Faraday disk/n-machine questions

[redrichie]

I attempted a faraday disk replication with some things I had last night. 1. 3.5inch diameter copper disk/.25 inch thick. 2. two 3 inch diameter ring magnets with 1 inch hole. (very strong) 3. hollow aluminum shaft. hand drill.

drill was coupled with shaft using plastic collar that is Non-conductive. copper disk forced onto aluminum shaft. magnets spaced .25 inch from disk on each side by acrylic wall.
I could not get any Amperes out. NAdda. Either spin direction, varying rpms from 1-1000. tried a resistor as load, with meter in line with load. nothing.
So switched to N-machine type configuration with magnets first directly contacting copper on each side. about 2mA. with magnets insulated from copper with thin film of rubber, about 2mA. varying rpms 1-1000 again.
I went to original configuration again. Used 2 smaller magnets of 1.5X.5 inch and placed them on each side of disk on just one edge. Original Faraday experiment style. NOTHING!!!????
Can someone please explain what might be my malfunction? Am I not achieving a high enough rpm with such a small copper disk. ANy insight will be helpful. I am completely at a loss on this one.
Thanks

[Farmhand]

Hi redrichie, So I will assume you had the meter connected to the disc rim and the axel. Did you spin the disc while holding the magnet still, and also while allowing it to rotate with the disc, did you try with only one magnet or were they stacked together on one side? Another posibility is that you grounded the charge somehow, how did you support things while doing it. No need to answer all those questions just any you may feel are relevent given how you did it. The only other thing I can think of at present is if you used two magnets the may have influenced each others fields somehow.
How come you used two ? Oh and some meters can have a fair amount of capacitance did you use a galvanometer, a regular meter may not detect the small charge very reliably.

Cheers.

[redrichie]

Hi redrichie, So I will assume you had the meter connected to the disc rim and the axel. Did you spin the disc while holding the magnet still, and also while allowing it to rotate with the disc, did you try with only one magnet or were they stacked together on one side? Another posibility is that you grounded the charge somehow, how did you support things while doing it. No need to answer all those questions just any you may feel are relevent given how you did it. The only other thing I can think of at present is if you used two magnets the may have influenced each others fields somehow.
How come you used two ? Oh and some meters can have a fair amount of capacitance did you use a galvanometer, a regular meter may not detect the small charge very reliably.

Cheers.

Thanks for replying Farmhand. Ok let me clarify a little. I used 2 pieces of acrylic sheets. flat faces facing each other at a distance of 1 inch apart, inside to inside. I drilled a hole in each sheet to act as the bushing for my aluminum pipe/axle. I then place copper disk in-between the 2 pieces of acrylic and push axle through center. The magnets are big rings like I stated previously. I slide them over the axle on the OUTSIDE of the each acrylic upright. They hold each other in place due to their attraction. The magnets do not contact the axle. They are isolated from the copper and the axle. I then attach a hand drill to the axle through an insulated plastic coupling that I fabricated. So from left to right is: drill, coupling, axle, acrylic, copper, acrylic, axle. Is that better?
I think the acrylic is an insulator, so it should not ground out anything. Right?
Yes, first the magnets where stationary. the copper disk was spun inside the magnetic field up to 1000 rpm's. Later I attached the magnets (insulated then not) to the copper disk and spun the whole thing as a unit like Depalma showed.
I have never seen any drawing that showed only one magnet in any Faraday disk/N-machine style configuration. So I didnt even think it was possible to do it that way. Thanks
The only thing I can think of through the day is one of 2 things. The magnets I used are doughnut shaped so their field will be also. They are extremely powerful but a dead spot is still a dead spot. Maybe I need MORE space in-between the magnets so the full field will be present, and not a dead zone from the 1 inch hole in the center.
Next It may be possible that I do not have ENOUGH rpms. The small disk I have may not have enough flywheel to activate/excite the copper as it spins through the magnetic field.
Opinions?

[Farmhand]

Oh yes I see I missunderstood your first post i'm sorry.

I have never actually done that experiment myself. I applaude you for being so thourough in your learning. I would hope that someone that has actually been successful with this would comment. You have put some real effort into your construction. well done.

This might help you. Figure 1. shows only one conductive disc and one magnet, they appear to be completely isolated from each other. Electrically that is.
Faraday’s “Paradox” and Spin-Induced Electric Fields

I would usually jump at the chance do these things if I haven't done them before, i'm just a bit busy at the moment, it's a pleasure if I can help a bit though, and in that respect it's better than work.

There is still the meter capacitance, or so i've been told, I have always just taken for granted about that. The theory I see as being correct is that the magnetic field of a dohnut shaped permanant magnet does not rotate with the magnet always.

Hope someone else can help. I am starting to wonder.

Cheers

[broli]

It's best to try to measure from the outer edge to as close as the inner diameter of the ring magnet for maximum voltage. However that doesn't explain the situation with attached magnets showing current. Or why even that current is so low. I would suggest to improve your brushing mechanism.

[Jetijs]

Just a guess, your shaft is aluminum, the disc is copper. Those are two dissimilar metals that can develop a voltage due to galvanic action. This voltage might work against the voltage you are trying to develop.

[redrichie]

Thanks for insight guys.
@jetjis & broli:
The Faraday disk/N-machine is not a very high Voltage producer as far as ive read and watched. They all seem to produce exceptionally high current.
@all
I reconstructed the experiment again tonight. Still no success. This time I even connected a 30,000 rpm high speed dewalt router type device as prime mover.
I switched to a .25 inch i.d X 2 in o.d. copper disk. I also sized down the axle to a .25 inch stainless steel rod. Not magnetic.

experiment 1. 1.5 inchX.5 inch ring magnet with .25 hole. n/s with disk in-between with no insulation between copper magnets. 20rpms=.5mA/@1000 rpms=1mA/@30000rpms=2-4mA.

experiment 2. same copper and magnet sizes. This time magnets .5inches from disk on either side. repeat of last nights experiments. all same readings as previous test. even @ 30,000 rpm

experiment 3. same copper but with 3 inch ring magnets. all reading similar to 2 previous experiments.
All experiments were preformed in either a clockwise or counterclockwise rotation.

really thought the extra rpms would show a significant rise in voltage. I can feel NO Eddie currents when I spin the copper disk in the field by hand. And no eddie currents can be felt when the magnets and disk are spun as one unit either.
Kinda confused. all depalmas papers on his website show I am doing this right.
I can get photos if needed

[Farmhand]

Are you doing the experiment with the disc in a horazontal orientation or vertical ? I'm stumped.

[redrichie]

Try these on for size

[citfta]

Hi redrichie,

I think I see the problem. I tried the Faraday disc as a brake using the eddy currents to load down a motor for testing. In my set up I used a strong neo magnet and an aluminum plate. I could almost stop the motor if I got the magnet close enough to the plate so I am sure I had strong eddy currents. I think you have too much of the copper disc covered with the magnet. I had a rectangular magnet that only went from the axle out to the edge. I did not have another magnet on my set up. My plate is 6 inches in diameter and the magnet is only 2 inches long by 1 inch wide by 1/2 inch thick. I hope this info helps.

Good luck, Carroll

[synchro]

copper disk.

She's right. All DePalma's generators have copper discs that are larger and outside the perimeter of the ring magnets.

[broli]

What is the resistance between axle and perimeter? Have you tried to run this in motor mode?

[redrichie]

ok this is just one set of photos to show what type of setup I was using. I used smaller than the disk magnets as well. I also did not have the smaller magnets attached to the shaft in one experiment; I had them located just off the shaft toward the periphery of the disk as Carroll stated.
I know Depalma had a lip that protruded just beyond the magnet. Tesla also stated he had great success having the magnet come all the way to the edge of the disk. I have tried in every configuration possible with the items I have. I even hand spun the device to eliminate the possibility of a ground to the prime mover.
I will try tonight with a clear head.
Broli, there is hardly any resistance. When i first touch probes to edge of disk and to end of shaft it says 300 Ohms, then it instantly goes to zero in the matter of a second. Not open, it goes to Zero.
Syncro, I know you said you experimented with this. What kind of Amperage were you getting? I know you have large magnets and a similar sized disk. Any way for you to do a mock up of this. It took me an hour to get the setup right, so you wont be out much time...

[gravityblock]

What is your voltage readings? If the voltage is extremly low, then you will lose most or all of your amps even over a very short length of wire or external circuit. The voltage can be increased by using stronger magnets, higher rpm's, and larger diameter magnets. Also check or improve your brushing mechanism as Broli suggested.

Lumen is generating 30mV in his homopolar test rig with 3 inch diameter magnets. The amps will be lost over short distances at these low voltages.


GB

[Loadstone]

Hi all.
When you push a coil through a U magnet you get a voltage as the coil approaches the U magnet, but the voltage geos to zero when the coil is in the middle of the U magnet, where the magnetic strength is greatest.
During that time all the flux is pointing across the copper wires and no "electricity" is running along the wire.

Because the copper disc is in a stable field it may be the case that the magnets are too strong and the flux is giong straight through the copper disc and not making the currents that run at 90deg to the magnets.

Tesla wrote "This, however, is true only 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."

"Assume the magnets slightly energized at the start; they could be strengthened by the action of the eddy currents in the solid disc..." N.T