Feedback and control

This chapter covers electronic signals which can be used to control a property, such as the position of a piece of equipment, the intensity of a light, or the temperature of a system. It discusses feedback as an example of the return of the measurement to the controlling device, wherein the control systems that incorporate a feedback loop can be regarded as types of servo system. It also mentions the position of an object that is set electrically by a motor or other output transducer and the feedback signal that is derived from a position-sensitive input transducer.

The chapter describes an open loop situation that has no feedback, wherein the accuracy of the final response relies on the complete transfer function between initial input and ultimate output. It highlights the accuracy of the closed loop incorporating feedback which is determined by the calibration of the sensing transducer.