Electric motors convert electrical power into mechanical energy for rotational motion. You can find them in many applications including household appliances like mixers and power tools, industrial machinery such as blowers and pumps, disk drives and car engines. The rotational movement of the engine can be controlled to produce the desired speed and torque. They also use regenerative braking to recover energy that would otherwise be lost as heat.

The operation of an electric motors consists of two primary mechanical and electrical components: the stator that remains stationary and the rotor that rotates. Electricity is supplied to the coils of the rotor to make it a temporary magnet that interacts with a stationary magnetic field created by either permanent magnets (PMs) or one of the windings of the stator to produce the necessary rotating electromagnetic field. The interaction is powered by the law of magnetic attraction, where like poles attract and unlike poles repel.

Electric Motors: How They Work and Where to Find Them

A conductor in a closed loop will induce a voltage proportional to the current through it, based on Faraday’s law of induction. Since the rotor conductors are shorted together at their ends, this produces an induced current in each of them that interacts with the magnetic field across the air gap to generate torque.

The rotor bar conductors are often skewed, which helps distribute the magnetic fields across multiple bars and prevent them from ever fully aligning with each other, resulting in jamming. A mechanical device called a commutator is used to switch the brushes of the armature between different positions to keep them supplied with power.