Matters needing attention on the ordering of aluminum electrolytic capacitor

Rated voltage, peak voltage

The voltage waveform applied to a dc container has a dc part and an ac part. The sum of the maximum voltage of the dc part and the peak voltage of the ac part shall not exceed the rated dc voltage value at the time of use.

Second, the frequency

The condition of capacitor affected by frequency, especially the relationship between the permissible current and frequency of capacitor must be understood in advance. Because when the frequency is constantly increasing, the effective cross-sectional area of the electrode and the conductor decreases inversely proportional to the square root of the frequency, that is, the skin effect is generated, the metal resistance of the capacitor is greatly increased, that is, the equivalent series resistance is increased, often resulting in excessive internal heating and failure.

Three, capacity,

In the case that the capacitance is required to be particularly large, or the voltage is particularly high, several capacitors are often used in parallel or in series. At this time, it should be noted that the connection between the capacitors should be as short as possible to reduce the inherent inductance.

4. Ambient temperature

The higher the ambient temperature of the capacitor is, the higher the failure rate is, and the shorter the service life is. Especially when the temperature exceeds the upper limit category, the failure of the capacitor will be accelerated due to the accelerated aging of the medium, the heating of the product and the damage of the sealing property.

Five, humid environment, pressure changes

When the capacitor is used in the case of rapid change of air pressure, or the capacitor is kept in a humid environment for a long time, the package shell should be fairly strong, and the humidity should not be allowed to enter the insulation medium, which will make the capacitor performance worse.

Rated current, peak current

The rated current and the peak current directly affect the professional capacitor design.