Switching Devices

Logic gates, as introduced in the previous chapter, represent the connectives used in logic formulas. Assume you have drawn a circuit diagram using logic gates, and you now want to build the circuit using switching devices of a given technology (pneumatic, electric, or electronic). To be able to do so you need to know how to translate each logic symbol into a symbol or a collection of symbols of the technology you intend to employ. This chapter is restricted to discussing symbols used for pneumatic valves, electric relays, and CMOS transistors, and to showing how they correspond to logic gates.