Homopolar Generators (N-Machine) by Bruce de Palma

[sm0ky2]

if this is correct, what would happen if it was the disc that was fixed stationary and the magnet was put on the drive shaft instead? like that the problem of brushes would be eliminated.

would the operating principle be the same? or have i got it all totally wrong?

You have come across the anomaly of the Faraday disk.  A rotating magnet has no effect on a stationary disk while a rotating disk with a rotating or non rotating magnet will produce a potential.  The effect seems to be that the magnetic field does not rotate with the magnet.  Actually it may be that the spin of the atoms within the disk may have something to do with relativity because the outer edge of the disk is traveling at a faster rate of speed than the portions of the disk nearer the axle.

its not really an anomaly,  the type of magnetic field used in these devices in a uniform, circular field. turning this field, still gives us a uniform, circular field.  So with respect to the disk, the field is not "moving".

turn the disk, and the copper moves through the field - while it does not "cut through" and perpendicular flux lines, it still causes induction within the copper of the disk.

They perform better when the magnet and disk are both moving together. (taking into consideration the additional mass that is being rotated)

[mfred68]

I can get my hands on some 12" copper discs, but i only have several 1" magnets, how do i place the magnets onto the disc? do they have to be evenly spaced n,s,n,s and do the magnets have to attract each other through the disc by placing some on both sides?

or have i got it totally wrong again?

do lots of small magnets work or would i need two equal sized 12" magnets to the same size as the disc?

Also is the output ac or dc?

[sm0ky2]

at a constant RPM, the output will be a high current DC.
(in most situation, load on the drive motor will increase as power is taken from the leads.)


The magnet can be a single magnet, presssed against the face (or slightly spaced) of the disk.
an alternative method i have seen uses two magnets, one below and one above:    s -disk- n (or vise versa)

with a 12" disk, the magnet should be 11 inches at least,. so that the disk is entirely inside the magnetic field.
you dont want portions of your disk extending out past the field - this causes an adverse effect and will cause extra 'drag' as well as lower the total power output of the device.

[Paul-R]

I can get my hands on some 12" copper discs, but i only have several 1" magnets, how do i place the magnets onto the disc?

Can you lay your hands on a dumped video recorder which actually works? Take the lid off,
and when you see the main video head, it is, in effect, most of a homopolar generator but
without the magnets. Dismantle the recorder making sure that the head is running (you
will need to put an old tape in, set it going, and try to dismantle it whilst keeping the head
rolling.

Find out what lever is the thing which is forced back to tell the recorder that the tape is there.
Glue it fast. When the tape runs out, it should keep rolling unless there is another sensor
(which is in the tape path with a light bulb).

You will then need to get magnets as close as possible, maybe form an old micrwave oven
(inside the magnetron - a bit of a hassle). Mount them in position, and meter from the edge
of the video head to the shaft (maybe on the other side of the main board.

You should get a low vloltage but with a surprising amouunt of current.

[mikestocks2006]

I can get my hands on some 12" copper discs, but i only have several 1" magnets, how do i place the magnets onto the disc? do they have to be evenly spaced n,s,n,s and do the magnets have to attract each other through the disc by placing some on both sides?

or have i got it totally wrong again?

do lots of small magnets work or would i need two equal sized 12" magnets to the same size as the disc?

Also is the output ac or dc?

Hi mfred68,
That would be a very good experiment to do.
If you have access to some basic machining, you?d need 2 wafers with holes the size of you mags and sandwich the disk between them. Poles as an example would be N-S-CopperDisc-N-S. With such a setup the expectation would be a DC out Voltage.

Also see



more complete info pics and explantions here
http://www.stardrivedevice.com/over-unity.html

I?ve attempted to contact them numerous times, as they indicated on their site that they would be posting results out soon after the build, but they have not replied.
The build had started back a a couple of years, but no results yet.

If you could replicate this and post some results either proving or disproving the design setup it would be much appreciated.

Thanks