Electromagnets in Electric Motors

Electric Motors:

Electric motors are electric machines that convert electrical energy into mechanical energy. Electric motors can also use both AC and DC sources such as a power grid or batteries. Electric motors can be either brushed or brushless, and can be either air-cooled or liquid-cooled.  Standard general purpose electric motors are able to provide convenient mechanical power for use in the industrial field. There are electric motors in machines such as power tools and disc drives, machine tools, household appliances, and industrial fans.  Sometimes, small electric motors can be found in electric watches. Electric motors are unique because in certain uses as generators, they can be used to recover energy that could have otherwise been lost to friction and heat. Electric motors produce torque, which is linear force.  This distinguishes them from other devices that do not generate usable mechanical force, but solely convert electricity into motion.

Use of Electromagnets in Electric Motors:

Electromagnets are the base of the electric motor.  The motor uses magnets to create motion. The attracting and repelling forces of the North and South end of the magnets create rotational motion in the electric motor.  There is a part of the electric motor called the armature. This armature is made up of electromagnets, which have a copper wire wrapped around them. The natural way that magnets repel and attract one another creates a half-turn of motion.  The key to an electric motor is that at the moment the half-turn of motion completes, the field of the electromagnet flips, allowing the electromagnet to complete another half-turn of motion. The magnetic field can be flipped by flipping the battery over, and therefore changing the direction of the electrons flowing in the wire.  The electric motor completes the “flipping” process by using the commutator and the brushes. If the field of the electromagnet, which in the case of the electric motor is the armature, was flipped at precisely the right moment when each half-turn of motion was completed, the electric motor would spin freely and continuously.