In class of Automatic Control, students learn a lot of tools like root locus and Bode plot to analyze the plant under study. However, even with the aid of software simulation like MATLAB, students who first reach this subject usually wonder how simple control scheme like PID is implemented when it comes to real-world applications. PID control, though pretty fundamental, plays an important rule in industrial applications. When reaching such topic, professors usually asks those who are interested in this to build a circuit like Fig. 1 to get some insights.
