8Capacitors: And Electric Charges
8.1 Introduction
In this chapter, we will examine capacitors, basic electronic components very popular in all kinds of circuits.
8.2 History
The capacitor or originally known as condenser1 is a two‐terminal electric component that can store potential energy in the form of electric field.
Technically, a capacitor is composed of two metal plates, separated by a medium. This medium, called dielectric, can be any nonconductive element like air, oil, plastic, etc.
8.3 How It Works
Capacitors are basically two metal plates in parallel. The plates are put very close to each other, without touching. These plates are at rest and have roughly the same number of electrons (see Figure 8.1).
Figure 8.1 Two metallic plates in parallel, at rest.
Something magical happens when a battery is connected to the plates. Suddenly, an electric field (F) is formed between the plates, as shown in Figure 8.2.
Figure 8.2 A battery is connected between the plates.
The electric field makes the plate connected to the battery’s negative pole (A) to accumulate an excess of negative charges (electrons) and the other one to accumulate positive charges, or lack of electrons (B).
Because both plates ...
Get Introductory Electrical Engineering With Math Explained in Accessible Language now with the O’Reilly learning platform.
O’Reilly members experience books, live events, courses curated by job role, and more from O’Reilly and nearly 200 top publishers.
