Quote from: lumen on May 11, 2009, 05:53:29 PM
The misconception is that you need changing polarity or a field changing in strength to induce a current flow but in fact all these cases only work on the same principal, lines of force cutting the conductor.

lines of mag force cutting the conductor implies that the conductor does see a changing field. You cannot have one without the other. The arbitrary lines that we use to visualise fields (ala FEM) are just like contour lines on a topographical map, if you move accross a line you are changing height, it´s just the same with mag fields. Brolis mention of cylindrical field lines around the mag is pretty much how I see it also. You spin the mag and the cylindrical field will remain the same.

One more thing to consider is that it theoretically impossible to achieve continuous DC current using induction alone, to achieve that you would need a field that increases in strength forever.

Quote from: lumen on May 11, 2009, 05:53:29 PM
unless it actually worked in the last schematic on the picture I posted. ( I have not tested this but believe it not to work)

I would love to test this also, I have never seen reference to any attempt at this experiment. On the peswiki site that particular combination is listed as "untested".

If the magnet, disk, wires and load are all rotating and current still flows then the doors will be open for overunity.

I could imagine a drum like device, one end containing the disk magnet, in the middle some mag shielding, the other end containing a storage capacitor being constantly charged by the homopolar effect. The cap would periodically pulse a high current electromagnetic coil (also in the drum) which would in turn drive the drum against external stator mags. Such a drum once started might selfrun up to equilibrum speed governed only by mechanical and electrical resistance.

Quote from: Yucca on May 11, 2009, 08:33:38 PM
I would love to test this also, I have never seen reference to any attempt at this experiment. On the peswiki site that particular combination is listed as "untested".

If the magnet, disk, wires and load are all rotating and current still flows then the doors will be open for overunity.

I could imagine a drum like device, one end containing the disk magnet, in the middle some mag shielding, the other end containing a storage capacitor being constantly charged by the homopolar effect. The cap would periodically pulse a high current electromagnetic coil in the drum which would in turn drive the drum against external stator mags. Such a drum once started might selfrun up to equilibrum speed dictated only by mechanical and electrical resistance.

Any type of asymmetry can be easily tested. Your capacitor idea you mentioned earlier is the best to do this. Just spin everything up together and then stop it and measure the voltage on the cap. My belief is that it would give 0 voltages but maybe with some combination of ferrite shielding around the wire it might give a net voltage. The advantage of this is the fact you can wind many turns and if there was voltage generation it can be measured easily.

These type of experiments have been performed by noone as far as I know. They could lead to new and interesting results.

Quote from: broli on May 11, 2009, 08:39:21 PM
Any type of asymmetry can be easily tested. Your capacitor idea you mentioned earlier is the best to do this. Just spin everything up together and then stop it and measure the voltage on the cap. My belief is that it would give 0 voltages but maybe with some combination of ferrite shielding around the wire it might give a net voltage. The advantage of this is the fact you can wind many turns and if there was voltage generation it can be measured easily.

These type of experiments have been performed by noone as far as I know. They could lead to new and interesting results.

Yes, it´s an experiment which I´d love to do, the only problems I have at the moment is getting everything to stay together and be well balanced enough for a high speed spin. I will probably end up getting some clear epoxy and trying to pot everything up then statically balance it by drilling holes in the epoxy.

My first experiment will just use a neo disk as the generator (no windings) next to this some shielding, probably laminate of food tin and cereal box card, then a 10k resistor feeding an electrolytic with external probe points. My DMM has 1mV resolution.

Quote from: lumen on May 09, 2009, 08:13:38 PM
@Broli,

I have a setup that I built just for that purpose. It can test spinning just the disk, spinning just the magnet, spinning the disk and the magnet, spinning the external brushes, spinning the disk and brushes, spinning a magnet and a disk in opposite directions.

I have already tested all the combination's! I can tell you that spinning the magnet does spin the magnetic field. It is hard to know the field is spinning but I know how to prove this.

I've been away for a while and I see there's been a lot discussed, but I just wanted to address this one old point. I think I have experimental evidence from several sources that seems to support the idea that the field does not spin with the magnet, at least not in a simple physical sense like little springs or something.
It's hard to see how the magnet could spontaneously begin to rotate over a superconductor, because we know for sure (I think) that the SC pins the flux lines so they can't be rotating in the SC, yet the magnet physically spins---I even made a video of this phenomenon, it's pretty weird, on my YT channel.
Also, the one-piece homopolar motor, with just a magnet, brush and axle contacts--it spins, and it seems to react against the brush--but where's the relative motion, unless the field is "stationary"? EDIT I mean of course the motive force which moves the disk acts only on the disk, it isn't the brush pushing the disk, even though the brush reacts oppositely...
And of course there are the brushless one-piece HP generator/motors, that use a band or belt to take power off the disk...
So I think this issue isn't decided, and our experiments should be compared and extended in an effort to answer the question. At some point.

Quote@Yucca, 
One more thing to consider is that it theoretically impossible to achieve continuous DC current using induction alone, to achieve that you would need a field that increases in strength forever.

That cannot be true, the field in the homopolar generator is of constant magnitude and outputs DC current.

I am sure the source of operation is just as I said! When a magnet spins on it's axis the magnetic field rotates with it. This accounts for the operation and non operation of every configuration of the homopolar generator.

If the magnetic field was stationary in space then a homopolar motor (like the simple ones everyone build on youtube) would generate no torque back into the magnet, but indeed it does.

And, the last configuration shown on the picture I posted would operate, would violate lenz's law and be extremely over unity!

The field around a axially spinning magnet would look the same as always, like a doughnut. 
So you can see that any conductor running from the center of the magnet towards the outer edge would cut all the lines of force leaving the face of the magnet, then again as the force lines curve to reach the other side of the magnet.

You are just going to make me get the test rig out and hopefully prove myself wrong!