Transistors, Logic Gates and Boolean algebra

Insights into Mathematics

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We introduce transistors and how they combine to create logic gates. These include prominently the gates called NOT, AND, OR, XOR, NAND, NOR and XNOR which input a pair of signals A and B and output a single signal. So these gates act as connectives, or even operations, on pairs of numbers {0,1}.

Transistors were introduced by Bardeen, Brattain and Shockley in 1947, although a patent in a similar direction goes back to J. E Lilienfeld in 1925. They rely on remarkable properties of the semiconductor silicon. By putting together transistors in clever ways, we can create logic gates, which are then the building blocks for more elaborate circuits, these days involving possibly millions of transistors.

The question of how to mathematically model what is happening with logic gates--in other words how to analyse them, is a separate question from how to construct them physically. We will be pursuing the idea that the original Algebra of Boole is in fact superior for the majority of applications involving logic gates over the classical Boolean algebra.

This is quite a novel position, but there are strong arguments for it. It has major ramifications for the education of electrical engineers around the world!