Capacitor, Inductor, and Transformer

Abstract

From the viewpoint of power handling capability, electronic circuits can roughly be placed into two groups: signal processing circuits and power processing circuits. In general, the power level processed by the signal processing circuits ranges from a fraction of 1 milliwatt to several milliwatts. In contrast, the power processing circuits treat power flow exceeding several watts. Besides being distinguishable in power level, the two groups also differ in their current handling capability. Whereas signal processing circuits treat currents of no more than several milliamperes, the current level managed by power processing circuits ranges from a few amperes to hundreds of amperes. Owing to the higher current levels in power processing circuits and the fact that high current capacity is directly translated to the requirement of larger wire size and components, the physical size of the power processors tends to be large. As a result, power processing assemblies are often very bulky, difficult to manufacture, and costly in price. Therefore, to save manufacturing cost and to minimize equipment volume, it is essential to thoroughly understand the two passive elements, capacitors and inductors, which play major roles in power electronics, but also take up the most space.