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magnetic flux / faraday disc idea .

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Salvador

Mon Sept 14 2015, 09:19PM

Registered Member #54402 Joined: Mon Feb 02 2015, 11:09PM
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Posts: 86

well i think it would be better to just get a iron toroid then take some cylinder shaped iron pieces and weld them with ends on the inside of the toroid to the toroid core , then put some coils on them then put the rotor in and excite the coils and see what happens when spinning the rotor, what happens in the output coil sitting on the toroid.

I do believe it's not so much about getting the toroid core to all be like one big single pole, it's rather about directing the flux from a field coil through the coil sitting on the toroid at the right angle. I tink of it this way, the toroid core serves as being the flux collector to extend that flux back into the field coils from which it then goes back into the rotor through the wires bak into the toroid core again, and so on and so forth.

Salvador

Tue Sept 15 2015, 04:17PM

Registered Member #54402 Joined: Mon Feb 02 2015, 11:09PM
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Well I don't know I;m becoming more skeptical about this whole idea.
First of all a man to whom I talked about this who knows something about EM said that since the flux doesnt encircle the whole coil like the one which would come from the inside of the toroid core , the induced current would be smaller than it could be , then again well i'm not so sure about the whole layout.

Well heres one interesting thing maybe one of you has a speaker magnet to do the experiment.I basically took a speaker magnet and wrappen some insulated wire on it , then the idea is to attach one of the backplates to the end of it , like the one with the cylinder in the middle , then you can add some metalic ball from a ball bearing in the middle and put some bar magnet or metal piece on top and jut rotate the flux should cut the upper part of each loop on the toroid speaker magnet.
I wrapped the coil and just took a magnet and moved it pas the coil with hand and i couldn't get any numbers on my multimeter and no moving on my needle of another one.

Oh by the way , a man from Oak Ridge laboratory has made such a form of the homopolar generator

Oh I also wonder , could a faraday disc have current if the flux that cuts it would be a time and polarity varying flux ?
then one could just divide the disc into say 4 equal parts , have another disc or coil on the rotor to which these parts are connected to and so in the one disc current would be induced in the other that current would circulate creating a field which then could induce current in surrounding stator coils.

Well basically these are just some thoughts , would love to hear someone's input.

Ash Small

Tue Sept 15 2015, 08:25PM

Registered Member #3414 Joined: Sun Nov 14 2010, 05:05PM
Location: UK
Posts: 4245

Interesting link.

Wastrel

Thu Sept 17 2015, 02:28PM

Registered Member #4095 Joined: Thu Sept 15 2011, 03:19PM
Location: England.
Posts: 122

(Reads patent)

HAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHA

Ahahahaha......HAHAAAHHHAAHAHAAA!(tries to breathe)

please no more I can't take it. Oh go on then more more!

ORNL! ORNL! Are you kidding me! AHAHA! How the hell did ORNL fall for that?!

I'm sorry, I don't mean to be disrespectful, but this is a seriously funny lesson that people who want to change the world are best placed to do so inside their field of education.

Salvador

Thu Sept 17 2015, 08:36PM

Registered Member #54402 Joined: Mon Feb 02 2015, 11:09PM
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Posts: 86

Could you please explain more of what you are talking about Wastrel? I really didn't understand exactly what was so funny?
I'm nopt saying its a genious idea but it seems to work , also could someone share any more thoughts about my last question in my previous post?

thanks.

Wastrel

Thu Sept 17 2015, 09:37PM

Registered Member #4095 Joined: Thu Sept 15 2011, 03:19PM
Location: England.
Posts: 122

A logical process to go from a Faraday generator to that design might be as follows..
The design forbids multiple turns without individual contacts because the induced current on the other side of the disc is in the same direction but the wire is backwards, cancelling out the induced EMF.

Solution, have a second magnet on the other side backwards so the induced EMF adds.
New problem is that the field escaping in between the magnets is at right angles to the spinning wires, and in cutting them there is an induced EMF. When all the induced EMFs are added the total of all the extra turns sum to zero again. you can talk about Lorentz force but at the end of the day it's all just induction.

The solution in the patent to this is to SHIELD THE SOUTH POLES OF THE MAGNETS. Yes that's right, the design hinges on the existence of a north magnetic monopole by shielding the south poles. The actual shield isn't a problem, we have materials that will do that pretty well, the problem is the nature of magnetism. Magnets behave like a circuit, you have a coercive force and you have a path with a permeability. Adding more coercive force gives you a bigger magnetic field. Using materials with higher permeability will also do that, free air is pretty crappy. The total field from north to south will still add up. In effect all the flux lines that leave the North pole will enter the south. Wrap the south pole in a perfect barrier and you kill the field dead, the north pole no longer has any magnetic properties at all.

It goes back to what I said before. Wonderful things like contact-less homopolar generators are possible if you have a magnetic monopole, but they don't exist. He's working at ORNL so my guess he's a very smart guy, but he's a biotech guy. What's more surprising is that no one with clue stepped in before they started offering it as a technology.

Just a tip, whenever a design calls for a magnetic shield that instead of shorting flux to create a clean space needs to interrupt flux - run don't walk away. Physics allows both but anyone insisting on the latter is always expecting something wrong.

Conundrum

Fri Sept 18 2015, 03:54AM

Registered Member #96 Joined: Thu Feb 09 2006, 05:37PM
Location: CI, Earth
Posts: 4062

Oops.

Salvador

Fri Sept 18 2015, 08:00AM

Registered Member #54402 Joined: Mon Feb 02 2015, 11:09PM
Location:
Posts: 86

thanks for the explanation Wastrel , a pretty good one I should say.Yes kinda funny that people who have serious jobs get out patents for something that doesn't hold and isn't even their full area of expertise.

So I suppose the only real attempt at a homopolar generator wich has any other shape and properties as the original well know copper disc is to have a coil and have a flux which firstly cuts the wire at the right angle and secondaly were the flux goes into the same direction at all places.
the simplest example of this would be a simple solenoid type coil with an empty middle and a magnet passing it rhough both from the inside and outside , the inner magnets outer wall should be say either N or S and the outer magnets inner wall should be also either one of the twoso that the flux through the coil is for example N-S at all points, correct?

if correct then what are your thoughts about the toroid thing I was talking here earlier? does it come even close to that ?

thanks.

Ash Small

Fri Sept 18 2015, 09:04AM

Registered Member #3414 Joined: Sun Nov 14 2010, 05:05PM
Location: UK
Posts: 4245

So I take it that, if I was to obtain two neodymiums with holes in, and bolt them together with both 'south poles' together, they would cease to have any magnetic field because their fields would cancel?

(Same as connecting the two negative terminals of a battery together)

Uspring

Fri Sept 18 2015, 09:55AM

Registered Member #3988 Joined: Thu Jul 07 2011, 03:25PM
Location:
Posts: 711

Nice analysis, Wastrel.

@Salvador: I believe, that a DC hompolar generator is impossible without sliding contacts. If you move a (rigid) wire loop in a magnetic field in such a way, that the flux through it doesn't change, you might get voltages along some parts of the loop, since crossing field lines with a wire will induce voltages. But since the flux is constant, you will have the same number of field lines crossing into the loop as leaving it. So the total voltage along the loop is 0.

You can induce voltages in the loop by increasing the flux through it. But for a constant DC output, the flux would have to increase forever, which is obviously impossible.

A homopolar generator consists of a non rigid loop. So some parts of the loop, i.e. the spinning disk, will have a conductor crossing field lines to induce a voltage. The other parts of the loop are stationary with respect to the magnet, so that they don't add to the voltage. For a homopolar generator you need to have parts of the loop moving and the other parts not. I don't have any idea, how that might be possible without sliding contacts.

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