Angular velocity control for a windmill radiometer

In this paper, an inexpensive and simple control experiment which could be readily used to demonstrate proportional integral (PI) compensator design through root locus is presented. This work is also a useful example of analog control, which is not often seen today. It is of interest to anyone teaching an introductory control course. The variable to be controlled is the angular velocity of a windmill radiometer whose vanes turn when exposed to infrared radiation. An experimental setup using a reflexive photoelectric sensor and basic electronic circuitry makes possible the design and implementation of a high-performance control system.