Electrical circuits need DC power supply to provide energy when they work. Batteries are usually used only in portable instruments and equipment with low power consumption because of their high cost. Generally, DC power supply consists of the following parts: rectifier circuit is to convert power frequency AC to pulsating DC. The filter circuit filters the AC component of pulsating DC, reduces the AC component and increases the DC component. The voltage stabilization circuit uses negative feedback technology to further stabilize the DC voltage after rectification.

Half-wave rectifier circuit: Half-wave rectifier makes use of the single-conductor performance of the diode, So that the voltage Vo from the transformer can reach the load only half a cycle, as follows:

Full-wave rectifier circuit: Full-wave rectifier circuit is composed of transformer with central tap on secondary side and two diodes as shown in the figure below. It can be seen from the figure that current flows over the load in both positive and negative half circles, which improves the rectification efficiency.
 
Single-phase bridge rectifier circuit is the most basic circuit which converts AC to DC. When analyzing the working principle of rectifier circuit, the diodes in rectifier circuit have unidirectional conductivity. When the half-cycle is positive, the diodes D1 and D3 turn on, and the half-cycle of the sinusoidal wave is obtained on the load resistance. When the negative half-cycle is negative, the diodes D2 and D4 turn on, and the negative half-cycle of sinusoidal wave is obtained on the load resistance. The positive and negative half cycles of the load resistance are synthesized and the one-way pulsating voltage in the same direction is obtained.