What should be paid attention to when using electrolytic capacitor?

What should be paid attention to when using electrolytic capacitor, mainly including the following ten points:
1. The DC electrolytic capacitor has polarity: the polarity mark of the capacitor is on the base of the capacitor to avoid circuit short circuit or capacitor damage due to polarity. If you want to use a bipolar electrolytic capacitor with uncertain polarity or on an uncertain circuit, please use a bipolar electrolytic capacitor. Note that DC electrolytic capacitor cannot be used for AC.
2. Do not use a voltage greater than the rated voltage: If the voltage is greater than the rated voltage, the leakage current will increase and may damage the capacitor. The recommended working voltage is 70% -80% of the rated voltage, and using the capacitor at the recommended working voltage will extend the lifespan of the capacitor.
3. Do not allow excessive ripple current to pass through the capacitor: Applying ripple current exceeding the rated value can cause the capacitor body to overheat, reduce capacity, and damage the capacitor's lifespan. The peak value of the applied ripple voltage should be less than the rated working voltage.
4. The temperature range of the working environment is appropriate: the characteristics of the capacitor vary with the working temperature. At higher temperatures, the capacity and leakage current increase, and the loss decreases; At low temperatures, capacity and leakage current decrease and losses increase. Capacitors used at lower temperatures will extend their lifespan. According to scientific statistics, for every 10 ℃ decrease in ambient temperature, its service life doubles.
5. Check the working frequency: the capacitance of electrolytic capacitor is usually measured at the frequency of 100~120Hz. However, capacity will decrease with increasing frequency, loss will increase with increasing frequency, and surrounding temperature will increase.
6. Long term storage of capacitors: Adding rated DC voltage before use for long-term storage does not actually have much impact on the capacity and loss of the capacitor. However, it can increase the leakage current of the capacitor and reduce its withstand voltage. For capacitors stored for a long time, DC voltage should be gradually applied to the rated voltage before use.
7. The shell of the electrolytic capacitor is not insulated from the cathode end: the shell of the electrolytic capacitor is connected to the cathode through electrolyte. If the shell of the capacitor must be insulated from the line, insulation measures must be taken at the installation position of the capacitor.
8. Do not apply too much force to the terminal or lead of the electrolytic capacitor: if too much force is applied to the terminal or lead, the tension will act on the inside of the capacitor, which may cause the breakage of the lead or the splitting of the terminal, which in turn will cause damage to the internal connection of the capacitor, resulting in short circuit, open circuit or rising leakage current inside the capacitor, leading to damage to the capacitor. Do not forcefully shake the capacitor when soldering it onto the circuit board.
9. Pay attention to temperature and duration during welding: The soldering iron should be kept at a certain distance from the plastic sleeve of the capacitor. When the capacitor is immersed in the solder tank, it is recommended to keep the temperature within 260C for no more than 10 seconds to avoid damage to the capacitor. The plastic sleeve may rupture or shrink due to excessive welding time or temperature.
10. Layout of holes on printed circuit boards: When designing printed circuit boards, the installation hole spacing should be equal to the lead spacing. When the hole spacing is greater than or less than the lead spacing, stress will be applied to the lead when installing capacitors, which may cause short circuits, circuit damage, and increased leakage current.