Require help with electron flow in a circuit, and when the wavelength is much longer than the size of the circuit.

Re: electron flow in circuit, when wavelength is very longer than size of circuit ?

A radio to receive 1000m wave length station must be long 1000m or high 1000m or wide 1000m to satisfy your metaphysics philosopher needs. All electronics science belongs to physics. Learn about abstract thinking.

Re: electron flow in circuit, when wavelength is very longer than size of circuit ?

volker@muehlhaus said:

No.

No.

No.

I give up, this makes no sense because you don't read answers.

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whay no sense?

i read all your answer again and again.
you told in short circuit and low frequency phase shift and delay is zero that means no sense change of voltage in change lenght. i accept it but how do you imagine full period sine wave in 2 cm lenght?(full period sine wave lenght is 3 kilometer)

Re: electron flow in circuit, when wavelength is very longer than size of circuit ?

The full period of the sine wave exists in time (instantaneous voltage/current variation over the time period of a full cycle) not the space (length of a connection). You don't need to be an RF engineer to understand this. You're just mentally stuck on equating period with distance, which doesn't bode well for a career in engineering where you need to be mentally flexible .

Re: electron flow in circuit, when wavelength is very longer than size of circuit ?

Borber said:

A radio to receive 1000m wave length station must be long 1000m or high 1000m or wide 1000m to satisfy your metaphysics philosopher needs. All electronics science belongs to physics. Learn about abstract thinking.

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Do you have very hight abstract thinking? So please answer me.
I know in practice this work not happen that resiver lenght 1000 meter but I want to know whay?

Re: electron flow in circuit, when wavelength is very longer than size of circuit ?

Frequency and wave length of electrical signal or voltage can be physically noted only indirectly as different in acoustic or mechanics where we have ears and eyes. Wave length for example on voltage along mismatched line. Frequency by counter.
Problem in this misunderstanding is a sort of professional deformation when we talk about both terms we talk abstractly we keep it in the mind till the point where comes to the physical realization. For example when we talk about length of antenna we use wave length as unit of measure.

Re: electron flow in circuit, when wavelength is very longer than size of circuit ?

It helps to think along the line of post #23... The entire cycle does not need to be contained within the circuit at one time.

There are scenarios where we can visualize a circuit, or a conductive material, which is as large as a cubic mile. Then it could contain an entire wavelength of, say 186,000 Hz. Perhaps in outer space we might build such a structure, in order to take advantage of electrical properties (including resonant properties), that are possible with such large sizes.

It might lead to new avenues of:
* energy
* communication
* manufacturing
* scientific research
* exploration of the cosmos
Etc.

Just doing some harmless brainstorming at this end.

Re: electron flow in circuit, when wavelength is very longer than size of circuit ?

Normally one can ignore transmission line effects if the length of the path is <10% of wavelength.
When wavelength is 1/4 wave or any odd harmonic, load impedance appears inverted at source.( e.g. open = short)

When not a perfect transmission line, it is usually dominated by L & R, so lumped model applies for signal path d, d istance < 10% of Lambda, where RLC have incremental values that depend on cable type.

BTW Electrons don't flow at the speed of light down a wire, , however the wave approaches this speed ( usually 2/3 due to dielectric). The wave is like a domino effect of electron collisions that occurs at this speed while actual electron migration is very very very slow. ElectroMigration is not the relevant part of analysis in RF propagation effects and more a concern to corrosion diffusion and aging.

Re: electron flow in circuit, when wavelength is very longer than size of circuit ?

SunnySkyguy said:

Normally one can ignore transmission line effects if the length of the path is <10% of wavelength.
When wavelength is 1/4 wave or any odd harmonic, load impedance appears inverted at source.( e.g. open = short)

When not a perfect transmission line, it is usually dominated by L & R, so lumped model applies for signal path d, d istance < 10% of Lambda, where RLC have incremental values that depend on cable type.

BTW Electrons don't flow at the speed of light down a wire, , however the wave approaches this speed ( usually 2/3 due to dielectric). The wave is like a domino effect of electron collisions that occurs at this speed while actual electron migration is very very very slow. ElectroMigration is not the relevant part of analysis in RF propagation effects and more a concern to corrosion diffusion and aging.

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Yes, quite right.

do you agree below Sentence?? I agree

((But at low frequency 300kHz = 1km wavelength, the difference in phase between two points that are 50cm away is only 360° x 0.5/1000 = 0.18° and there is almost no voltage difference.))

360° x 1000/1000=360° when two points that are 1km away.how do you Justify this Case?
i justify when electron domino charge reach 1km lenght the period full sine wave complete.

Re: electron flow in circuit, when wavelength is very longer than size of circuit ?

linuscomex said:

360° x 1000/1000=360° when two points that are 1km away.how do you Justify this Case?

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Hi linuscomex,

All wave motion (let's simplify to a simplistic, one dimension system) can be described as a function of x + v*t, where x is a spacial variable, v is the velocity of the wave and t is a temporal variable.

A sinusoidal wave can then the described as A*sin(x + v*t), where A is just the amplitude of the wave.

Therefore, you have a choice: you can either describe the wave as a function of space (x), which is what you seem intent on doing, OR you can describe in in terms of time (t), OR both!

Inside a circuit, at low (electrically small) frequencies, we tend to describe waves in terms of time, but the most thorough results are achieved by describing both, which is generally how "RF" engineers operate. No one really describes waves in terms of space (unless resonances are involved), which is what you are doing.

However, they are all equivalent.

To answer your question, a 360 degree phase shift could also be related to points in time. At 1 Hz, If we look at a single electron in the circuit, 360 degrees simply corresponds to a period of one second.

You are not talking about a circuit; you are talking about a photon travelling at the speed of light in inbounded, free space. Of course, in this case, you are correct!

Re: electron flow in circuit, when wavelength is very longer than size of circuit ?

linuscomex said:

Yes, quite right.

do you agree below Sentence?? I agree

((But at low frequency 300kHz = 1km wavelength, the difference in phase between two points that are 50cm away is only 360° x 0.5/1000 = 0.18° and there is almost no voltage difference.))

360° x 1000/1000=360° when two points that are 1km away.how do you Justify this Case?
i justify when electron domino charge reach 1km lenght the period full sine wave complete.

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Remember again what I said.

ignore distances <10% for now.

But at 25% or 90 degrees impedance inverts so that after reflection back to source waves are inverted and cancel at 180deg, thus inverted impedance at source.

And load impedance at 50% or 100% f wavelength reverts back normal, or 360 or 720 deg.respectively.

So it is tuned to be in phase at these harmonics of half wave lengths and impedance is not transformed.

Re: electron flow in circuit, when wavelength is very longer than size of circuit ?

PlanarMetamaterials said:

Hi linuscomex,

All wave motion (let's simplify to a simplistic, one dimension system) can be described as a function of x + v*t, where x is a spacial variable, v is the velocity of the wave and t is a temporal variable.

A sinusoidal wave can then the described as A*sin(x + v*t), where A is just the amplitude of the wave.

Therefore, you have a choice: you can either describe the wave as a function of space (x), which is what you seem intent on doing, OR you can describe in in terms of time (t), OR both!

Inside a circuit, at low (electrically small) frequencies, we tend to describe waves in terms of time, but the most thorough results are achieved by describing both, which is generally how "RF" engineers operate. No one really describes waves in terms of space (unless resonances are involved), which is what you are doing.

However, they are all equivalent.

To answer your question, a 360 degree phase shift could also be related to points in time. At 1 Hz, If we look at a single electron in the circuit, 360 degrees simply corresponds to a period of one second.

You are not talking about a circuit; you are talking about a photon travelling at the speed of light in inbounded, free space. Of course, in this case, you are correct!

Click to expand...

thanks bro.
do you agree the 300 khz sine wave need 1 km wavelenght to complete one period???? so pleuase show below image and answer my questions in image thanks.

Re: electron flow in circuit, when wavelength is very longer than size of circuit ?

linuscomex said:

thanks bro.
do you agree the 300 khz sine wave need 1 km wavelenght to complete one period????
View attachment 118909

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In general? No.

In free space? Yes.

Dispersion engineering is the engineering of artificial media in which the wavelength can be set to (within reason) any desirable value. I could (in theory) develop a periodic medium in which the wavelength was 1mm at 300 kHz. (this is unrelated to your question, but one needs to consider such cases for a good understanding of the topic).

A circuit is not free space. Wavelength only has meaning in a specific context. In this case, you are trying to apply a concept from free space propagation and force it to work in a circuit, which obviously does not have the same bounds as free space.

Re: electron flow in circuit, when wavelength is very longer than size of circuit ?

Velocity is only speed of light in a vacuum or air

VF = k*c = where k is the reciprocal of the square root of the dielectric constant (relative permittivity) of the material through which the signal passes:

Typically VF= 2/3c ~ 0.7c

otherwise you are close

Re: electron flow in circuit, when wavelength is very longer than size of circuit ?

linuscomex said:

do you agree the 300 khz sine wave need 1 km wavelenght to complete one period????

Click to expand...

300kHz sine wave needs 1/300000 s in time to complete one period. No length is needed.

Your picture of travelling electrons is wrong, and you confuse yourself. The electrons move one direction during half the wave period, and then polarity and current direction changes in the other half period. Now electrons change direction and move backwards. So over one period, the electron movement has cancelled.

And now?

Re: electron flow in circuit, when wavelength is very longer than size of circuit ?

If wave length in free space is 1km then in average antenna coaxial cable it is only 660m. In both cases frequency is 300kHz.

Re: electron flow in circuit, when wavelength is very longer than size of circuit ?

PlanarMetamaterials said:

In general? No.

In free space? Yes.

Dispersion engineering is the engineering of artificial media in which the wavelength can be set to (within reason) any desirable value. I could (in theory) develop a periodic medium in which the wavelength was 1mm at 300 kHz. (this is unrelated to your question, but one needs to consider such cases for a good understanding of the topic).

A circuit is not free space. Wavelength only has meaning in a specific context. In this case, you are trying to apply a concept from free space propagation and force it to work in a circuit, which obviously does not have the same bounds as free space.

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pleause tell me the meaning of wavelenght for sine wave.wavelenght is for sine wave not for free space and when you have the sine wave you can define wavelenght for wave. the wave can be anywhere(space or circuit)

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SunnySkyguy said:

Velocity is only speed of light in a vacuum or air

VF = k*c = where k is the reciprocal of the square root of the dielectric constant (relative permittivity) of the material through which the signal passes:

Typically VF= 2/3c ~ 0.7c

otherwise you are close

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i dont remember speack about speed of electromagnetic in circuit. yes the velocity speed is 0.7c but i dont undrestand
what relation sheep between it and wavelenght distance.

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volker@muehlhaus said:

300kHz sine wave needs 1/300000 s in time to complete one period. No length is needed.

Your picture of travelling electrons is wrong, and you confuse yourself. The electrons move one direction during half the wave period, and then polarity and current direction changes in the other half period. Now electrons change direction and move backwards. So over one period, the electron movement has cancelled.

And now?

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i know direction during half the wave period change.
half the wave period need 0.5 kilometer lenght to complete.
and now?

Re: electron flow in circuit, when wavelength is very longer than size of circuit ?

What book you are reading? It looks like you have a physics book in your hands. Those misunderstandings must came out from somewhere.

Re: electron flow in circuit, when wavelength is very longer than size of circuit ?

Borber said:

What book you are reading? It looks like you have a physics book in your hands. Those misunderstandings must came out from somewhere.

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no!!!!

i am electronic engineer.
i ask you read wavelenght theory.

Re: electron flow in circuit, when wavelength is very longer than size of circuit ?

Which book? Where from you are reading? optics, acoustic, mechanics, electromagnetic...

Re: electron flow in circuit, when wavelength is very longer than size of circuit ?

Borber said:

Which book? Where from you are reading? optics, acoustic, mechanics, electromagnetic...

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My friend I dont read this problem anywhere just I imagine this problem.This logic

Please imagin this problem.
when sine wave propagate in circuit need Physical distance to propagate. My problem in 10cm physical distance how propagate 1 km distance?