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Permanent Magnets Vs. Electromagnets (1 Viewer)

velox

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Whats the difference in having permanent magnets or an electromagnet in a DC motor? Does it make it more efficient or more powerful? Or just cheaper?
 

Sphyx

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electromagnets weigh less, therefore lighter motor and/or generator.
permanent magnets have magnetic properties all the time, so it will be in a magnetic field and will be interacting with other metals even when theres no current cutting through it.
thus, electromagnets are better because they act only when the motor is being used.
 

zenger69

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yes what Sphyx said is true.

But electromagnets are a lot stronger compared to permanent magnets.
(electromagnets and strong permanent magnets are similiar in costs).

And electromagnets do not loose magnetic field strength when it gets hot compared to permanent magnets. (If you did Chemistry in Yr11 you learnt that when you heat magnets to high temperatures they loose their magnetic field properties).

The electromagnets are used in big motors where the motor is likely to heat up and also where the motor/turning force needed is great.
Also electromagnets are used when the amount of power used isn't a concern.


Hope it helps
 

SoVeReIgN

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Are electromagnets usually run in parallel to the circuit running through the coil or series or on their own circuit?
 

Sphyx

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good question. i think both can work, although same circuit seems more efficient.
 

SoVeReIgN

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Hrmm.. also - How much electricity do electromagnets use? i understood it was next to none? Only wire resistance?
 

zenger69

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depends on how many coils the electromagnet has.

same with the question before. The electricity used will depend on how many coils the electromagnet has.

electromagnets can be connected up in both series and parallel I think. Series circuit would use less power compared to parallel. But then one of the electromagnets in the series circuit (if there was two) would be 1/2 as powerful as one in the parallel circiut (theoretically).
 

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