전압 감소, 정류 및 필터링 회로는 그림 3-1에 나와 있으며

降压，整流和滤波电路如图3-1所示，主要由变压器，整流桥和滤波电容器组成。通过变压器降低电源电压后，将220V AC转换为低压AC，然后整流成整流桥，整流后，可使用电解电容器进行滤波，通常需要470μF至1000μF的电容器。。通过执行这三个步骤，您可以获得直流电流（约30V）。从稳定的交流电源获得的经过整流和滤波的直流电源不是准确且稳定的直流电压。输入交流电源有一定的变化，因此获得的直流电源也有很大的波动。可以使用LM7812设计12V输出DC。。

图3-1显示了电压降低、整流和滤波电路，主要由变压器、整流桥和滤波电容器组成。变压器降低电源电压后，将220V交流电转换为低压交流，然后修正为整流器桥，经整整后可用于过滤电解质电容器，通常需要470μF至1000μF的电容器。.通过执行这三个步骤，您可以获得直流电流（约 30V）。从稳定交流电源获得的校正和过滤直流电源不是准确稳定的直流电压。由于输入交流电源存在某些变化，因此采集的直流电源也会显著波动。您可以使用 LM7812 设计 12V 输出直流。.

In Figure 3-1, the step-down, rectifier and filter circuits are mainly composed of transformer, rectifier bridge and filter capacitor. According to the transformer, when the main power supply voltage drops, 220V AC is converted to low-voltage AC, and then it can be distilled to the rectifier bridge. After rectification, the electrolytic capacitor can be used for filtration, which generally requires 470 μ f ~ 1000 μ f capacitance. The DC current (about 30V) can be obtained by performing these three phases. The rectified and filtered DC power obtained from stable AC power is not exactly stable DC voltage. Because the input AC power has some changes, the DC power will also change greatly. 12V output DC can be designed with LM 7812.<br>