What is a Rectifier?

In the electronics industry, one of the most popular applications of semiconductor diodes is to convert alternating current (AC) signal of any frequency, which is typically 60 or 50 Hz, to a direct current (DC) signal. This DC signal can be used for powering electronic devices, rather than batteries. The circuit which converts the AC into DC signal commonly consists of a particular arrangement of interlocked diodes and is known as a rectifier. In power supply circuits, two types of rectifier circuits are commonly used — half-wave and full-wave. Half-wave rectifiers only permit one-half of the cycle through, whereas full-wave rectifiers permit both the top half and bottom half of the cycle through, while converting the bottom half to the same polarity as the top. This difference between them is shown in Figure 1.

Figure 1 : Difference between outputs of half- and full- wave rectifiers

Between the two types, the full-wave rectifier is more efficient as it uses the full cycle of the incoming waveform. There are two types of full-wave rectifiers — the center-tapped full-wave rectifier, which requires a center-tapped transformer, and the bridge rectifier, which does not need a center-tapped transformer.  The bridge rectifier will be discussed in this article as it is the most popular and usually comes in preassembled modules, making them easier to use.