The speed and position control of the electric motors is performed in feedback cycles, where the position and the speed of displacement create fundamental information for the management of the motor.
Electric motors applied in feedback cycles usually already come with sensing installed to their axis. In this case, the motor becomes known as “servomotor”, as it becomes a total “slave” of the feedback loop.
They are servo motors PN-35T of direct current and of alternating current. When acquiring the electrical signals from the sensors, the control module operates to change the electrical power of the motor. This is usually done by modifying the values of the electrical voltages delivered to the motor or, also, by administering the time during which the motor receives these voltages.
Currently, the comparison element is elaborated by means of computer or, at least, with electronic instrument with computer characteristics. The computer must be adequate with a program capable of receiving signals (in the form of electrical voltages), comparing them with predetermined values and returning signals to the control to take the essential actions in relation to the motor: starting, accelerating, decelerating, stopping, conforming the situation.