What is a Capacitor?
A capacitor is a passive electrical component with two terminals which is used in order to store energy in an electric field. Capacitors contain at least two electrical conductors which are separated by a dielectric. When there is a voltage difference across the conductors, a static electric field develops across the dielectric, thus causing negative charge to collect on one plate and positive charge on the other. Energy is accumulated in the electrostatic field. Capacitance, measured in farads, is the ratio of the electric charge on each conductor to the voltage difference between them.
Types of Capacitors
Aluminum Electrolytic Capacitors
Aluminum Organic Polymer Capacitors
Film Capacitors, metallized polyester capacitors, metallized polypropylene capacitors
Niobium Oxide Capacitors
Applications for Capacitors:
Capacitors have several uses in electrical and electronic systems. They are so widely used that it is rare that an electrical product does not contain some type of capacitor. A capacitor can store electric energy when it is disconnected from its charging circuit, so it can therefore be used like a temporary battery. They are often used in electronic devices in order to maintain a power supply while batteries are being changed thus preventing loss of information in volatile memory applications. In car audio systems, large capacitors are used to store energy for the amplifier to use when required. An uninterruptible power supply may be equipped with maintenance-free capacitors in order to extend its service life.