Latest: No back torque generator.

[broli]

If you indeed got current from 2 counter rotating magnets with a completely stationary output circuit you should make your own thread about it. Because that is NOT normal behavior and you may have discovered something new whether you realize it or not.

[Yucca]

@All, this thread of Brolis is a good read.

Somewhat related: I spun a 2inch diameter 0.25inch thick neo disk mag, poles on the faces, at about 4000RPM.

I measured about 150mV open circuit between axle and rim, and 300mA closed circuit. I did not have proper brushes, just my meter probes pushed against the moving surfaces so very noisy, with proper brushes the values would probably be much higher.

I presume most of the electons flow through the thin nickel magnet coating which has much lower resistance than the neodymium bulk.

Like many of you I would like to remove static brushes and have the takeoff and load rotate in the same frame as the disk. If the takeoff and load is rotating with the mag and it still produces this current then something weird is going on that the books don´t mention.

With such a low voltage, the only thought I have at the moment is to charge a small electrolytic cap rotating on the magnet. charged via a diode so as not to discharge when stopped. Spin it all up, then stop it and quickly measure the cap. Whether I can find a diode that would pass such a small voltage I don´t know yet? If I can´t then I will use a very high resistance instead, spin it up for along time then stop and read the cap very quickly before it discharges.

The capacitor and takeoff leads will need to be seperated from the magnet using a moderate shielding material like multiple tin and card laminations, otherwise the takeoff leads will produce a current (via the same effect) that fights against the disk current.

[petersone]

Hi Yucca
Would your demo have been subject to Lenz's law?
peter

[Yucca]

Hi Yucca
Would your demo have been subject to Lenz's law?
peter

hi Peter,

I´m not sure myself, I´ve heard many say that homopolar generators with static brushes will suffer from lenz. But I fail to see how when I imagine the field which will behave for all intents and purposes just the same as if the magnet were still.

The only mechanism which I can see slowing the mag disk (in the static brushes config) is conservation of momentum, as the electrons are thrown off the disk they would tend to slow the disk, like an ice skater spins faster with their arms pulled toward the body and then slows when the arms are extended.

To draw any conclusion I will have to test myself by measuring the disk RPM very accurately with the brushes in contact but the takeoff circuit open, then close a switch to short out the takeoff circuit and see if the RPM drops.

To do this I will need to create some mechanicaly stable brushes, at the moment I push probes against the magnet and the speed is all over the place as my hand pressure varies slightly. Any ideas on easy brushes with fairly low friction are appreciated.

[petersone]

Hi Yucca
Thanks for your very comprehensive answer,from what I have read some say it has Lenz,some say it doesn't,about 50/50, I can't see Lenz being coursed by the electrons being thrown out,as I understand it they have no mass.
peter