Amplification of an EM wave by mechanical rotation, the Zaldovich effect

[F6FLT]

This recently published paper by M. C. Braidotti and colleagues describes an experiment in which a tuned coil generates a low-frequency magnetic field in the air gap of a ferrite toroid, in which an aluminum cylinder rotates.
If the rotation of the cylinder is less than the signal frequency, the magnetic wave in the torus is attenuated. If it's higher, it's amplified. This is equivalent to having a negative coil resistance, the effect being most obvious around the resonant frequency (see figure 3 in the pdf). This is the Zaldovich effect.
As the rotation of the cylinder must be of the order of magnitude of the signal frequency, we need a very low frequency, hence the coil's enormous inductance (20,000 turns, 263 H).

In the process, we rediscover an essential fact that is often overlooked: a linearly polarized wave (such as that of an electromagnetic field) is strictly equivalent to the superposition of 2 counter-rotating, circularly polarized waves. This is what allows Mr. Braidotti to apply the general Zaldovich effect specifically to the angular momentum of the field rotation, by the difference of the Doppler effect of the rotating cylinder, on the two counter-rotating waves.
Apart from the conceptual interest of the experiment, I don't yet know if it can be of practical interest in our FE research, but I'm trying to imagine what we could do with it. It could also explain certain apparently anomalous effects observed in past experiments.

[chief kolbacict]

Does core actually must be ferrite ?  Or will regular transformer steel do ?

[maxmalone]

How much faster should this aluminum cylinder rotate? A few more frames or hundreds?

Currently, high-speed electric motors can accelerate to 200,000 rpm, although the record is about 1 million rpm.

You can easily reach 60,000 rpm, which would give 1000 Hz, so this is indeed a problem for the core frequency.

However, if we try to make a resonant transformer, e.g. at 50 Hz, and use a rotating aluminum cylinder, say > 3000 rpm, I have a large margin to increase the rpm without special motors and precision balancing of the aluminum cylinder.

The question remains whether negative values ​​will reduce friction and increase the engine speed? Will there still be an effect of eddy currents? Which would result in greater current consumption on the cylinder and, as a result, no amplification for our FE purposes.

And what current amplification are we talking about?

[Verpies]

Most of these questions are answered in the attached document.

[maxmalone]

The rotation of the cylinder strengthens the magnetic field but only up to the momentum of the cylinder and the energy needed to accelerate it. In other words, there is no FE here. Isn't it something like a Faraday disk?

[F6FLT]

Does core actually must be ferrite ?  Or will regular transformer steel do ?

I can't think of any reason why iron cores shouldn't be used, as they are in low-frequency transformers.

How much faster should this aluminum cylinder rotate? A few more frames or hundreds?
...
And what current amplification are we talking about?

The answers are in the paper linked in my previous post.
Resonance frequency f0 = 277 Hz, so the cylinder rotates around 277 revs/s and more for gain.
From figure 3, we can estimate the gain at 113%.

Of course this is not FE, the electromagnetic energy is taken from the mechanical energy of rotation of the cylinder. It has nothing to do with Faraday's disc. It's not the Lorentz force that ensures the coupling between the fixed and moving parts, but induction effects (time varying field needed).

What's interesting for us is that the more possibilities we have for slightly exotic energy exchanges, the more likely we are to find new effects.

[Verpies]

I can't think of any reason why iron cores shouldn't be used, as they are in low-frequency transformers.

What about eddy currents ?

[F6FLT]

What about eddy currents ?

This is probably the reason for using ferrite, but I'm not sure it's a good one.
Since the working frequency is low, the iron losses should be low and also compensated, for the same inductance, by a shorter winding length due to greater permeability, and therefore a lower ohmic loss due to lower resistance.  The current winding resistance is 2.03 kΩ, which is a lot.

[lfarrand]

Here's a more easily digestible article from SciTechDaily: 50-Year-Old Physics Theory Proven for the First Time With Electromagnetic Waves

"The Zel'dovich effect works on the principle that waves with angular momentum, that would usually be absorbed by an object, actually become amplified by that object instead, if it is rotating at a fast enough angular velocity. In this case, the object is an aluminum cylinder and it must rotate faster than the frequency of the incoming radiation," explains a Research Fellow at the University of Southampton, Dr. Marion Cromb.

[chief kolbacict]

Is it possible to use an induction motor with a hollow aluminum rotor like this one in replicating this device?

[F6FLT]

This experiment has a strong family resemblance to the magnetic diode: https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.121.213903
See attached image.

In the latter, two parallel coils are inserted into a U-shaped cylinder. The first coil induces currents in the U cylinder, and as the cylinder rotates in the direction from the first coil to the second, it carries the magnetic field effects of these currents to the second coil. In this way, the coupling of the first coil to the second is much stronger than the opposite, resulting in the magnetic diode effect.

In the amplification experiment, I wonder if the explanation might not be the same. The currents induced in the aluminum cylinder add or subtract their field from the mean field across the gap, depending on the phase relation of the cylinder's rotation to the frequency of the variable field.

The principle of both experiments would therefore be the same: induction in a moving conductor creates eddy currents, and as the object moves, the field created by these currents modifies the external field that gives rise to them, in a non-symmetrical way unlike the static case. The energy gained or lost due to asymmetry is obtained from the mechanical energy of displacement.

I found the Zeldovich effect explanation rather twisted. After re-reading it, I think we can finally do without it. What do you think?

In this case, where the simple explanation is an effect of the mechanical displacement of eddy currents, and to answer chief kolbacict's question, the use of a hollow cylinder should considerably reduce the effect by reducing the mass of metal and therefore the eddy currents.

[chief kolbacict]

This experiment has a strong family resemblance to the magnetic diode: https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.121.213903
See attached image.

What's stopping us from using this magnetic diode of yours in a transformer to kill Lenz ?

[F6FLT]

What's stopping us from using this magnetic diode of yours in a transformer to kill Lenz ?

Instead of having 2 objects interacting through their fields (two coils), we now have 3: the two coils and the U-shaped cylinder, which acts as a 3rd coil since induced currents rotate in it.
Lenz's law seems to be at fault only if we consider the two coils alone. If we consider all three coils, Lenz's law is still valid: the current in coil 2 opposes the currents that give rise to them, the eddy currents that flow in the U, and these oppose the current that gives rise to them in coil 1.

The idea that certain conditions would render Lenz's law invalid is part of the speculative beliefs found in FE. It makes no sense for one simple reason: charges in one circuit, which induce currents in another by magnetic coupling, can only be explained by charges in one circuit feeling the field of charges in another circuit. If one charge is subject to the field of another, the other is subject to the field of the first, by virtue of the Coulombian influence.
In other words, to deny Lenz's law is also to deny induction from the secondary circuit to the primary circuit, and thus to assert one thing and its opposite, since nothing distinguishes electrons in a primary circuit from those in the secondary circuit.

[F6FLT]

Coming back to this mobile intermediary like the U-shaped cylinder of the magnetic diode, or the aluminum cylinder of the (supposed) Zaldovich effect experiment, it gives us one more degree of freedom to play with variable magnetic fields, and we've seen that it can provide additional energy. Now we just need to find a way of replacing the moving object with a natural phenomenon whose energy we can then pump out. I'm also thinking of replacing the eddy currents induced in the mass of the moving object with those induced in one or more tuned coils short-circuited on themselves and mobile, which should reduce losses.

[Centraflow]

Coming back to this mobile intermediary like the U-shaped cylinder of the magnetic diode, or the aluminum cylinder of the (supposed) Zaldovich effect experiment, it gives us one more degree of freedom to play with variable magnetic fields, and we've seen that it can provide additional energy. Now we just need to find a way of replacing the moving object with a natural phenomenon whose energy we can then pump out. I'm also thinking of replacing the eddy currents induced in the mass of the moving object with those induced in one or more tuned coils short-circuited on themselves and mobile, which should reduce losses.

It is easier than you think, you are a radio ham.

You create a small magnetic loop where it has a high self resonant frequency, in other words close to the loop is the magnetic field and not the electric field.

By squeezing that field mono directionally it will be the same as a magnet dropping through a solenoid coil.

Now where have I seen that before!!!

🤐

[F6FLT]

...
You create a small magnetic loop where it has a high self resonant frequency, in other words close to the loop is the magnetic field and not the electric field.

By squeezing that field mono directionally it will be the same as a magnet dropping through a solenoid coil.

Now where have I seen that before!!!

🤐

The idea is to couple a variable magnetic field between two coils (the equivalent of the magnetic diode), or between a single coil and itself (the equivalent of the Braidotti experiment) via a moving device where the induced currents also have a relative speed with respect to the magnetic circuit, enabling the phase of the signal to be modified and capable of contributing electromagnetic energy from the mechanical energy of displacement.
Unlike the case of a simple magnet displacement, here the displacement of the intermediate coupler can modify the phase of an input signal, adding or subtracting energy from it, since its rotation speed is constant.
But it could also modify the frequency of the signal if its movement were itself variable back and forth. We have the mechanical equivalent of a "heterodyne" type frequency-changing device, but without the non-linear elements: it's a mixer without a diode, and therefore without a threshold effect.

The frequency of the resulting signal can thus be decorrelated from motion, unlike in the case of a "magnet dropping through a solenoid coil". That's why I was talking about an additional degree of freedom that I don't yet know how to exploit.

Finally, with regard to your distinction "the loop is the magnetic field and not the electric field", note that the magnetic field is simply the coulombic electric field of the electrons, deformed according to special relativity by their movement since there is a current, and which therefore can no longer be masked by the static rearrangement of charges in the environment. There is no difference in nature, its' just a question of charges feeling their mutual coulombic field differently because of their relative speed.

[Centraflow]

The idea is to couple a variable magnetic field between two coils (the equivalent of the magnetic diode), or between a single coil and itself (the equivalent of the Braidotti experiment) via a moving device where the induced currents also have a relative speed with respect to the magnetic circuit, enabling the phase of the signal to be modified and capable of contributing electromagnetic energy from the mechanical energy of displacement.
Unlike the case of a simple magnet displacement, here the displacement of the intermediate coupler can modify the phase of an input signal, adding or subtracting energy from it, since its rotation speed is constant.
But it could also modify the frequency of the signal if its movement were itself variable back and forth. We have the mechanical equivalent of a "heterodyne" type frequency-changing device, but without the non-linear elements: it's a mixer without a diode, and therefore without a threshold effect.

The frequency of the resulting signal can thus be decorrelated from motion, unlike in the case of a "magnet dropping through a solenoid coil". That's why I was talking about an additional degree of freedom that I don't yet know how to exploit.

Finally, with regard to your distinction "the loop is the magnetic field and not the electric field", note that the magnetic field is simply the coulombic electric field of the electrons, deformed according to special relativity by their movement since there is a current, and which therefore can no longer be masked by the static rearrangement of charges in the environment. There is no difference in nature, its' just a question of charges feeling their mutual coulombic field differently because of their relative speed.

You will have to rethink that. The real current in the loop is running perpendicular to any coils wound around that loop, so no induction can take place, but if you squeeze that current around the loop then induction will take place.

It is how you squeeze it.

Mike

[F6FLT]

You will have to rethink that. The real current in the loop is running perpendicular to any coils wound around that loop, so no induction can take place, but if you squeeze that current around the loop then induction will take place.

It is how you squeeze it.

Mike

What's the connection between what you're saying and the two experiments I've cited and on which I intend to base my next steps?

The induction I'm talking about is the eddy currents in the rotating cylinder, or in any intermediate moving part we can place along a magnetic circuit, which cause a phase shift (or even a frequency change) and a coupling to their mechanical energy, which is of interest.

[Centraflow]

What's the connection between what you're saying and the two experiments I've cited and on which I intend to base my next steps?

The induction I'm talking about is the eddy currents in the rotating cylinder, or in any intermediate moving part we can place along a magnetic circuit, which cause a phase shift (or even a frequency change) and a coupling to their mechanical energy, which is of interest.

You can create both inputs with the same, small to start, energy input, and collect the output.

Power increases internally up to "some equilibrium", not really looped (power from output put back into the input).

Regards

Mike

[F6FLT]

I'm still cogitating, because before doing anything, it's better to be sure of having an interesting lead. Experimentation is for later.

First idea:
Transposing the principle to the electrical rather than the magnetic domain would considerably reduce losses, since we no longer have those due to the Joule effect of induced currents.
A dielectric cylinder or disk rotating between the plates of a capacitor in a tuned circuit should be able to increase the signal. The problem is to get the working frequency low enough to be of the order of the speed of rotation.

Second idea:
It follows maxmalone's above reference to Faraday's disk.
The general principle of the Faraday disc is a constant magnetic field passing through a circuit made up of two half-circuits, one of which is movable relative to the other. This creates the conditions for the charges in each half-circuit to influence each other, creating a current in the circuit. The problem is that the necessary sliding contacts between the two half-circuits are difficult to achieve without significant losses, and the low voltage limits cannot be overcome without putting several disks in series, so with additional sliding contacts and losses, nothing is gained.

Here, the principle is different but we note that the currents in the rotating cylinder that creates the relative speed of the charges with the fixed part, necessary to obtain a current as in the case of the Faraday disk, do not require any sliding contact, nevertheless we can exploit the currents of this "moving circuit". Could we increase voltage now by multiplying the number of moving parts, like cylinders? And then I'd find a serious family resemblance with Searl's generator, so there could be a solid theoretical basis for Searl's generator which has yet no proven explanation:

[chief kolbacict]

A dielectric cylinder or disk rotating between the plates of a capacitor in a tuned circuit should be able to increase the signal. The problem is to get the working frequency low enough to be of the order of the speed of rotation.

https://youtu.be/MzqQ4Fc0RTg  There are subtitles. You can turn on the translation.
There are electrostatic machines without metal sectors and without brushes. If you also remove the Leyden jars, maybe this will be what you need ?

[F6FLT]

@chief kolbacict

That's not the idea here, since we're in the field of time-varying fields, whereas Wimshurst's machine is electrostatic, but the video is very interesting on the operating principle, which is easier to understand once you've eliminated the metal plates from the dielectric discs (very well explained from minute 9 onwards), an elimination which, to my astonishment, also improves operation!