Today, a customer asked us what is the capacitance error of aluminum electrolytic capacitor? This problem may not be a problem for professionals, but it is a bit confusing for non-professionals.

　　The capacity of aluminum electrolytic capacitor is determined by the anode foil. The specific capacity and area of the anode foil are two important parameters to control the capacity of the electrolytic capacitor. The anode foil is formed by the corrosion of pure aluminum light foil. During the corrosion process, chemicals constantly form large and small holes in the pure aluminum light foil. Because the size and depth of each hole cannot be controlled, there is a slight difference in the capacity of each part of the anode foil, Some places may have larger capacity and some places may have smaller capacity.

　　In the production process, aluminum electrolytic capacitors can only be designed according to the measured minimum specific capacity point, so the actual capacity of the produced aluminum electrolytic capacitors will vary greatly, so generally, the tolerance of ± 20% is the default for aluminum electrolytic capacitors. For example, the measured capacity of 400V470uf aluminum electrolytic capacitors is between 376uf-564uf, but generally it is a negative tolerance.