TABLE OF CONTENTS This section describing the principles and applications of various electronic components and circuits is not intended to explain their detailed operation. Overall, an understanding of basic electronic principles will help to show how electronic systems operate. These can range from a simple interior light delay unit to the most complicated engine management system. Testing individual electronic components is a useful diagnostic procedure.
The symbols for the following electronic components are shown in Figure 9.1.
Resistors are probably the most widely used component in electronic circuits. Two factors must be considered when choosing a suitable resistor, the ohms value and the power rating. Resistors are used to limit current flow and provide fixed voltage drops. Most resistors used in electronic circuits are made from small carbon rods; the size of the rod determines the resistance. Carbon resistors have a negative temperature coefficient (NTC) and this must be considered for some applications. Thin-film resistors have more stable temperature properties and are constructed by depositing a layer of carbon on to an insulated former such as glass. The resistance value can be manufactured very accurately by spiral grooves cut into the carbon film. For higher power applications resistors are usually wire wound. Variable forms of most resistors are available. The resistance of a circuit is its opposition to current flow.
A capacitor is a device for storing an electric charge. In its simple form it consists of two...
