电解电容几乎是所有开关电源必用元件之一，位置相当醒目，在电路的高压侧，作用巨大，它决定着电源的纯净程度，并且也算易损元件，电解电容厂家就结合实际谈谈电解电容的一些特性和在维修更换中的注意事项。

　　Electrolytic capacitor is almost one of the necessary components of all switching power supply. Its position is quite eye-catching. It plays a huge role in the high-voltage side of the circuit. It determines the purity of the power supply and is also a vulnerable component. The manufacturer of electrolytic capacitor will talk about some characteristics of electrolytic capacitor and the matters needing attention in maintenance and replacement.

　　电解电容在开关电源中主要是起到滤波作用，主要用来净化电路，很多开关电源从整流桥出来的直流电之间就并联两个串联的电容，以此点切入展开讲解一下。

　　Electrolytic capacitor in the switching power supply mainly plays a filtering role, mainly used to purify the circuit, many switching power supplies from the rectifier bridge out of the DC between two series capacitors, starting from this point to start to explain.

　　第一，电解电容是并联在直流电路中滤波，体现它的通交流而隔直流特性，如果不阻隔直流电路就大短路了直接爆了，通交流隔直流其实也是所有电容的共性，这里就不详谈了。

　　First, the electrolytic capacitor is parallel connected in the DC circuit to filter, reflecting its AC and DC isolation characteristics. If the DC circuit is not blocked, there will be a large short circuit, and it will explode directly. In fact, it is common for all capacitors to connect AC and DC, so I will not discuss it in detail.

　　第二，因为电解电容用在开关电源整流桥后边，是脉动直流电路，频率非常低，并不是高频场合，说明电解电容是用低频场合，如果常接触电路就会知道，电解电容不会被用到高频电路中，这也是它的应用局限性。

　　Second, because the electrolytic capacitor is used behind the rectifier bridge of switching power supply, it is a pulsating DC circuit with a very low frequency, not a high-frequency occasion. It shows that the electrolytic capacitor is used in low-frequency occasions. If you often contact the circuit, you will know that the electrolytic capacitor will not be used in the high-frequency circuit, which is also its application limitation.

　　第三，两个电容是串联后并联在整流桥后面的，整流桥整流后出来的应该是310伏左右的直流电，而图上所串联起来的两个电容额定电压是200伏，说明一个问题，电容器串联可以和电阻一样分配电压，但是，电容器的容量是越串越小，意思就是两个容量220uF的电容串起来后使用，它的容量相当于110uF，反之亦然，电容器越并容量越大。

　　Third, the two capacitors are connected in series and connected in parallel behind the rectifier bridge. The output of the rectifier bridge after rectification should be about 310 V DC, while the rated voltage of the two capacitors connected in series in the diagram is 200 V, which indicates that a problem is that the series capacitor can share the same distribution voltage as the resistance. However, the capacity of the capacitor is the smaller the series, which means that two capacitor strings with 220uF capacity can be connected in series After use, its capacity is equivalent to 110uf, and vice versa. The more the capacitor is combined, the greater the capacity is.

　　第四，从开关电源上的两电容先串联再并联方式可以做作更深度理解，整流块整流后电源有正负之分，用在它后边的电解电容也有正负之分，既然这里有正负之分，电解电容就不能用错或接反，否则，接反通电后直接会爆炸，非常危险。

　　Fourth, the two capacitors on the switching power supply are connected in series and then connected in parallel. The power supply after rectification of the rectifier block is divided into positive and negative, and the electrolytic capacitor used behind it is also positive and negative. Since there are positive and negative points here, the electrolytic capacitor can not be used wrongly or reversely. Otherwise, it will explode directly after being connected reversely, which is very dangerous.

　　第五，如果维修开关电源需更换电解电容时，在焊接过程中，除了注意极性不能弄反外，还要快速，因为电解电容内部含有电解质，不要让烙铁高温破坏了封口的密封性，造成使用中漏液，影响性能和寿命。

　　Fifthly, if it is necessary to replace the electrolytic capacitor during the maintenance of the switching power supply, in addition to paying attention to the polarity can not be reversed, but also need to be fast, because the electrolytic capacitor contains electrolyte, do not let the high temperature of the soldering iron damage the sealing of the seal, resulting in leakage in use, affecting performance and life.