ABSTRACT

A feedback control circuit is one in which the value of a controlled variable signal is compared with a reference value. The difference between these two signals generates an actuating error signal which may then be applied to the control elements in the control system. This principle is shown in Figure 11.1. The amplified actuating error signal is said to be fed back to the system, thus tending to reduce the difference. Supplementary power for signal amplification is available in such systems.