Homopolar generator idea

[F6FLT]

Hi Arne,

Could you try this, in both configuration with a ferromagnetic axle and non ferromagnetic?

[seaad]

Hi Arne,

Could you try this, in both configuration with a ferromagnetic axle and non ferromagnetic?

Hi  With the "naked" brass axle and the same speed as before and a distanse between the meas. points about 2 cm (=.8 ")  only 0.1 mV
     With a  soft Fe rod inserted inside the brass tube, that gave 0.4 mV
     Not much to put in a christmas tree!

Regards Arne

[F6FLT]

Hi  With the "naked" brass axle and the same speed as before and a distanse between the meas. points about 2 cm (=.8 ")  only 0.1 mV
     With a  soft Fe rod inserted inside the brass tube, that gave 0.4 mV
     Not much to put in a christmas tree!

Regards Arne

It's strange, because on my side I easily reach 100 mV between my 2 sliding contacts on the ferromagnetic axis, in front of the two ferrite magnets recovered from a microwave oven. With an aluminium axle, the voltage is too weak to be measured

The largest magnet diameter, the better the effect. A much stronger neodynium magnet but with half the diameter gives weaker voltage. That's why I think that the magnetic field gradient plays an important role.

It is important that both contacts are on the same side of the magnet, one as close as possible and the other further away.
The difference with my setup is that in yours the magnet rotates, not in mine. But this should not change anything.

[seaad]

Hi F6FLT
You can use my readings as a rough comparison to different set ups. I only used 2 Volt to my motor here. But feeded with maximum 12V  it produced about 30 - 35 mV at my first test with two magnets. 8 -9-mV with 2 Volt to the motor.
I'm sorry I don't have any wider magnets at home to make some comparison tests.

https://www.youtube.com/watch?v=gduYoT9sMaE

Regards Arne

[F6FLT]

Hi Seaad

After seeing the video, I think it is the angular velocity that makes the difference in the amplitude of our voltages. My motor seems to run much faster.

On the principle, there is no paradox, it's only a misinterpretation of relativity that leads us to say that the result should be different depending on whether the magnet rotates or not.

Relativity is not between the circuit and the magnet, but between the two parts of the circuit, which rotate relative to each other in a magnetic field.
Each half-circuit between the two sliding contacts sees the other rotate. So the charges of one half-circuit see the charges of the other half-circuit subjected to the Lorentz force F=q.VxB, when they see themselves at rest (F=0). This creates the imbalance of forces and therefore the current. This is why turning the disc OR turning the sliding contacts is the same.

A magnetic field is only a set of vectors assigned to point positions in space. As the magnet rotates around its axis of magnetic symmetry, the vector field remains the same. B is constant and the same whether the magnet rotates or not.