Large electric machines such as single-phase induction motors, synchronous motors, three-phase asynchronous motors and DC motors are used when we need continuous energy conversion. However, there are some special applications where you do not have to use a continuous power conversion process. The servomotor is different in design, construction and operation mode. The servomotor, often called the motor for control, is an electric motor specially designed and built for use in feedback control systems, playing the role of actuator element.
The rated power of these motors can range from fractions to hundreds of watts. These motors have a high dynamic response requiring low inertia of the rotor. Another property of these engines is that they have smaller diameter and longer length. Servomotors normally operate at low speed with high torque and can operate at high speed since the speed range of the servomotors ranges from 2,000 to 6,000 revolutions per minute. Examples of applications where servo motors are used include: packers, mats with programmed stops, cutting and welding machines, graphic machines, computers, process controllers, etc.