，使用变压器将来自电源电压改变为次级上的电压或其他各种类型的电压。这些是根据电源将用于的应用来选择的。
First, a transformer is used to change the voltage from the power supply to a voltage on the secondary or various other types of voltages. These are selected according to the application for which the power supply will be used.
然后变压器的次级连接到所谓的整流器。整流器由二极管组成，将交流(50或60赫兹)转换为顿颁(0赫兹)。每次交流波形越过其过零点时，都有一段时间整流器完全关闭。这导致寄生交流分量是整流器后电源频率的两倍。这种波形称为波纹。
The secondary of the transformer is then connected to the so-called rectifier. The rectifier consists of diodes that convert AC (50 or 60 Hz) to DC (0 Hz). Each time the AC waveform crosses its zero crossing point, the rectifier is completely closed for a period of time. This results in a parasitic AC component that is twice the power frequency after the rectifier. This waveform is called ripple.
整流后使用电容器目的是储能和滤波。当整流器中的二极管正向偏置时，它们给电容器充电。在过零期间，整流器停止导通，从而停止向电容器提供电流。此时，电容器成为电力负载的唯 一电流源，并开始缓慢放电。当它们放电时，输出电压开始下降，直到下一个导通周期。整流后增加电容的过程减少了纹波，提高了DC电压。虽然一些波纹已经减少，但请记住，由于这些充电和放电循环，它仍然存在。
After rectification, capacitors are used for energy storage and filtering. When the diodes in the rectifier are forward biased, they charge the capacitor. During zero crossing, the rectifier stops conducting, thereby stopping the supply of current to the capacitor. At this time, the capacitor becomes the only current source of the power load and begins to discharge slowly. When they discharge, the output voltage begins to drop until the next conduction cycle. The process of increasing capacitance after rectification reduces ripple and improves DC voltage. Although some ripple has been reduced, remember that it still exists due to these charge and discharge cycles.
添加存储电容后产生纹波
Ripple after adding storage capacitor
这就引出了电力电容器的二个应用，即滤波。当从顿颁轨接地时，电容通过形成所谓的低通滤波器进行滤波。的基本一阶低通滤波器如下：
This leads to two applications of power capacitors, namely filtering. When grounded from the DC rail, the capacitance is filtered by forming a so-called low-pass filter. The basic first-order low-pass filter is as follows:
通常用于电源的一阶低通滤波器
First order low-pass filter commonly used in power supply
由于电容器的阻抗在接近顿颁时较高，在接近高频时较低，因此高频通过低于截止频率的大部分频率分流到地。截止频率，也叫转折频率，可以定义为蹿肠=1/(2搁颁)，是一个幅度降低3诲叠的频率。
Since the impedance of the capacitor is higher near DC and lower near high frequency, the high frequency is shunted to ground through most of the frequencies lower than the cut-off frequency. The cut-off frequency, also known as the turning frequency, can be defined as FC = 1 / (2RC), which is a frequency with an amplitude reduction of 3dB.
由于在该应用中需要高频电容，电源电容器通常是电解电容器。容量越高，截止频率越低;纹波衰减得越多。电解质基本上使用流体作为电 极，因此该流体开始变干，增加了串联电阻并降低了部件的电容。这通过将截止频率向上移动以及降低其衰减较高频率噪声的能力来降低低通的有效性。电容的减小也阻止它在非导通期间存储足够的电荷。结果是更高的纹波和更低的直流电压，两者都会在更高的输出电流下恶化。造成音响设备、嗡嗡声，高频噪声，动态损失，输出功率降低，以及良好的声音
Since high frequency capacitors are required in this application, power capacitors are usually electrolytic capacitors. The higher the capacity, the lower the cut-off frequency; The more ripple attenuation. The electrolyte basically uses a fluid as an electrode, so the fluid begins to dry, increasing the series resistance and reducing the capacitance of the component. This reduces the effectiveness of the low-pass by moving the cut-off frequency upward and reducing its ability to attenuate higher frequency noise. The reduction of capacitance also prevents it from storing enough charge during non conduction. The result is higher ripple and lower DC voltage, both of which deteriorate at higher output current. Cause sound equipment, buzzing, high-frequency noise, dynamic loss, reduced output power, and good sound
