An electric motor of direct current converts electrical energy into mechanical energy and has a characteristic of its own, it must be fed with continuous voltage. This continuous voltage can be derived from batteries and motors in the case of small motors or from an alternating grid after grinding in the case of larger motors.

The main components of a direct current (DC) motor are described as:

– Stator: contains a winding (field), which is fed directly by a source of continuous voltage; in the case of small motors, the stator may be a simple permanent magnet;

– Rotor: contains a winding (armature), which is fed by a DC voltage source through the switch and graphite brushes;

– Switch: mechanical device (axially segmented copper tube) in which the ends of the armature turns are connected, in order to invert the direction of the direct current flowing in the armature.

The operation of DC motors is based on the principle of classical electromagnetism where: “A conductor carrying an electric current through a magnetic flux is subjected to a force of an electromagnetic nature” (Faraday).