Capacitors A capacitor is an electrical device designed for storing electric charge. It consists of two parallel conducting plates separated by an insulating medium called a dielectric. The dielectric constant is a measure of the ability of the dielectric to support electrostatic forces. Larger plates provide greater capacity to store electric charge so that as the area of the plates increase, capacitance increases.
Capacitance is directly proportional to the electrostatic force field between the plates.
This field is stronger when the plates are closer together so that as the distance between the plates decreases, capacitance increases. The higher the dielectric constant of the material between the plates, the greater the ability of the dielectric to support electrostatic forces. Therefore, as the dielectric constant increases, capacitance increases. Every capacitor has a maximum working voltage which is determined by the dielectric strength of the material between its plates. The most common types of capacitors are paper, ceramic, polycarbonate and electrolytic capacitors.