<P> Large capacitor banks (reservoir) are used as energy sources for the exploding - bridgewire detonators or slapper detonators in nuclear weapons and other specialty weapons . Experimental work is under way using banks of capacitors as power sources for electromagnetic armour and electromagnetic railguns and coilguns . </P> <P> Reservoir capacitors are used in power supplies where they smooth the output of a full or half wave rectifier . They can also be used in charge pump circuits as the energy storage element in the generation of higher voltages than the input voltage . </P> <P> Capacitors are connected in parallel with the power circuits of most electronic devices and larger systems (such as factories) to shunt away and conceal current fluctuations from the primary power source to provide a "clean" power supply for signal or control circuits . Audio equipment, for example, uses several capacitors in this way, to shunt away power line hum before it gets into the signal circuitry . The capacitors act as a local reserve for the DC power source, and bypass AC currents from the power supply . This is used in car audio applications, when a stiffening capacitor compensates for the inductance and resistance of the leads to the lead - acid car battery . </P> <P> In electric power distribution, capacitors are used for power factor correction . Such capacitors often come as three capacitors connected as a three phase load . Usually, the values of these capacitors are given not in farads but rather as a reactive power in volt - amperes reactive (var). The purpose is to counteract inductive loading from devices like electric motors and transmission lines to make the load appear to be mostly resistive . Individual motor or lamp loads may have capacitors for power factor correction, or larger sets of capacitors (usually with automatic switching devices) may be installed at a load center within a building or in a large utility substation . </P>

Basic operating principles and applications of a capacitor