How electric motors work

How electric motors work

Electric motors use electricity to create the circular movement of many different things. From the blender on your kitchen counter to electric toys, the electric motor can be found everywhere in your home and work place. To understand how an electric motor works we must first understand two things; electrical circuits and electromagnetism.

Electrical circuits are made up of four things; the power source, the load, and two wires. In the case of electrical motors, the motor is the load. From the negative side of the power source electricity will energize the motor coil and then flow back to the positive side of the power source.

Electromagnetism is created by nothing more than current running though a wire. When the wire is wrapped around another conductive material, you can create a more powerful electromagnet, called the coil. If one took a nail and wrapped a small electrical wire around the nail several times and placed each end of the wire to the positive and negative ends of a battery, you would create an electromagnet. The electromagnet is the primary element of an electric motor.

An electric motor is made up of the casing, the axel, the armature, the brushes, a commutator, a field magnet, the coil, and a power supply.

The armature is the electromagnet and is commonly called the coil. It is charged with electricity, creating an electric field. It acts directly with the field magnet. The field magnet is a permanent magnet. As the North and South poles of the armature are attracted and repelled by the poles on the permanent magnet, the armature rotates on its axel. As long as the armature has electrical current flowing through it, creating the coil, the armature will spin, spinning the axel.

The brushes are what connect the power source to the armature. If one imagines the armature as a small round piece of metal, the brushes would usually be located on the ends of the armature, like an eraser on a pencil. The brushes allow the coil to be continuously energized.

One of the challenges in an electric motor is the spinning coil. As the coil rotates, its magnetic fields are constantly reversed in relation to the permanent magnet poles. Without a commutator, each time the armature turns to a neutral position, where the North and South poles of the armature are even with the South and North poles of the permanent magnet, it would cause a temporary short to the power source, constantly depleting its power.

It could also theoretically get stuck in this neutral or equilibrium. This is solved with the commutator. It is attached to the axel and allows for the turn over of the fields by creating a third pole. The commutator or third pole is offset on the armature to ensure the poles of the permanent magnet are always repelling and attracting the electromagnet poles.

The spinning axel is the work produced by the motor. This circular movement is what all-electric motors produce. Ideal for turning wheels on toys or the blades on a blender. Currently, electric motors are being perfected to be used in automobiles, replacing the gasoline engine with a cleaner, quieter, more efficient mode of transportation.

Leave a Comment