April 25, 2011


What Capacitor Is?
Capacitor is an electronic component that has the ability to store a specific amount of capacitance. Capacitance (C) is the ability of the capacitor to store electrical energy in an electrostatic field.

Capacitor ,metal plates and dielectric material
A capacitor is made up of two conductors which are separated by an insulator. The conductors are called metal plates while insulator is called dielectric material. The metal plates of the capacitor accumulate electrical energy from the power source. Dielectric material could be any insulator that prevents electrons from moving between the metal plates.

When capacitor is connected to a voltage source, current will flow until the capacitor is charged. Once the capacitor is fully charged the current will stop flowing. The capacitor’s voltage at this point is equal to the voltage of the voltage source.

In general, the amount of energy stored in capacitor is proportional to the size of the capacitor. Some capacitor used in home appliances such as radio receivers is usually small and can bring only small shock when discharged through your body. Large capacitors when charged with high voltage can bring a shock that can be fatal. Therefore, capacitors must be treated like any other source of voltage.

The unit used to express capacitance is called farad (F). Farad is a very large unit for ordinary use. Units such as microfarad (µF) and picofarad (pF) are the units usually used to express capacitance.