Views:1 Author:Site Editor Publish Time: 2018-05-05 Origin:Site
The common failures of electrolytic capacitors include reduction of capacity, disappearance of capacity, breakdown of short circuit and leakage of electricity. The change of capacity is caused by the gradual drying of electrolytes in the process of the use or placement of electrolytic capacitors, and the breakdown and leakage are usually caused by excessive voltage or poor quality of its own. In general, the capacitance of the power supply is measured by the resistance gear of the multimeter. The specific method is to short circuit the two feet of the capacitor and to connect the positive pole of the electrolytic capacitor with the black pen of the multimeter. The red surface pen is connected to the negative pole (for the pointer type multimeter, with the digital multimeter intermodulation). When normal, the needle should first swing to the small resistance direction, and then gradually return to the infinity. The larger the swing amplitude of the needle or the slower the speed of return, the greater the capacity of the capacitor, and conversely, the smaller the capacity of the capacitance. For example, the needle no longer changes somewhere in the middle, indicating that the capacitance is leaking, if the resistance indicator is very small or zero, indicates that the capacitor has broken through the short circuit. The battery voltage used by the multimeter is one. It is very low, so it is more accurate to measure the capacitance of low pressure. When the pressure of the capacitor is high, the measurement is normal, but the phenomenon of leakage or breakdown is possible when the high pressure is added.