Magnetic generator multiple poles. Cancel out or short circuit?

[Vandan]

Science project. Real generator. But self made generator multiple magnets.

What happens if I spin bar magnets inside a copper wire ring? Instead of rotating 2 separate copper rings inside a magnet that will split different flowing current on to different wires where a brush can join them together, what happens if I do the opposite putting the magnet inside the copper coil WITH ONLY 1 continuous copper wire exposed to both North and South poles simultaneously?

Will current cancel each other out trying to flow opposite direction and only the net difference will flow through the wire? Or will this create an electrical short heating up the wire like a resister?

Could place a diode on one end of the copper wire to prevent flow the wrong direction? Is there anyway I can gain electricity off something like that? I don't have the ability to separate this group of spinning magnets. I want to put them all inside the copper ring? I was hoping the magnetic fields or conflicting currents would cancel each other out? But then I thought what if the wire started to heat up?

 

[berkeman]

Welcome to PF.

Can you post a sketch of your proposed setup? That would help a lot. Just click the "Attach files" link at the lower left of the Edit window to upload a PDF or JPEG diagram. Thanks.

 

[Vandan]

Primary use for magnets are for mechanical work. Trying to grab current from them. Single copper coil exposed to N and S poles same time moving In and out of the copper coil side by side evenly but spaced a part a little. BUT one magnet stops moving 50% of the time remaining inside with no movement. Both magnets enter copper coil half way.

 

[hutchphd]

There are two issues here:

1. A single continuous coil with one magnet rotating will in fact produce alternating currents and heat in the coil.
2. If I understand, in your "two magnet" setup one magnet will largely cancel the other one. Most of the magnetic field from one will be pulled into the other and vice-versa. May I recommend a simulation program (vizimag) that has a 30 day free trial. See if you can simulate some magnets and play.

Of course you must know that this is a very, very, well researched engieering field. One brushless design is the "brushless DC Motor" which is really a three phase AC motor and a DC to three phase AC converter. These are used a lot on model RC airplanes and quadcopters. They are worth understanding. Look them up

 

[berkeman]

Single copper coil exposed to N and S poles same time moving In and out of the copper coil side by side evenly but spaced a part a little.

Are you familiar with Faraday's Law for Electromagnetic Induction? Basically to maximize the voltage that is induced in the coil by the moving magnet, you need to maximize the change in the B-field with respect to time:
$$ V(t) = - N \frac{d \phi (t)}{dt} $$
Where ## N ## is the number of loops in the coil that the magnetic flux ## \phi ## passes through. In order to maximize ## V(t) ## you need to have maximum flux change and maximize the speed with which that flux changes.

How does your proposed geometry accomplish those goals?

https://en.wikiversity.org/wiki/Faraday%27s_Law

 

[Vandan]

Thank you both. I will look at the magnetic simulator thanks. As I understand I will gain "nothing useable" with both magnets, heat up my wire. Next pass in when a single pole is inserted to the loop, the wire loop will be left heated from previous interaction. Too much opposing current maybe hot enough to damaging coil. Thank you both. :) This idea won't work.

PS. I wonder if I'm able to cool the wire down? I doubt a cooling fan is going to make much difference. It's alternating passes. 2 magnets and then 1 magnet at high velocity, it's unlikely I'll be able to cool the wire down within that fraction of a second? I'll have to test it to see how hot it gets. I think it's going to heat up immediately but I can test it. Thank you. :)

 

[berkeman]

Thank you both. I will look at the magnetic simulator thanks. As I understand I will gain "nothing useable" with both magnets, heat up my wire. Next pass in when a single pole is inserted to the loop, the wire loop will be left heated from previous interaction. Too much opposing current maybe hot enough to damaging coil. Thank you both. :) This idea won't work. I'll need to monitor other metal components with into be sure they aren't heating up, if so cool the unit while operating which might consume some of it's output energy gains. Thank you both so much.

Inserting a bar magnet into a long coil is a very inefficient way to induce a voltage in the coil and convert mechanical energy to electrical energy.

"Heating the coil" is not an issue, unless the generator is not well designed. The output current of the generator will depend on the output voltage ## V(t) ## and the impedance of the load connected to the coil output terminals; the coil wire gauge can be sized for the appropriate power transfer level of the generator.

To maximize the efficiency of the mechanical-->electrical power conversion, you use high-mu ferrous cores to connect the coils in the magnetic path (minimize the air gaps to maximize the strength of the B-fields [1]), and move the magnets past those cores and coils to maximize the output for the equation that I showed above.

What reading have you done so far about generators and motors? [2]

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[1] https://en.wikipedia.org/wiki/Magnetic_circuit

[2] https://www.animations.physics.unsw.edu.au/jw/electricmotors.html

 

[Vandan]

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The objective here was to create more current outside (not within the internal electric generation area), adding copper wire any place that has a moving magnet.

The majority of current is produced in a separate area with an isolated moving magnet. There's no more force to spin the motor faster, I hoped to add other areas that had been already consuming force from the engine.

I was lucky to find someone on YouTube who did something similar using water cooled copper tubing instead of copper wire. Their copper tubing without water cooling reached hundreds of degrees Fahrenheit. Water cooling worked.

I was hoping 2 bars of opposite polarity in the copper coil would produce useable current or cancel out resistance. But both bars will double resistance with copper while producing no useable current lost as heat. This doesn't work because it results in a net current loss due to slowing the motor without current gain from that resistance.

Instead I'll focus on the main current generation area trying to increase current efficiency. Although it seems more efficiency results in more resistance between magnets and copper slowing the motor down. I might try increasing the voltage using thinner gauge copper wire to see if that results in less resistance?

 

[berkeman]

I was lucky to find someone on YouTube who did something similar using water cooled copper tubing instead of copper wire. Their copper tubing without water cooling reached hundreds of degrees Fahrenheit. Water cooling worked.

Where are you currently in your education? Are you in high school? If you're done with high school, do you have a community college near you where you can take some basic math and electronics courses? It's pretty clear that you didn't understand or read my post about magnetic paths and Faraday's Law -- you really need to learn more math before shotgunning stuff you see on YouTube, IMO.