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Speaker wires don't carry any energy (power).

eriksson

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Incredible stuff.

I wonder if there might be a totally different way of understanding this - are we seeing the whole picture? I am going to have more beer and will get back to you on that one. Don't hold your breath!
 

Ingenieur

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Incredible stuff.

I wonder if there might be a totally different way of understanding this - are we seeing the whole picture? I am going to have more beer and will get back to you on that one. Don't hold your breath!
Yes, there is, 'field theory', taught 2nd or 3rd year of BSEE curriculum.
And discovered 100-200 years ago.
Maxwell, et al
 

ajawamnet

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Naw - this is pretty much how it is. Anyone that deals with Power Transmission, High Power RF, PCB design, or any other Signal Integrity critical interconnections realizes this. The field solvers in the tools he mentions (like Ansys they show which is about $40k for a basic seat) calculates Maxwell's and Poynting's equations quite accurately.

Dr. Eric Bogatin - a peer of Lee Ritchey and the Tech Editor of SI Magazine- explained a lot of what Dr. Muller states in this clarification way back when this first came out -
. To use EE"/PCB guys, they've been mentioning all this for a long time.

In the PCB Design and Fab magazine - a few weeks before the first Veritasium vid came out - an engineer at NXP wrote and article "The Billion Dollar Mistake" where he talks about all the wasted first spins of PC boards that fail EMI testing.
 

Ingenieur

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I have never seen a grad level text on power systems use field theory to calculate:
Power flow
Conductor size
Or even field strength for spacing.
Yes, the equations may be derived from fields, but field equations are not used.
Etc.

For 3 phase power symmetrical components are used and they are basically algebraic ohm/Thevenin based.
Not Maxwell

Mincing words, energy vs power
Unplug your toaster and see if it works.
Yes, a wire a waveguide.
This has been know for centuries. But you still need a circuit.

In a HV power line what percent of the energy/power flows within 110% of the conductor radius? Within the conductor?
 
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eriksson

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Yes, there is, 'field theory', taught 2nd or 3rd year of BSEE curriculum.
And discovered 100-200 years ago.
Maxwell, et al
If I understood correctly this gentleman (in the videos) is indeed introducing his audience to field theory. For those of us familiar to ohms law this looks incredible, I was (am) aware of some of the equations he refers to -- but I have never seen it explained the way he does, but I am no EE for sure.
 

Ingenieur

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Let's put some context into this nonsense.
ACSR is
If I understood correctly this gentleman (in the videos) is indeed introducing his audience to field theory. For those of us familiar to ohms law this looks incredible, I was (am) aware of some of the equations he refers to -- but I have never seen it explained the way he does, but I am no EE for sure.
it is hyperbole and misleading clickbait, lol
 

Ingenieur

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ACSR Al conductor steel reinforced used for OH power transmission. Sizes are named after birds. Lol
Steel core wrapped with Al
Assume 'scoter', OD 1", steel 0.44"

Equations for magnetic field strength B
I = current = 640 (80% of rated)
u = relative permeability to uo air
r = radius of calculation
R = radius of conductor (or portion of)
uo = u Al = 1.000022, I'll use 1 :)
u electrical steel 4000

Within conductor B = u I r / (2 Pi R^2)
Outside of conductor B = uo I / (2 Pi r^2)

Within the steel core
= 4000 x 640 x 0.22 / 2 Pi 0.22^ 2)
= 1,851,928 or 1.85e6

Within the aluminum = B at 0.5 - B at 0.22
= 114

Outside of conductor, 10% of radius or 0.55" or 0.05" from surface, <1/16"
1 640 0.55 / (2 Pi 0.55^2)
= 185

Total 1.85e6 + 114 + 185
1,852,282
In steel 99.98%
Out side of conductor ~ 0.01%
Is it reasonable to say the energy flows in the wire? Or at least 99.98% of it in the crude example. ;)

6FCDC75A-3F88-4D69-8A1E-B30C669D2B32.jpeg
 
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charleski

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A follow-up:
Great follow-up.
The only quibble I would raise is that the old classical idea of electrons as pinballs bouncing off nuclei is not really something that should be pushed as a model these days. The whole system is a collection of wave functions with interacting energy states as shown here:

Of course, this is quantum mechanics, and the phenomenon being discussed here is a purely classical consequence of Maxwell's equations with no need to apply quantum descriptions at all, so I suppose the use of pinballs is forgivable in this context. :)
 

Ingenieur

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From my post above we see >99% of the magnetic field B exists within the conductor. And the primary variable is I current. The same derivation can be done for E the electric field and the variable will be V, voltage or potential.
B ~ I
E ~ V
P = V I
S = 1/u E x B (S~rate of energy xfer~Power)
Equivalency if fields constrained to conductor.

If the geometry is captured by other means, ie R = p Length / Area and the permeabilities replaced by physical parameters L (B associated, magnetic) and C (E associated, electric) the computations become simpler.

In addition, measuring and controlling V and I are simpler. How do you interrupt B? By opening a switch and stopping I,
The are mutually inclusive in the transfer of P or S.

Those videos confuse the issue imo and lead to a misunderstanding of the concepts. I creates the field, the field can create I. A xfmr or motor. V or E initiates the generation of I/B in the case under study.

The model is contrived.
Infinite length in essence.
No R
But we have C
C in // adds, so it will approach infinity
X the impedance to AC ~ 1/(2 Pi f C)
Since C >>> 2 Pi ~ 1/(f C)

If DC , f = 0 and as f approaches 0, and C constant, X approaches infinity.
No DC current flows, lol, we know this.

But as C approaches infinity it negates f inversely approaching 0 ~ 1/infinity, the result is some value, so current may flow.

If the V is AC, then as C goes to infinity X approaches 0 and you get a short circuit ie, no impedance.

The way he shows the fields leaping from source to load are ridiculous. As we know >99% of the fields are are constrained within the conductor.
Junk science for YouTube $.
 
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Ingenieur

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That was without doubt their intent.
Lol
That is a heck of a construct for an educational tool.
Unless all you want to do is gin up confusion, controversy and generate revenue.
;)
 
OP
C

Cbdb2

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ACSR Al conductor steel reinforced used for OH power transmission. Sizes are named after birds. Lol
Steel core wrapped with Al
Assume 'scoter', OD 1", steel 0.44"

Equations for magnetic field strength B
I = current = 640 (80% of rated)
u = relative permeability to uo air
r = radius of calculation
R = radius of conductor (or portion of)
uo = u Al = 1.000022, I'll use 1 :)
u electrical steel 4000

Within conductor B = u I r / (2 Pi R^2)
Outside of conductor B = uo I / (2 Pi r^2)

Within the steel core
= 4000 x 640 x 0.22 / 2 Pi 0.22^ 2)
= 1,851,928 or 1.85e6

Within the aluminum = B at 0.5 - B at 0.22
= 114

Outside of conductor, 10% of radius or 0.55" or 0.05" from surface, <1/16"
1 640 0.55 / (2 Pi 0.55^2)
= 185

Total 1.85e6 + 114 + 185
1,852,282
In steel 99.98%
Out side of conductor ~ 0.01%
Is it reasonable to say the energy flows in the wire? Or at least 99.98% of it in the crude example. ;)

View attachment 203685
So you think you know better than a Phd EE that works at LIGO? Talk abou Dunnig Krugger. If you actually studied EM fields you need to relearn it.
 
OP
C

Cbdb2

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From my post above we see >99% of the magnetic field B exists within the conductor. And the primary variable is I current. The same derivation can be done for E the electric field and the variable will be V, voltage or potential.
B ~ I
E ~ V
P = V I
S = 1/u E x B (S~rate of energy xfer~Power)
Equivalency if fields constrained to conductor.

If the geometry is captured by other means, ie R = p Length / Area and the permeabilities replaced by physical parameters L (B associated, magnetic) and C (E associated, electric) the computations become simpler.

In addition, measuring and controlling V and I are simpler. How do you interrupt B? By opening a switch and stopping I,
The are mutually inclusive in the transfer of P or S.

Those videos confuse the issue imo and lead to a misunderstanding of the concepts. I creates the field, the field can create I. A xfmr or motor. V or E initiates the generation of I/B in the case under study.

The model is contrived.
Infinite length in essence.
No R
But we have C
C in // adds, so it will approach infinity
X the impedance to AC ~ 1/(2 Pi f C)
Since C >>> 2 Pi ~ 1/(f C)

If DC , f = 0 and as f approaches 0, and C constant, X approaches infinity.
No DC current flows, lol, we know this.

But as C approaches infinity it negates f inversely approaching 0 ~ 1/infinity, the result is some value, so current may flow.

If the V is AC, then as C goes to infinity X approaches 0 and you get a short circuit ie, no impedance.

The way he shows the fields leaping from source to load are ridiculous. As we know >99% of the fields are are constrained within the conductor.
Junk science for YouTube $.
Wow you really don't know field theory. A perfect conductor has no E field inside, and as the resistance goes up the field in the conductor rises but it stays small and near the surface. Try checking your "facts", the truth is easy to find.


Stop spreading your nonsense.
 

xaviescacs

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This reference is a bit weak, don't you think? It talks about a conducting material inside an electrical field, it's a well known electrostatic's result, but not exactly the same situation. Where is the equation that depicts how E distributes differently inside the conductor depending on its conductivity? I was expecting that given your previous assertion. Not saying either of you is right or wrong, just that your reference does no explain the situation at hand IMHO.
 
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