Electric motors are all around us. In our homes alone, almost all the mechanical and electrical movement you see around you is caused by a DC (direct current) electric motor and an AC (alternating current) electric motor.
It was in 1873 that Zénobe Gramme created the contemporary DC electric motor. Gramme linked his dynamo motto to another apparatus and directed it like a motor. His invention, the Gramme device, was the first electric motor to be started in the field.
Two good examples of DC electrical inventions are the innovative ball-bearing motor and the unusual homopolar motor created by Michael Faraday.
In general, a simple DC electric motor consists of six basic parts. These are the rotor or armature, the brushes, the shaft, the commutator, the field magnet, and the DC power supply. An electric motor is powered by magnets that use magnetic fields to produce torque, setting the motor in motion. Those who have played with magnets before are familiar with the elementary principle of magnets, that like poles repel each other and opposite poles attract. The electromagnetic forces of attraction and repulsion within an electric motor cause the DC motor to create rotary motion.
Magnets are polarized, with a negative and a positive section. Even with relatively small magnets, the repulsion of like poles and the attraction of opposite poles are evident. The DC electric motor uses these components to virtually transform electrical current into shifting motion.
A DC electric motor needs at least one electromagnet. An electromagnet serves as the source of an electric motor and changes the flow of electricity as the motor moves, altering its bias to keep the motor running. The other magnetic fields are electromagnets or permanent magnets. The electromagnet is normally located in the hub of the motor and rotates on the permanent magnets.
A DC electric motor features coils of wire that rotate in a magnetic field. The coil is placed on a fixed magnet. The electrical flux in the coil is delivered by means of two brushes that produce moving connections with a split ring. The forces applied on the coils of wire initiate a movement or twist in the coil. The coil also acts as a small magnetic dipole.
To better understand and imagine a simple DC electric motor, imagine a wheel split in two between two magnets. In this case, the wheel of the DC motor is the electromagnet. The two outer permanent magnets are negative and positive. Now suppose the right magnet is positive and the left magnet is negative.
The wire coils in the DC motor wheel are fed with an electrical flux and this current ignites a magnetic pulse. To make the DC motor turn and more, the positive permanent magnet wheels must have a positive charge and the negative permanent magnet must also have a negative charge. And since opposite charges attract and like charges repel each other, the wheel is shifted so that its negative part turns to the right and the positive part of the wheel moves to the left. The magnetic force allows the wheel to turn, so movement is used to perform and operate.
The consistency and simple pattern of DC motors make it an ideal choice for countless different purposes. DC motors are widely used for many applications, such as remote control cars and electric shavers.