Chapter 4. Semiconductors (Diodes and Transistors)
Herding Wild Electrons
As we noted in Chapter 2: Atoms, Molecules, and Crystals, electricity may be considered to be vast herds of electrons migrating from one place to another, while electronics is the art and science of controlling these herds: starting them, stopping them, deciding where they can roam, and determining the activities they are going to perform while on their way. Ever since humans discovered electricity (as opposed to electricity—in the form of lightning—discovering us), taming the little rascal and bending it to our will has occupied a lot of thought and ingenuity.
The first, and certainly the simplest, form of control is the humble mechanical switch. Consider a circuit consisting ...