TABLE OF CONTENTS To understand the operating principles of an electronic drive, it is necessary to understand the basic principles of electricity, electronics, and mechanical devices. In this chapter, we will review the required basic concepts, and relate them to AC- and DC-drive systems. This section is by no means a complete digest of electronics and mechanics but will provide for a baseline of understanding. Consult the Appendix when more information is needed. This will be a review for some readers and a basic introduction into the electrical and mechanical world for others.
Electricity comes in two forms: alternating current (AC) and direct current (DC). We will first consider the effects of DC on various electrical components and identify the three main characteristics of any electrical circuit. Figure 2-1 illustrates the basic atomic structure where it all begins.
When we take a close look at nature, we find that all matter is composed of atoms. In the basic structure of an atom, we find that the nucleus is at the center, surrounded by one or more orbiting electrons. This structure is replicated many times for any material. If the material is an insulator, the orbiting electrons do not move from place to place or from atom to atom.
For the purposes of discussion, we will consider a conductor as an atom with three or less orbiting electrons in the outer shell. An atom with five or more orbiting electrons will be considered...
