Capacitors are devices which store electrical charge. They are a basic component of electronics and have a host of various applications. The most common use for capacitors is energy storage. Additional uses include power conditioning, signal coupling or decoupling, electronic noise filtering, and remote sensing. Because of its varied applications, capacitors are used in a wide range of industries and have become a vital part of everyday life.
Capacitors for Energy Storage
One important application of capacitors is the conditioning of power supplies. Capacitors allow AC signals to pass but block DC signals when they are charged. They can effectively split these two signal types, cleaning the supply of power. This effect has been exploited to separate or decouple different parts of electrical circuits to reduce noise which could lead to reduction of efficiency. Capacitors are also used in utility substations to counteract inductive loading introduced by transmission lines.
Capacitors for Signal Processing
Capacitors have found increasingly advanced applications in information technology. Dynamic Random Access Memory (DRAM) devices use capacitors to represent binary information as bits. The device reads one value when the capacitor is charged and another when discharged. Charge Coupled Devices (CCDs) use capacitors in an analogue form. Capacitors are also used in conjunction with inductors to tune circuits to particular frequencies, an effect exploited by radio receivers, speakers, and analog equalizers.