No magnet motors

[Sceadwian]

Out of curiosity, are there any kinds of motors that use electromagnets exclusively instead of permenant magnets?

 

[audioguru]

Most motors that operate from the AC mains don't have permanent magnets.

 

[CheapSlider]

They are called "Universal Motors"

They will run off either DC or AC*

A mains powered drill will have a universal motor.



* single phase AC

 

[RODALCO]

Difference between AC and DC motors is that AC motors have laminated iron cores, to reduce eddy currents.

Other very powerfull motors are Starter motors. ( short term rating )

If a motor is continuously rated it usually has a cooling fan attached, or enough surface area on its housing to dissipate its heat, a wiper motor for instance.

 

[Hero999]

All motors have a laminated core, even DC motors. The current in the armature is always alternating so it makes sense to reduce the core losses.

Permanent magnet motors are more efficient than universal motors which are more efficient when run from DC.