Keith Dysart wrote:
Your imcompleteness is that you forgot to include the
energy flow into the electric and magnetic fields around
the coil. When one does not forget this flow, all of
the flows will balance at every instant.

Sorry, it may or may not be a coil. It is in a black box
whose contents are unknown. Including the energy flows
inside the black box is impossible. The instantaneous
power into the black box does not balance the instantaneous
power out of the black box.
--
73, Cecil http://www.w5dxp.com

On Apr 13, 8:41*pm, Cecil Moore wrote:
Keith Dysart wrote:
Your imcompleteness is that you forgot to include the
energy flow into the electric and magnetic fields around
the coil. When one does not forget this flow, all of
the flows will balance at every instant.

Sorry, it may or may not be a coil. It is in a black box
whose contents are unknown. Including the energy flows
inside the black box is impossible. The instantaneous
power into the black box does not balance the instantaneous
power out of the black box.

Black boxes are an excellent way to set problems which help us
learn about the meaning of theories.

Conservation of energy and its corollary, conservation of power,
is used in a different way for analyzing black boxes than it
is when we analyzed the fully specified circuit in your Fig 1-1.

With the black box, knowing the power function on the two ports,
we can compute the energy flow into the storage elements within
the box. If the flow out of one port is not always exactly
balanced by the flow into the other, then we know that the black
box is storing some energy and therefore that it has some elements
which store energy. In a more typical situation, we do not have
a completely black box, but we know some of its elements. We can
use the balance of energy flows to help us decide if we have all
the elements. If some of the energy flow is unaccounted for, then
we have not yet found all the elements.

If the box is truly opague, then all we can say is that it has
some energy storage elements and that collectively, the flow
into these elements is described by
Pport1(t) - Pport2(t)

The situation is somewhat different in Fig 1-1. All the elements
of the system are completely specified in Fig 1-1 and we used
circuit theory to compute the energy flows. Not surprisingly, they
completely balanced:
Ps(t) = Prs(t) + Pg(t)
Associated with Fig 1-1, there is a secondary hypothesis that it
should be possible to account for another energy flow, the imputed
flow in the reflected wave on the line. The inability to account
for this flow, given the conservation of power corollary to the
conservation of energy law, is a very strong indicator that the
energy flow imputed to the reflected wave is not an actual energy
flow.

...Keith

Keith Dysart wrote:
All the elements
of the system are completely specified in Fig 1-1 and we used
circuit theory to compute the energy flows. Not surprisingly, they
completely balanced:
Ps(t) = Prs(t) + Pg(t)

Yes, but that is only *NET* energy flow and says nothing
about component energy flow. Everything is already known
about net energy flow and there are no arguments about it
so you are wasting your time. Your equation above completely
ignores reflections which is the subject of the thread.

You object to me being satisfied with average energy flow
while you satisfy yourself with net energy flow. I don't see
one iota of conceptual difference between our two positions.

After hundreds of postings, all you have proved is that
Eugene Hecht was right when he said instantaneous powers
are "of limited utility", such that you cannot even tell
me how many joules there are in 100 watts of instantaneous
power when it is the quantity of those very joules that
are required to be conserved and not the 100 watts.

The limit in your quest for tracking instantaneous energy
is knowing the position and momentum of each individual
electron. Good luck on that one.

I am going to summarize the results of my Part 1 article
and be done with it.

In the special case presented in Part 1, there are only
two sources of power dissipation in the entire system,
the load resistor and the source resistor. None of the
reflected energy is dissipated in the load resistor
because the chosen special conditions prohibit reflections
from the source resistor. Therefore, all of the energy not
dissipated in the load resistor is dissipated in the source
resistor because there is no other source of dissipation
in the entire system. Only RL and Rs exist. Pr is not
dissipated in RL. Where is Pr dissipated? Even my ten year
old grandson can solve that problem and he's no future
rocket scientist.
--
73, Cecil http://www.w5dxp.com

On Mon, 14 Apr 2008 09:10:20 -0500
Cecil Moore wrote:

Keith Dysart wrote:
All the elements
of the system are completely specified in Fig 1-1 and we used
circuit theory to compute the energy flows. Not surprisingly, they
completely balanced:
Ps(t) = Prs(t) + Pg(t)

Yes, but that is only *NET* energy flow and says nothing
about component energy flow. Everything is already known
about net energy flow and there are no arguments about it
so you are wasting your time. Your equation above completely
ignores reflections which is the subject of the thread.

You object to me being satisfied with average energy flow
while you satisfy yourself with net energy flow. I don't see
one iota of conceptual difference between our two positions.

After hundreds of postings, all you have proved is that
Eugene Hecht was right when he said instantaneous powers
are "of limited utility", such that you cannot even tell
me how many joules there are in 100 watts of instantaneous
power when it is the quantity of those very joules that
are required to be conserved and not the 100 watts.

The limit in your quest for tracking instantaneous energy
is knowing the position and momentum of each individual
electron. Good luck on that one.

I am going to summarize the results of my Part 1 article
and be done with it.

In the special case presented in Part 1, there are only
two sources of power dissipation in the entire system,
the load resistor and the source resistor. None of the
reflected energy is dissipated in the load resistor
because the chosen special conditions prohibit reflections
from the source resistor. Therefore, all of the energy not
dissipated in the load resistor is dissipated in the source
resistor because there is no other source of dissipation
in the entire system. Only RL and Rs exist. Pr is not
dissipated in RL. Where is Pr dissipated? Even my ten year
old grandson can solve that problem and he's no future
rocket scientist.
--
73, Cecil http://www.w5dxp.com

This thread has one assumption that I find very frustrating, a voltage source that is a steady source of power but can not absorb power. My view is that any source must both absorb and deliver power at some none zero impedance. As justification for this view, I offer that current always flows from high voltage to lower voltage, so a real voltage source would have to absorb energy if the external voltage exceeded the voltage of the voltage source.

While it can be agrued that the ideal voltage source would have zero internal resistance, that argument does not address the fact that power flowing in the reverse direction (into the source, against the source supplied voltage) delivers power into the source. Charging a battery with zero internal resistance is a good example. Another example is the observation that a generator becomes a motor when the externally suppied voltage exceeds the voltage supplied by the generator.

Yes, we can make the assumption that the voltage source can not absorb power at any time, but the assumption takes us into an unreal world and gives answers that are impossible to duplicate with measurements. Some would call that a world of science fiction.
--
73, Roger, W7WKB

Roger Sparks wrote:
While it can be argued that the ideal voltage source would
have zero internal resistance, that argument does not address
the fact that power flowing in the reverse direction (into the
source, against the source supplied voltage) delivers power
into the source.

I thought I had already addressed that topic when I added the
one-wavelength of transmission line to the example in between
the source and source resistance.

But here's an example that may allow better tracking
of the energy flow. Let's modify my Part 1, Fig. 1-1
to add a 50 ohm circulator and load to the ground
leg of the source. Everything else remains the same.

Gnd--1---2---Vs---Rs-----45 deg 50 ohm----------RL
\ /
3
|
50 ohms
|
GND

How much power is dissipated in the circulator
resistor?

How much power does the source have to supply to
maintain 50 watts of forward power on the transmission
line?

Does this example answer your questions?
--
73, Cecil http://www.w5dxp.com

On Mon, 14 Apr 2008 16:54:47 GMT
Cecil Moore wrote:

Roger Sparks wrote:
While it can be argued that the ideal voltage source would
have zero internal resistance, that argument does not address
the fact that power flowing in the reverse direction (into the
source, against the source supplied voltage) delivers power
into the source.

I thought I had already addressed that topic when I added the
one-wavelength of transmission line to the example in between
the source and source resistance.


I thought the addition of a one wavelength transmission line did not address the issue, and only added more reflections. We still need a reason to assume that a voltage source should *not* absorb power.

But here's an example that may allow better tracking
of the energy flow. Let's modify my Part 1, Fig. 1-1
to add a 50 ohm circulator and load to the ground
leg of the source. Everything else remains the same.

Gnd--1---2---Vs---Rs-----45 deg 50 ohm----------RL
\ /
3
|
50 ohms
|
GND

How much power is dissipated in the circulator
resistor?

How much power does the source have to supply to
maintain 50 watts of forward power on the transmission
line?

Does this example answer your questions?
--
73, Cecil http://www.w5dxp.com

No, I'm sorry but no. I offered the examples of two real sources that will absorb power when the returning voltage exceeds the output voltage (a battery and a generator turned into a motor). I think that we must allow our voltage source to have that same real property.

I do understand that when we allow the source to receive power, then we need to address source impedance. If we assign a single impedance, then we expect reflections from the source. The simple solution that I propose is to add a source property of absorbing all reflections. This can be accomplished in the real world by making the transmission so long that reflections never return from the source over any reasonable time, or by making the tranmission line sufficiently lossy to absorb reflections. Your example uses the first method.

Does the idea of source receiving power run counter to what you were planning to write in Parts 2 and 3? I am trying to understand why you have such great reluctance to accept that the source could receive power for part of a cycle, especially when it could easily bring the instantaneous power and energy calculations into balance.
--
73, Roger, W7WKB

Roger Sparks wrote:
I offered the examples of two real sources that will absorb
power when the returning voltage exceeds the output voltage
(a battery and a generator turned into a motor). I think that
we must allow our voltage source to have that same real property.

A battery converts electrical energy to chemical energy, i.e.
it transforms the electrical energy. A motor converts electrical
energy into physical work, i.e. it transforms the electrical
energy. An ideal source does not dissipate power and there is
no mechanism for storing energy. It seems what you are objecting
to is the artificial separation of Vs and Rs.

I do understand that when we allow the source to receive
power, then we need to address source impedance.

The series source impedance is zero. It acts like a short
circuit to reflections, i.e. there are no reflections.
However, there seem to be 100% reflection from the GND on
the other side of the source.

Does the idea of source receiving power run counter to what
you were planning to write in Parts 2 and 3?

The source will be shown to adjust its output until an
energy balance is achieved. It will throttle back when
destructive interference occurs at the source resistor
and will gear up when constructive interference requires
more energy.

I am trying to
understand why you have such great reluctance to accept that
the source could receive power for part of a cycle, especially
when it could easily bring the instantaneous power and energy
calculations into balance.

There is no known mechanism that would allow an ideal
source to dissipate or store energy. Consider that the
energy you see flowing back into the source is reflected
back through the source by the ground on the other side
and becomes part of the forward wave out of the source.
That would satisfy the distributed network model and
explain why interference exists in the source.
--
73, Cecil http://www.w5dxp.com

On Apr 14, 12:06*pm, Roger Sparks wrote:
On Mon, 14 Apr 2008 09:10:20 -0500

Cecil Moore wrote:
Keith Dysart wrote:
All the elements
of the system are completely specified in Fig 1-1 and we used
circuit theory to compute the energy flows. Not surprisingly, they
completely balanced:
* *Ps(t) = Prs(t) + Pg(t)

Yes, but that is only *NET* energy flow and says nothing
about component energy flow. Everything is already known
about net energy flow and there are no arguments about it
so you are wasting your time. Your equation above completely
ignores reflections which is the subject of the thread.

You object to me being satisfied with average energy flow
while you satisfy yourself with net energy flow. I don't see
one iota of conceptual difference between our two positions.

After hundreds of postings, all you have proved is that
Eugene Hecht was right when he said instantaneous powers
are "of limited utility", such that you cannot even tell
me how many joules there are in 100 watts of instantaneous
power when it is the quantity of those very joules that
are required to be conserved and not the 100 watts.

The limit in your quest for tracking instantaneous energy
is knowing the position and momentum of each individual
electron. Good luck on that one.

I am going to summarize the results of my Part 1 article
and be done with it.

In the special case presented in Part 1, there are only
two sources of power dissipation in the entire system,
the load resistor and the source resistor. None of the
reflected energy is dissipated in the load resistor
because the chosen special conditions prohibit reflections
from the source resistor. Therefore, all of the energy not
dissipated in the load resistor is dissipated in the source
resistor because there is no other source of dissipation
in the entire system. Only RL and Rs exist. Pr is not
dissipated in RL. Where is Pr dissipated? Even my ten year
old grandson can solve that problem and he's no future
rocket scientist.
--
73, Cecil *http://www.w5dxp.com

This thread has one assumption that I find very frustrating, a voltage source that is a steady source of power but can not absorb power. *My view is that any source must both absorb and deliver power at some none zero impedance. *

I am not sure why you desire a non-zero impedance. The usual
definition of an
ideal voltage source is that it provides or sinks what ever current is
needed to
hold the desired output voltage. When it is sourcing current then it
is providing
energy. No statement is made about where this energy comes from. When
it is
sinking current, it is absorbing energy. No statement is made about
where
this energy is going.

A non-zero impedance is not required to make any of the above
behaviour work.

If you include a non-zero impedance, then you have a more real world
source
which can often be modeled using the Thevenin equivalent circuit; an
ideal
voltage source (zero impedance) in series with a resistor representing
the impedance of the real world source.

As justification for this view, I offer that current always flows from high voltage to lower voltage, so a real voltage source would have to absorb energy if the external voltage exceeded the voltage of the voltage source.

This is true.

While it can be agrued that the ideal voltage source would have zero internal resistance, that argument does not address the fact that power flowing in the reverse direction (into the source, against the source supplied voltage) delivers *power into the source. *Charging a battery with zero internal resistance is a good example. *Another example is the observation that a generator becomes a motor when the externally suppied voltage exceeds the voltage supplied by the generator.

Yes, we can make the assumption that the voltage source can not absorb power at any time, but the assumption takes us into an unreal world and gives answers that are impossible to duplicate with measurements. *Some would call that a world of science fiction.

...Keith

Keith Dysart wrote:
When it is sourcing current then it is providing
energy. No statement is made about where this energy
comes from.

The question is: Is that energy being created or
dissipated as needed according to your omnipotent
whims?
--
73, Cecil http://www.w5dxp.com

On Mon, 14 Apr 2008 13:40:20 -0700 (PDT)
Keith Dysart wrote:

On Apr 14, 12:06*pm, Roger Sparks wrote:
On Mon, 14 Apr 2008 09:10:20 -0500

Cecil Moore wrote:
Keith Dysart wrote:
All the elements
of the system are completely specified in Fig 1-1 and we used
circuit theory to compute the energy flows. Not surprisingly, they
completely balanced:
* *Ps(t) = Prs(t) + Pg(t)

Yes, but that is only *NET* energy flow and says nothing
about component energy flow. Everything is already known
about net energy flow and there are no arguments about it
so you are wasting your time. Your equation above completely
ignores reflections which is the subject of the thread.

You object to me being satisfied with average energy flow
while you satisfy yourself with net energy flow. I don't see
one iota of conceptual difference between our two positions.

After hundreds of postings, all you have proved is that
Eugene Hecht was right when he said instantaneous powers
are "of limited utility", such that you cannot even tell
me how many joules there are in 100 watts of instantaneous
power when it is the quantity of those very joules that
are required to be conserved and not the 100 watts.

The limit in your quest for tracking instantaneous energy
is knowing the position and momentum of each individual
electron. Good luck on that one.

I am going to summarize the results of my Part 1 article
and be done with it.

In the special case presented in Part 1, there are only
two sources of power dissipation in the entire system,
the load resistor and the source resistor. None of the
reflected energy is dissipated in the load resistor
because the chosen special conditions prohibit reflections
from the source resistor. Therefore, all of the energy not
dissipated in the load resistor is dissipated in the source
resistor because there is no other source of dissipation
in the entire system. Only RL and Rs exist. Pr is not
dissipated in RL. Where is Pr dissipated? Even my ten year
old grandson can solve that problem and he's no future
rocket scientist.
--
73, Cecil *http://www.w5dxp.com

This thread has one assumption that I find very frustrating, a voltage source that is a steady source of power but can not absorb power. *My view is that any source must both absorb and deliver power at some none zero impedance. *

I am not sure why you desire a non-zero impedance. The usual
definition of an
ideal voltage source is that it provides or sinks what ever current is
needed to
hold the desired output voltage. When it is sourcing current then it
is providing
energy. No statement is made about where this energy comes from. When
it is
sinking current, it is absorbing energy. No statement is made about
where
this energy is going.

A non-zero impedance is not required to make any of the above
behaviour work.

My thought needed more developement. When the source delivers power, we readily accept that the impedance of delivery will be the impedance of the attached circuit. We make the same assumption when a reflection is returned to the source. If we make the assumption that the source has the same impedance as the refection, then no reflection from the source is expected. So yes, I agree with your observation.

If you include a non-zero impedance, then you have a more real world
source
which can often be modeled using the Thevenin equivalent circuit; an
ideal
voltage source (zero impedance) in series with a resistor representing
the impedance of the real world source.


--
73, Roger, W7WKB