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Author Topic: Homopolar Generators (N-Machine) by Bruce de Palma  (Read 291149 times)

TinselKoala

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Re: Homopolar Generators (N-Machine) by Bruce de Palma
« Reply #270 on: January 01, 2015, 07:39:30 AM »
@mags:
Yes, the "magnet mover 1.jpg" rendering is very strange, a new one on me. It might be possible to test this using the standard one-piece HPM that you described. By a curious coincidence I made one a couple of months ago myself, but I never thought to try it with two brushes on the edge, I've just run it with the single brush and the axle point connections.

http://www.youtube.com/watch?v=wFMq1Cvtg1s

What is being pushed against, even in the ordinary configuration? In my setup the copper braid brush is very limp, it doesn't seem like it could be taking the "stator back reaction" that we usually think must exist somewhere for the rotor to spin. Push against that braid and it just flops out of the way.

Tomorrow I'll try it with two brushes on the edge, diametrically across the magnet disk. This "may" duplicate the mover 1 configuration, or there may be something special about the extended surface of the aluminum foil that is needed. We'll see...

Thanks for the puzzler!

broli

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Re: Homopolar Generators (N-Machine) by Bruce de Palma
« Reply #271 on: January 01, 2015, 10:37:01 AM »
Tomorrow I'll try it with two brushes on the edge, diametrically across the magnet disk. This "may" duplicate the mover 1 configuration, or there may be something special about the extended surface of the aluminum foil that is needed. We'll see...

Thanks for the puzzler!

I think you should try both, a brush on one side and a large conductive planar body on the other if that's possible. Honestly I tried this myself and got no indication of rotation. However I had major fusing issue where the wire would cause a spark upon touching the magnet and stick to it, even if there was a slight tendency for rotation I wouldn't have been able to notice it. The approaching angle of the top wire might also be important.

The reason I find the possible operation of this strange is that in this kind of operation there should in theory be no induced EMF as you go from rim to rim.

TinselKoala

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Re: Homopolar Generators (N-Machine) by Bruce de Palma
« Reply #272 on: January 01, 2015, 02:52:23 PM »
I think you should try both, a brush on one side and a large conductive planar body on the other if that's possible. Honestly I tried this myself and got no indication of rotation. However I had major fusing issue where the wire would cause a spark upon touching the magnet and stick to it, even if there was a slight tendency for rotation I wouldn't have been able to notice it. The approaching angle of the top wire might also be important.

The reason I find the possible operation of this strange is that in this kind of operation there should in theory be no induced EMF as you go from rim to rim.
I agree with all of that.

My fusing problem was somewhat reduced when I used a current-limiting power supply set to a maximum of 6 amps. With a battery that can produce a lot more current the problem is "sticky" all right, things weld together easily especially if you use a fine braid like I used. The braid wires also tend to burn away, even at 6 amps maximum, and the braid gets shorter.

Another thing that is interesting about using the current-limiting supply is that it lets you see that the voltage needed goes way down. I see readings of 1 volt or so, at 6 amps, as the supply automatically reduces voltage to keep the current at the set limit.

If you have some mercury or GalInStan liquid metal (I don't, at present)  you could try that for contacts, but beware of the mercury vapor that happens when you have sparking and big currents in the mercury.

ElectricPirate

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Re: Homopolar Generators (N-Machine) by Bruce de Palma
« Reply #273 on: January 01, 2015, 03:21:40 PM »
Hi guys i like to share my idea to know whether the magnetic field is stationary or not. My idea is to use capacitor to collect charge in the disc. If charge is collected, this means the magnetic field is stationary because there is voltage generated in the disc. If no charge collected this means the disc doesnt generate voltage because the magnetic field is rotating as magnet rotate.

Magluvin

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Re: Homopolar Generators (N-Machine) by Bruce de Palma
« Reply #274 on: January 01, 2015, 07:58:16 PM »
Thanks for the interest guys

Tk

I see the braided brush, once it makes contact, it is magnetically pulled in for heavier contact, then releases at times. I have that with the mag on foil.

Was thinking last night about the 2 positions of the wire on the mags in my depictions, and the opposite movement direction of the mag.  This could get very interesting.  One thing, if you try to make contacts with opposite outer edges of the mag in your config, I myself, did not see spin with my setup as you have it. Only rotation with contacts of outer edge with either or both axles. Meaning current from the center of the mag to the outer edge, or outer edge to center causes rotation. Now on the foil, edge to edge does cause 'apparent' rotation, so you may see the mags in your setup possibly 'move' within the space tolerance of your axle looseness on the base. Like the mag will jump, up, or you will see a bit of movement, but no rotation. My setup like yours is a bit tighter at the axle holes on the base, so I was just burning the mags edge surface.

So on the foil, where the mag is more free to move instead of just rotate, if I make contact as in depiction 2, I believe that only the bottom portion of the mag is being pulled/pushed in a particular direction, causing the rotation we see on the fixed axle setup. But on the foil in depiction 1, I believe the mag as a whole is being pushed/pulled, perpendicular to the contacts.

Think about this, which Ill try today also.  make a very light weight floating device. Arrange a magnet and a small battery, with + and - connected to the outer edges of the mag. Will the little boat move in water based on that?   ;D Similar to the pendulum idea but possibly simpler to construct. ;)

Thanks again for showing. Will be taking camera to shop today. 

Mags

Magluvin

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Re: Homopolar Generators (N-Machine) by Bruce de Palma
« Reply #275 on: January 01, 2015, 08:10:35 PM »
Hey Electric Pirate

I do believe that the fields of the rotating disk mag is stationary as it rotates. Ive done tests with a large, very sensitive coil(5kohm 42awg wire) with a magnet attached to the coil, off center, and movement of the coil/mag through the air does not light an led, but moving the mag with the coil sitting fixed, the led lights with slow movements.  So, I have seen some out there using a bunch of small magnets to replace the solid disk magnet in a traditional homopolar setup. In those cases, the fields are not stationary. 

So in my pic 1, Im thinking that the current flowing through the mag, 90deg of the magnets pole alignment, moves the field within the mag, causing the mag material to want to move with the field. ;D

Mags

TinselKoala

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Re: Homopolar Generators (N-Machine) by Bruce de Palma
« Reply #276 on: January 01, 2015, 10:20:42 PM »
Ah...OK, I think I see it now. The magnet on the foil isn't rotating like a homopolar  motor, it's trying to slide, like a railgun armature, and the sliding friction makes it rotate. I think.

So if you had, say, a brass tube that would be a good fit for the OD of the magnet, or even better just a long skinny cylinder magnet polled endwise, and you set it onto a pair of rails and then supplied current to the rails, it would scoot down the rails and also roll. Maybe.

keithturtle

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Re: Homopolar Generators (N-Machine) by Bruce de Palma
« Reply #277 on: January 02, 2015, 12:51:22 AM »
Happy new year Chet, and all.   ;D

Mags
Happy new year to everyone, and especially to those determined to unravel this mysterious Faraday disk potential
Turtle, slow but still at it

Magluvin

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Re: Homopolar Generators (N-Machine) by Bruce de Palma
« Reply #278 on: January 02, 2015, 01:22:51 AM »
Ah...OK, I think I see it now. The magnet on the foil isn't rotating like a homopolar  motor, it's trying to slide, like a railgun armature, and the sliding friction makes it rotate. I think.

So if you had, say, a brass tube that would be a good fit for the OD of the magnet, or even better just a long skinny cylinder magnet polled endwise, and you set it onto a pair of rails and then supplied current to the rails, it would scoot down the rails and also roll. Maybe.

Not sure yet on the first part above, but been thinking it till I find out. ;) There could be more complexity to it all. But initial feelings from the experiments on the foil lead me to that possibility so far, from my experiences, so far. ;D

Well, not on rails.  just connect the battery to the magnet, and the battery just goes along for the ride. :o ;) ;D Depending on the magnets orientation when the current is applied. I have some 1/2 x 1/8 x 1/16 bar neos. The 1/8 x 1/16 ends can be where the connections are made. Heck, Im already conjuring up configs with the lil bar mags stacked in series, yada yada yada.  But tests first.  Just got to the shop a bit ago. Cant upload pics n vids from here. Will do later at home.

Mags

Magluvin

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Re: Homopolar Generators (N-Machine) by Bruce de Palma
« Reply #279 on: January 02, 2015, 06:07:43 AM »
The first pic below is of the magnet set up like a homopolar motor, as TK presented a vid of that in a recent post here.

The second pic is of the pendulum test and the magnet didnt move when I applied current to the wires on the pivot axle.

Got a YT vid loading of the mag on the foil. Will post the link when its done.

Mags

Magluvin

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ElectricPirate

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Re: Homopolar Generators (N-Machine) by Bruce de Palma
« Reply #281 on: January 02, 2015, 09:44:03 AM »
Hey Electric Pirate

I do believe that the fields of the rotating disk mag is stationary as it rotates. Ive done tests with a large, very sensitive coil(5kohm 42awg wire) with a magnet attached to the coil, off center, and movement of the coil/mag through the air does not light an led, but moving the mag with the coil sitting fixed, the led lights with slow movements.  So, I have seen some out there using a bunch of small magnets to replace the solid disk magnet in a traditional homopolar setup. In those cases, the fields are not stationary. 

So in my pic 1, Im thinking that the current flowing through the mag, 90deg of the magnets pole alignment, moves the field within the mag, causing the mag material to want to move with the field. ;D

Mags

Hi mags

Like you said many believe that field is stationary but im still not satisfied without experimental proof. Experimenting is the only way i can see to end up this mind bogling paradoxes.  If only i have a large magnet i will do that experiment.

ElectricPirate

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Re: Homopolar Generators (N-Machine) by Bruce de Palma
« Reply #282 on: January 02, 2015, 01:55:33 PM »
Mag on foil vid

https://www.youtube.com/watch?v=s56ghlm0oJw&feature=youtu.be

Mags

Amazing vid but why the magnet move? If we apply left hand rule it shouldnt supposed to move?

broli

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Re: Homopolar Generators (N-Machine) by Bruce de Palma
« Reply #283 on: January 02, 2015, 02:51:57 PM »
Ah...OK, I think I see it now. The magnet on the foil isn't rotating like a homopolar  motor, it's trying to slide, like a railgun armature, and the sliding friction makes it rotate. I think.

So if you had, say, a brass tube that would be a good fit for the OD of the magnet, or even better just a long skinny cylinder magnet polled endwise, and you set it onto a pair of rails and then supplied current to the rails, it would scoot down the rails and also roll. Maybe.

I haven't looked at it this way but this seems completely possible. In fact if you prevent it from sliding and forced it to roll I can't tell how it will even induce a back EMF. Atached is my analysis of such setup. The upper illustration shows the generated forces, the lower images show the 2 different motion cases. Something to ponder on indeed.

DreamThinkBuild

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Re: Homopolar Generators (N-Machine) by Bruce de Palma
« Reply #284 on: January 02, 2015, 05:49:17 PM »
Happy Belated New Years @All


Hi Magluvin,

Thanks for sharing. That is very interesting.

A small test platform could be setup to see if it's sliding or rolling as TK and Broli state.

If the friction is too great for the top rail it can be replaced with a smaller wire with a slight slack to it so it droops and touches the top of the magnet.

If you feed in a bipolar square wave into the rails it should oscillate back and forth.

These all need testing still but it opens some really interesting ideas like a linear homopolar generator.