Introduction
A semiconductor device is one made of
silicon or any number of other specially prepared materials
designed to exploit the unique properties of electrons in a
crystal lattice, where electrons are not as free to move as
in a conductor, but are far more mobile than in an
insulator. A discrete device is one contained in its
own package, not built on a common semiconductor substrate
with other components, as is the case with ICs, or
integrated circuits. Thus, "discrete semiconductor
circuits" are circuits built out of individual semiconductor
components, connected together on some kind of circuit board
or terminal strip. These circuits employ all the components
and concepts explored in the previous chapters, so a firm
comprehension of DC and AC electricity is essential before
embarking on these experiments.
Just for fun, one circuit is included in
this section using a vacuum tube for amplification
instead of a semiconductor transistor. Before the advent of
transistors, "vacuum tubes" were the workhorses of the
electronics industry: used to make rectifiers, amplifiers,
oscillators, and many other circuits. Though now considered
obsolete for most purposes, there are still some
applications for vacuum tubes, and it can be fun building
and operating circuits using these devices. |