Principle of operation
Servomotor’s principle of operation is based on using the pulse signal, which has three important characteristics - repetition rate, minimum and maximum duration. The pulse duration determines the rotation angle of the engine. The pulse signals received by the servo have a standard frequency, but their duration, depending on the model, can be from 0.8 to 2.2 ms. In parallel with receiving the control pulse, the reference pulse generator is activating, which is connected to the potentiometer. That, in its turn, is mechanically coupled to the output shaft and is responsible for correcting its position. The electronic circuit analyses the pulses taking into account the duration and, based on the difference value, determines the difference between the expected (given) position of the shaft and the real one (measured with a potentiometer). Then correction is made by applying voltage to the motor supply.