Homopolar generator

[cala]

Hello.

I looked for information about how the homopolar generator works, because there are some claims (N-machine, Space Power Generator...) that say there is no backEMF or opposition to obtain the work.

The homopolar generator is a disc magnet glued to a conductor disc. When you make it turn, there is a EMF between the axis and the periphery of the discs.

Well, we usually explain the working of the motors saying that a change of magnetic flux causes a current on coils. The magnetic flux change is the method we normally use to move the electrons.

On the homopolar generator, the magnet does not impulse or move the electrons of the disc. A motor moves the disc and the magnet, so the electrons of the disc move. The only difference with normal motors is the method to impulse the electrons. The homopolar generator does not use the relative movement respect the magnet, it uses the relative movement respect the motor.

On this page there is better explained all the forces and energies involved (sorry, in Spanish, but the drawings and the formulas should help):

www.sc.ehu.es/sbweb/fisica/elecmagnet/induccion/homopolar/homopolar.htm

Well, finally it's stated that it's just like the linear version of the experiment, but on a rotary fashion.

But i'm not so sure. My question is about the current supposed to run on the radius of the disc, that is supposed to create the opposite torque to the motor.

On the linear device, the electrons that run through the rod creating the current are the same electrons (they have PERPENDICULAR velocity to the path, but they feel an EMF ALONG the path, and they move in a current ALONG the path, so they finally create backdrag also).

But in the homopolar generator, every moment, the electrons that creates the EMF from the radius of the disc are different ones (they have a velocity PERPENDICULAR to the radius, so they feel an EMF ALONG the radius, but they finally move PERPENDICULAR to the radius).

My question is:

Stated that the electrons on the radius are not the same every time step on the rotary disc, can we consider that it is a real current?, is really a current running through the disc radius?

[cala]

Other interesting thing about the homopolar generator is that it can work also as a motor:

If you apply EMF between the axis and the periphery, the rotor start to turn, due to the existence of the B field of the magnet, and so, the electrons begin to move.

On normal batteries and circuits, the moving charges must be replaced by the EMF source (because the movemnet of the charges is ALONG the path. Finally, the source of EMF goes empty.

But what happens on the homopolar generator working as a motor?

The electrons always follow a PERPENDICULAR path to the aplication of EMF, and also, the electrons that left the radius are replaced by more electrons from the conducting disc, so it seems that the EMF source will not get empty!.

[BoulderHead]

Might be interested in checking the links I posted in this thread;

http://www.physicsforums.com/showthread.php?s=&postid=98132#post98132

The man behind this thing (and brother of the Hollywood director with the same initials) has been toying with it for a very long time. Investors have come an gone, if you know what I mean.

[cala]

Hello Boulderhead.

I checked your links (some i've checked yet before) and other ones new.

On your topic you say you are skeptic by some reasons. I'll thank you to post your reasons on this topic.

I'll tell somethings i think about this term:

Firstly, I don't understand the sentence on much of the pages where it's said that it's not easy to understand (or is not contempled by clasical electromagnetism) that the magnet attached to the rotating disk produce EMF, because there is no change on magnetic flux to get the EMF.

That method is not used on the homopolar generator, but the mechanism to get the EMF is explained on clasical electromagnetism:

everytime you've got a moving charge and a magnetic field, an electric force is generated in some direction (so is not necesary a moving or changing B field).

Nobody said that the only method to move a charge were the magnetic flux change method.

Also, on the clasical example that relates the flux change with the generation of EMF, the same principle is being used. If you move one rod perpendicular to a uniform B field, no flux is changing, and also, the EMF is created. Of course, if you connect the rod with a circuit, it's clear that the space between the rod and the rest of the circuit will change (you've got to move the rod somewhere!). If you move all the circuit behind the B field, the EMF on some parts will cancel on others.

That change on surface to the conections is something that doesn't happen on the rotational example. It's not needed a change on the flux. That only happens on the linear version of the experiment, and i think it's just a consequence of that kind of motion (that's to say on normal motors induction also, because of the change of normal surface to the magnetic flux).


Other point about the homopolar generator:

I said before that i think no current is on the radius of the rotor. If so, maybe the current should be on a circular path, due to the rotational movement we are doing to the disc. But moving the disc, you move the charges on one direction... ALL the charges (positive and negative), so there is no current on the disc, because all the charges move on the same direction. A current is a displacement of negative charges to one side, then, the positive charges to the other side. If ALL that charges move on the same sense, no current is created.


And finally, viewing the homopolar generator as a motor, if you apply an EMF between axis and periphery, you'll obtain positive charges moving on one sense, and the negative ones on the other. That will create a current rounding the disc, but i dont know if this current will make the rotor move. Also, this circular current will create an EMF force around all the disc, centered and in opposite direction to the EMF applied.


Maybe the configuration and working of this device is not free energy or overunity, but in some way, it's strange and astonishing.

[Jonathan]

I have heard these claims and done many experiments, and all point to the homopolar generator not working. Any measured voltage seems to be due to jumpy contacts and the relative motion between the contact leads and the spinning magnet. The experiments I have performed aren't very accurate, as I really didn't need to know the numbers unless something happened, and nothing interesting or unusual did. But I have not conclusivly proved there is nothing to the claims, just that I couldn't replicate it with my modest budget and resources.
I do have an interesting idea on a related device that works again using the as yet untested by me Tesla bifilar coils. However, when I get around to it I will not use that idea, prefering the motionlessness of the transformer one previously descrbed. But I'm getting off topic.
Cala, I suggest you take some physics classes rather than ask about every overunity scheme you find on the net, it will take years to test and answer them all, not to mention that you have a much greater chance of being told they don't work here, regardless of whether they do or don't. Note that I'm not accusing anyone of unscientific bias, it's just that most people who visit physics forums understand and accept current physics and by definition therefore do not consider systems which should run by the normal laws as being capable of overunity, which the normal laws forbid.
That, getting off topic again, is the greatest reason why I consider the Tesla bifilar coil as being a real contender, because Tesla actually suggests (implicitly) in his patent that the coil doesn't follow the normal laws, and so may therefore somehow circumvent the CoE law.

[cala]

Jonathan, i'm only trying to see if all that overunity and free energy devices can be seen from the point of view of actual physics (on my limited view).

in this case, I just make the analisys of force related to velocity and related to magnetic field, they all orthogonal, and the results seems to be strange ones. Do you remember that i said that if you applied EMF, a current will flow on a circular path, and will create a radial EMF opposite to the applied EMF?... Actually, the EMF created is ON THE SAME SENSE than the applied!!!

The analisys is very easy to do under clasical physics, but the results seem not to agree with it, so I only want people more skilled than I to analyze the homopolar generator on all the cases that I pointed out, and tell me if their results agree with i said or there is something i'm not counting, and what it is. I'll try to do some drawings to explain myself.

I'm not looking for a new physics theories, i'm looking for new physics results.

[Jonathan]

This is why I suggested you take a physics class: because the right hand rules, etc. do agree with current physics and this device doesn't agree with them, and your interpretation of them is incorrect.
If you pass a current radially through the disk, there will be a force to make the disk and magnet rotate relative to each other. But unless this force is of such unbelievable strength as to break the bonding agent used to hold the disk to the magnet, it will not spin, becuase the bonding agent eliminates the possibility of relative motion. Of course, if one did the experiment hoping it would move, one would have contacts on the rim and the axle. And the wires connected to those contacts will feel a force, and supposing they're held down, will exert a force on the whole assembly, making it want to turn relative to these two wires, though it is almost always not of enough strength to over come bearing friction. (Notice though, that though I say two wires and we know they must have current traveling in opposite directions, their effects don't cancel each other out completely because one comes and touches the rim, while the other must go right across the B-field to get to its contact, giving it more direct interaction with the assembly than the first.)
The claims I have heard are that the device generates electricity when rotated despite the fact that there is no relative movement between the parts, and this contradicts current physics. The proponents have said that this is due to the unrecognized fact that when one spins a magnet on a the same axis as it is magnetized on, the field doesn't spin with it. They assert that magnetism is an effect of the spacetime occupied by, and apparently inseparable from, the magnet.
None of my experiments have pointed in this direction. One did a little, but I think it was due to the magnet's nonuniform field, but I have no way to test and see if it really has enough of a nonuniformity to cause me to notice. It is a cheap magnet though, not designed for physics experiments like this, esp. givent he smallness of my set up.
I encourage you to do your own experiments and see, since mine aren't conclusive.

[russ_watters]

I didn't read all the posts or check the links (maybe tomorrow) but I am reminded of the experiment in physics class where you drop a magnet down a metal tube (non-ferrous). The magnet drops slowly because as it drops it induces a current and magnetic field in the pipe. The current is on the order of a few THOUSAND amps. Enormous. But free energy? No.

[Jonathan]

No, I think that is almost completely unrelated. The electrical energy is due to the kinetic energy of the magnet which is from the potential energy you put in. I'm sure we all agree on that.
Summary:
This thread, as I understand it, is about whether or not there is any truth to the claims that homopolar generators can put out more enrgy than they take in. My experiments, though inconclusive, generally point to no. Accepted physics, as what I can tell of what cala understands, is not completely understood by cala (no offense of course).

[cala]

Jonathan, you don't see that in the case of the homopolar generator, it will work the same with the disc in relative motion to the magnet or with the magnet attached to the disc. In this case, the relative motion about these parts is not the prime mover. The prime mover on the homopolar generator is the motor that applyes the torque to rotate the magnet and the disc.

The electricity obtained by the method of relative motion of magnet and wires is a consequence of the physic principle better used on the homopolar generator: i think it's like the poynting vector. The relative motion method is a subset or subclass of this poynting vector like method. So finally, you can have electricity with no relative motion between B and the charges, but you need to move the charges by another method, and it's done with the motor. The magnet and the disc can be moved by the motor, and this will also create EMF because the charges have velocity into a B field,so EMF is then created, and it's clasical physics.

Also, take notice than on all the physics books, the principle of this moving charge into a B field creating a force is always explained before the flux variation and relative motion method, so to me, this relative motion method is derivated from this primordial fact used to get the electricity on the homopolar generator.

[russ_watters]

Originally posted by cala
Jonathan, i'm only trying to see if all that overunity and free energy devices can be seen from the point of view of actual physics (on my limited view). Save yourself a lifetime of effort and accept the first law of thermodynamics.

[cala]

Well Russ, first, let me try a final (and a bit extense) explanation of the homopolar generator under clasical physics. Then, put the first law of thermodinamics where you consider it comes into play.

I'll put a detailed explanation on what I think is happening on the homopolar generator, and it could be true that it could be more output than input, without strange energies coming from nowhere:

First, i’ll make a little change on design. Imagine the rotating conducting disc, but only a radial region is under the B field of a magnet (the magnet is not attached to the disc also). The reason to do this change will be lately exposed.

When the motor gives torque to the disc, the situation of moving charges into a B field will happen, so a radial EMF will be created under the B field affected zone. Now, we connect the periphery and the axis of the disc with an external circuit, closing the circuit through a radius on the B field affected region of the disc.

Due to the EMF created by the moving charges on the disc under the B field, a current is created on the circuit, but this current (in principle) can't go through the radius of the disc under B field, because the charges move perpendicular to the radius in the disc on this zone, as previously stated.

So how can be a current through the circuit and no current running on the disc radius?.

Well, the disc is neutrally charged (the charge is equally distributed), but due to the rotation and the EMF created, the negative charges take the external circuit path to go to periphery of the disc, and the positive ones go through the circuit on opposite direction to the center axis of the disc. The periphery of the disc becomes negatively charged , and the axis positively charged as the charges pass through the circuit. Then, a polarizing current that polaryzes the disc runs through the external circuit (this polaritation will be recombined on all the disc parts unafected by the B field, as exposed later, but now, we will consider that the disc remains polaryzed to explain what happens on the B field part). As the disc goes polarizing, a radial E field goes increasing by polarization of the disc, and this E field has the same sense than the one created by rotation of the disc on B field zone. This new E field will add to the one created, so rotation and polarization of the disk work together on the B field zone. Now, the E field is greater than the one created by particle movement, so the movement of the charges is affected, and now, a radial component of the charges movement is generated by the polarization effect on the disc B field affected zone. Now, a current is allowed to flow radially also throgh the B field zone. This current will tend to recombine the charges distribution on the disc to make it neutral again. This recombination current take place radially around ALL the disc. This current was always present on the disc part not affected by B field, and now, could also be generated on the B field zone, if the recombination is slower than the polarization, as exposed.

The important fact is that ALL the charges to polaryze the disc must go through the external circuit (so huge current on the circuit), but the same huge current must redistribute through ALL the disc radius to recombine the charges against disc polarization, and only a little portion of this current (if any) pass through the radius affected by the B field, (so little current through that specific radius of the disc will cause an EMF opposing to the motor torque).

That is the reason to change the design of the homopolar generator: If all the recombining currents of the disc were under the B field, the EMF generated against the motor torque will count, and the output will be the same than the input.

But current under B field creates EMF, and current alone does not generate opposition, so distributing the same huge current that run through the circuit through the disc, causes that only a little portion of the huge current go through the radius under the B field, and that reduce the quantity of EMF that the motor must to overcome.

So the current to polaryze and depolaryze the disc has the same amount, but the disc polaryzes through the external circuit (all that current runs on the circuit), and the disc depolaryzing current runs through all the disc radius, and only a little portion of the total current ( only the part under the B field ) causes a force opposing to the prime mover motor.

As you can see, if the radial depolaryzing current is 1A on each radius of the disc (for example), then we could have a polarizing current of 2*PI A on the circuit at the same time (every point of the periphery is neutralyzed at the same time). Theoretically, we could get an output/input ratio of 2*PI=6.28... or 628 % eficiency. The bigger the B field region, the less eficiency (because we have to take more recombination currents into the tangential EMF calculation), and sustract all the looses.

Russ, I think the homopolar generator acts just like an open system, not like a closed one ( like all the motors and generators we use ), so the thermodinamic law you talked about doesn’t apply here.

The conducting disc has a part that is part of the electric circuit, creating the EMF under the B field, but also have another part that receives different charge distribution, and works recombining without opposition, because the currents on this part are not under B field. So that part is just a surrounding environment to the active parts, and restores the effects made by the B field part and the circuit, taking advantage on the fact that the recombination current that occurs on this part of the disc ( making the charge distribution neutral again to repeat the procces on active parts by rotation ) has no back-effects from the point of view of the motor prime mover, and so, the motor that gives torque only have to apply the work that will be involved on the active part energy exchanges of the disc. The energy exchanges on the part of the disc that is not under B field are “free” from the point of view of the active parts, and that is to say, on the motor that impulse the disc.

Now I see why on normal circuits the work we must do is the same than the work we can get, and we can never get more than 100% eficiency: because the polarization (EMF source) and recombining (external circuit) currents run through the very same conditions!.

On the homopolar generator, the polarizing current pass through the external circuit at a time, but this current is fractioned to fill every radius of the disc on the recombining step, and only works against the motor torque if it’s under the B field part. So we use only one circuit to make all the polarization current run to the disc, and we collect only a little portion of radial recombining current on the disc active part. So it's to say, we see a certain amount of EMF and huge current through the external circuit, and we get the same EMF, but little current on the active radius under the B field part, and then little torque opposition to the motor, that only have to work to supply the energies involved on the active disc part, not on the rest of the disc exchanges of energy.

[cala]

Image is better than thousand words:

[russ_watters]

Originally posted by cala
Russ, I think the homopolar generator acts just like an open system, not like a closed one ( like all the motors and generators we use ), so the thermodinamic law you talked about doesn’t apply here. All "open" means is that heat/energy can flow throught the boundaries of the system and ny system can be open or closed based on how you define the system. For example my desk lamp here is an open system. It produces light and heat without doing any mechanical work inside the lamp.

A heat pump is an open system where overunity efficiency sometimes causes confusion. Its confusing because a typical thermodynamic system involves heat (or electrical energy) in, heat out, and mechanical work out. Efficiency is simply Wout/Hin. But a heat pump (and an air conditioner) moves heat around instead of producing mechanical work (or converting heat, in the case of a simple electric heater). The output heat is greater than the input electrical energy, but that is NOT overunity efficiency and the first law of thermo still applies. To avoid confusion, its usually termed "coefficient of performance." And the conditions are known: ie, the heat it moves from the environment into the system is quantifiable and quite well understood.

So: Where does this energy come from in your systems? And don't say its irrelevant - if its relevant to me, its relevant to anyone who would ever buy one of your inventions.

[cala]

Russ, you're right, the homopolar generator can't go against the 1st law of thermodinamics (as any device can go against it).

I thought you was talking about the second one, but later I decided to let my error there to get a faster and stronger response.

So we are in agreement that the homopolar generator can go against the second one... but how?

Take a look to the image i attached at the initial post on this page.

Consider the working of the homopolar generator like a serial to pararel conversion on a transfer of charges.

On the circuit, the charges have a serial transfer fashion, and on the whole disc, the charges have a paralel transfer fashion.

Now, you can see that given a certain time step, the speed needed on the serial path is much greater than the speed needed on the paralel paths to carry the same amount of charges to the same place. The only difference is that on serial path, the charges goes arriving one by one, and on the parallel path, they arrive all at the same time.

You can use this fact , and keep a high velocity transfer of charges on a serial path (the circuit), using the parallel paths to go back to initial conditions (the disc axis and periphery).

The trick is that only one (or some, but not all) of the parallel paths taken by the charges oppose to the prime mover that keeps the whole thing working.

We can get volts by storing one kind of charges on some place, and other kind on other place, but the current through this places will make the store finally get empty, so the volts dissapear.

But the homopolar generator does not use the charges that create the volts to create also the current. The charges that creates the volts are different ones than the ones taken into the circuit current, so the volts can be maintained, and the current can run also. To keep the voltage, you only must maintain the speed.

The current on circuit is on a serial path (so high amount of current as charge/time) and the current on the disk is taken a lot of paralel paths, where only a few ones make resistance to the rotation that keeps the voltage.

That is where the difference on energy cames from. the charges that creates the EMF are different than the charges collected to make the circuit current. The motor speed gives the EMF created, but the current is marked by the circuit resistance, and the collection of this current charges from the disk does not affect the EMF generation. So we are "de-coupling" the correlation between current on circuit and EMF source. Once you can do that, the currents on the source of the EMF and on the circuit can be different (as explained by the serial and paralel paths examples), and the output energy be greater than the input.

I've got to think more the way to explain this fact, but now i think i understand the proccess very well, and sure it works. I only have to get an easy example to explain myself.

[russ_watters]

Originally posted by cala
So we are in agreement that the homopolar generator can go against the second one... but how? Lolololololoolololololololoololol.

No.

[cala]

Well, i'm sorry, i talked under your point of view, and i had not license to do that.

Ok, so you think the system can't do more output than input COP.

Yesterday I was thinking how to explain the working of the homopolar generator on an easy way. A lot of things came to my mind (i could not sleep yesterday), and one thing that came to my mind was the Maxwell Daemon example.

Here, i put just an ad-hoc explanation of the Maxwell Daemon from a web page:

"Maxwell was a famous scientist who discovered electromagnetic waves. But only theoretically; he could not prove it. It was proven by Heinrich Hertz 20 years later. But Maxwell put forward a theory saying that in the world there must be something called electromagnetic waves. There is a famous second law of thermodynamics which states that in each system, energy must be constant. But Maxwell said, imagine two spaces: between the two spaces you have a door with a little slit. One space filled with gas is very hot, and the other is very cold. According to the law of thermodynamics, when such a door is opened, both spaces will be of equal temperature. But Maxwell could mathematically prove that the hot space would become hotter, and the cold space would become colder. So this was a riddle, a paradox: Maxwell's daemon.(...) But then along came Zurek, a scientist, who wrote an article in 1984, "Maxwell's daemon, Szilard's engine and Quantum measurement." He solved the paradox in such a way that it could even obey the second law of thermodynamics. He said, this daemon is doing work - Somebody is doing work. Even when he just counts molecules, this also uses energy, this also uses information. So when something is becoming hotter, and something is becoming colder, we can exactly measure this difference of energy, and we can say this is an amount of information, that is energy which the daemon uses for himself. So we could explain it even within the second law of thermodics. He calls this daemon 'Quantum daemon.'" Peter Weibel, "Ways of Contextualisation," Place, Position, Presentation, Public,(ed. Ine Gevers), De Balie, Amsterdam, 1991-1992, pp.232-3.

Ok. Russ, now imagine the conducting disc of the homopolar generator as a "charge gas". positive and negative particles are there, but they are mixed and externally, the disc is neutral, but internally, the particles are there for the daemon.

We always see this daemon as something intelligent that not only have to count the particles, in order to get potential, it should recognyze them, and order the particles depending on their charge, changing also their location.

But on the homopolar generator, our "maxwell Daemon" is just an autistic one: We help the daemon, and create a zone on the disc (by the B field and velocity of the disc) were the daemon have not to move any single one of the particles passing under the B field. Our daemon only have to count the positive and negative particles to create the EMF!.

I mean, the "charge gas" is neutrally distributed on the whole disc, but as we make the disc rotate, there is a specific radius on the disc (under the B field) where the existence of this particles is taken into account. Imagine that this special radius is a kind of toll or frontier where we have our Maxwell Daemon. As the disc moves, the neutral "charge gas" of the disc goes passing through the toll. Then you have the daemon saying:

659 positive charges, 678 negative charges - 0.080 V (for example)
698 positive charges, 687 negative charges - 0.081 V
....
645 positive charges, 643 negative charges - 0.079 V

He must do nothing else to get potential! he have not to move the charges. If we take the Zurek explanation, the work or information than the Daemon must have on these conditions is less than if the Daemon had also to move the charges depending on their charge type.

I have other examples, and you can't imagine how clear now I see some other ideas that use a similar principle on other physic concepts.

For example, i tried to do an homopolar generator rotating water analogy, and then it reminded me the experiments of Viktor Schauberger, a man that is known on the free energy world by claim that vortex of rotating water can also extract more output than input.

[cala]

Hello.

Long time without any comment about this. Well, i'll now risk myself with some calculus. Tell me if you see some errors or simply have something to say...

the explanation on how the homopolar generator works was early exposed. Now, let's use some equations and parameters:

Imagine a conducting disc that weights 0.02 Kg. The conducting disc has R = 40 cm. Also, this conducting disc is turning at W = 27 rad/s = 257.83 RPM.

The disc is turning into a B field of 0.2 Teslas, and the magnet that gives the magnetic field covers 1/16 of the disc surface.

A conductor with a resistance of Rc = 0.000185 Ohms is the electric circuit that links the periphery and the center of the disc.

The physical parameters described are:

B = 0.2 T on 1/16 of the circular area of the disc.

m = 20 g = 0.02 Kg
R = 40 cm = 0.4 m

Rc = 0.000185 Ohms.

Now, lets make some calculus of the electric power we can get:

V = 0.5 * B * W * R * R = 0.432 Volts

I = V / Rc = 2332.8 A

Pe = V * I = 1005 W = 1 KW

Now, the portion of current on the disc behind the magnet oppose the movement of the disc:

Iact = 1 / 16 * I = 145.8 A

Me = 0.5 * Iact * B * R * R = 2.332

That is the mechanical force we must to do also:

Mm = m * W * W * R * R = 2.332

So finally, we have a mechanical power of:

Pm = Mm * W = 62 W

So, finally, the power gain is:

Pe / Pm = 16

We can get 1KW of electric power with 62 W of mechanical input!

Some technical considerations about the device (how to collect the high current, how to reduce this high current-low voltage DC electric energy to normal or usable values) have now to be taken, but the calculus agree with spected theory.

If the whole disc surface is covered by the B fields, the EMF will be the same on every radius of the disc , but ALL the disc currents will create an opposition that will cause the mechanical input work to be equal than the total electric energy obtained.

But if only a portion of the currents on the disc take place under the B field, the EMF on this zone will be the same than before (so the electric energy on the external circuit is the same also) but only a portion of the currents on the disc will opose the disc movement, so less mechanical input is required to obtain the same electric energy output.

The ratio between the conducting disc area and the magnet area gives the gain on energy, or the electric / mechanical ratio.

[cala]

Now we can see two distinct methods to get electric voltage:

The "standard" method is having an ordenation of charges of different types on different locations of space. That is creating a "dipole", or having a polarized element (like a capacitor). So we can say that an specific static ordenation of charges causes voltage. The voltage is maintained if the ordenation of charges is maintained. In this case, we have a pre-polarized device.

Also, there is another method to obtain voltage, that is used on the homopolar generator: An specific movement of charges under specific conditions (the B field) creates voltage. The voltage is maintained if the movement of charges is maintained. We have no polarized device.

What happens if we have electric current on the "standard" method? The current re-order the charges, and the specific ordenation of charges needed to keep the voltage drops down, as the charges go from one side to the other. We are depolarizing the device. The voltage can't maintain, because the current affects the charges ordenation. The device was pre-polarized, and the current de-polarizes it. V is I dependent in such a way. The I we use on circuit is this de-polarizing current.

What happens if we have current on the homopolar generator? The current also re-order the charges, BUT THE ORDER OF THE CHARGES WAS NOT THE CAUSE OF THE VOLTAGE. The charges can re-order, but there is also the movement of the charges than before, so voltage remains. The current in this case is not depolarizing the device, in fact IT'S POLARIZING IT!. We have voltage due to the movement, and new voltage on the same way, due to the polarization by the current. On normal method, the new charges added by the current tends to compensate the previous ordenation of charges, so finally, the voltage drops as the charges mix. But on the homopolar method,there is no previous ordenation of charges, so the charges re-order and goes acumulating, creating new voltage by re-ordenation, because there is no previous ordenation to deplete. The voltage now is due to the movement and to the ordenation.

The V and I in this case are independent. The pass of current through the circuit does not affect the creation of the V method by movement, only the polarization effect. That’s the part that is used always on normal method.

On "standard" method, we have only the de-polarizing current (once the device is pre-polarized).

On the homopolar generator, we have two currents: One runs through the circuit, and also polarizes the disc, and other runs through the disc, and de-polarizes it. The homopolar generator is doing both proccesses at a time, but on different parts. Also, the real cause of the voltage (the charges movement, not position) is not affected.

On "standard" method, the depolarizing current is also the current that we must take into acount to get the loses or the input work. (because we could get only the same energy that previously polarized the device).

On the homopolar generator method, we have two different currents at the same time (in principle of the same amount, one counteracting the effects of the other.) , and we use the polarizing current to get the output, but only a part of the de-polarizing current counts on the loses or input work.

In fact, the depolarizing current on the disc is free, and the little the active part on the disc (the region affected by the B field that creates the EMF) the greater the energy gain. Polarizing and de-polarizing currents will have the same amount, but not the same effects on the device.

On the “standard” method, the cause of V is the charges position, a current running will kill this cause of V.

On the homopolar generator, the cause of V is the charges movement, a current running will re-order the cahrges and create another cause of V that will add to this cause of V, and another current will kill the cause of V due to re-ordenation, but not the voltage due to movement. So finally, we have currents that not depletes the primary source of the voltage (the movement of the charges, not their ordenation).

Finally, the currents only affects the ordenation of the charges, so if we use the standard method to get potential, it’s easy to understand why we can’t get more output than input, because the cause of the voltage and the cause of the current is the same thing: the modifications on ORDENATION of the charges.

On the homopolar generator, the cause of voltage is the charges MOVEMENT, not ordenation. The currents created affects only the charges ordenation, not their movement, so the cause of voltage (charges movement) is different than the effects of the currents (ordenation changes).

[pallidin]

OK, let's make this simple. A homopolar generator is a proven electrical generation device. What makes it different is that a "normal" generator produces more voltage than current. A homopolar generator produces more current than voltage.
The "power factor" remains the same, but a homopolar generator is useful in special applications requiring high current/low voltage.
That's all. Sweet and simple.

[Binki]

OK I just stumbled across this thread and found it very interesting to see ideas being mulled over. I have to agree with 'cala' on the fact that the faraday disk stands up to standard electrical generating/motor formulas.

I have worked on such experiments -generators and motors- which were produced 5-6 volts at 3000+ amps from an 8 inch disc. once the generator was turning and fully operational the magnetic field (generated by coils) could be adjusted on the motor very gradually and the speed and torque was in direct proportion to the current/volts drawn. Heating was only proportional to conductor size/resistance. as regards overunity this was never proven due to the dificulty and expense of drive power measurement.

I have formulated my own ideas due to having worked with people that work on non-proveable theories which annoy me greatly :-). (like one person felt that the electrons were being spun of the edge of the disc by centrifugal force ;})

The main problem I found was working with such high current caused very high losses through conductors and the near imposibility to multiply the voltage levels to an acceptable level. ie higher speed makes slipring contacts impractical for high currents even with 95% silver-carbon brushes and putting two faraday discs in series was the furthest practical solution which gave us 5.7V at 2600A at 3000rpm.(if I remember correctly 1.6-1.8T) with a continuous and equeal magnetic field over the surface of the disk. and liquid metal (Mercury, Galium/tin) evaporated due to the current level.

The previously quoted N-Machine has an uneven B field (Quadrapole)as far as I can understand and therefore has a return path for the current through the same conducting disc. the experiment according to a report I have read was driven by an AC motor which does not permit an acurate power measurement.

Also as has been said the source of the field ie a ring magnet can be static or attatched to the disc and still produce the same result, implying that the field is independant to the source, but I wont dare to state that a magneting field is a universal field simply concentrated by the magnetic material :-)

I have since gone through -over the last ten years- all that has been discussed above and finally found a way to make an experimental machine that induces the current(yes with a constant m-field and avoiding the return path) into a static coil with no frictional sliding contacts but with the advantage of a coil giving multiples of the generated emf of pure DC.

I would be interested in further discussion.

[cala]

Hey, great new look! Physicsforums XP, i think... :biggrin:

Well about the homopolar generators, it always seem to be a problem the high current and low voltage that we can extract. I have an idea to transform the high current low voltage into normal values before the carbon brushes:

Imagine a cilindrical ring magnet (like soundspeaker ones). Then, you make a coil with wire, rounding the magnet through the magnet hole (just like a ring electromagnet, but it have a magnet inside. From one side, the wire is close to the N or S magnet surface. On the other side, the wire is far away from the S or N magnet surface.

Then, each turn of wire will add the little voltage in series to the other turns. Also, the force will also increase:

Imagine:

From 0.7V and 1000A (then 700W), we could do:
70V and 10A with a coil of 100 turns around the magnet.

As all the thing will rotate together (the magnet and the transforming coil), it will behave like the normal homopolar generators, but with low current levels.

[Binki]

cala wrote: On the other side, the wire is far away from the S or N magnet surface.

From practical experiments you will find that no voltage is generated. It appears that the magnetic field does not turn with the magnet! in any case even if the wires are further away from the other pole they would intersect with exactly the same magnetic field although at lesser density (Lines per cm squared ie Gauss- if indeed magnetic lines existed and could be counted you would count the same going through the wires and doing the opposite work to the oposite pole).

the only way prove this is by taking a C shaped magnet and passing a wire through the centers of the facing but oposing poles then take a conductor from the center of the gap perpendicular to the first wire (axis) now connecting the axis to the conductor via a galvanometer you will see current apear when turning the conductor around the axis or holding the conductor stationary and moving the magnet or keep.

I once pondered on making form permanent magentic materials a magnetic ring made of four pieces that is two sides one outer rim and one inner rim or hub all tapered in order to fit snugly together. All would be pre magnetized to give only one magnetic pole externally having the oposite pole hidden inside. This would give us a ring that would take a winding like cala is suggesting to generate only. It can be tried maybe to prove that the field can be rotated or not.

Edited by Binki 2 hours later

I have been thinking (It hurts sometimes). This composite ring should generate a voltage when any magnetic material comes close to the rotating ring. It could be called the magic ring due to the fact that there should be no losses except the bearings therefore as near as possible 100% efficient causing the same proportional drag as the energy drawn. :cool:

Keep thinking cala thats good.

[Jdo300]

Hello Cala,

I have been doing research into the field of Free energy and different types of devices ranging from permanent magnet motors to overunity pulse motors and Tesla radiant energy systems. The Homopolar Generator was the very first device that I heard of when I jumped on the bandwagon, and though I had abandoned the idea for a while in pursuit of other devices, I have been interested in working on one again. The information you present in your posts is very interesting (although I'm not sure that I understand all the details). I *think* I get the gist of it. I have been mulling over some different ideas to setup my own Homopolar generator and I was thinking about the problem of the brushes. For me, eliminating friction for this application is a must so I had an idea and thought I might run it past you. Do you think it would be possible to draw the power from the spinning disk using electrostatic induction? This idea is only half-baked but I was thinking that if you could somehow convert the charges to static charges and electrostaticly move them from the disk to something like an outer ring that is surrounding the disk. Perhaps that would be a good way to connect the external circuit without messing around with mercury or brushes. I have no idea how to implement this though but just an idea. What do you think?

Jason O

[cala]

Hello Jason.

Looking to your messages, i see some "correlations" with many of my own questions about electromagnetism and static charge.

The homopolar generator is just the device you said that creates static charge with a magnet: If you turn a neutral metallic disc in front of the magnet, a charge difference will build up on periphery and on the axis.

But i think that there is no method to move this electrostatic charges or variations out from the disc without contact, or without making this electrostatic charge change in time, thus wasting the same power.

[pallidin]

A homopolar generator has the distinct property of generating a power factor(watts) characterized by more current than voltage. There is NOTHING in the sciences alluding to any other special attribute.
The notion that a magnetic field, rotated, is yet static in influence is complete BS, and has never been demonstrated. I repeat, NEVER. Can anyone show me different?

[Jdo300]

Hello Cala,

Yeah, I’ve been having great interest in electrostatics and electricity lately. My main focus though is permanent magnet powered motors. There’s definitely something to them even if people believe that magnetic fields are conservative (which they are no doubt). My research in that area has been centered on the interactions of magnetic fields at the quantum level to see how they influence magnets at the macroscopic level. I would go more into this, but I don't know enough yet to intelligently explain myself or discuss the topic so I'll leave this subject alone for now.

But back to what I was talking about earlier, it seems to me that there should be some way to inductively transfer power from the spinning disk-magnet assembly to something like an electrode or ring or something. I’m guessing that there’s no way you could make a spark jump from the spinning disk to an electrode due to the low amount of voltage, but what if you could use a specially wound electromagnet coil with thin gauge wire to create the needed high voltage? I’m not sure how one would go about it or even which direction/pattern would work if any, but it just seems to me that if electrical power can be generated, then there must be some way transfer it inductively.

What if we could somehow store the charge on the outer rim of the disk, and as it builds up, discharge it into a surrounding outer ring, kind of like a large capacitor. I’m guessing specific materials would be needed for this to work if it’s even possible, but since the Homopolar generator has high amperage and low voltage, could storage of the charge be sufficient enough to jump a narrow gap separating the disk and something to receive the charge? Here's another random thought: what if you took a large coil cylinder with the magnet in the center and spun both together? If a current is created in the coil, could you set another coil in close proximity to create an induction current in the second coil? Or would the power have to be alternating for this to work? Just some thoughts :smile: .

Jason O

[Binki]

Hi

Jason/Cala: the magnetic field does not produce electrostatic charges, if they exist it is due to the proximity of a stationary object to the rotor/disc.

Pallidin: take two ring magnet place them on both sides of a conducting disc and rotate them all together, you wil have a charge between axis and perimeter. You would not see a charge if the field was rotating with the disc.

Jason: yes it is possible to induce the voltage into a winding but only under very specific conditions.

Binki

[pallidin]

Hi

...take two ring magnet place them on both sides of a conducting disc and rotate them all together, you wil have a charge between axis and perimeter. You would not see a charge if the field was rotating with the disc.

Binki

Binki, I am aware of the theory you stated, but I am also aware that this has never been experimentally shown to exist! That is, the phenomenon you stated has been attributed to the rotating magnetic force interacting with the static lines of the measuring leads, inducing a current in those static lines through conventional means due to RELATIVE motion.
Or perhaps I am wrong, and a scientist has affixed a current/voltage measuring device to the disk, allowing NO relative motion between the disk arrangement and measuring apparatus, and the phenomenon occurs.

It is my understanding that such an experiment, which is NECESSARY to prove the theory, has NOT been sucessful.
Perhaps you could give any authoritative reference to a well designed, peer-reviewed experiment showing otherwise. I would be very interested if such were the case.

[Jdo300]

Hi

Jason/Cala: the magnetic field does not produce electrostatic charges, if they exist it is due to the proximity of a stationary object to the rotor/disc.

Pallidin: take two ring magnet place them on both sides of a conducting disc and rotate them all together, you wil have a charge between axis and perimeter. You would not see a charge if the field was rotating with the disc.

Jason: yes it is possible to induce the voltage into a winding but only under very specific conditions.

Binki
Thanks for the information. It still seems to me though that we can somehow inductively transfer power. Please correct me if I have a wrong understanding here but this is why I’m thinking this way. Is the charge that builds up on an electrostatic plate identical to the same charge that would build up on the plate of a capacitor, which has been fed power from a battery? This is my logic so if it is even remotely true, then it seems like there should be a way to discharge the electricity across the gap between to places/rings/whatever that are close to each other. But going back to the coil idea. Binki, what type of coil setup do you think would work to produce the high voltage that could be discharged? I know a lot of what I’m saying here might be a lot of misunderstandings on my part so please correct me in my understanding if I’ve got the wrong idea :smile: .

Cala, I have another idea to maybe create an alternating current in the disk. I have no idea if this is even possible but I was thinking, what if you were to take the doughnut magnet, cut it in half, take one of the halves and turn them around and stick the things back together so that it’s still a doughnut shape but the polarity is reversed on one half of it. DO you think that would do anything if it were spun? Just my random thoughts here.

Jason O

[zoobyshoe]

The homopolar generator is a disc magnet glued to a conductor disc. When you make it turn, there is a EMF between the axis and the periphery of the discs.
Cala,

I just noticed this thread. I am not sure if someone has corrected you about this yet, but it is not true that the magnet and conducting disc are glued together and run together in a homopolar generator.

This was the first kind of generator invented, and it was invented by Michael Faraday. He rotated a copper disc between the poles of stationary magnets, and took current off the disc by connecting to the shaft on which the disc was mounted and to the periphery of the disc by brushes.

The disc rotates, the magnets are stationary. There is relative motion between the two. They do not rotate together.

I have heard of the N machine. It is another bogus item, like the Newman energy machine and the Johnson magnet motor.

Homopolar generators are real, but there is nothing remarkable about them. There are many different configurations possible: you can spin a conducting cylinder in a lathe, hold two magnets up to it, one inside, one out, and take current from the two ends of the cylinder. There is no "free" energy here. In fact it isn't a very efficient generator because of the eddy currents in such a large area conductor.

Tesla actually designed the best one I've ever heard of: it had spokes like a wagon wheel which kept the eddy currents to a minimum. Still, he didn't find it was a particularly promising way of generating elecricity and never persued it.

[Jdo300]

Hi, I won't get into an argument about weather the Homnopolar generator is OU or not, but I have found lots of research information from reputable universities that have verified that electrical current can be generated when both the magnet and disk are rotated together as well as just when the disk spins past the magnet. I was trying to find this particular site from some university that had a reserch study specifically oriented in studying the Homnopolar generator and they had their test models and data all up on the site. I'll have to keep looking and then I'll post the link later but I did find some other interesting information:

http://www.pixii.com/theory.htm
http://128.252.223.112/cgi-bin/circR?/posts/archives/oct98/907332555.Ph.r.html

[pallidin]

Cala,

I just noticed this thread. I am not sure if someone has corrected you about this yet, but it is not true that the magnet and conducting disc are glued together and run together in a homopolar generator.

This was the first kind of generator invented, and it was invented by Michael Faraday. He rotated a copper disc between the poles of stationary magnets, and took current off the disc by connecting to the shaft on which the disc was mounted and to the periphery of the disc by brushes.

The disc rotates, the magnets are stationary. There is relative motion between the two. They do not rotate together.

I have heard of the N machine. It is another bogus item, like the Newman energy machine and the Johnson magnet motor.

Homopolar generators are real, but there is nothing remarkable about them. There are many different configurations possible: you can spin a conducting cylinder in a lathe, hold two magnets up to it, one inside, one out, and take current from the two ends of the cylinder. There is no "free" energy here. In fact it isn't a very efficient generator because of the eddy currents in such a large area conductor.

Tesla actually designed the best one I've ever heard of: it had spokes like a wagon wheel which kept the eddy currents to a minimum. Still, he didn't find it was a particularly promising way of generating elecricity and never persued it.

You are correct, zoobyshoe, a true homopolar generator does not have the magnet and disk glued together(or in any way relationally fixed).
But it does have the unique property of generating extremely high current/low voltage such that conversion circuitry in a standard generator could not handle it. Efficiency aside, it is unique.
So much so that homopolar generators are in fact used by industry and the military for special applications requiring very high current to voltage ratios.


But there are some that insist the "glued" arrangement works as well, somehow indicating that when rotated together a current is generated. Furthermore, those adherents suggests that this shows that magnetic fields do not rotate even when the source magnet is rotated.
I have seen claims but absolutely zero evidence of that.

[zoobyshoe]

Hi, I won't get into an argument about weather the Homnopolar generator is OU or not, but I have found lots of research information from reputable universities that have verified that electrical current can be generated when both the magnet and disk are rotated together as well as just when the disk spins past the magnet. I was trying to find this particular site from some university that had a reserch study specifically oriented in studying the Homnopolar generator and they had their test models and data all up on the site.
I went poking through my rexresearch infolio on Unipolar Dynamos (homopolar generators) and it looks like you are quite correct.

I must retract what I said earlier.

The infolio includes an article published in the American Journal of Physics (46:7) July 1978 with the following abstract:

"In the conventional Faraday generator a conducting disk rotates in an axial magnetic field. If the disk is replaced by a cylindrcal permanent magnet that supplies it's own magnetic field, the effect is identical. (Bold letters mine-Zooby) It follows that any moving magnet generates an induced electromotive force due to the presence of it's own field..."

-One-piece Faraday generator : A paradoxical experiment from 1851

It goes on to state that Faraday discovered this himself in research done after the original rotating disk/stationary magnet discovery. His published this information the next year (1852) and it can also be found in his diary for that time.

So, I apologize to Cala for asserting that the magnet must be stationary in order for it to work.

-Zooby

[zoobyshoe]

You are correct, zoobyshoe, a true homopolar generator does not have the magnet and disk glued together(or in any way relationally fixed).
See my post above. It looks like I was wrong about that.
But it does have the unique property of generating extremely high current/low voltage such that conversion circuitry in a standard generator could not handle it. Efficiency aside, it is unique.
So much so that homopolar generators are in fact used by industry and the military for special applications requiring very high current to voltage ratios.
Skimming through the infolio mentioned above, I see that the amperage to voltage ratio in this kind of generator is staggering: they can deliver thousands of amps at 3 volts!!!
But there are some that insist the "glued" arrangement works as well, somehow indicating that when rotated together a current is generated. Furthermore, those adherents suggests that this shows that magnetic fields do not rotate even when the source magnet is rotated.
I have seen claims but absolutely zero evidence of that.
The publication in which Faraday apparently reported being able to generate electricity with a rotating conducting magnet alone is listed at the end of this paper as:M Faraday. Philos. Trans. R. Soc. 1852 p.25. I immagine that "R. Soc." stands for "Royal Society", but don't know what "Philos. Trans." might mean. The diary is listed as: Faraday's Diary, vol V. p 403. paragraph 11 371.


Such a thing ought not to work by my understanding of how electricity is generated.

Speculating off the top of my head, however, I suppose it could be that the magnetic field has its own inertia separate from the magnet generating it. Moving the magnet would not necessarily cause an instantaneous movement of it's field. I know this is true of electric fields - there is a lag when you move a charged object between the time you move it and when it's electric field catches up to resume its former radiant configuration. That being the case, the same may be true for the magnetic field and might account for how a conducting magnet (hard steel, say) or a magnet/conductor sandwich could be made to induce current in itself. That is just a guess.

Zooby

[pallidin]

Such a thing ought not to work by my understanding of how electricity is generated.

Speculating off the top of my head, however, I suppose it could be that the magnetic field has its own inertia separate from the magnet generating it. Moving the magnet would not necessarily cause an instantaneous movement of it's field. I know this is true of electric fields - there is a lag when you move a charged object between the time you move it and when it's electric field catches up to resume its former radiant configuration. That being the case, the same may be true for the magnetic field and might account for how a conducting magnet (hard steel, say) or a magnet/conductor sandwich could be made to induce current in itself. That is just a guess.

Zooby

A great speculation! Best I've heard yet. Much better than the "static magnetic field" theorists. Good job. Reminds me of the free-space field-effect I proposed on another post for something entirely different, so I do understand what you are getting at. Now, let's examine this:

- The far end of a magnetic field that is 1-foot away from the source magnet cannot move "instantaneously" with the movement of a rotating source magnet, because to do so would directly imply that a reaction is effected faster than the speed of light. So, a "lag" as you stated, is highly likely to occur. The higher the rotational speed, the greater the lag. Lag "recovery" would necessarily cause the magnetic field to cut across the conductive disk attached also 1-foot from the magnet, therefore generating current flow. Or would it?
Think about it. What's missing here?
Well, the attached conductive disk that is 1-foot away from the source magnet ALSO CANNOT FOLLOW the rotation of the source magnet "instantaneously", so it lags as well!
Ah, now we have the picture. The magnetic field lags, but the conductive disk it hopes to cut across also lags, and so that local reference frame is completely static with respect to each other, producing no induced current!

But, what if the system was such that the lags were not complimentary(and perhaps this is true even in this case) would current be produced? I would think so. But there is another problem. Once a load circuit is completed to allow the generated electron movement to produce work, a local back EMF is also produced, tending a resistance to the lag field and thus the source magnets rotation, thus requiring work to continue generation.

Interesting. This would seem to imply that such a mechanism, spun very fast, would actually slow down faster than an identical mass system without magnetic influence.
That would make for one hell of a good experiment. I think I'll have another beer and think about this. :surprise:

[zoobyshoe]

The thing is, when you speak of the conducting disk also lagging, there doesn't even have to be a conducting disk if the magnet itself is a conductor. This could be a hard steel magnet or an alnico one. Some ceramic magnets I have seem to conduct and others don't. [The ones that don't may simple have an enamel coating, I can't tell.]

The authors of the paper I cited report having rotated a small alnico cylindrical magnet in a lathe. They connected to the axis of rotation by means of a carbon brush held in the tailstock and to the circumference of the rotating magnet by a separate carbon brush. There was no separate conducting plate or anything. The voltage they measured increased with the speed and they measured a top voltage of about 1.5 volts. (Unfortunatly, they didn't bother to see how many amps they could draw.) They gave the dimensions of the magnet as about 1 cm diameter by 4 cm length. It was held in a plastic bushing to insulate it electrically from the chuck.

It occured to me after I wrote my previous post that once the magnet got up to speed the "lag" would become uniform and cease to change. There would be no further relative motion between the magnet and its own field. The field might appear torqued if you could see it, but it would be unchangingly torqued, and you couldn't expect any current.

If, as you mention, the back emf opposed the "lag" field, then we might propose a kind of simple harmonic motion or resonance where the two are constantly oscillating back and forth thus continuing the relative motion between field and magnet.

Magnetic fields have electric field lines as their "raw material" so to speak, and the notion that axial rotation does not also cause a rotation of the magnetic field would mean that electric field lines can jump from one electron to another, if you see what I mean. I very much doubt that. Each electron has its own, personal electric field lines that it carries with it where ever it goes, and I don't see them being exchanged among each other.

The energy, of course, is always actually coming from the work it takes to rotate the magnet.

Zooby

[Binki]

Palladin / zoobyshoe

The faraday disk itself as a generator is no mistery to science, take an electrical engineering text book to see your typical diagram of a sigle conductor passing through a magnetic field and its corresponding formula to show the relation of field strength by conductor length by speed gives you the voltage generated. The text books go on to the next step very rapidly expalining that you can multiply the voltage by windings. The fact is that the faraday disk exactly relates to just one conductor moving through a magnetic field (Gaus x legth x speed).

You will also find that on applying a load to the circuit you will have a breaking effect exactly proportional to the power drawn (right hand rule).

Many people (including Tesla) have mused over making a spoked wheel until they have realized that the disk is simply a single conductor moving through the field non stop.

Some of us :-) believe that the 'field could be independant' to the source when rotating axially - but as has allready been shown there is no real proof - maybe the insistance on this is due to the fact that somewhere in all this manipulation of the field there seems to be some anomalies to the standard text book theories or are these so called anomalies just badly conducted experiments givien false results.

In any case I believe sincerely that as long as we can keep imagining new ways of using the magnetic field we can only advance and giving in to "Text book science" is a defeatist attitude. Thrashing the magnetic field back and forth causing all sorts of losses through histerisis and back emf has given modern society an energy back bone in order to advance in many other fields of science, but maybe some day we could come back to the roots and generate electricity in a more harmonious way like the earth itself is probably generating for some other unknown purpose.

[zoobyshoe]

Palladin / zoobyshoe

The faraday disk itself as a generator is no mistery to science, take an electrical engineering text book to see your typical diagram of a sigle conductor passing through a magnetic field and its corresponding formula to show the relation of field strength by conductor length by speed gives you the voltage generated. The text books go on to the next step very rapidly expalining that you can multiply the voltage by windings. The fact is that the faraday disk exactly relates to just one conductor moving through a magnetic field (Gaus x legth x speed).
Yes, I don't think anyone here is mystified by a conventional Faraday generator. It is this matter of a rotating magnet with no conductor attached being able to generate current that is mystifying me.

You will also find that on applying a load to the circuit you will have a breaking effect exactly proportional to the power drawn (right hand rule).
Do you mean "braking" effect? As in it slows it down? Or "breaking" meaning the circuit is shorted?

As far as I know the "right hand rule" is an outdated version of the "left hand rule", the revision having occured when it was realized that electrons flow rom the negative terminal tothe positive, and not the other way around as was previously thought. Its purpose is to determine the direction of the lines of force around a conductor, or to determine the polarity of a solenoid from the direction in which the current is flowing. It doesn't seem to have anything to do with effects following a load on a generator.
Am I missing something?
Many people (including Tesla) have mused over making a spoked wheel until they have realized that the disk is simply a single conductor moving through the field non stop.
I believe the purpose of the spokes is to selectively diminish the area in which current is being generated in order to diminish the eddy currents. Tesla's design additionally configured the spokes as involute curves.

Some of us :-) believe that the 'field could be independant' to the source when rotating axially - but as has allready been shown there is no real proof - maybe the insistance on this is due to the fact that somewhere in all this manipulation of the field there seems to be some anomalies to the standard text book theories or are these so called anomalies just badly conducted experiments givien false results.
Yes, in addition to the links by jdo300 I have come across other people who maintain the field doesn't rotate axially. I don't find that to be a persuasive explanation of the effects.
In any case I believe sincerely that as long as we can keep imagining new ways of using the magnetic field we can only advance and giving in to "Text book science" is a defeatist attitude. Thrashing the magnetic field back and forth causing all sorts of losses through histerisis and back emf has given modern society an energy back bone in order to advance in many other fields of science, but maybe some day we could come back to the roots and generate electricity in a more harmonious way like the earth itself is probably generating for some other unknown purpose.
Models are never complete and are usually subject to revision. The earth's magnetic field is not understood, and there are many researchers trying to find a good model for how it may be generated. I wouldn't jump to the conclusion that it is being generated in a particularly harmonious way. It is known to be quite unstable, as you're probably aware, constantly shifting position and subject to periodic reversals in polarity. That, however, is a subject for the Geology forum.

[zoobyshoe]

O.k. everyone.

I located a small cylindrical conducting magnet and recreated the set up reported in the paper I read. I found one measuring .510 diameter x .592 length. I am not sure what material the magnet is, but it is either hard steel or alnico. It is not ceramic. It had a resistance of about 2 ohms when I placed the leads one on the axis of rotation and the other on the circumference, to check that it was a conductor.

I chucked it into my little bench lathe insulating it from the jaws with plastic and made contact with the circumference with an electrical brush taken out of an electric mixer motor. The brush was also insulated from the toolholder by shims of plastic, top and bottom. I made contact with the axis of rotation by chucking a pencil into the tailstock and touching it up against the magnet. I cut the wood away from the pencil down to the carbon about an inch back from the tip to have a place to touch the meter leads.I checked for continuity with an ohmmeter both before and during spinning of the magnet and there was always continuity.

There was, however, no voltage and no amperage during spinning.

I checked at several increasingly faster speeds, checking the continuity each time. There wasn't the slightest little jiggle of the needle when I set it on dc volts or dc amps.

As far as I'm concerned, a rotating conducting magnet does not generate any current in the absence of a stationary conductor.

I can't account for the results reported in the paper I read, but I no longer believe what was reported is accurate.

[zoobyshoe]

Pallidin: take two ring magnet place them on both sides of a conducting disc and rotate them all together, you wil have a charge between axis and perimeter. You would not see a charge if the field was rotating with the disc. Binki
I want to try this one next. When you say "ring" magnet, will the annular magnets from a common audio speaker suffice?

You say to put one on each side of the conductor. They are concentric with the axis of rotation, correct? Also, you mean with unlike poles facing each other so there is attraction between the magnets through the conducting disk, correct?

And you are saying that if I rotate them all together, magnets and disk, at the same time at the same rate I will be able to take current off by connecting to the axis of rotation and to the periphery of the conducting disk?

-Zooby

[Binki]

Do you mean "braking" effect? As in it slows it down? Or "breaking" meaning the circuit is shorted?

Yes, braking/slowing down, the same way any generator when free running (ie no load) draws less power from the driving source than when it is loaded.(Please excuse my spelling)

As far as I know the "right hand rule" is an outdated version of the "left hand rule".

Right hand, Left hand - I'm not trying to rewrite text books and for the sake of simplicity I have simply stated something that we all should understand. :smile:

I believe the purpose of the spokes is to selectively diminish the area in which current is being generated in order to diminish the eddy currents. Tesla's design additionally configured the spokes as involute curves.

If you have the same intensity of magentic field over the surface of the disk, there are no eddy currents, the electrons are pushed all in the same direction (from or to the axis) and there is no return path other than an external circuit. This is what causes a lot of confusion.

What I was trying to show on my last post was that a conductor in a magnetic field either a wire or a disc will stand up to the standard generator/motor formulas. I know it, Ive Done it.

I must also add on zooby's experiment that you will need a reasonably powerfull magnet to get any effect, some rare earth magnets get up to 10,000 Gauss aprox but iron based magnets are very weak. Also the larger the diameter gives you logically more conductor length and therefore a higher voltage with the obvious mechanical problems of a higher speed peripheral for your sliding contact or brushes.(Maybe I'm just stating the obvious to all you guys out there! :rolleyes: )

[zoobyshoe]

Yes, braking/slowing down, the same way any generator when free running (ie no load) draws less power from the driving source than when it is loaded.(Please excuse my spelling)
Thanks for clarifying. The point is now understood.


Right hand, Left hand - I'm not trying to rewrite text books and for the sake of simplicity I have simply stated something that we all should understand. :smile:
Either way, I think the actual concept you wanted was Lenz's law not a hand rule. Lenz's law states that "induced current always flows such that its magnetic field opposes any change in the original magnetic field that induced it." This "opposition" is why it is harder to turn a generator under load. The left hand rule can be used in conjunction with Lenz's law to find out what direction current flows, or what polarity the fields have, but Lenz's law and the left hand rule are two distinct things and aren't interchangable.
If you have the same intensity of magentic field over the surface of the disk, there are no eddy currents, the electrons are pushed all in the same direction (from or to the axis) and there is no return path other than an external circuit. This is what causes a lot of confusion.
Yes, I see your point here. The "spoked" generators, Tesla's included, are not designed for uniform fields over the whole disk. Like Faraday's original generator, the magnetic field is applied in one place.
What I was trying to show on my last post was that a conductor in a magnetic field either a wire or a disc will stand up to the standard generator/motor formulas. I know it, Ive Done it.
I think everyone is OK with this.

I must also add on zooby's experiment that you will need a reasonably powerfull magnet to get any effect, some rare earth magnets get up to 10,000 Gauss aprox but iron based magnets are very weak. Also the larger the diameter gives you logically more conductor length and therefore a higher voltage with the obvious mechanical problems of a higher speed peripheral for your sliding contact or brushes.
The magnet I used was reasonably powerful for its size but was a pretty small magnet. If a more powerful magnet is needed to get any current I would tend to side with Palladin in his suggestion that the current you may see is simply what is being induced in the conducting material of the brushes.

I tried the configuration you mentioned of two magnets on each side of a conducting disk all rotated together. I used two speaker magnets on opposite sides of an aluminum disk.
The magnets are 2.937 inches in diameter x .404 thick. The disk is 3.414 diameter x .025 thick.

I glued both magnets to the aluminum with superglue but wasn't able to get them perfectly concentric with each other. One was about .005 eccentric. This made the lathe vibrate a little when I spun them, and I never dared to crank it up to full speed. I got up to about 1500 RPMs and didn't dare go higher.

Anyway, with this configuration, I did, in fact, get the tiniest little voltage and current. The needle on the meter moved enough that I was sure it had actually moved and I was sure it was actually dropping back to zero when I removed the leads from the circuit. It looks to have generated one or two millivolts.

It rose half a hair higher when I doubled the speed.

I really think all that was happening is that I was inducing a miniscule current in the brush that was in contact with the circumference of the disk, and expending quite alot of watts to do it.

Zooby

[Binki]

Maybe its time to explain a little about on of the experiments I was involved in. (There being some interest in the subject :smile:)

The machine set up was to clear up some initial doubts on the faraday generator/motor effect and was built to completely enclose the magnetic field to eliminate any claims of induction in the external circuit. the field was created by copper coils calculated and tested to give 1.6-1.8 Tesla (16000-18000 Gauss) which was the saturation of the iron we were using. The core was made of two F/disks of 8 inches diameter mounted on a hardened copper shaft with a copper slip ring silver soldered to its perimeter. The disk was part of or centre of the main magnetic keep that enclosed the coils leaving only a 5mm gap through which a copper plate passed in order to extract the current and also a base to hold the coils and brushes. You can imagine the shape as something like two dinner plates cupped together. there were two units on the same shaft in order to double the voltage generated. The brushes were made of 95% silver/carbon (No expense spared) so the no load consumption of the DC motor was only 200 watts approx. Even after all this the machine only produced the calculated 5.6 Volts at 3000 rpm and 3000 Amps approx.

An almost identically sized faraday disk Motor would turn proportional to the intensity of the magnetic field etc.

One of the fascinating features of this set-up was to see the motor side turn at any speed (from almost standstill to the equivalent speed of the generator) adjusted by the field strength, with a torque equivalent to the Watts involved. That is even at 1 rpm the turning power was there you could hold on to the shaft and it was humanly impossible to stop by hand.

If you capture the set-up from my basic explanation you may appreciate that the generated current could have been produced in the core/centre or in the gap through which the copper plate passed in order to extract the current, which of course does not prove or disprove movement of the field.

After all this experiment gave me a very clear view of the concept and did not give any inclination towards OU.

The use of coils maybe give an easier comprehension of the field being independant to the source but does not prove rotation or non rotation of the field.

[zoobyshoe]

The machine set up was to clear up some initial doubts on the faraday generator/motor effect and was built to completely enclose the magnetic field to eliminate any claims of induction in the external circuit.
I have questions about this that I'll ask later because they are less important to me than others I have.
the field was created by copper coils calculated and tested to give 1.6-1.8 Tesla (16000-18000 Gauss) which was the saturation of the iron we were using.
Very strong magnets.
The core was made of two F/disks of 8 inches diameter mounted on a hardened copper shaft with a copper slip ring silver soldered to its perimeter. The disk was part of or centre of the main magnetic keep that enclosed the coils leaving only a 5mm gap through which a copper plate passed in order to extract the current and also a base to hold the coils and brushes.
This I don't understand. The disks were copper. How could they form part of a magnetic circuit? You cannot put a piece of copper across the pole of a horseshoe magnet and form a magnetic circuit. A "keeper" must be of a material in which a magnetic field can be induced by proximity to another magnetic field.

I'm also not understanding the 5mm gap. Perhaps because I'm not sure of the orientation of the electromagnets with regard to the disks. You spoke earlier of a "uniform magnetic field". What that says to me is that on one side of the copper disks you have a north pole pointed at the disks which completely covers the whole area of that side of the disk. On the other side you have a south pole that completely covers the whole area of that side of the disk. There is attraction between the magnets and the magnetic lines of force go directly through the copper disks. Is this how you had it set up?
You can imagine the shape as something like two dinner plates cupped together.
And there was nothing in the space between the "dinner plates, correct?
there were two units on the same shaft in order to double the voltage generated. The brushes were made of 95% silver/carbon (No expense spared) so the no load consumption of the DC motor was only 200 watts approx. Even after all this the machine only produced the calculated 5.6 Volts at 3000 rpm and 3000 Amps approx.
Here, now, is something I find very problematic. 5.6 volts times 3000 amps makes 16,800 watts. You say you're putting roughly 200 watts into the driving motor, and so the rest must be going into the electromagnets. The trouble is that since it is a static magnetic field there is no reason you couldn't replace the electromagnets with permanent magnets of the same strength and apparently harvest the same 16,800 watts with only a 200 watt imput.

I understand this wasn't the focus of your experiment, but you can see that you are proposing something that inadvertantly becomes a case for "Free Energy".


One of the fascinating features of this set-up was to see the motor side turn at any speed (from almost standstill to the equivalent speed of the generator) adjusted by the field strength, with a torque equivalent to the Watts involved. That is even at 1 rpm the turning power was there you could hold on to the shaft and it was humanly impossible to stop by hand.
What do you mean "the motor side"? Thus far, all you have mentioned is a generator.

If you capture the set-up from my basic explanation you may appreciate that the generated current could have been produced in the core/centre or in the gap through which the copper plate passed in order to extract the current, which of course does not prove or disprove movement of the field.
In view of these other claims about rotating the conductor and magnet together and still generating current, what I need you to make clear is whether or not your electromagnets were fixed to the disks and rotating with them, or whether the conducting disks, alone, rotated.
After all this experiment gave me a very clear view of the concept and did not give any inclination towards OU.
I'm not exactly sure what the concept of OU means or implies, but if the claim is that you're getting more energy out than you had to put in, then your set up seems to have that capability were you to replace the electromagnets with permanent magnets of the same strength. That ought not to be possible, and I don't suppose it is. I hope you can understand the problem I am percieving with getting 16,800 watts out of a device that is essentially only drawing about 200 watts to operate.
The use of coils maybe give an easier comprehension of the field being independant to the source but does not prove rotation or non rotation of the field.
Which brings us back to your other claim about gluing two magnets to a conductor and rotating the whole sandwich together and being able to take current off of it. I think I will try rotating the magnets, one on each side of the conductor, opposite poles, and holding the conductor still. If I get an appreciable amount of current from the conductor it should demonstrate that the magnetic field rotates with the magnets. Does that sound right?

[Binki]

Zooby

The whole rotor was soft iron including what is conceptually the "faraday disk" then in order to get a good contact to the circumference of the disk a copper slip ring was silver soldered to it and then the shaft between the two assemblies was also hardened copper in order to offer the lowest possible resistance to the current.

Take the analogy of an apple having been eaten in a way that the waist or thinner part is the generating disk and the upper and lower stubs which have a greater diameter are such as to almost touch each other creating a kind of cavity. Now imagine squashing this apple down to the shape I described of two dinner plates cupped together with its core still in tact, all soft iron. Through the gap passes the copper plate that doubles as a support for the coils and brushes inside the cavity and also is the conductor extracting the current. The total diameter of the rotors was approx 15-16 Inches

Here, now, is something I find very problematic. 5.6 volts times 3000 amps makes 16,800 watts.

No, remember I said this 200 Watts was under a “NO LOAD” Situation just the friction of the brushes( Sorry no Over Unity) and the 16,800 Watts was the machine fully loaded (By the way, no permanent magnets have this strength of magnetic field- another reason to use coils was to take everything to as higher limits as possible in order to overcome any thresholds that might be involved and achieve the most accurate data possible).

In view of these other claims about rotating the conductor and magnet together and still generating current, what I need you to make clear is whether or not your electromagnets were fixed to the disks and rotating with them, or whether the conducting disks, alone, rotated.

The coils where stationary on the copper platform inside the cavity(of the magnetic keep) this copper plate passed through the 5mm gap, which could as I have mentioned have been the generating area but either way the generation of current was produced by only one side of the system by a stationary field or by a rotating field because as you may now have captured through my analogy to a half eaten apple the conductor that draws the current passes through the return path of the magnetic field (5mm gap). If the generation was to occur on both sides then I would have had a big fat Zero result.

I'm not exactly sure what the concept of OU means or implies.

OU = Over Unity (Sorry someone had already used the abbreviation and I thought that it was clear)

but if the claim is that you're getting more energy out than you had to put in, then your set up seems to have that capability were you to replace the electromagnets with permanent magnets of the same strength.

No I didn’t state the power used by the coils and if I remember correctly it was 200-300 Watts, but this was not an issue to address in this experiment we needed to go as far as possible with the field strength which was eventually limited by the saturation point of the iron we were using. some silicon irons and other alloys can reach 22,000 gaus or more before saturation.

Which brings us back to your other claim about gluing two magnets to a conductor and rotating the whole sandwich together and being able to take current off of it. I think I will try rotating the magnets, one on each side of the conductor, opposite poles, and holding the conductor still. If I get an appreciable amount of current from the conductor it should demonstrate that the magnetic field rotates with the magnets. Does that sound right?

Once again as I have already said on the experiment the generating part could be in the core ie the faraday disk or in the gap where the conductor passed this could only have been in one of the two areas as the generated voltage was exactly as the formula suggested it would be for the area of the disk multiplied by the rpm’s and by the gauss(and then by another figure that I cant remember exactly).

Your test is well worth doing and I would be interested in knowing the results. I would like to add that on discussing with a manufacturer of permanent magnets some years ago that the field is not always even over the whole surface (this was another reason for us to use a coil) and may produce some ripple’s of current and therefore the experiment might not give a true result. Mankind’s constant battle in all kinds of research is to avoid ambiguity in experimental results by making sure that the conditions of the experiment don’t give us a false result.

Some have stated in the past that if the field rotates or not has no meaning. But I feel that we not ignore any of the possibilities as we conduct our experiments.

[zoobyshoe]

Binki,

Unfortunately, I am more confused than ever about how your device was configured.

However, the important point is clear: that when you were drawing 3000 amps from it, the driving motor was drawing a correspondingly higher amount of power. When you were getting 16,800 watts from the generator, the driving motor was drawing even more than 16,800 watts to run the device. It is important to point this out for Cala and others who are prone to believe the stories of getting more energy out than is consumed. An electrical generator does not create energy out of nothing. It converts one form of energy to another, always with less than perfect results. We want 100% electricity out, but, instead, some of the imput always gets converted to heat and sound, among other things, and we end up with a few different forms of energy, only one of which is of direct use to us.

I went to work yesterday putting together the configuration I suggested: stationary conductor with rotating magnets.

The conductor is a thick, upright, square aluminum plate. I drilled a hole in the center of the square and pressfit a .5 inch aluminum shaft into it. This sticks out on both sides about 3 inches.This will serve both as the axle for the rotating magnets and as one of the potential power take off points. According to what you said earlier about a uniform field over the whole area of induction, I can take power off any point on the edge of the flat, upright conductor, because it should be the same everywhere.

I machined two Aluminum flanges to hold the magnets. These are essentially pulleys with magnets attached. The pulleys go onto the axle that goes through the conductor with the magnets facing each other through the conductor: north facing south. The attraction of the magnets for each other holds them rght up to the conducting plate. When I machined the pulley/flanges I left a small ring standing proud of the face of the magnets around the hole through which the axle goes to prevent the magnets from contacting the conductor over their whole face. They are prevented from getting closer than .010 to the conducting plate. Friction is limited to the area of contact with this small ring of material. Even so, I found there was alot of friction due to the strength of the attraction of the magnets for each other. I greased the axle, which improved things.

I cannot make any direct mechanical connection between the magnets so that they rotate together. If I did, it would prevent making an electrical connection to the conducting plate. Therefore, the magnets have to be driven by belts that are going to be driven by to pulleys on a separate shaft.

At first, I hoped that I could just drive one magnet and the other would be dragged along by the magnetic field of the rotating one. However, this doesn't happen. Rotating one magnet has no effect on the other. This may mean the field doesn't rotate or it may mean it does rotate but there is too much friction for the second magnet to freewheel along with the first. It might also mean that, even if the field is rotating, it simply changes its orientation to the other magnet without any sort of angular pull arising.

Today, I will work on the driving pulleys and the shaft for them. I'm am debating about what belts to use and haven't decided, therefore, on the dimensions of the pulleys. The belts I have are too large or too small.

The way I see it, if the field does not rotate, any current that might arise from imperfections in the uniformity of the magnetic field would only generate some miserably insignifigant spikes. If the field does rotate, it should generate a clear and unambiguous high current.

If rotating the magnets generates no current, I will reconfigure to hold the magnets still, and rotate the conductor.

I have actually always wanted to try this idea of rotating the magnets and keeping the conductor stationary, because if it worked it would eliminate the brush problem everyone always encounters.

If this doesn't work, another thing I will try is rotating magnets with an asymetrical magnetic field with a stationary conductor. North-South on one side of the conductor, and South-North on the other side. In truth, I think this latter is the only configuration that has any possibility of generating any current, but I will try the others to be sure.

Zooby

[Binki]

Binki,

However, the important point is clear: that when you were drawing 3000 amps from it, the driving motor was drawing a correspondingly higher amount of power. When you were getting 16,800 watts from the generator, the driving motor was drawing even more than 16,800 watts to run the device. Zooby

Very little more it was very close to the 100%, I cant recall the exact value. This is what has made me ponder over how to acheive a situation to multiply the voltage by some kind of winding. I belive that I have found a way to do it but I will need time and finance to test the idea

Binki

[zoobyshoe]

Very little more it was very close to the 100%, I cant recall the exact value. This is what has made me ponder over how to acheive a situation to multiply the voltage by some kind of winding. I belive that I have found a way to do it but I will need time and finance to test the idea

Binki
I was just reading today about motors and it seems the higher the voltage the more losses: higher voltage means more turns of wire which ends up increasing the general resistance, which create more losses. The low voltage of your machine could be the very reason it was so efficient.

The low voltage high current output makes it good, as is, for anything that needs that to begin with. This would be an excellent generator for dissociating water into hydrogen and oxygen, probably for large plating operations such as when they purify copper, and for making hydrogen, chlorine, and sodium hypochlorite. All that large scale electrochemical stuff.

[Binki]

Zooby

Yes agreed, but Resistance is its main problem at 3000 Amps you can only take that sort of power a few meters distance, even with 300mm squared conductors that we used 7 meters of conductor reduced the voltage by half. If you change the ratio voltage to amps you can do more with it (i.e. the national grid is working at thousands of volts in order to reduce losses, the American 110V network needs heavier conductors and more frequent knock down transformers than the 220-240V systems in Europe). I have seen through these experiments that resistance is our ally not our enemy, electronics would simply not work without resistance, electrical systems need a resistive load or you will have a short circuit etc. There must be a happy medium between voltage and amperage.

This system is already used for many applications like a ships propeller drive therefore eliminating mechanical clutches etc but also needs super conductors with their expensive cooling etc. and also many other uses some of which you have mentioned.

Binki

[zoobyshoe]

Binki,

Would the voltage/amperage ratio be closer together if you used a less powerful magnetic field? Or would that cause a drop in voltage as well?

[zoobyshoe]

Another solution to the voltage vs amperage problem occured to me today, Binki. Since you doubled the voltage in your machine by using two disks it should be possible to take that very much farther. You could construct the conducting rotor as a sandwich of many very thin layers of conducting metal separated by thin layers of anything non-conducting. Aluminum foil is about .0005 inches thick and most metal is available in thin sheets or rolls from .001 on up. Using the cheapest and thinnest, aluminum foil, you could fit 125 layers in a mere eighth inch with a comparably thin insulation between them. 125 x 3 volts per layer = 375 volts right from the starting gate. I don't believe the amperage could be very high from such thin conductors.

Does this make any sence given what you know from your experience?

-Zooby

P.S. I am still curious about how the magnetic field was oriented in your machine. You havent explained the orientation of the poles yet.

[Binki]

Zooby

Dont forget that in order to get two disks mounted on the same shaft each had to be completely contained in opositely oriented fields because they were rotating in the same direction. This is more complicated than it seems, I will try to send a diagram.

Binki

[Binki]

Zooby

Voltage is directly related to flux density.

Here is a very quick sketch, it is not very neat but maybe you will get the drift from this sectional view. The two units are magnetically independant which is the only way to put them in series and double the voltage.

As to you other comment on the current drawn fron a thin conductor: The current is only limited by the load capacity of the conductor before losses i.e. copper has a limit before heating of 3000 Amps per square inch of conductor. If you were able to draw more current than the capabilities of the conductor you obviously reach a meltdown point.

Binki

[zoobyshoe]

Thanks for the sketch, Binki. Your machine is much more complex than I thought, and I still don't quite understand how it worked, but I'm more clear on the setup.

You say the voltage is tied to the flux density. In a normal generator voltage is tied both to the number of turns and the speed of rotation. What does faster rotation do in the homopolar dynamo? Increase the amps?

[Binki]

Zooby

Revise a little bit the calculation for generating a VOLTAGE: Speed, Field strength, Conductor Length.

Speed relates to only one conductor on the faraday disk as oposed to being multiplied by the number of turns in a conventional generator.

Field strength (Gauss) is the same for both systems - although optimizing is recomended in the farady disk for the above reason.

Conductor Length is the radius of the disk (within the field) whereas in the conventional generator this is multiplied by the turns.

Amperage can be drawn from both systems up to the limits of the conductors (Before they burst/burn out. Lower resistive load=Higher Amperage drawn.

[Binki]

Zooby

From the text books

Voltage=number of lines of force cut per second divided by 100,000,000

Binki

[zoobyshoe]

Thanks, Binki, that makes sence.

My impression from your sketch is that the coils created a pole over the whole area of each side of the disks, all north on one side and all south on the other side of the disk. Is that how it was?

I'm still working on that other test. Something blew in my lathe motor controls and I have been playing with ways to make a new control system. Figured it out tonight and will put the lathe back together tomorrow. (It's almost one A.M. here.)

Zooby

[Binki]

My impression from your sketch is that the coils created a pole over the whole area of each side of the disks, all north on one side and all south on the other side of the disk. Is that how it was?
Zooby

Yes, but dont forget that the faraday disk was also iron like the rest of the magnetic circuit, the only gap in the magnetic circuit was the famous 5mm gap all the rest was iron, so you get a perfectly even magnetic field.

Binki

[zoobyshoe]

Oh. I didn't catch that about the disk being iron before. That certainly complicates what was going on.

Do you think that in a conventional Faraday generator, which has the magnetic field in just one spot, like Faraday had, would work with my notion of the sandwich of thin conductors to multiply the voltage?

[Binki]

Zooby

Here's a fresh and better diagram of just one side of a rotor

Binki

[Binki]

Oh. I didn't catch that about the disk being iron before. That certainly complicates what was going on.

Do you think that in a conventional Faraday generator, which has the magnetic field in just one spot, like Faraday had, would work with my notion of the sandwich of thin conductors to multiply the voltage?

Zooby

the disk being iron or any other conducting material is not imortant, if we had placed a copper disk in the centre we would have had to increase substantially the field windings in order to keep the field strength at a maximum.

About your sandwich idea, remember you will achieve oposite charges between axis and outer edge of the disk, you can only invert this direction by inverting the field and then you can place each disk series with each other like a pack of batteries +-+-+- and the only way you can invert the field without influencing each other is to isolate each unit magnetically, which is what I did in my experiment but two disks is allready mechanically cumbersome.

Binki

[zoobyshoe]

Yes, I understand the problem now. Each layer of my sandwich will have its own voltage, but they will simply combine in parallel, and the total voltage will be only be equal to that in any one layer, not more. Thanks for saving me the trouble of testing that idea.

What do you expect would happen if I rotated the magnets if each magnet had both a North and South pole facing the opposit pole through the conductor? Do you think it would produce alternating current? Or would everthing just cancel out and produce no current?

[zoobyshoe]

Here's a fresh and better diagram of just one side of a rotor
I'm still completely confused. Why are the brushes on the inside? I also have no idea about what elements were rotating and which were stationary. The plate sticking through the gap is labeled as copper. I though you said it was iron? Totally confused. Sorry.

[zoobyshoe]

My lathe is now running again (though not as well as it used to) and today I machined the four pulleys. I also turned the ends of the drive shaft down to fit into the ball bearings in which they will run. Tomorrow I need to make supports for the bearings and then get everything mounted together on a board. I plan to simply chuck the driveshaft into an electric drill to power the thing for the test. If all goes well I should be able to see if I can get any current out of it tomorrow.

[Binki]

I'm still completely confused. Why are the brushes on the inside? I also have no idea about what elements were rotating and which were stationary. The plate sticking through the gap is labeled as copper. I though you said it was iron? Totally confused. Sorry.

I have explained all this before, but in order to make it clearer:

The copper conductor is the support for the coils and the brushes and it is stationary(the coils and brushes also).

The brushes draw current from the edge of the (so-called)F/Disk but you are seeing also is the iron keep surrounding the brushes and coils giving the whole rotating assembly a much larger aspect. The iron keep is essential in order to give a return path for the field and therefore maintain the field strength. The whole iron keep rotates(because it is part of the f/Disk), therefore it is necessary to have a gap in order to pass out the current. As I have already stated I cannot prove that the generation of current is in the f/Disk or in the gap, this depends on whether the field rotates or not!

Binki

[zega]

Here i will attach a picture of my experiment with homopolar generator...
I have NdFeB magnet 7cm diametar and 1cm thickness, field is around 0.4Tesla at the edge little bit lower at center, it is zinc coated, that zinc i used as conductor...
In this setup i spun a magnet that holds itself on fan steel cup rotor, RPM is around 1500...
Voltage i get from it range from 50-100mv depending on speed (how mutch i press the copper wire contact, rotor slows down, voltage drops) oscilloscope input is straight (no probe) terminated with 50ohm terminator to avoid static, and spikes on waweform are there on purpose to avoid confusion regarding people that don't belive that voltage is available from this setup (so they cannot claim that i just rise a line on scope via zero/offset knob on scope), so i pressed wire contacts little bit lighter for you to see both zero and max voltage because of weak contact, if i use proper force to obtain good contact line becomes solid...
Here is a pic...
ZEGA

[zoobyshoe]

OK, I finally understand. It is quite a bit more complicated than you realize. No doubt you are used to it, but it is nothing like any other homopolar generator I have read about.

I can see how it is so difficult to tell if the field is rotating or not.

[zoobyshoe]

zega,

Did you check for how much amperage seemed to be available from it?

Yours is like my second set up: magnet + conductor, in which I did manage to get a very tiny voltage and current. You got much more. I have no way to measure the strength of the magnet I used, but yours is probably stronger. My magnet was slightly larger in dia. : 7.459 cm.

Question: what is the material of the brushes you are using to make contact with the rotating magnet?

Edit: I see you already mentioned that "copper wire contacts". This is one difference. I used carbon brushes.

So let me ask what the orientation of the magnetic field is on the magnet? Is this magnet from an audio speaker?

[zega]

I have tried to shunt it with 0.1ohm and manage to get around 1/3 of the no shunt voltage, that is around 0.2 amps...
Limiting factor was thin wires, thin zinc coating, and overall high internal resistance of the system (it is all known in electrical engineering).
Magnet is full disc (as you can see) custom fabricated in China for me, i bought a big bunch of Neodymium magnets in china for some stuff and added this round magnets for experimenting...
It is very strong, i have borrowed gaussmetar and measured them, and i constructed and made my own gaussmetar with quad OP and hall from VCR, some magnets i got can pull 500KG (around 1000lbs) dimensions 10cmx3cmx1.5cm orientation trough 10x3 thickness and magnets are VERY dangerous...
These round magnet i oriented trough thickness (1cm) as you can see in experiment via contact placement and waweform...
All in all i plan to make two faraday generators combo in one that has edges rubbing each other at 20000RPM-s and brushes at the centers to minimise power loss due to the friction...
In center there is no high angular velocity so frictional power loss is mutch mutch reduced...
Even then if i manage to get 1-2 Volts i do not expect to run full circle because it is not that efficient...
If there is OU effect in this device i count for at least 5V out and high current (around KA) capability that can be used to close a loop...
But that kind a device is very expensive and i cannot afford it...
I plan to use this small device to test it to the power increase regarding no current drawn spinning condition, and increase in mechanical load when i increase loading of the device, to see if there is a proportional ratios, if there are no proportional ratios i will then consider making larger device to satisfy my curiosity and maybe something else...
ZEGA

[zoobyshoe]

Zega,

You sound quite dedicated to these projects.

Those powerful magnets you got sound awesome.

I'm curious to know how you think the current that you got from the set up in the picture was generated.

Have you read Tesla's report of his experiments with unipolar dynamos? I just reread it today and found it all extremely interesting in regards to this thread.

Zooby

[zoobyshoe]

Binki,

I finally ran my set up today, and to my disapointment, it generated no voltage and no amperage.

This is the one where the magnets alone are rotated. I was kind of amazed that there wasn't the slightest reaction in the meter, and I kept switching it back to the ohms setting to make sure there was continuity in the circuit, which there always was. Rotating the magnets alone apparently generates no current. This tends to support the notion that the field doesn't rotate. I can't say it proves it, because there may be some other effect at work I'm not aware of. By all acounts, if I were to take the same set up, hold the magnets still and rotate the conductor, I should get the usual very high amperage and minimal voltage. It strikes me as perverse that the reverse doesn't seem to also be true.

I guess my next step should be to do just that: hold the magnets still and rotate only the conductor. That should generate definite, indisputable current according to what several sources say, Tesla included. If it doesn't there must be something quite wrong with my set up I'm not aware of.

Zooby

[zoobyshoe]

In his article; Notes on a Unipolar Dynamo Tesla starts by discussing what he finds interesting about the Faraday machine when run as a motor. He is fascinated by the fact that no mechanical or electrical alteration of the field is necessary to produce motion: simply run current through the disk and it turns, no alternating current, no commutators.

It occured to me that, as a motor, the Faraday disk is simply a variation of the effect Faraday observed when he ran current through a wire suspended over a magnet, with the wire making contact with a dish of mercury that was grounded to the same battery, if any of you know that experiment. It is considered to be the first motor ever invented.

A guy who used to post here alot, named Ambitwistor, explained to me that the wire/magnet/mercury motor was easily explained in one of Maxwell's equations, and the motion resulted from the torque experienced on a current carrying conductor which is always at right angles to the direction of current flow in a magnetic field. The same is obviously true of a disk carrying current in a magnetic field, which behaves like a mass of current carrying wires all oriented so the current flows from the axis of rotation to the periphery, or from the periphery to the axis. Instead of mercury, brushes are used to complete the circuit in the case of a disk.

Tesla published this article in 1892. He frankly admitted he didn't understand what was behind the operation of this kind of motor, which must mean he wasn't familiar with Maxwell's work. I'm not sure how well accepted Maxwell was in general at this time anyway. He was right, though, that it works on a very different principle than all other motors.

[zoobyshoe]

In the same article, Notes on a Unipolar Dynamo, Tesla goes on to say:

"Considered as a dynamo machine, the disc is an equally interesting object of study. In addition to its peculiarity of giving currents of one direction without the employment of commutating devices, such a machine differs from ordinary dynamos in that there is no reaction between armature and field. The armature current tends to set up a magnetization at right angles to that of the field current, but since the current is taken off uniformly from all points of the periphery, and since, to be exact, the external circuit may also be arranged perfectly symetrical to the field magnet, no reaction can occur. This, however, is only true as long as the magnets are weakly energized, for when the magnets are more or less saturated, both magnetizations at right angles seemingly interfere with each other.

"For the above reason alone it would appear that the output of such a machine should, for the same weight, be much greater than that of any other machine in which the armature current tends to demagnetize the field. The extrordinary output of the Forbes unipolar dynamo and the experience of the writer confirm this view."

This much greater output of the unipolar dynamo must be the origin of the rumors of Over Unity. Notice, however, that Tesla states this lack of reaction between armature and field only occurs when he "magnets are weakly energized". He says that when the magnets are more or less saturated this effect is destroyed.

The rest of the article is extremely interesting. He was a very thorough experimenter and writes fairly clearly on a complex subject.

It is contained in the book The Inventions, Researches and Writings of Nikola Tesla compiled by Thomas Commerford Martin, published by Barnes and Noble. The paperback edition I have is from 1995, there may be more recent ones. I have seen it for sale in many places and am sure you can get it online from Amazon.

[Binki]

Zooby

About your experiment: If the field was rotating it would be generating the oposite current in the stationary plate and the external circuit, so would be giving you a null result. But I am inclined to believe the field doesnt move.

Binki

[zoobyshoe]

About your experiment: If the field was rotating it would be generating the oposite current in the stationary plate and the external circuit
Hmmmm. This, I don't follow. Why should there be an opposite current in the external circuit?

[Binki]

Hmmmm. This, I don't follow. Why should there be an opposite current in the external circuit?

If the field is turning, you dont have it contained in any sort of way and the lines of force return to the oposite poles of your magnets. they pass through a very large area of space around your experiment you can follow them to some extent with a normal magnetic compass and you will find that your external circuit will be cut by exactly the same number of lines as the part you believe to be generating. (the analogy to lines in a magnetic field is only a way to understand the field strength. You will see iron filings form lines but it doesnt mean that the lines exist in the field)

Binki

[Binki]

Zooby

Let us go a little further in this subject of whether the field turns or not.

Lets assume that it does just for a moment and imagine that large fat ball or donut shape field is rotating and passing through all the surrounding materials some will be conductors and others not and still others may be material that are to some extent magnetic in themselves. What is happening as the lines of force are travelling through these materials? Wont they will be generating current that in turn opposes the movement of the field? I think so and this is exactly why I believe that the field will not turn when you rotate the magnet on its axis because in effect it is anchoring itself to everything around it. You will need to give the field more incentive in order to rotate it! :wink:

[zoobyshoe]

What is happening as the lines of force are travelling through these materials? Wont they will be generating current that in turn opposes the movement of the field? I think so and this is exactly why I believe that the field will not turn when you rotate the magnet on its axis because in effect it is anchoring itself to everything around it. You will need to give the field more incentive in order to rotate it! :wink:
Everything is either magnetic, diamagnetic or paramagnetic. However only good conductors generate enough counter EMF to be of consequence. If you were to spin a bar magnet 20 cm long, North on one end, South on the other, on an axis located between the two poles, with no conductors withing a meter of it, but plenty of other non-conducting material, the most resistence you would get would be from air friction.

Rotating the magnets as I did shows either that the field doesn't rotate or some other cancelling effect we haven't thought to test.

Anyway, I should have my setup where only the conducting disk rotates ready to test today. If this set up (uniform field over the whole area of both sides of the disk) generates a current then it will constitute a strong indication that the field does not rotate when you rotate the magnets.

[Binki]

Tesla published this article in 1892. He frankly admitted he didn't understand what was behind the operation of this kind of motor, which must mean he wasn't familiar with Maxwell's work. I'm not sure how well accepted Maxwell was in general at this time anyway. He was right, though, that it works on a very different principle than all other motors.

As far as I Know about Tesla that he studied all the known information on electricity of his time in colleges in his native Yugoslavia. Faraday was some 40 years before and it was Maxwell as a mathmetician that put into formulas Faradays research.

Binki

[Binki]

Everything is either magnetic, diamagnetic or paramagnetic. However only good conductors generate enough counter EMF to be of consequence. If you were to spin a bar magnet 20 cm long, North on one end, South on the other, on an axis located between the two poles, with no conductors withing a meter of it, but plenty of other non-conducting material, the most resistence you would get would be from air friction.

Dont forget we are dealing with a subject that could have much wider conotations and that thrashing a magnetic field back and forth north to south etc has no bearing -in my mind- on a homopolar system. You have already quoted Tesla's suprise to the faraday motor effect and quite frankly I dont believe that we now have any greater undestanding than then.

Binki

[zoobyshoe]

As far as I Know about Tesla that he studied all the known information on electricity of his time in colleges in his native Yugoslavia.
I think you'd be interested in the unipolar dynamo he designed and built. It was actually two separate ones right next to each other connected in series to increase the voltage. They were on separate parrallel shafts, not on the same shaft like yours. They were the same except that he changed the direction of the exiting field on one of them so that he could run them both in the same direction by means of a conducting band that was looped around the periphery of both conducting disks. This allowed him to only make connections to the rotating shafts. This is something like what Zega wants to make with the two disks touching as they rotate. That sounds like a very good idea to me, because you double the voltage and solve the friction problem with brushes on the periphery of the disks. I think Zega's way you could gang them up indefinitely.

[zoobyshoe]

Dont forget we are dealing with a subject that could have much wider conotations and that thrashing a magnetic field back and forth north to south etc has no bearing -in my mind- on a homopolar system. You have already quoted Tesla's suprise to the faraday motor effect and quite frankly I dont believe that we now have any greater undestanding than then.

Binki
I agree that the unipolar dynamo is different. I am questioning your explanation of the mechanism whereby the field doesn't rotate. It obviously moves nearly instantaneously in response to any motion that is not along the axis of magnetisation; any non-north-south movement. It seem exclusively to be non-rotational on the north-south axis.

Anyway, today I tried the next set up: rotating the conducting disk while the magnets were stationary.

I was appalled at the miserable results.

Much like in my second set up, the needle on the meter gave only the slightest response.

Due to reports of huge amperage, I started with a slow drill as my driving motor, and had the meter set on the highest amp level. No response. I clicked the meter down to microamps and put the drill on full speed: 550 rpms. The needle moved up to about 20 microamps. I changed to a different drill which goes up to 1200 rpms and ranked it up full speed. This only managed to double the amperage to about 40 microamps.
--------
Why is it I'm not getting the famous unipolar amperage?

I made the disk to more or less match the size of the magnets I was using, but a little larger to make sure the brush contacted the disk and not the magnets.

The disk is aluminum, very close to 9 cm in diameter and 9 mm thick. It is mounted on a shaft of aluminum 1/2 half inch (1.27 cm) in diameter. The magnets are, as I said before from audio speakers and are quite strong; finger pinching strong - you have to be careful putting them together.

The continuity through the circuit was aways fine when I checked it. The brush was the same carbon brush taken from an electric mixer motor I used in the other set up.

I realize that the diameter is quite a bit smaller than yours, and most, but I find it hard to believe this could account for my results. I would expect to have gotten at least a full amp, since the drills were drawing more than that.

The only thing I can think of that I know for sure is different is the thickness of the disk. It is quite a bit thicker than any I've read about. I have seen pictures of Faraday's disk and it doesn't look to be more than 3mm thick.

What do you think, Binki?

[Binki]

I agree that the unipolar dynamo is different. I am questioning your explanation of the mechanism whereby the field doesn't rotate.

I Just had a little bit of inspiration at the time and it seemed like a good explanation because we dont know how much the field is anchored to the magnet anyway, the space through which the field travels may have a greater influence on it than the source of the field - Just another hypothesis without proof I'm afraid.


I was appalled at the miserable results.
Why is it I'm not getting the famous unipolar amperage?


Remember the return path of the field will be counter productive - we can supose that aproximately half the field will return through the hole in the centre of your magnets which is part of your generating conductor and the other half or maybe a little more take the easy way round on the outside which it seems you have contemplated by making the disk just a little larger than the magnets but still it will have some counter effect.

The disk is aluminum

Not the best for contacts but is a good conductor, remember that Aluminium oxide is a very good insulator but as you have said you seem to have a good continuity(copper would be better).

The magnets are, as I said before from audio speakers and are quite strong; finger pinching strong - you have to be careful putting them together.

If they are ferrite ceramic magnets you will find the probable field strength on the web (I think approx 4000 Gaus ie. 4000 lines per square cm). Do your sums to check the voltage that should be given by the formula that I sent before. You can actually calculate the field strength and or voltage if you can rely on your speed measurements.

The only thing I can think of that I know for sure is different is the thickness of the disk. It is quite a bit thicker than any I've read about. I have seen pictures of Faraday's disk and it doesn't look to be more than 3mm thick.

the thickness shouldnt make any difference except that the further apart your magnets are the lesser the field strength. Try to assemble some sort of soft iron keep in order to controll the return path of the field and you will probably allready be generating a lot more current. :wink:

Binki

[zoobyshoe]

I Just had a little bit of inspiration at the time and it seemed like a good explanation because we dont know how much the field is anchored to the magnet anyway, the space through which the field travels may have a greater influence on it than the source of the field - Just another hypothesis without proof I'm afraid.
It seems pretty well completely anchored to the magnet to me, except for this maddening, apparent non-rotation around the North-South centerline. Perhaps this can be explained if we think of a permanent magnet as having exactly the same rotation of authentic current going on inside of it as a coil of conducting wire. Something like this logic: of course you're not going to find any rotation when you physically rotate the magnet because the electrons inside the magnet are already rotating around that axis, virtually, even when the magnet is stock still, faster than anyone will ever be able to physically rotate the magnet to begin with.

By the same logic, no one could physically rotate the magnet in the direction opposite to the direction the electrons are rotating fast enough to demonstrate any slowing in that direction.
I think the speed we're talking about here is c or close to it: the speed an electron orbits a nucleus. I'm not sure about that though. Can't be faster. We know that at least. Might be somewhat slower.

I actually like that explanation. The field doesn't seem to rotate with the magnets because it is already rotating on that axis at near light speed to begin with, so smoothly and with no change in the number or intensity of lines that it does not induce current in conductors. Rotate the magnet in the opposite direction all you want, you'll never be able to go fast enough to percieve any slowing.
Remember the return path of the field will be counter productive - we can supose that aproximately half the field will return through the hole in the centre of your magnets which is part of your generating conductor and the other half or maybe a little more take the easy way round on the outside which it seems you have contemplated by making the disk just a little larger than the magnets but still it will have some counter effect.
Good catch, Binki. I didn't even consider this. I actually have room to turn the disk diameter down some more, too. Come to think of it. I could make it just a touch smaller than the magnets and file the brush thin enough to fit between them.
Not the best for contacts but is a good conductor, remember that Aluminium oxide is a very good insulator but as you have said you seem to have a good continuity(copper would be better).
I didn't think about the Aluminum oxide either. That would certainly be a consideration in the fine tuning stage. At this point I don't think it could be the big problem.
If they are ferrite ceramic magnets you will find the probable field strength on the web (I think approx 4000 Gaus ie. 4000 lines per square cm). Do your sums to check the voltage that should be given by the formula that I sent before. You can actually calculate the field strength and or voltage if you can rely on your speed measurements.
Hmmm. Speed measurements? Have no capacity to really do this. I'm just figuring + - 100rpms the drill rating at max speed.
the thickness shouldnt make any difference except that the further apart your magnets are the lesser the field strength.[QUOTE]
This is good to know, because the thinner I have to make it the less sturdy it will be on the shaft. It is simply press fit on there. I was thinking earlier that if thin was better I would have to make a whole different shaft: two parts, one screws into the other with the disk held between. More work.

[QUOTE]Try to assemble some sort of soft iron keep in order to controll the return path of the field and you will probably allready be generating a lot more current. :wink:
Sounds like an excellent idea. What sort of arrangement do you suggest? It wouldn't be a problem to do just about anything involving flat disks, or disks with steps. I couldn't machine anything with a curved profile, though, like your plates. Except very roughly. The holes through the magnets are 3.175 cm in dameter. Quite a bit larger than the shaft.

Zooby

[Binki]

Use two square iron plates a little larger than your disk and brush assembly with a hole in the centre for the shaft then join the two top and bottom with other plates. The magnets will stick themselves to the plates with holes. you obviously already have supports for your magnets, I dont know how these would conflict

Binki

[zoobyshoe]

Use two square iron plates a little larger than your disk and brush assembly with a hole in the centre for the shaft then join the two top and bottom with other plates. The magnets will stick themselves to the plates with holes. you obviously already have supports for your magnets, I dont know how these would conflict

Binki
The plates go between the magnets and the rotating conducting disk, or on the other side of the magnets farthest away from the conducting disk?

I understand about the top and bottom pieces.

Thanks,

Zooby

[Binki]

The plates go between the magnets and the rotating conducting disk, or on the other side of the magnets farthest away from the conducting disk?

I understand about the top and bottom pieces.

Thanks,

Zooby

Outside of the magnets

Binki

[wolfblum]

Hi Everyone, (I'm new here and like your interest in Acyclic EM interactions!!!)

Anyway, I've performed thousands of experiments involving homopolar, unipolar, and acyclic generator and motor topologies. They all are real and work (i.e., they produce EMF or MMF predictably.)

Don't use carbon brushes (the brush drop will exceed the induced EMF or back-EMF, which is usually max. 50mV-100mV, depending on your peripheral displacement velocity of your translating disc or other conductor, it's median length and of course the flux density of your magnetic field that you supply, which is not likely to be much more than 1 Tesla, or @10,000 Gauss!)

If you want quantitative and reproducible results, use copper braid brushes (cheap) and no!, the observed EMF in the case of an acyclic generator is not due to thermal/frictional etc. effects. Copper on copper provides minimal brush loss (and further, that's why all the high-energy research efforts (read US Military) have used eutectic (i.e., liquid metal, such as mercury etc.) current collectors to minimize such losses.

In any event, acyclic topologies are certainly not overunity, but yes, they are low-impedance (i.e., high current/low voltage, as someone observed earlier on on this forum), and they also do provide a source for a great many apparent paradoxia when viewed in light of inertially constrained relativistic quantum electrodynamics, yet they don't when properly viewed in non-inertial frames (i.e., rotational non-relativistic QED.)

The question as to whether a cylindrical and symmetrically uniform magnetic flux field does or does not rotate (i.e., rotationally translate) about it's physical macroscopic axis has never been definatively answered or proven (ask me for the reasons/paradoxical explanations), but they might soon be. Several groups are working on developing very small and independant "observer" platforms that may "ride along" atop or with a homopolar/acyclic generator disc and relay it's own action observations to a stationary (i.e., laboratory or observer frame) via radio or optical means.

We are getting very close ourselves in this regard, but won't know until later this fall!

Anyways, sorry for my lengthy diatribe, just one more comment to an earlier poster on this forum (and good on you!), and to paraphrase you (sorry I don't remember your name right now), "you couldn't spin a magnet fast enough" (physically) to approach relativistic effects to second order on the face of this planet! I like it - Wolf

[zoobyshoe]

Hi Everyone, (I'm new here and like your interest in Acyclic EM interactions!!!)
Hi, wolfblum,

'Acyclic EM interactions"? A new term to me. What's the specific definition?

If you want quantitative and reproducible results, use copper braid brushes (cheap) and no!, the observed EMF in the case of an acyclic generator is not due to thermal/frictional etc. effects. Copper on copper provides minimal brush loss (and further, that's why all the high-energy research efforts (read US Military) have used eutectic (i.e., liquid metal, such as mercury etc.) current collectors to minimize such losses.
Good to know. I had no idea it might make a difference. I've just been reading the original Faraday and he amalgamated the perifery of the copper plate as well as the copper brushes.
In any event, acyclic topologies are certainly not overunity, but yes, they are low-impedance (i.e., high current/low voltage, as someone observed earlier on on this forum), and they also do provide a source for a great many apparent paradoxia when viewed in light of inertially constrained relativistic quantum electrodynamics, yet they don't when properly viewed in non-inertial frames (i.e., rotational non-relativistic QED.)
Cool.
The question as to whether a cylindrical and symmetrically uniform magnetic flux field does or does not rotate (i.e., rotationally translate) about it's physical macroscopic axis has never been definatively answered or proven...
I'm glad to hear this, because I couldn't find any rotation of the field with the magnet. I'm glad to know there isn't some obvious answer I stupidly missed.
Anyways, sorry for my lengthy diatribe, just one more comment to an earlier poster on this forum (and good on you!), and to paraphrase you (sorry I don't remember your name right now), "you couldn't spin a magnet fast enough" (physically) to approach relativistic effects to second order on the face of this planet! I like it - Wolf
You may be refering to something I said, but you have generously imbued it with more sense than it had when I said it. That's OK, as long as you find some inspiration in my loose speculation. I have a feeling the answer is going to be found by some variation of this way of looking at it. My point, if I recall it, was something to the effect that the reason rotation can't be detected is that the field is already rotating in some important, but not obvious, way even when at rest. It is probably physically impossible to rotate the magnet at a speed where a increase in the speed of that "at rest" rotation could be detected. The "at rest" rotation I have in mind is something like a combined effect from the zillions of electric field lines that are all being towed in in circles, in the wake of their respective electrons as they orbit. I hope that's not too whacky.

[wolfblum]

Hello Zooby,

I don't know how to do those nice quote panes yet, so please bear with me.

"Acyclic EM interactions"? A new term to me. What's the specific definition?

Acyclic Electromagnetic interactions are those that are time invariant (as in any true homopolar machine.) This, as opposed to the Cyclical (time varying) EM interactions found in all other electromagnetic machinery (AC or DC.)

As an example, a copper disk rotating perpendicular to an applied uniform and symmetrical magnetic flux field will never experience any flux density variations (or polarity variations.) Cylindrical topologies are also possible, as you already know.

As a result, the conduction electrons in the disk (i.e., the so-called free electron gas) experience the Lorentz force and a displacement current flows, leading to the EMF gradient observed between the center and periphery of the disk.

Please do not amalgamate anything, mercury is nasty stuff! Faraday used to lick his experimental apparatus to have his tongue "sense" electric potential, that's what probably caused his mental and health problems in later life and his death. FYI, I have a complete original set of Faraday's diaries and can tell you that he did co-rotate a disk with a cylindrical magnet and observed the generation of EMF (although he was never certain himself about the rotation of the field itself.)

Further stuff, the term unipolar should not be used, it means "having one pole" and that is not possible. The term homopolar is acceptable and means "poles on the same center." One has to be carefull though, for example, most of Faraday's reported disk experiments may well be classified as homopolar, in that the magnetic poles were on the same center, however, they were not acyclic, in that the rotating disk axis was not on the magnetic pole axis. So the EMF that Faraday measured was really due to eddy currents (if he had been able to measure drag torque as he turned the disk faster and faster, even with no brush connections and external circuit, he would have noticed the required effort increase and that the temperature of the disk was also rising. Hmm... just the exact same setup as the brake disk in our electric watthour meter on the side of the house!)

I'll comment more on the "spin" aspects involved in magnetic fields later.

Ciao - Wolf

[zoobyshoe]

Acyclic Electromagnetic interactions are those that are time invariant (as in any true homopolar machine.) This, as opposed to the Cyclical (time varying) EM interactions found in all other electromagnetic machinery (AC or DC.)
I think I get the concept. What branch of study does this term come from?
Please do not amalgamate anything, mercury is nasty stuff!
Good advice. Don't worry.
Faraday used to lick his experimental apparatus to have his tongue "sense" electric potential, that's what probably caused his mental and health problems in later life and his death.
I think you could well be right. I read him speaking about "the flash", which apparently was a flash of light in the field of vision when he got a particularly strong shock from touching his leads to his tongue. He simple considered it a measure of of current and seemed to have no conception it might be dangerous.
FYI, I have a complete original set of Faraday's diaries and can tell you that he did co-rotate a disk with a cylindrical magnet and observed the generation of EMF (although he was never certain himself about the rotation of the field itself.)
I'm quite envious. When you say "original" you mean first edition? I'd be happy to have any edition of them. Haven't discovered where I might get them. I just happened to find these published experimental findings of his last week, and I am amazed, page after page, by how thorough and meticulous he was, leaving no potential question unanswered, exploring every possible angle of every phenomenon.

I think it would be great, if you had the time, if you could quote the text of that particular experiment, if it isn't too long. So far, I haven't found anything about it in the book I have.
Further stuff, the term unipolar should not be used, it means "having one pole" and that is not possible. I see what you mean.

Are you interested in the homopolar dynamo for theoretical reasons or for engineering?

-Zooby

P.S. To quote you hit the "quote" button at the bottom of the post you want to quote from and respond to. To quote a section you write QUOTE in brackets in front of the first word of the quote, and /QUOTE in brackets after the last word of the quote.
You write your own reponses just like in a normal post with nothing in brackets.

You can delete anything in the person's post you don't need to respond to.

At the bottom there is a place to select "Preview Post". This will show you what your finished post will look like without actually submitting it. If it looks OK, and you have made all your quotation brackets properly, you can hit submit. If you need to correct you just scroll down to the box where the text is waiting to be corrected.

[wolfblum]

Zooby, Thanks for your helpfull guidance on quotes etc.

The term acyclic is a general physics term you would see most often used in biology / chemistry, but it simply means what it means, i.e., no cyclical variation of a parameter, in our case magnetic flux density (or polarity.)

Faraday and others investigators of that era did things that we all now know are incredibly dangerous, but that's how it was back then. I sometimes chuckle and sometimes scream (e.g., the Curies!)

As far as "Faraday's Diary" is concerned, there is of course only one original set by him (bequeathed to, and in the possession of the Royal Institution in London. BTW, I have been there and snooped extensively, lots of forgotten and misconstrued stuff on exhibit, ask me sometime!)

There was one transcription and printing thereof (i.e., there was only one edition), and it was over a period of 1932 to 1936 by G. Bell and Sons of London (wait I have to run downstairs and check... yes, eight volumes total, last one index, two volumes apparently printed per year.)

Zooby, depending on what country/state you are in, you might be able access the set at a University library. If you want, let me know your rough location and I can run it through the International library database. It's funny, there are apparently seven sets here in Canada (mine appears to be the only private one) yet in the rest of the world there are precious few (i.e., UK six, Japan two) and yet in the USA there are dozens in University repositories.

The Faraday's Diary set is somewhat hard to find and purchase, I know of booksellers who own two or three volumes, will not part or sell with them under any circumnstances, and yet are hoping and seeking to buy the missing volumes to complete their set! I was very, very, very lucky many years ago, my set was for sale on ebay by a collector in Toronto and appeared to be leaving the country. I bid it up to around U$1200.- and got it (most of the bidding was from European book antiquarians)! I was happy, but even more so when two years I went to London to visit the Royal Institution (and for some other books) and found out that the last set sold on the open market for several thousand pounds. Sorry, I shouldn't be so gleefull.

In any event, if there is such interest in Faraday's EM researches and findings relating to and surrounding his homopolar/acyclic experiments (they occured primarily in 1821 and 1831-32), I think I would be prepared to post the text of his relevant experiments on this forum. Mind you, I don't want to overload this forum venue either. So I propose to perhaps post one important experiment per week (this should keep the final total number of posts to about 60 or so.) I will not do this unless there appears to be some positive endorsement and agreement by the forum group as a whole.

As to the specific experiment I referred to and that you refer to Zooby, that one is very enlightening and I will post it over the next few days, OK?

Lastly, Zooby, I'm interested in acyclic/homopolar machinery from both a theoretical and practical viewpoint, hence my research over the past ten years or so - Wolf

[zoobyshoe]

As far as "Faraday's Diary" is concerned, there is of course only one original set by him (bequeathed to, and in the possession of the Royal Institution in London. BTW, I have been there and snooped extensively, lots of forgotten and misconstrued stuff on exhibit, ask me sometime!)
Wow! That must have been fun!
There was one transcription and printing thereof (i.e., there was only one edition), and it was over a period of 1932 to 1936 by G. Bell and Sons of London
It's amazing to me there haven't been more editions.
Zooby, depending on what country/state you are in, you might be able access the set at a University library. If you want, let me know your rough location and I can run it through the International library database.
San Diego, Ca.
Sorry, I shouldn't be so gleefull.
Don't be hard on yourself. In your shoes, I would be insufferable.
So I propose to perhaps post one important experiment per week (this should keep the final total number of posts to about 60 or so.) I will not do this unless there appears to be some positive endorsement and agreement by the forum group as a whole.
Hmmm. My assessment is that the people interested would more likely form a small, enthusiastic group. Faraday is under- appreciated around here in my opinion and there is also a lack of interest in reading anyone's original papers for some reason.

Since you're willing to make the effort to copy them, though, it would be a shame not to get them onto the web somewhere. There is alot of interest at large in homopolar dynamos and Faraday.

What is the copyrite situation with these diaries? Any chance they're in the public domain?
As to the specific experiment I referred to and that you refer to Zooby, that one is very enlightening and I will post it over the next few days, OK?
That would be great. I'm looking forward to it. I had decided it must not be true before you came along.
Lastly, Zooby, I'm interested in acyclic/homopolar machinery from both a theoretical and practical viewpoint, hence my research over the past ten years or so - Wolf
My own interest is practical. I'm fascinated by how simple they are. I have a penchant for reducing things to the lowest possible level of complexity, labor, and expense, and maintenence. It's a kind of laziness, I guess.

[wolfblum]

Wow! That must have been fun! It was amazing to see some of Faraday's original experimental apparatus and his laboratory (in the basement of the Royal Institution, almost a dungeon I might add!)

It's amazing to me there haven't been more editions.There was only the one printing, also I don't think anyone has even attempted a Project Guttenberg on the diaries, because the most important and amazing part of them are the many, many margin drawings and illustrations Faraday made throughout. There have been text only attempts for small partial periods of the diary, but that's about it. I'll come back to this later 'cause of your post Zooby.

San Diego, Ca.Aha, San Diego State U. has a copy. You should be able to at least view.

Hmmm. My assessment is that the people interested would more likely form a small, enthusiastic group. Faraday is under- appreciated around here in my opinion and there is also a lack of interest in reading anyone's original papers for some reason.Point taken, I'll hold back until we see what we should do (except for the specific set of experiments from 1831 that I promised.)

Since you're willing to make the effort to copy them, though, it would be a shame not to get them onto the web somewhere. There is alot of interest at large in homopolar dynamos and Faraday. & What is the copyrite situation with these diaries? Any chance they're in the public domain?If there is such an interest, I might be willing to start a most interesting project. The copyright situation isn't an issue, and as I said above, only little bits have made it into the public domain. Let me warn everyone though, as simple as acyclic/homopolar machinery may seem, this subject leads to the involvement of the likes of Ampere, Barlow, Foucalt, Siemens, Kirchoff, Tesla, Lorentz, Einstein (yes!, his Special Theory of Relativity), Westinghouse, WWII German stuff, Feynman (Quantum Electrodynamics) and others, General Electric, the US Navy, the U. of Texas at Austin, Parker Kinetic Design, Dresser Engineers and Constructors, rail guns, plasma fusion reactors, directed energy beam weapons and pipe welding, and also the US Army (&NASA). Quite a handfull of players, don't you think?

Please give me feedback as to what we should do - Wolfblum

[wolfblum]

Zooby, here is the experiment by Michael Faraday on December 26, 1831.
(Faraday's Diary, Vol. 1, pp 402, G. Bell and Sons, London, 1932)

255. A copper disc was cemented on the top of a cylinder
magnet, paper intervening, the top being the marked pole;
the magnet supported so as to rotate by means of string,
and the wires of the galvanometer connected with the edge
and the axis of the copper plate.

When the magnet and disc together rotated 'unscrew'
(CCW) the marked end of the needle went west. When the
magnet and disc rotated 'screw' (CW) the marked end of
the needle went east.

256. This direction is the same as that which would have
resulted if the copper had moved and the magnet been still.

Hence moving the magnet causes no difference provided the
copper moves. A rotating and a stationary magnet cause the
same effect.

257. The disc was then loosed from the magnet and held still
whilst the magnet itself was revolved; but now no effect upon
the galvanometer.

Hence it appears that, of the metal circuit in which the
current is to be formed, different parts must move with
different angular velocities.

If with the same, no current is produced, i.e. when both parts
are external to the magnet.


I took pictures of the relevant passages and the margin drawing, but have no idea as to how to post those? - wolfblum

[zoobyshoe]

I took pictures of the relevant passages and the margin drawing, but have no idea as to how to post those? - wolfblum
The easiest and fastest way is to put them on a webpage somewhere and then just give us a link to the page.

It is also possible to "attach" images that will show up in a post. The problem there is that Greg Bernhardt, PF owner and administrator, wants to personally inspect all attachments before he will approve them. He wants to avoid taking up alot of bandwidth with junk pictures, which is reasonable, but it takes him forever to get around to approving stuff. If you post the images as "attachments" therefore, it could take three or four days before anyone could see them.

I would definitely love to see what the pages look like. I'm particularly interested to see what he means by the magnet being supported "so as to rotate by means of a string."

It is quite exiting to see this whole thing described in his own words, and it clears up about two mysteries in my mind, which I'll explain after I dig up a couple quotes.

Thanks, wolfblum!

-Zooby

[zoobyshoe]

OK, here goes. I was reading a bio of Einstein and the author says that in the pre-relativity days there was a contradiction about the relative motion between conductor and magnet which this author attributes to Faraday's law of induction:

"This had for years been one of the accepted facts of life and to raise awkward questions about it was to spit in a sacred place. yet, Einstein pointed out, the current induced between a magnet and a conductor depends according to observation only on the relative motion of the conducting wire and the magnet `whereas the customary view', in other words, the accepted theory of currents, `draws a sharp distinction between the two cases in which either the one or the other of these bodies is in motion.' Faraday had discovered the induction law in 1834 but, as Born put it, `everybody had known all along that the effect depended only on relative motion, but nobody had taken offense at the theory not accounting for these circumstances.'"

Einstein, The Life and Times
Ronald W. Clark, p.116

In fact, this issue was very important to Einstein because the first paragraph of On the Electrodynamics of Movng Bodies, where Special Relativity made its first appearance, addresses this very thing:

"It is known that Maxwells electrodynamics--as usually understood at the present time--when applied to moving bodies, leads to asymmetries which do not appear to be inherent in the phenomena."

He is saying, in other words, that Maxwell (following Faraday's lead) misunderstood something.

"Take for example, the reciprocal electrodynamic action of a magnet and a conductor. The observable phenomenon here depends only on the relative motion of the conductor and the magnet, whereas the customary view draws a sharp distinction between the two cases in which either the one or the other of these bodies is in motion."

At this point I start not being able to follow Einstein:

"For if the magnet is in motion and the conductor at rest, there arises in the neighborhood of the magnet an electric field with a certain definite energy, producing a current at the places where parts of the conductor are situated."

First, I don't understand if he is saying this is the incorrect "customary" view, or if it's supposed to be the correct one. I haven't come across the notion that a magnet in motion produces an electric field in it's neighborhood. All I'm aware of is that a magnetic field in physical, kinematic motion can induce current in a conductor.

"But if the magnet is stationary and the conductor in motion, no electric field arises in the neighborhood of the magnet. In the conductor, however, we find an electromotive force, to which in itself there is no corresponding energy..." Huh? "...but which gives rise--assuming equality of relative motion in the two cases discussed--to electric currents of the same path and intensity as those produced by the electric forces in the former case."

Again, I can't sort out if he is presenting stuff as the erroneous "customary" view, or if he is presenting what "everybody knows" is actually happening.

Anyway, 16 pages later Einstein, having made many points, concludes this first section by saying:

"Furthermore it is clear that the asymmetry mentioned in the introduction as arising when we consider the currents produced by the relative motion of a magnet and a conductor, now disappears. Moreover, questions as to the `seat' of electrodynamic electromotive forces (unipolar machines) now have no point."

So, it is clear that he is aware of and seems to be discussing the Faraday disc dynamo. I don't know, however, to what extent Faraday's induction laws were meant to explain "homopolar" configurations, and if the strange case that you quoted is taken into account. Did Maxwell know about it, and did figuring it into his equations cause the "asymmetry" that was bugging Einstein? Or, am I barking up the wrong tree, and the asymmetry in Maxwell has nothing to do with this experiment?

-Zooby

On the Electrodynamics of Moving Bodies
Address:http://www.fourmilab.ch/etexts/einstein/specrel/www/?CFID=4299126&CFTOKEN=28870118&jsessionid=06302662281082217897574

[zoobyshoe]

It was amazing to see some of Faraday's original experimental apparatus and his laboratory (in the basement of the Royal Institution, almost a dungeon I might add!)
Yes, I can imagine this was incredible.
Aha, San Diego State U. has a copy. You should be able to at least view.
This is good to know. I wonder if they let people make photocopies of any of it? I'll have to call and see what their policies are.
If there is such an interest, I might be willing to start a most interesting project.
If you google various permutations of "Faraday Dynamo" Homopolar Dynamo" and all that, you come up with ton's of sites, indicating that there is alot of interest at large in this particular aspect of Faraday's experiments. Quite alot of people are crazies looking for overunity, but there are plenty of level headed researchers.
The copyright situation isn't an issue, and as I said above, only little bits have made it into the public domain.
By "Public Domain" I'm refering to the situation where the copyrite of a written work has lost all claims to be legally owned by any person or organization. Works that are in the public domain can be reprinted by anyone without anyone's permission. This happens to all books after a certain amount of time has elapsed. In some cases, though, people can take special measures to hold on to a copyrite beyond the normal time period. Some of Mark Twain's books are in the public domain, for instance, but some of his writing is not (last I heard); it is still owned by the decendents of one of his daughters, or the Mark Twain Society, or whatever.

It could be, therefore, that the Royal Philosophical Society, or the publishers of your edition, or Faraday's descendents have managed to retain the copyrite to Faraday's diaries in some way, shape, or fashion.

The thing I had in mind was to create a website on which to put the experiments that have to do with the disc dynamo, just because it would be nice to have it on the web where people could have access to it.

The other idea that occured to me would be to collect them all into a small book, publish them yourself, and get them distributed by Lindsay Books. This is a fascinating little company that specializes in reprints of old technology books. I have ordered several dozen of their fascinating and sometimes quirky books over the years.

Lindsay distributes quite a few self-published books for people, odd ball subjects like "How To Make Tiny Drills", "How to Make Your Own Charcoal in the Backyard", "How to Melt Iron and Steel in a Backyard Cuppola" "How to Make an Entire Machine Shop from Scratch", that sort of thing. The collected disk dynamo experiments of Michael Faraday would be right up his alley.

Lindsay Publications Books Available
Address:http://www.lindsaybks.com/prod/index.html

Quite a handfull of players, don't you think?

Don't get complicated on me, wolfblum. A disc, some magnets, and some wire. That's all we need.

[Binki]

Yes

The Faraday Original notes are very interesting - please dont leave me out :smile:

And it is nice to find someone else on the forum who has done some real and objective experiments with the homopolar theme

Binki

[shmr]

Dear All
I am new to this forum and it looks now everyone is quiet, Have you made homopolar generator or not?
If not I have two questions
a) instead of making a brush on outer surface of copperconductor if we solder insulated wire on outer surface of Copper disk and connect other end to the rotating shaft as it is done in most of car dynamos then due to less surface velocity heat will not cause any demage
b) After getting so huge current , if we switch this current (using appropriate transformers) to rotatining motor then will not it be a self rotating device(generator)?