Non-electromagnet neodymium motor-thing

[JebKeb]

Neodymium appears to be a very strong magnet. Would it be possible to replace the electromagnets in a electric motor with normal magnets and have it spin. Then...use it to spin a generator *gasp* 

It isn't a pertpetual motion machine - the energy in the magnetism was added when the neodymium was formed in a supernova or some other dramatic event. It shouldn't last forever - I think it would decay and lose it's magnetism slowly as the energy is used up. But that would probably take billions of years.

If it works, we have probably solved the world's power problems. But it won't be safe enough to replace batteries...

Not that impressive, but still. The magnets to run a car generator would be much stronger.

 

[JebKeb]

Don't go searching around for anything more about magnets crushing things...pls...

[Steel]

59 minutes ago, JebKeb said:

Neodymium appears to be a very strong magnet. Would it be possible to replace the electromagnets in a electric motor with normal magnets and have it spin. Then...use it to spin a generator *gasp* 

It isn't a pertpetual motion machine - the energy in the magnetism was added when the neodymium was formed in a supernova or some other dramatic event. It shouldn't last forever - I think it would decay and lose it's magnetism slowly as the energy is used up. But that would probably take billions of years.

If it works, we have probably solved the world's power problems. But it won't be safe enough to replace batteries...

Not that impressive, but still. The magnets to run a car generator would be much stronger.

 

Yes. There's no requirement for a magnet in a motor to be an electromagnet. The power from a motor come from the current passing through the coils, not the magnetic field

Edited May 14, 2016 by Steel

[magnemoe]

You get the energy from rotating the shaft, not the magnets themselves.
Know that some small electrical motors uses permanent magnets but then usually as stator so it should work, downside is that generators tend to be larger while you often need tiny electromotors.

[pincushionman]

An electric motor works by the interaction of two magnetic fields: a static field (from the "stator") and a rotating field (oddly enough, from the "rotor"). In order to turn in one direction continuously, one or the other fields must be able to change polarity twice per revolution. Therefore one (or both) of the fields must be provided by an electromagnet. Which one doesn't matter.

The non-switching field may be provided by a permanent magnet because it doesn't have to do anything but make a magnetic field, so using a permanent type results in s simpler (cheaper) motor. But you could use an electromagnet if you wish. It's more complex, but you'd have no net magnetic field when the device is switched off. Some applications might call for such behavior, but I can't think of any off the top of my head.

So…no. You can build a motor with two electromagnets, or one electro- and one permanent, but not with two permanents. The only way to reverse polarity is with an electromagnet.

[JebKeb]

Thanks for clearing this up. I was rather sceptical of it when I first heard the concept, but still thought it would work because I didn't have a very good understanding of electric motors.

[p1t1o]

A magnet is not a source of energy. Think of them as springs, can't power a motor with a spring. Or you can, but first you have to compress it, and then you only get out what you put in (at most). You can store energy in a magnetic field, but you cannot have a machine that consumes magnetism and spits out energy.

Good rule of thumb - if you think you have solved the worlds energy problems with a machine that fits on your desk, check your working! (Which you did, so you are sciencing properly :D)