What is a DC Motor?
Release Date:03/05/2016
A direct current (DC) motor is a fairly simple electric motor that uses electricity and a magnetic field to produce torque, which causes it to turn. At its most simple, it requires two magnets of opposite polarity and an electric coil, which acts as an electromagnet. The repellent and attractive electromagnetic forces of the magnets provide the torque that causes the motor to turn.
Anyone who has ever played with magnets knows that they are polarized, with a positive and a negative side. The attraction between opposite poles and the repulsion of similar poles can easily be felt, even with relatively weak magnets. A DC motor uses these properties to convert electricity into motion. As the magnets within the motor attract and repel one another, the motor turns.
A DC motor requires at least one electromagnet, which switches the current flow as the motor turns, changing its polarity to keep it running. The other magnet or magnets can either be permanent magnets or other electromagnets. Often, the electromagnet is located in the center of the motor and turns within the permanent magnets, but this arrangement is not required.
To imagine a simple DC motor, a person can think of a wheel divided into two halves between two magnets. The wheel in this example is the electromagnet. The two outer magnets are permanent, one positive and one negative. For this example, the left magnet is negatively charged and the right magnet is positively charged.