Standing-Wave Current vs Traveling-Wave Current
 

Roger wrote:

I see your example as identical to Keith's example of two wave pulses
traveling in opposite directions.

Not quite. The voltage following a pulse is zero; with my sine wave
example the source continues producing a sine wave at all times while
wave interaction is occurring.

At the point of interaction, Keith's example has a reflection factor of
1 or zero, depending upon whether the waves bounce or pass. Keith's
example is not a short circuit because two pulses of identical polarity
are interacting so a reflection factor of -1 could never exist.

Because there are no mathematics and, as far as I can see, no mechanism
for wave interaction, I can't discuss Keith's example except from the
standpoint that the waves don't interact. (Excluding, of course,
superposition from the meaning of "interact".)

In your example, the presence of voltage from the ideal source creates
conditions identical to Keith's example for the returning reflected
wave. Accepting this premise, then the reflection factor must be either
1 or zero, depending upon whether the waves bounce or pass.

Sorry, I don't accept the premise.

By assuming that the waves reflect at the ideal source, you proved that
the reflection factor is -1, which is the factor for a short circuit.

Yes, that is correct.

This can not be the case, so waves must not reflect at the ideal voltage
source, they must pass.

Well, yes it can be the case, and is. But let's see where rejection of
this fact leads.

vtot(t, 0) = vf(t, 0) + vr(t, 0)

= sin(wt)tot = sin(wt) + sin(wt)

= 2*sin(wt)

Someone will certainly say the the vtot(t,0) at the source location is
the source voltage, because it is defined that way.

I certainly say that.

The conditions at
point (t,0) itself is actually unknown (because vf mysteriously appears,
and vr disappears by going off the transmission line), but point (t, 0)
is defined by assumptions. Therefore, at

vtot(t, 0) = vf(t, 0) + vr(t, 0)

= sin(wt)tot = sin(wt) + sin(wt)

= 2*sin(wt)

So by rejecting the fact that the waves reflect at the ideal source,
you're forced to conclude that the voltage at the output of a perfect
source is unknown, with waves "mysteriously" appearing and disappearing.
It also appears that you've violated Kirchoff's voltage law at the
input. My analysis requires no such contradictions, unknown voltages, or
mysteries. As an engineer, I like my analysis a whole lot better,
because it can give me answers which are testably correct.

Can you use your theory to show the voltage at all times at the input
or, if you choose, just inside the input of the line, as I've done using
conventional theory?

I've used SPICE to verify my analysis. If I modify the SPICE model to
show the voltage just inside the line, do you think it will show the
voltage to be 2*sin(wt)? SPICE makes no assumptions about waves,
bouncing or not, so if it shows sin(wt) (as it certainly will), where do
you think its error is?

Roy Lewallen, W7EL

Standing-Wave Current vs Traveling-Wave Current
 

Cecil Moore wrote:
Gene Fuller wrote:
The entire point of s-parameter analysis is that the "network" can be
treated as a black box, ...

Gene, I cannot find anywhere in the s-parameter information
where some of the network must be hidden inside a black box.
I always thought an s-parameter analysis could be done without
a black box. Could you help us out here and point out exactly
where it says a black box is a requirement. Seems to me the
purpose of an s-parameter analysis is to alleviate ignorance
which obviously doesn't match your agenda.

Why don't you try your favorite s-parameter reference, AN 95-1, page 6?

Since you are playing words games again by changing "can be treated"
into "requirement", I suppose you already are well aware of what AN 95-1
says.

73,
Gene
W4SZ

Standing-Wave Current vs Traveling-Wave Current
 

Gene Fuller wrote:
My definition of "sloshing" is as I stated.

Look up "slosh" in the dictionary and then get
back to us.
--
73, Cecil http://www.w5dxp.com

Standing-Wave Current vs Traveling-Wave Current
 

Roger wrote:

By my using the words 'power' "storage factor", you got my point, hence
the reaction.

Before dismissing the concept of "storing power", consider that when
discussing a transmission line, it could be a useful description.

As you know, power is energy delivered over a time period.

No, it's the rate of energy delivery or movement, which is not quite the
same thing.

It always
carries a time dimension having beginning and end. Power(watt)
=v*i/(unit time) = 1 joule/second.

Sorry, you've got this wrong. One watt is indeed one joule/second, but
P(t) = v(t) * i(t), period. Energy is the integral of P(t) dt. Power is
the time derivative of energy, or dE(t)/dt where E is the energy.

You could as reasonably say that energy always "carries a time
dimension". After all, one joule = 1 watt-second.

In the example you give of charging a capacitor, the time dimension is
lost, so you are correct that only energy is conserved. Power is lost.

Sorry, I don't understand that.

With a transmission line, we have an entirely different case. Here
power is conserved because the time information is maintained. Power is
stored on the line during the period it resides on the line. For
example, we excite the line at one end and some time period later find
that power is delivered to some destination. During the time period
that the power was on the line, the information that defines the energy
distribution over time has been preserved.

Ok, let's test this. Please tell me exactly how many watts are stored on
the line of the second analysis (where the perfect source is in series
with a 150 ohm resistor). Next, tell me how many watts will come out of
the line if we quickly disconnect the perfect source and source
resistance and replace it with:

A: A 50 ohm resistor, or
B: A 150 ohm resistor

If power is stored, we implicitly store energy. Energy is v*i measured
in joules without a time factor.

No, Energy is not v*i. Power is v*i. Energy is the time integral of v*i.
Power is not stored; energy is.

Obviously we store energy on a
transmission line when we store power.

I guess it would be obvious if you believe you can store power. But
before going further, please demonstrate what you mean by calculating
how many watts of power are stored on the example line. I showed exactly
how many joules of energy were stored, you can show how many watts of power.

So if in the future, I use the term "power storage", please take it to
mean that energy distributed over time is under consideration.

I'm afraid I'm not very good at translating what people mean when they
say something else. Why not call energy storage "energy storage", power
"power", and energy "energy"? Then I and hopefully other readers will
know what you mean. The MKSA unit of power is the watt, and of energy,
the joule. The two are no more the same than speed and distance, or
charge and current.

I hope
the term might be useful to you as well.

No, I have enough trouble communicating when I take great care with my
terminology. The last thing I need is to be saying something which means
something else -- or means nothing at all. When I mean energy storage,
I'll say "energy storage", thank you.

Roy Lewallen, W7EL

Standing-Wave Current vs Traveling-Wave Current
 

Gene Fuller wrote:
I suppose you already are well aware of what AN 95-1
says.

Yes, nowhere can I find where a black box is required
for the purpose of hiding part of the system from the
observer.

When a concept is used to alleviate ignorance, it is good.
When a concept is used to promote ignorance, it is bad.
What you are trying to do is pretty obvious.
--
73, Cecil http://www.w5dxp.com

Standing-Wave Current vs Traveling-Wave Current
 

Gene Fuller wrote:

Cecil,

If your only concern is the definition of "sloshing", then about 100,000
messages have been wasted.

My definition of "sloshing" is as I stated. I believe that Roy would
have the same definition. If your definition involves the speed of
water, then I have no idea why that topic would be relevant here.

I've used the term a few times in this forum, and in the context exactly
as you explained, clearly, in your previous posting. And as I also have
explained several times in this forum since I first used it to describe
energy in a line with infinite SWR in a posting in December 2002. But
you can fully expect to see the question asked again and again as it has
been over the intervening five years. This is a good example of the
reason I plonked Cecil some time ago.

I don't see Cecil's postings unless quoted by someone else, nor do I
consider it anything but a waste of time and cause of pointless
frustration to respond to him unless the answer would also potentially
benefit other readers. So no one should interpret my lack of response to
anything he directs to me as any sort of endorsement or agreement.

Roy Lewallen, W7EL

Standing-Wave Current vs Traveling-Wave Current
 

Roy Lewallen wrote:
I've used the term a few times in this forum, and in the context exactly
as you explained, clearly, in your previous posting.

You really should have looked up the definition in the
dictionary before willy-nilly using it. FYI, it is impossible
for EM energy to slosh.

I don't see Cecil's postings unless quoted by someone else, nor do I
consider it anything but a waste of time and cause of pointless
frustration to respond to him unless the answer would also potentially
benefit other readers. So no one should interpret my lack of response to
anything he directs to me as any sort of endorsement or agreement.

You still haven't posted the equation for standing wave
current and explained how you used that current to make
your phase/delay measurements through a 75m bugcatcher
loading coil. Pretty convenient that you can ignore my
postings, huh?
--
73, Cecil http://www.w5dxp.com

Standing-Wave Current vs Traveling-Wave Current
 

On Thu, 03 Jan 2008 20:58:52 GMT, Cecil Moore
wrote:

Richard Clark wrote:
There is a vast gulf between seeming and proving.

Richard, you seem to exist. Please prove that you
indeed do exist.

Gad, with built-in failures of logic like this question, it is SO, SO
easy, I can do it in stereo:

First, I can pinch myself: corporeal reality! However, you are just
amusing words on a screen that I can erase at will, hence you are a
figment of the imagination - the essential seeminess.

Second (this is the same mystery investigated as the Chinese Room
Argument), your messages only appear to be intelligent. Subsequent
correspondence reveals that to be a fiction.

What a pair of slam dunks for the home team.

Want to go for the trifecta?

Both the first and second tests can be independently corroborated by a
multitude of other posters here!

Dubito Tu Es

Standing-Wave Current vs Traveling-Wave Current
 

On Thu, 03 Jan 2008 17:58:51 -0600, Cecil Moore
wrote:

Pretty convenient that you can ignore my
postings, huh?

You still haven't demonstrated how to balance the energy equations for
a battery in one pocket, and a mouse in the other.

Pretty convenient that you can ignore my postings, huh?

Standing-Wave Current vs Traveling-Wave Current
 

Richard Clark wrote:

...
You still haven't demonstrated how to balance the energy equations for
a battery in one pocket, and a mouse in the other.

Pretty convenient that you can ignore my postings, huh?

Remove the Dick in the way?

They do call you Dick for short, don't they? ROFLOL

JS