On Jun 8, 10:30*am, joe wrote:
Here is a thought experiment for you.

* * * * * * * * * *A * * * * *C * * * * *E
* * * *+----\/\/\--+--/\/\/\--+--/\/\/\--+--/\/\/\--+
* * * *| * * * * * * * * * * * * * * * * * * * * * *|
* * * --- * * * * * * * * * * * * * * * * * * * * * -
* * * *- * * * * * * * * * * * * * * * * * * * * * ---
* * * *| * * * * * B * * | * *D * | * * *F * * * * *|
* * * *+-----------+-----||---+---||-----+----------+
* * * * * * * * * * * * *| * * * *|

Four resistors, equal value.
Four DC sources, equal value.
Voltage A-B = 0, no power past here.
Voltage C-D = 0, no power past here.
Voltage E-F = 0, no power past here.

No power crossing the boundaries on either side of the resistor between
A and C. The resistor is not directly connected to a supply, how is it
dissipating power, if any?

(Yes, I do know the answer.)

the first step of the analysis of this circuit is to combine the 4
voltage sources into a single source, thus rendering point b,d,f
irrelevant. you can then analyze for the currents and voltages
through the 4 resistors easily and show that current flows one way
through all 4 of them equally. circuits 101, 2nd day.

On Jun 8, 6:30*am, joe wrote:
Keith Dysart wrote:
These simple thought experiments definitely helped my understanding.
Some of the assertions that have been made can be shown to be false
when tested with these waveforms and analysis.

...Keith

Here is a thought experiment for you.

* * * * * * * * * *A * * * * *C * * * * *E
* * * *+----\/\/\--+--/\/\/\--+--/\/\/\--+--/\/\/\--+
* * * *| * * * * * * * * * * * * * * * * * * * * * *|
* * * --- * * * * * * * * * * * * * * * * * * * * * -
* * * *- * * * * * * * * * * * * * * * * * * * * * ---
* * * *| * * * * * B * * | * *D * | * * *F * * * * *|
* * * *+-----------+-----||---+---||-----+----------+
* * * * * * * * * * * * *| * * * *|

Four resistors, equal value.
Four DC sources, equal value.
Voltage A-B = 0, no power past here.
Voltage C-D = 0, no power past here.
Voltage E-F = 0, no power past here.

No power crossing the boundaries on either side of the resistor between
A and C. The resistor is not directly connected to a supply, how is it
dissipating power, if any?

(Yes, I do know the answer.)

Very nice. How about:
A C E
+------+--/\/\/\--+--/\/\/\--+----+
| |
| |
| |
| B | D | F |
+------+-----||---+---||-----+----+
| |
In any case, ABCD do not form a network, being, in fact, two
disjoint networks. All bets are off.

Consider:

+------+--/\/\/\--+--/\/\/\--+----+
| |
| |
| |
| B | D | F |
+------+-----||---+---||-----+----+
| | |
-----
---
|
| A C E
+------+--/\/\/\--+--/\/\/\--+----+
| |
| |
| |
| | | |
+------+-----||---+---||-----+----+
| |
There can be current flowing at C and at D, as well as a large
voltage difference between C and D, but these have nothing to
do with each other and are not an indication of energy flow.

For Cecil, using Google Groups, look for 'Options' and select
'Fixed Font'.

....Keith

On Jun 8, 8:54*am, Cecil Moore wrote:
On Jun 8, 6:04*am, Keith Dysart wrote:

It is too bad, because the time domain is quite enlightening.

Nothing wrong with a time domain analysis but analyzing problems whose
basic premises violate the laws of physics is a waste of my time and
yours.

I assume that you do not consider that the problems you propose to be
ones "whose basic premises violate the laws of physics".

Consider then, the problem you propose in http://www.w5dxp.com/nointfr.htm.
A time domain analysis (http://sites.google.com/site/keithdysart/
radio6),
demonstrates that the analysis presented in http://www.w5dxp.com/nointfr.htm
results in the wrong answers.

Perhaps you could locate a flaw in the time domain analysis. Finding a
flaw
would pretty much settle the matter.

....Keith

On Jun 8, 8:33*pm, Keith Dysart wrote:
Perhaps you could locate a flaw in the time domain analysis. Finding a
flaw would pretty much settle the matter.

Everything I covered is covered in "Optics", by Hecht. If you can
locate a flaw, you need to convince Hecht (and Born & Wolf) to expand
their reference books to cover your pet subjects that they consider
"of limited utility".
--
73, Cecil, w5dxp.com

On 8 jun, 22:33, Keith Dysart wrote:
On Jun 8, 8:54*am, Cecil Moore wrote:

On Jun 8, 6:04*am, Keith Dysart wrote:

It is too bad, because the time domain is quite enlightening.

Nothing wrong with a time domain analysis but analyzing problems whose
basic premises violate the laws of physics is a waste of my time and
yours.

I assume that you do not consider that the problems you propose to be
ones "whose basic premises violate the laws of physics".

Consider then, the problem you propose inhttp://www.w5dxp.com/nointfr.htm..
A time domain analysis (http://sites.google.com/site/keithdysart/
radio6),
demonstrates that the analysis presented inhttp://www.w5dxp.com/nointfr.htm
results in the wrong answers.

Perhaps you could locate a flaw in the time domain analysis. Finding a
flaw
would pretty much settle the matter.

...Keith

Hi Cecil. Yes, good comment, definitions of terms specifying their
meanings in each context avoid innecessary disagreements. I think that
it is an essential predialogal "must".

Keith: I just saw your web page = http://sites.google.com/site/keithdysart/radio3
where you seems disagree (please correct me if I am wrong) with our
ideas about superposition principle. I search examples in the Net -for
not paid the price of my hard and slow translations ;)- What do you
think about them?

http://www.physics.ucla.edu/demoweb/...rposition.html

http://www.phy.ntnu.edu.tw/ntnujava/...php?topic=18.0

73

Miguel Ghezzi - LU6ETJ

On Jun 8, 11:27*pm, lu6etj wrote:
On 8 jun, 22:33, Keith Dysart wrote:





On Jun 8, 8:54*am, Cecil Moore wrote:

On Jun 8, 6:04*am, Keith Dysart wrote:

It is too bad, because the time domain is quite enlightening.

Nothing wrong with a time domain analysis but analyzing problems whose
basic premises violate the laws of physics is a waste of my time and
yours.

I assume that you do not consider that the problems you propose to be
ones "whose basic premises violate the laws of physics".

Consider then, the problem you propose inhttp://www.w5dxp.com/nointfr.htm.
A time domain analysis (http://sites.google.com/site/keithdysart/
radio6),
demonstrates that the analysis presented inhttp://www.w5dxp.com/nointfr..htm
results in the wrong answers.

Perhaps you could locate a flaw in the time domain analysis. Finding a
flaw
would pretty much settle the matter.

...Keith

Hi Cecil. Yes, good comment, definitions of terms specifying their
meanings in each context avoid innecessary disagreements. I think that
it is an essential predialogal "must".

Keith: I just saw your web page =http://sites.google.com/site/keithdysart/radio3
where you seems disagree (please correct me if I am wrong) with our
ideas about superposition principle. I search examples in the Net -for
not paid the price of my hard and slow translations ;)- What do you
think about them?

http://www.physics.ucla.edu/demoweb/...osition/waveSu...

http://www.phy.ntnu.edu.tw/ntnujava/...php?topic=18.0

Superposition works just fine for voltage and current, but is mostly
invalid for power. Attempting to apply superposition to power will
lead to inaccurate results.

From any circuit analysis, superposition is used to find the voltages
and the currents, and then the resulting total voltages and currents
are
used to compute powers. Doing it in the other order does not work.

I am curious as to what I wrote on the web page that suggested
disagreement with the superposition principle.

....Keith

On Jun 9, 7:44*am, Keith Dysart wrote:
On Jun 8, 11:27*pm, lu6etj wrote:





On 8 jun, 22:33, Keith Dysart wrote:

On Jun 8, 8:54*am, Cecil Moore wrote:

On Jun 8, 6:04*am, Keith Dysart wrote:

It is too bad, because the time domain is quite enlightening.

Nothing wrong with a time domain analysis but analyzing problems whose
basic premises violate the laws of physics is a waste of my time and
yours.

I assume that you do not consider that the problems you propose to be
ones "whose basic premises violate the laws of physics".

Consider then, the problem you propose inhttp://www.w5dxp.com/nointfr..htm.
A time domain analysis (http://sites.google.com/site/keithdysart/
radio6),
demonstrates that the analysis presented inhttp://www.w5dxp.com/nointfr.htm
results in the wrong answers.

Perhaps you could locate a flaw in the time domain analysis. Finding a
flaw
would pretty much settle the matter.

...Keith

Hi Cecil. Yes, good comment, definitions of terms specifying their
meanings in each context avoid innecessary disagreements. I think that
it is an essential predialogal "must".

Keith: I just saw your web page =http://sites.google.com/site/keithdysart/radio3
where you seems disagree (please correct me if I am wrong) with our
ideas about superposition principle. I search examples in the Net -for
not paid the price of my hard and slow translations ;)- What do you
think about them?

http://www.physics.ucla.edu/demoweb/...osition/waveSu...

http://www.phy.ntnu.edu.tw/ntnujava/...php?topic=18.0

Superposition works just fine for voltage and current, but is mostly
invalid for power. Attempting to apply superposition to power will
lead to inaccurate results.

From any circuit analysis, superposition is used to find the voltages
and the currents, and then the resulting total voltages and currents
are
used to compute powers. Doing it in the other order does not work.

I am curious as to what I wrote on the web page that suggested
disagreement with the superposition principle.

...Keith

I should have mentioned that the two references you provide are
superposing amplitude (i.e. voltage or current) and not power.

On Jun 9, 6:44*am, Keith Dysart wrote:
Superposition works just fine for voltage and current, but is mostly
invalid for power. Attempting to apply superposition to power will
lead to inaccurate results.

It is invalid to try to use superposition on scalar values. There is a
particular way to obtain the total power from the superposition of two
EM waves. It's called the power density equation and contains an
interference term, the sign of which tells us whether destructive,
constructive, or zero interference results when the two EM waves are
superposed. It agrees perfectly with calculating the total power from
the voltage and current end products of superposition. It would
explain everything that Roy is missing in his food-for-thought
article. I first saw this equation in Dr. Best's QEX article.

Ptot = P1 + P2 + 2*SQRT(P1*P2)*cos(A)

where A is the angle between the electric fields (voltages) of the two
superposed waves.

We get the same equation when we square the s-parameter equations.

(b1)^2 = (s11*a1 + s12*a2)^2, where (b1)^2 is the reflected power
toward the load.

(s11*a1 + s12*a2)^2 = (s11*a1)^2 + (s12*a2)^2 + 2(s11*a1)(s12*a2)

If it is not obvious, this is the same equation as the power density
equation above. The interference term in the squared s-parameter
equation contains phasors whose dot product involves cos(A), where A
is the angle between those two phasors. More s-parameter information
available below - Please note pages 16 and 17 involving powers.

http://www.sss-mag.com/pdf/hpan95-1.pdf
--
73, Cecil, w5dxp.com

Keith Dysart wrote:
On Jun 8, 11:27 pm, lu6etj wrote:
On 8 jun, 22:33, Keith Dysart wrote:





On Jun 8, 8:54 am, Cecil Moore wrote:
On Jun 8, 6:04 am, Keith Dysart wrote:
It is too bad, because the time domain is quite enlightening.
Nothing wrong with a time domain analysis but analyzing problems whose
basic premises violate the laws of physics is a waste of my time and
yours.
I assume that you do not consider that the problems you propose to be
ones "whose basic premises violate the laws of physics".
Consider then, the problem you propose inhttp://www.w5dxp.com/nointfr.htm.
A time domain analysis (http://sites.google.com/site/keithdysart/
radio6),
demonstrates that the analysis presented inhttp://www.w5dxp.com/nointfr.htm
results in the wrong answers.
Perhaps you could locate a flaw in the time domain analysis. Finding a
flaw
would pretty much settle the matter.
...Keith
Hi Cecil. Yes, good comment, definitions of terms specifying their
meanings in each context avoid innecessary disagreements. I think that
it is an essential predialogal "must".

Keith: I just saw your web page =http://sites.google.com/site/keithdysart/radio3
where you seems disagree (please correct me if I am wrong) with our
ideas about superposition principle. I search examples in the Net -for
not paid the price of my hard and slow translations ;)- What do you
think about them?

http://www.physics.ucla.edu/demoweb/...osition/waveSu...

http://www.phy.ntnu.edu.tw/ntnujava/...php?topic=18.0

Superposition works just fine for voltage and current, but is mostly
invalid for power. Attempting to apply superposition to power will
lead to inaccurate results.

From any circuit analysis, superposition is used to find the voltages
and the currents, and then the resulting total voltages and currents
are
used to compute powers. Doing it in the other order does not work.

I am curious as to what I wrote on the web page that suggested
disagreement with the superposition principle.

...Keith


I think the issue is the assertion there is no energy flow when I or V
is 0 is where people disagree.

I've tried to show with very simple (EE101) circuits that just because v
= 0 at some points in a circuit there is still energy flowing.

But, nobody apparently saw that.

The leap from v=0 to energy flow=0 is the source of contention. Just
because the amount of power sourced in one part of a circuit matches the
power dissipated in that portion does not mean that all the power
sourced in a portion of a circuit stayed in that portion to be
dissipated there. The whole rest of the circuit is involved.

When you do your Spice evaluation you only see the _net_ results of the
underlaying evaluation and note the _apparent_ lack of energy flow.

By selecting situations that give the results you want, you are
reinforcing the misperception. If the generators did not put out
identical pulses would you see the same lack of energy transfer?

A linear system, where superposition applies should not change based on
minor changes to the signals in it.

Limiting any analysis to steady state sine waves or uniform pulse trains
may cause you to reach the wrong conclusions.

On Jun 8, 11:05*pm, Cecil Moore wrote:
On Jun 8, 8:33*pm, Keith Dysart wrote:

Perhaps you could locate a flaw in the time domain analysis. Finding a
flaw would pretty much settle the matter.

Everything I covered is covered in "Optics", by Hecht. If you can
locate a flaw, you need to convince Hecht (and Born & Wolf) to expand
their reference books to cover your pet subjects that they consider
"of limited utility".

Let us follow the chain:
1. Hecht writes a book on OPTICS that includes some models.
2. Cecil reads the book.
3. Cecil interprets his readings.
4. Cecil applies his interpretations of the models to transmission
lines.
5. Cecil draws some conclusions on the behaviours.
6. Keith, using basic circuit theory, reflection coefficients and
analysis in the time domain, shows that Cecil's conclusions do not
align with expected behaviours.
7. Cecil says any disagreement with Cecil's conclusions is a
disagreement
with Hecht.

I suggest the error is more likely in steps 2 to 5; Hecht is, after
all,
well respected.

In particular, 4. seems like a candidate. It is quite possible that
Hecht understood the limitations of his models and that these models
do not align with the detailed behaviour on a transmission line,
though
they might be completely adequate for the behaviours with light that
Hecht was addressing in Optics.

One must always be careful when applying a model in a different
domain.

Cecil

....Keith