Capacitors Blog

A capacitor or condenser is a passive electrical component consisting of an insulating, or dielectric, layer between two conductors. When a voltage potential difference occurs between the conductors, an electric field occurs in the insulator. This field can be used to store energy, to resonate with a signal, or to link electrical and mechanical forces. Capacitors are manufactured as electronic components for use in electrical circuits, but any two conductors linked by an electric field also display this property. The effect is greatest between wide, flat, parallel, narrowly separated conductors.

An ideal capacitor is characterized by a single constant value, capacitance, the ratio of the amount of charge in each conductor to the potential difference between them. The unit of capacitance is thus coulombs per volt, or farads. Higher capacitance indicates that more charge may be stored at a given energy level, or voltage. In actual capacitors, the insulator allows a small amount of current through, called leakage current, the conductors add an additional series resistance, and the insulator has an electric field strength limit resulting in a breakdown voltage.