ABSTRACT

This chapter discusses the primary function of a capacitor and describes the essential components of any capacitor. It explains the charging/discharging process of a capacitor and also describes what is meant by 'the charge on a capacitor'. Capacitors are manufactured in a huge range of physical sizes, ranging from the size of a match head to the size of a distribution transformer. A variable-value capacitor is an air-dielectric capacitor designed to allow its capacitance to be varied over a given range. The chapter examines how electric charge behaves with capacitors connected in series and explores the circuit symbols for different types of capacitor. It also explains how a capacitor's dielectric affects capacitance of that capacitor and also examines the relationship between absolute permittivity, the permittivity of free space, and relative permittivity. The chapter provides the basic construction of practical fixed-value and variable-value capacitors and also discusses solve simple problems on the time constant of a resistive-capacitive circuit.