INTRODUCTION

A DC machine is an electromechanical energy conversion device. It can convert mechanical power (ωT) into DC electrical power (EI) and is known as a DC generator. On the other hand, when it converts DC electrical power into mechanical power, it is known as a DC motor.

Although battery is an important source of DC electric power, it can supply a limited power. There are some applications where large quantity of DC power is required (e.g., electroplating electrolysis) and, at such places, DC generators are used to deliver power.

It has been seen that AC motors are invariably applied in the industry for the conversion of electrical power into mechanical power; however, at the places where wide range of speeds and good speed regulation are required (such as electric traction), DC motors have to be applied.

In short, we can say that DC machines have their own role in the field of engineering. In this chapter, we shall study the common topics of DC machines.