energy and some
do not is not new to you. Dr. Best was the first to
theorize that canceled waves continue to propagate
forever devoid of energy. Someone else asserted that
canceled waves never contained any energy to start
with. I strongly suspect that what you are seeing
in the mirror are the waves that didn't cancel and
that do contain energy. :-)

So the energy is not being stored
in the reactive component of the line input
impedance.

Assuming you have not made an error, so what? Energy
stored in the reactance is only one of the possibilities
that I listed earlier. As I said in an earlier posting
which you declared a non-sequitor (sic), one or more of
the following is true:

1. The source adjusts to the energy requirements.

2. The reactance stores and delivers energy.

3. Wave energy is redistributed during superposition.

4. Something I haven't thought of.

The ExH reflected wave energy exists and cannot
be destroyed. It goes somewhere and its average
value is dissipated in the source resistor in
my special case example. You are attempting to
destroy the reflected wave energy using words
and math presumably knowing all along that
reflected wave energy cannot be destroyed.
--
73, Cecil http://www.w5dxp.com

The Rest of the Story
 

Keith Dysart wrote:
I had not realized that you had these alternate sources for
the interference energies, not having seen that in your papers.

I only posted it three times here and you chose to
ignore all of those postings. I have published only
one paper with three more to go. The special case
Part 1 contains zero average interference so there
is no alternate source for average interference and
indeed, none is needed for Part 1.

But it is one way to sidestep the issue; different rules for
the expectations of superposition and interference in different
scenarios.

That's why I have four parts only one of which has
been published. The rules are not different but the
conditions within the examples are different. Part 2
will be an example with the condition of average
destructive interference existing at the source
resistor. Although there are no ordinary reflections
because the reflection coefficient is 0.0, there will
exist something that looks a lot like a reflection
caused by superposition/interference. The FSU web page
calls it a "redistribution", not a "reflection".
I am satisfied with FSU's word "redistribution" for
the results of coherent wave interaction.

I am surprised then, for the example of Fig 1-1 with 12.5 ohms,
that you don't just say "There is a source nearby, that *must*
be where the unaccounted energy comes from", and leave it at
that.

Since my special case example contains zero average
interference, the average power output of the source
is constant and unaffected by zero interference.
There is zero average energy unaccounted for.

Part 2 will illustrate the source adjusting its power
output to compensate for destructive interference.
--
73, Cecil http://www.w5dxp.com

The Rest of the Story
 

Roger Sparks wrote:
I think "redistributed" would be the word if the discontinuity
included a resistance. "Reflection" is the historical word for
wave reversal and implies a "mirror image", which is not the same
as the forward image.

What I am suggesting is that "redistribution" be used
instead of "reflection" for cases where there exists
no discontinuity. If the source resistor matches the
Z0 of the feedline, there is no discontinuity and
therefore no conventional reflection, yet there are
cases where reflected energy is redistributed back
toward the load. That reversal appears to be a reflection
but is actually the result of superposition along
with destructive interference between *two* waves.
That is what causes the disparity between the physical
reflection coefficient, (Z1-Z2)/(Z1+Z2), and the virtual
reflection coefficient, SQRT(Pref/Pfor).

I hope the surgery does not take you away from the discussion
for long.

At the least, I should still have one good eye left. ;-)
--
73, Cecil http://www.w5dxp.com

The Rest of the Story
 

Cecil Moore wrote:


What I am suggesting is that "redistribution" be used
instead of "reflection" for cases where there exists
no discontinuity.

This is sad.

But I suppose that if you are going to invent new science you might as
well invent new terminology as well. 8-)

Yes, I know that the now-famous FSU web page uses "redistribution". Did
you happen to notice that the page was created by a lab tech and a Java
programmer? Do you suppose Hecht, Born and Wolf, and all of the other
acknowledged experts would support dumping "reflection"?

73,
Gene
W4SZ

The Rest of the Story
 

Gene Fuller wrote:
Yes, I know that the now-famous FSU web page uses "redistribution".
Do you suppose Hecht, Born and Wolf, and all of the other
acknowledged experts would support dumping "reflection"?

I would guess the answer is "yes" when the physical
reflection coefficient is zero - in order to avoid
a logical contradiction.

How does a "reflection" occur when the physical reflection
coefficient is zero, in violation of the wave reflection
model? Why is there often a difference between the
physical reflection coefficient and the virtual
reflection coefficient? Which one is wrong?

The convention that I have adopted is that the word
"reflection" is reserved for single wave events.

For multiple wave events where interference exists,
something besides a simple "reflection" takes place.
The intricate color patterns on the surface of a thin
film of oil floating on a puddle of water are not
simple reflections but instead an interaction of
multiple reflected waves. The resulting image bears
absolutely no resemblance to the incident image.

Following the FSU web page usage, the word "redistribution"
is used for multiple wave interaction events like wave
cancellation. (The words we choose to use to describe the
phenomena have zero effect on the phenomena.)

"A rose by any other name would smell as sweet."
--
73, Cecil http://www.w5dxp.com

The Rest of the Story
 

Gene Fuller wrote:
Did you happen to notice that the page was
created by a lab tech and a Java programmer?

Gene, if a tech asserts a fact and an expert
asserts a falsehood, who are you going to
choose to believe?
--
73, Cecil http://www.w5dxp.com

The Rest of the Story
 

On Mar 27, 6:44*pm, Cecil Moore wrote:
Gene Fuller wrote:
Did you happen to notice that the page was
created by a lab tech and a Java programmer?

Gene, if a tech asserts a fact and an expert
asserts a falsehood, who are you going to
choose to believe?

The simulator at that web site does seem to have
its issues. Ask it to simulate 700 nm + 680 nm
at the same amplitude and see if the result
represents reality.

...Keith

PS. The result should look like a 689.8 nm sine
wave of continuously varying amplitude.