Faradox revisited - NO brushes, V measurement co-rotating with 2-disk magnets and radial coils

[PhysicsProf]

  I'm interested in Egerly stuff, also in the Faraday Paradox (I call it, Faradox).
This from my personal journal this morning:

Woke up with Faradox on my mind, then quickly visualized the test:  Two disk magnets with hole in center, South OUT for each (thus two N-poles together, perhaps a steel plate between to cut down repulsive force).  Then copper wire wound around both Radially, such that the wire goes out over the edge, down the other side, looping through the center holes.  Repeat for many loops.

By the Lorentz force and right hand rule, spin the disk-set CCW.  So fingers above axis, RHR, pointing left in the direction of the upper-disk motion, rotate INTO the disk (following magnetic B lines for S-pole) and thumb shows direction of current which is down, towards disk-center.   Same procedure on the opposite side finds that the thumb points UP, so the current loops (up on the far side, down on the near side).  Electrons move in the opposite direction.

Spin fast, high omega....
Near the axle for driving the rotation, we place a JT circuit which lights red LED at 0.2V..  force on the JT is mr(omega)^2, so keep forces small by low mass and minimal r = distance to axis of rotation.
I already commissioned an excellent builder, Mark Vaughan, to give me a JT circuit which will light at very low voltage.  His small circuit lights the red LED I supplied at 0.2 volts!

Question:   will there arise a VOLTAGE when everything co-rotates?   what would YOU PREDICT?   
(I predict YES, there will be a voltage.)
NO brushes, V measurement is co-rotating with the magnets and coils.

[Magluvin]

i think the magnets should be in attraction with the conductive plate in between. otherwise there should be no current in the disk.  similar to just 1 magnet and a disk, makes only 1 magnetic pole polarity through the disk, or even a horseshoe magnet, as we should have all seen before, where each leg of the horseshoe is an opposite polarity.

if the magnet/magnets are as i propose, then i believe yes, there should be current flow if both the disk and the magnets spin together.  the big question is, if both the disk and the magnets spin together, will there be any drag/lenz on the rotation as we pull current from the disk !!  if so, what is the rotor as a whole, spinning, dragging against?  and, if there is no drag and we get current output, boom. lenz free generator.      that is the paradox in question.

mags

[panyuming]

Thanks to PhysicsProf for sharing the great idea!

[Verpies]

Question:   will there arise a VOLTAGE when everything co-rotates?   what would YOU PREDICT?   

Does the magnitude of the magnetic flux, which threads this winding, change as the disk-set rotates ?
If "yes" then yes.
If "no" then no.

[Magluvin]

now, if we get currents radialy through the disk when that disk and the magnet rotate together, then what if we set up a coil mounted to the edge of the rotor and mount a magnet to the rotor also.  mount the coil to the rotors edge and the magnet mounted to the rotor where its pole is in a position that its flux is producing the most say positive voltage swing as when a coil is a stationary as a stator.  so if the disk and magnet produce current, this should also.  ill draw up a 3d example. 

one of the big problems with the disk is having to use the outer edge of the disk as a commutator.  lots of drag and high speed, high current brushing.  needs to be good low resistance contact, thus more physical resistance on the outer edge. probably why they used a bowl of mercury at the bottom of the disk back in the day.  maybe still in use somewhere today.  but if we can mount coils and magnets on the rotor to get the same effect, as long as we understand the effect, then we solve the low voltage, high currents issues by using multi turn coils instead, and can make a smaller radius comutator and brushes just like anything else.

tried it once but as i look back, i wasnt doing it right.  have a rotor to try this.  heck, just put an led on the coil in the right polarity and give it a wirl....

mags

[Magluvin]

but,,,,, as i said in my previous post, will there be drag on the rotor?  if not then great. lenzless gen. but if there is drag, what are we dragging against if the magnet and coil are rotating together on the rotor?   might say, well if it works and there is drag, then we are just back at square one, just in a different way.  i say not.   the question of "what is it dragging against" should become clear as it would be an effect that could be developed into a magnetic drive system.  if they rotate together, disk or coil with magnets in place, and there is drag, and say its pushing against the fields that are all around us, can we use that to move a cart on the table? id see it as an ore on a row boat. only short or load the coil when it is pushing in the opposite direction you want to go.  think on that a bit. either way, there would be an advanced advantage, one way or the other.

if it does produce electrical output, id say there is going to be drag.  the whole paradox is about knowing that the magnet is not the origin of the field, it is just a lens that alters the existing field all around us.  spin the disk alone and we got current. spin the ring magnet alone, no current.  spin both, we again have current, because the disk is cutting the field that does not spin with the magnet.

mags

[Verpies]

,,, as i said in my previous post, will there be drag on the rotor? 

Are you asking about the drag over 1° or 360° ?

[Smudge]

I have done a quick sim using FEMM in axissymmetric mode.  The first image below is the result (you can use pnyuming's images to visualize the arrows).  The red rounded corner rectangle represents a single turn winding.  The next image is the normal component of B (B.n) crossing that turn, starting at the bottom left of the rectangle and going round CW.  The next image is the radius from the central axis (the vertical blue line).  The final image is B.n multiplied by the radius.  That represents the electric field induced at each point due to the rotation velocity, and the feature of note is the average value of zero.  Yes the wire across the top and the bottom have the same field value in the same direction but that is completely negated by the field along the vertical wire down the outside.

Smudge

[panyuming]

Figure 8 in my previous post is a modified version of PhysicsProf's scheme. Imagine a single, solid ring-shaped magnet with a coil wrapped around it. 
The wires on the vertical part of the outer ring may cut through the magnetic lines and generate electricity. 
The wires on the vertical part of the inner ring will also produce electricity of reverse polarity, counteracting the output from the outer ring. 
However, I think the linear speed of the inner ring is lower, so it might generate less electricity, counteracting less, and there might still be some net output. 
Looking further, the magnetic lines are denser on the inner ring than the outer ring, so more of the output may be canceled. 

If we further modify the structure, as shown in Figure 9, 
so that the inner ring's coil does not pass through the magnetic lines, then most of the net output might remain. 

I think Lenz's law still applies in the same way. In the end, this results in a DC generator.

[PhysicsProf]

  I appreciate the thoughts and effort put into this experiment...
   In the end, Experiments will provide the answer - to me at least.

  I have wondered Why it is that when I search "Faraday's Paradox Experiments" I find spinning disk-magnets and conducting DISKS (co-spinning, or not), but so far, NO EXAMPLES of winding wire RADIALLY as I have shown.  Why is that? 
Also, I don't find paired disk magnets and a steel plate between, such that both exterior faces are  both SOUTH poles - Why hasn't someone tried this?  (Perhaps they did, somehow ?)

Bottom line is - I don't find that this experiment has been done yet.  And that encourages me to "TRY the experiment."

I may start with ends of the wire connected to slip-rings on the axle - and to use conducting brushes of some sort to collect current - easier I think than using a JT circuit fixed to the rotating system.

PS - as I'm the caregiver now for my wife who has had a stroke, progress may be slow at first, getting this set up...  Magnets, drive system, etc. will take time... weeks not days probably... sorry about that.

[Magluvin]

ah.  sorry.  now i get what you were thinking. 
i have thought of this years ago, trying to up the voltage as such.  my thoughts on it were just as you describe but with just multiple disks and magnets in a rotating pile with the disks connected in series through the pile at the inner radius and outer for every other connection. so say the first disk has current flowing outward and the next disk will have current flowing inward, repeat...

the issue that kept comming about was between the magnets, like poles facing, that concentrated field at the outer and inner radius edge will counter induce the windings(or the connections putting the multiple disks in series) opposing what is being induced on the windings that are radially induced.  cant say there would be more or less on either the outer edge induction or the radial portion being induced.  we cannot negate the like facing fields of the magnets. they need to exist somewhere. they will be very prominent at the outer and inner radius.

mags

[PhysicsProf]

ah.  sorry.  now i get what you were thinking. 
i have thought of this years ago, trying to up the voltage as such.  my thoughts on it were just as you describe but with just multiple disks and magnets in a rotating pile with the disks connected in series through the pile at the inner radius and outer for every other connection. so say the first disk has current flowing outward and the next disk will have current flowing inward, repeat...

the issue that kept comming about was between the magnets, like poles facing, that concentrated field at the outer and inner radius edge will counter induce the windings(or the connections putting the multiple disks in series) opposing what is being induced on the windings that are radially induced.  cant say there would be more or less on either the outer edge induction or the radial portion being induced.  we cannot negate the like facing fields of the magnets. they need to exist somewhere. they will be very prominent at the outer and inner radius.

mags

Interesting points, mags.  Did you approach this theoretically - or did you do actual experiments?

[PhysicsProf]

About this which mags wrote:  "the issue that kept comming about was between the magnets, like poles facing, that concentrated field at the outer and inner radius edge will counter induce the windings(or the connections putting the multiple disks in series) opposing what is being induced on the windings that are radially induced.  cant say there would be more or less on either the outer edge induction or the radial portion being induced.  we cannot negate the like facing fields of the magnets. they need to exist somewhere. they will be very prominent at the outer and inner radius."

  Consider 20 wires wrapped radially around the magnet-disk-pair.   The force on the electrons in the wires can be found using the Lorentz force equation:
F = q(v x B)  where F, q and B are vectors and "x" represents the cross product of the v and B vectors.

I agree that the B fields are concentrated at the outer and inner radii.  To get around this, one can place a cylinder or envelope of mu-metal shielding around the coil-bundle as it goes across the inner and especially the outer edge of the disk-pair (where v is largest).  That should drastically reduce the B fields there, so F-on electrons will be much less than F-on electrons in the wire on the 2 faces of the magnet-disk-pair,  F = q(v x B).

For me, this means - experiments... but it is great to explore in thought-experiment mode to identify and work out solutions for various problems that can be foreseen - as you are doing.

An alternative approach would be to connect face A to one side of a // plate capacitor (on the edge of the pair, shaped perhaps like a double-arc over a portion of the circumference) and face B to the other side.  Like that, there would be no electron flow OVER the edges, just a weird-shaped cap charging. 
  (With a diode in the circuit, the cap would not be able to discharge as the rotation stops.)

[Magluvin]

Interesting points, mags.  Did you approach this theoretically - or did you do actual experiments?

theoretically.  just because there is a iron disk between 2 like pole disk magnets doesnt mean it simply absorbs the field.  in fact, why use the iron disk at all.  all of the fields need a return path. it may appear to be theoretical thinking, but more of a hypothetical educated guess.

most of what i posted should leave one to focus on the fact that the fields of the ring magnet do not rotate with the magnet itself.  i find that fascinating. it should clearly describe the magnet as a field influencer rather than a producer.  to further test that, i have a large rotor to try my idea of a coil and magnet or magnets fixed to the outer edge of the rotor to see if it does what i think it might do.   

lets say it doesnt.  then we would need to find out why.  if in the original paradox experiments, the copper disk spinning creates currents in the disk, then we would know that it is not a changing mag field that induces the current and it must be flux cutting.  if the individual magnet with the coil on the edge of the rotor does not produce current as i describe, then why is that?  in faradays tests, the magnet can be rotating or not and the rotating copper disk will still be induced. my train of thought is that if a single magnet is moving with a coil positioned properly, then that moving magnets field is shifting its way through the fields all around us. thus the fields that the magnet is concentrating in that particular portion of the coil, it would seem likely that the coil should be induced as the magnet and coil rotating on the rotor should be encountering field shifting causing flux cutting in the coil therefore producing current. if not, then it would need to be examined more as to why not in this case, because it seems to be happening in faradays case. 

mags

[CITFTA]

This is an interesting subject.  I like mags way of looking at it.  I want to add a thought.  I've only had about a 1/4 cup of coffee so far so this may not make any sense.  We all know that copper is non=magnetic.  What if the only way to disturb the field that mags is describing can only be disturbed by another magnetic field.  If that is true then rotating a copper coil in the field will not produce any current.  But in the presence of another magnet rotating with the coil, now the field will be disturbed and produce current in the copper coil.  The Coral Castle guy claimed he got more power from iron than from copper.  I wonder if he was just rotating an iron wire coil  without a magnet.  I've never tried that.  I wonder if anyone else has.

Carroll

[Verpies]

Thanks to PhysicsProf for sharing the great idea!

What is the name of the EM simulator that you have used ?

[panyuming]

What is the name of the EM simulator that you have used ?

Simple use of the old version of Vizimag318

[Allcanadian]

In the Faraday generator there are a few things to consider which anyone can easily prove for themselves.

1)We can move a magnet along any axis, towards-away or up-down or left-right, and the magnetic field will produce a force on a copper disk. However the magnet will not produce a force on the copper disk when the magnet is rotating. This proves the magnetic field does not rotate with the magnet. A magnet rotating on the N-S axis above a compass will also have no effect. The magnetic field does not rotate with the magnet.

My experimental proof is confirmed by an AI.
"When you rotate the magnet around that same axis: The field pattern in space is unchanged, Every field line at every point is exactly where it was before, So although the magnet material is rotating, the external magnetic field is not changing at all. This is very different from rotating the magnet end-over-end".

This is proven by the fact that when we rotate only the magnet in a Faraday generator no induction occurs. AI confirms this fact, "If you rotate only the magnet (about its own N–S axis) in a Faraday (homopolar) generator, and the conducting disk is stationary, then no induction occurs. Rotating the magnet about its magnetic axis does not change the magnetic field in space."

2)When the copper disk rotates but the "magnet is not rotating" induction occurs because the free electrons in the copper are moving through the stationary magnetic field.
When the copper disk rotates and "magnet is rotating" induction occurs because the free electrons in the copper are moving through the stationary magnetic field.
In effect, induction in the Faraday generator depends on charge motion, not on relative motion between magnet and conductor.

3)There is another interesting experiment we can do to prove this matter. Induction occurs in every case except when only the magnet rotates because the magnetic field is stationary. Whenever we rotate the copper disk the electrons start moving and are induced. We don't need a voltmeter with two wires or load to prove this. A charge separation occurs in the copper disk which can be measured by a electrometer or charge detector. This proves the external load or voltmeter wires are not being induced because there are no wires to induce. The EMF is generated inside the rotating conductor or copper disk not in the external wires.

[Verpies]

In effect, induction in the Faraday generator depends on charge motion, not on relative motion between magnet and conductor.

...but since all motion is relative and the motion of the charges wrt to the magnet does not matter, then their motion must matter wrt to something else.  Define that "something".

Also, your analysis would be more complete if you had discussed the brace/counterpoise for the back-torque that is experienced by a loaded Faraday generator.

[Allcanadian]

...but since all motion is relative and the motion of the charges wrt to the magnet does not matter, then their motion must matter wrt to something else.  Define that "something".

The "something" is the stationary magnetic field of the magnet.

The only "paradox" is that many falsely came to believe the magnetic field has field lines and said lines must rotate.

We could clear this up right now and ask ChatGPT if the field lines are real.
-"No—magnetic field lines are not real, physical lines. They are a visual and mathematical representation we use to describe a magnetic field."
-"The lines are a drawing tool to show the field's direction and strength. Each line shows the direction a tiny compass would point."
We now have a factual answer and nobody should be claiming the magnetic field rotates when we know as a fact it doesn't. AI is a game changer and it explained exactly how the Faraday generator works much better than any person could.

In the Faraday generator the copper disk moves free electrons through the stationary magnetic field the same as any other conductor in a generator. The moving charges then experience a Lorentz force or sideways force moving the electrons towards the disk center or perimeter. It's really that simple and there is nothing to it.

What does confuse many people, which relates more to our perspective, is that in theory we could spin up a Faraday disk floating in space not connected to anything and it would still produce a charge separation from center to perimeter. This is true because the magnetic field is stationary and does not rotate with the copper disk. The work which caused the charge separation was done when we initially spun the disk.

In any case, it's faster and easier to just ask an AI to explain how all this works.

[Magluvin]

field lines is a good way to visualize field direction and field strength.  otherwise how could we look at it? sims use it to show it this way. never the less, it gives us a basic way of understanding how to work with it. 

mags

[Verpies]

field lines is a good way to visualize field direction and field strength.

Indeed they are good for that.

[PhysicsProf]

What does confuse many people, which relates more to our perspective, is that in theory we could spin up a Faraday disk floating in space not connected to anything and it would still produce a charge separation from center to perimeter. This is true because the magnetic field is stationary and does not rotate with the copper disk. The work which caused the charge separation was done when we initially spun the disk.

OK, charge separation is what I'm after, in the lab - and store that in some kind of capacitor WHICH IS ATTACHED TO THE SPINNING SYSTEM.  THIS STORES ENERGY, E = 1/2 CV^2.

My question is - how can we do this?  perhaps using a diode in series with the Cap so that the Cap does not discharge when the spinning system is slowed to a stop, so we can measure the voltage 'in' the capacitor...

I think this can be done...  I'm seeing a flat disk-magnet spinning on axis.  A Cap in series with a Schottky diode is attached appropriately  - one wire to the outer edge (how?) and the other near the hole in the disk.  Spin it fast, charging the Cap, then stop and measure V in the Cap.

[PhysicsProf]

  I don't think this experiment has ever been done... that's what makes it particularly interesting to me. 
Then we can add additional diode+Caps, also measure Eout vs Ein (net).

[Verpies]

I don't think this experiment has ever been done... that's what makes it particularly interesting to me. 

Do you realize that the spinning measuring circuit will be in the same reference frame as the electrons in the spinning disk ...and penetrated by the same magnetic field ?