AC electric motors, or as they are known ‘AC electric motors’ are time varying, alternating the direction they circulate in an electric conductor. Unlike DC motors that have this name exactly because they are constant in time, having their value well defined, always going in the same direction in a conductor. The speed of AC motors is indicated by the frequency of the power supply, which results in fantastic conditions for its operation at constant speeds.
It is because of the advances in alternating current drive motors, 10 hp 215T motors with the soft-starter and frequency inverters, and the economical viability they have replaced DC motors. But when you need to maintain torque, even with varying load and motor speed, DC motors are the best choice as in paper machines, winders and unwinders, rolling mills, printing machines, extruders, presses, elevators, etc. Alternating current is used in many applications, especially in high power systems, industries and electrical machines, usually in induction motors that supply appliances such as electric kettles, refrigerators and washing machines.