Learning objectives serve as a preview of the information you are expected to learn in this chapter.
The comprehensive check-on-learning questions, found at the end of the chapter, are based on the
objectives. Upon completion of this chapter, you will be able to perform the following learning
Define the term "transistor" and give a brief description of its construction
Explain how the transistor can be used to amplify a signal.
Name the four classes of amplifiers and give an explanation for each.
List the three different transistor circuit configurations and explain their
Identify the different types of transistors by their symbolism and
List the precautions to be taken when working with transistors and describe
ways to test them.
Explain the meaning of the expression "integrated circuits."
Give a brief description on how ICs are constructed and the advantages they
offer over conventional transistor circuits.
Name the two types of circuit boards.
State the purpose and function of modular circuitry.
INTRODUCTION TO TRANSISTORS
The discovery of the first transistor in 1948 by a team of physicists at the Bell
Telephone Laboratories sparked an interest in solid state research that spread rapidly. The
transistor, which began as a simple laboratory oddity, was rapidly developed into a
semiconductor device of major importance. The transistor demonstrated for the first time in
history that amplification in solids was possible. Prior to the transistor, amplification was
achieved only with electron tubes. Transistors now perform many electronic tasks with
new and improved transistor designs being continually put on the market. In many cases,
transistors are more desirable than tubes because they are small, rugged, require no
filament power, and operate at low voltages with comparatively high efficiency. The
development of a family of transistors has even made possible the miniaturization of
electronic circuits. Figure 2-1 shows a sample of the many different types of transistors you
may encounter when working with electronic equipment.
23 June 2005