When choosing an electric motor from direct current, it is necessary to observe some factors, such as the identification of the main characteristics of performance, power and size. We must also consider the environmental requirements for its application.
A DC machine is composed of an axis, which is properly coupled to the rotor, the element being responsible for the rotating of the motor. The stator is composed of a magnet, the switch having the function of transferring power from the power supply to the rotor.
Thus, the stator is formed by the north and south magnets, whereby the rotor, represented by a coil, receives power from the commutator, in which a current flows.
We can state that the basic principle of operation of motors operating from direct current refers to the fact that whenever a conductor at the exact instant of commanding an electric current, placed in a magnetic field, the conductor can cause a mechanical force , thus producing torque and rotation of the motor shaft.
In the process of supplying the DC voltage switch, a direct current is generated which is subsequently transferred to the coil via the contact of the switch brushes.