Advanced Electrical Installation Work, Fourth Edition

Chapter 4: Electronic Components

There are numerous types of electronic component diodes, transistors, thyristors and integrated circuits each with its own limitations, characteristics and designed application. When repairing electronic circuits it is important to replace a damaged component with an identical or equivalent component. Manufacturers issue comprehensive catalogues with details of working voltage, current, power dissipation etc., and the reference numbers of equivalent components, and some of this information is included in the Appendices. These catalogues of information, together with a high-impedance multi-meter as described later in this chapter and show at Fig. 4.74 should form a part of the extended tool-kit for anyone in the electrotechnical industries proposing to repair electronic circuits.

Electronic circuit symbols

The British Standard BS EN 60617 recommends that particular graphical symbols be used to represent a range of electronic components on circuit diagrams. The same British Standard recommends a range of symbols suitable for electrical installation circuits with which electricians will already be familiar. Figure 4.1 shows a selection of electronic symbols.


Figure 4.1: Some BS EN 60617 graphical symbols used in electronics.

Resistors

All materials have some resistance to the flow of an electric current but, in general, the term resistor describes a conductor specially chosen for its resistive properties.

Resistors are the most commonly used electronic component and they are made in a variety of ways to suit the particular type of application. They are usually manufactured as either carbon composition or carbon film. In both cases the base resistive material is carbon and the general appearance...