Chapter 25 a.c.principles

25.1 Alternating voltage and current

Unlike direct currents that have steady values and always flow in the same direction, alternating currents flow alternately one way and then the other. The voltage produced by an alternating current is thus partly positive and partly negative. An understanding of alternating currents and voltages is important in a number of applications including a.c. power distribution, amplifiers and filters.

25.1.1 Waveforms

A graph showing the variation of voltage or current present in a circuit is known as a waveform. Some common types of waveform are shown in Figure 25.1. Note that the waveforms ...

Get Engineering Science now with the O’Reilly learning platform.

O’Reilly members experience live online training, plus books, videos, and digital content from nearly 200 publishers.