Related topics: energy

Toward a low-cost industrialization of lithium-ion capacitors

Combining two additives instead of one to facilitate the incorporation of lithium within capacitors: that is the solution proposed by researchers from l'Institut des matériaux Jean Rouxel (CNRS/Université de Nantes), in ...

New power supply unit lets electrical devices live longer

From the charging unit for smartphones to the power supply of the laptop or washing machine to LED lights or charging stations of electric cars – switching power supplies are omnipresent in electrical devices. They convert ...

Researchers capture an image of negative capacitance in action

For the first time ever, an international team of researchers imaged the microscopic state of negative capacitance. This novel result provides researchers with fundamental, atomistic insight into the physics of negative capacitance, ...

Insulator becomes conductor at the push of a button

Ionic liquids are important in scientific research because they can apply a lot of charge over a surface. Physicists from Leiden University have now found that the charging process of ionic liquids depends purely on opposite ...

Capacitor-based architecture for AI hardware accelerators

IBM is reaching beyond digital technologies with a capacitor-based cross-point array for analog neural networks, exhibiting potential orders of magnitude improvements in deep learning computations. Analog computing architectures ...

Bringing signals into phase

How we use and generate electricity has changed dramatically over the past century yet the basic components that control its flow remain remarkably similar. Researchers at KAUST have now developed a novel type of component ...

New diode features optically controlled capacitance

A team of researchers at the Israel Institute of Technology has developed a new capacitor with a metal-insulator-semiconductor (MIS) diode structure that is tunable by illumination. The capacitor, which features embedded ...

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Capacitor

A capacitor (formerly known as condenser) is a passive two-terminal electrical component used to store energy in an electric field. The forms of practical capacitors vary widely, but all contain at least two electrical conductors separated by a dielectric (insulator); for example, one common construction consists of metal foils separated by a thin layer of insulating film. Capacitors are widely used as parts of electrical circuits in many common electrical devices.

When there is a potential difference (voltage) across the conductors, a static electric field develops across the dielectric, causing positive charge to collect on one plate and negative charge on the other plate. Energy is stored in the electrostatic field. An ideal capacitor is characterized by a single constant value, capacitance, measured in farads. This is the ratio of the electric charge on each conductor to the potential difference between them.

The capacitance is greatest when there is a narrow separation between large areas of conductor, hence capacitor conductors are often called "plates," referring to an early means of construction. In practice, the dielectric between the plates passes a small amount of leakage current and also has an electric field strength limit, resulting in a breakdown voltage, while the conductors and leads introduce an undesired inductance and resistance.

Capacitors are widely used in electronic circuits for blocking direct current while allowing alternating current to pass, in filter networks, for smoothing the output of power supplies, in the resonant circuits that tune radios to particular frequencies and for many other purposes.

This text uses material from Wikipedia, licensed under CC BY-SA