Common problem
The main causes of electrolytic capacitor bulging
Source：本站 | Time：2022-01-05 | Read：488
n the practical application of electrolytic capacitors, sometimes the aluminum electrolytic capacitors inserted on the board will bulge or even explode. When this happens, many manufacturers will directly find the capacitor supplier and suspect the quality of the capacitor, but very often, improper use of capacitors is the cause of most of the bulging phenomenon.
So what causes the capacitor to produce the phenomenon of bulging or even exploding?
1、Inverse polarity connection
In the process of capacitor maintenance, the polarity of the capacitor is not marked on the circuit board, or the two poles of the capacitor are reversed in the circuit when the capacitor is replaced, i.e. the negative pole is connected to the high potential and the positive pole is connected to the low potential.
In this case, the voltage withstand value of electrolytic capacitor will drop dramatically. After the power is applied, the leakage will increase sharply, resulting in internal heating and bulging or even explosion.
2、Insufficient withstand voltage
The withstand voltage value is the second most important parameter after the capacity of electrolytic capacitor. It is not allowed to use electrolytic capacitor with 25v voltage, and it is not allowed to use a value larger than the nominal voltage value of electrolytic capacitor.
3、Voltage drop
In the process of long-term use of capacitors, especially in high temperature environment, the electrolyte will be reduced or dry put, resulting in voltage drop, and the phenomenon of capacitor bulge will appear.
4、Electrolytic capacitor quality problem
When the electrolytic capacitor itself has quality problems, such as many residual devices in the process of use, it is very easy to have the same bulging problem.
Regardless of the capacity, most electrolytic capacitors have small slits of different shapes (such as the cross at the top of the capacitor in the picture) on the top, whose main function is explosion-proof. When the electrolytic capacitor explodes, it will be cracked by here first, thus playing a certain buffering role.
So what causes the capacitor to produce the phenomenon of bulging or even exploding?
1、Inverse polarity connection
In the process of capacitor maintenance, the polarity of the capacitor is not marked on the circuit board, or the two poles of the capacitor are reversed in the circuit when the capacitor is replaced, i.e. the negative pole is connected to the high potential and the positive pole is connected to the low potential.
In this case, the voltage withstand value of electrolytic capacitor will drop dramatically. After the power is applied, the leakage will increase sharply, resulting in internal heating and bulging or even explosion.
2、Insufficient withstand voltage
The withstand voltage value is the second most important parameter after the capacity of electrolytic capacitor. It is not allowed to use electrolytic capacitor with 25v voltage, and it is not allowed to use a value larger than the nominal voltage value of electrolytic capacitor.
3、Voltage drop
In the process of long-term use of capacitors, especially in high temperature environment, the electrolyte will be reduced or dry put, resulting in voltage drop, and the phenomenon of capacitor bulge will appear.
4、Electrolytic capacitor quality problem
When the electrolytic capacitor itself has quality problems, such as many residual devices in the process of use, it is very easy to have the same bulging problem.
Regardless of the capacity, most electrolytic capacitors have small slits of different shapes (such as the cross at the top of the capacitor in the picture) on the top, whose main function is explosion-proof. When the electrolytic capacitor explodes, it will be cracked by here first, thus playing a certain buffering role.
