Damage and failure of electrolytic capacitor in power supply (I)

1) The internal fault of electrolytic capacitor is short circuit and open circuit. The fault phenomenon is burning switch tube and other current limiting components, such as the current limiting resistor in the insurance and switching power supply. A filter capacitor in high voltage and high current (such as the switching power supply, line output circuit) of high voltage and high current (such as color TV). When the voltage is raised, and the voltage is exceeded, the breakdown is damaged by short circuit, or the electrolytic capacitor is equivalent to the work due to the damage of the rectifier diode. In AC circuits, the heat is generated under large reverse leakage current and short circuit is damaged. Because of the large current flowing through the capacitor during short circuit, the capacitor will burst or seal the rubber plug. After the short circuit of the filter capacitor, faults such as fuse or current limiting resistor burn, power thick film block or switch tube and breakdown of the rectifier tube often occur. The main performance is the whole machine "three no", this kind of breakdown is common in all kinds of switching power supply.

2) The low efficiency or slight leakage caused by the reduction of electrolytic capacitor capacity, its failure phenomenon is that the TV image "S" shape is distorted or unsynchronized, and there are some special failures for the TV set using IIC bus now. If the effect makes the synchronization card critical state, the accompaniment sound may affect the quality of the TV set, so that the company can be accompanied by the quality of the TV set. Zhang Suishi appeared. The main reason is the change of the parameters of the capacitor, but it does not completely fail, and it has some effect to some extent, but it can not reach its due role, which makes the existing failure phenomenon appear. And this kind of fault is not good to judge and eliminate.