Capacitors

A capacitor (formerly known as condenser) is a passive two-terminal electrical component used to storeenergy in an electric field. The forms of practical capacitors vary widely, but all contain at least two electricalconductors separated by a dielectric (insulator); for example, one common construction consists of metalfoils separated by a thin layer of insulating film. Capacitors are widely used as parts of electrical circuits inmany common electrical devices. Capacitors are widely used in electronic circuits for blocking directcurrent while allowing alternating current to pass, in filter networks, for smoothing the output of powersupplies, in the resonant circuits that tune radios to particular frequencies and for many other purposes.