Abuja Super Aluminum Electrolytic Capacitor

Basic construction of aluminum electrolytic capacitor is shown in Fig. 1. Aluminum electrolytic capacitors consist of anode aluminum foil formed with aluminum oxide film on the surface to function as the dielectric. The cathode aluminum foil functions as a collector, and the liquid electrolyte functions as the real cathode.

Aluminum electrolytic capacitor construction delivers colossal capacitance because etching the foils can increase surface area more than 100 times and the aluminum-oxide dielectric is less than a micrometer thick. Thus the resulting capacitor has very large plate area and the plates are intensely close together.

Alcon started manufacturing aluminium electrolytic capacitors for the Indian entertainment electronics industry in 1977. Over the years the focus has shifted and Alcon now manufactures a large range of high CV screw terminal type aluminium electrolytic capacitors and a large variety of film capacitors for power electronic applications.

Dielectric of an aluminum electrolytic capacitor is an oxide film formed on surface of aluminum foil by forming process. When voltage is applied to the dielectric, polarization occurs due to dielectric effect. The polarization does not immediately respond to the electrical field and may delay by the elastic viscosity of the molecules.

Therefore, the aluminum electrolytic capacitor charging is to be accompanied by the electric reaction of the electrolyte on the cathode electrode, and as a result, it goes to the equilibrium that the anode foil charge is not equal (larger) to the cathode foil charge.

On aluminum electrolytic capacitor, “ S ” is effective surface area of anode foil enlarged to 60 to 150 times of the projected area through etching process. “ d ” corresponds to the thickness of dielectric (13 to 15 angstroms per volt). Relative permittivity “r ” of aluminum oxide film is about 8.5.