Reliability Application of Electrolytic Capacitor

When working voltage is lowered

Reducing the working voltage of electrolytic capacitor is the most effective way to prolong the service life and improve the reliability of the capacitor. Because the failure rate of electrolytic capacitor is directly proportional to the ratio of applied voltage to rated voltage of capacitor. Electrolytic capacitor is used in the most occasions of power filter circuit, the input voltage changes or the load suddenly open circuit, the voltage at both ends of filter capacitor will change with it, if not designed to reduce the amount, it is likely to make the capacitor breakdown. In addition, the AC voltage coming in from the input is not a sinusoidal voltage. The peak voltage of the non-sinusoidal wave is higher than that of the sinusoidal voltage, which can have a great impact on the life and reliability of the capacitor. When using, the working voltage of the electrolytic capacitor should be reduced by a large margin. The voltage drop of the electrolytic capacitor should be determined according to the reliability requirements of the whole machine and the specific circuit used by the capacitor. Generally, it can be divided into three levels, one is 50 batches of rated voltage; the second is 60; and the third is 70%. The capacitor with high voltage and large capacity should choose the larger reduction range. The larger the capacitor capacity, the larger the area of oxide film, the greater the probability of dielectric defects and the lower the reliability.