Diode

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In electronics, a diode is a two-terminal device (thermionic diodes may also have one or two ancillary terminals for a heater).

Diodes have two active electrodes between which the signal of interest may flow, and most are used for their unidirectional electric current property. The varicap diode is used as an electrically adjustable capacitor.

The unidirectionality most diodes exhibit is sometimes generically called the rectifying property. The most common function of a diode is to allow an electric current in one direction (called the forward biased condition) and to block the current in the opposite direction (the reverse biased condition). Thus, the diode can be thought of as an electronic version of a check valve.

Real diodes do not display such a perfect on-off directionality but have a more complex non-linear electrical characteristic, which depends on the particular type of diode technology. Diodes also have many other functions in which they are not designed to operate in this on-off manner.

Early diodes included “cat’s whisker” crystals and vacuum tube devices (also called thermionic valves). Today most diodes are made of silicon, but other semiconductors such a germanium are sometimes used.

For more information about Diode, read the full article at Wikipedia.
This text uses material from Wikipedia and is available under the GNU Free Documentation License.


News tagged with diode


New laser -- it's a gas, gas, gas... sensor

New laser -- it's a gas, gas, gas... sensor

Technology / Engineering

created Dec 04, 2009 | popularity 4.8 / 5 (4) | comments 0

(PhysOrg.com) -- A new generation of optical sensors is enabling the development of robust, long-lasting, lighting-fast trace gas detectors for use in a wide range of industrial, security and domestic applications.





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Glitter-sized solar photovoltaics produce competitive results

Glitter-sized solar photovoltaics produce competitive results

Technology / Energy

created Dec 22, 2009 | popularity 4.4 / 5 (32) | comments 0

Sandia National Laboratories scientists have developed tiny glitter-sized photovoltaic cells that could revolutionize the way solar energy is collected and used.


Scientists improve chip memory by stacking cells

Technology / Semiconductors

created Dec 21, 2009 | popularity 4.5 / 5 (17) | comments 3

(PhysOrg.com) -- Scientists at Arizona State University have developed an elegant method for significantly improving the memory capacity of electronic chips.


Smarter cars are gaining traction

Smarter cars are gaining traction (w/ Video)

Technology / Engineering

created Dec 21, 2009 | popularity 5 / 5 (2) | comments 0

(PhysOrg.com) -- Lives can depend on a vehicle's moment-by-moment traction. New European technology promises to make cars as good as experienced, alert drivers at sensing and adjusting to wet, snowy or icy ...


Many take dim view of new-fangled Christmas lights (AP)

Many take dim view of new-fangled Christmas lights

Technology / Energy

created Dec 21, 2009 | popularity 1 / 5 (7) | comments 10

(AP) -- To Steven Walls, it's beginning to look nothing like Christmas, anywhere he goes.


A promoter shows off  liquid crystal display (LCD) television panels in Seoul earlier this year

LG Display claims world's thinnest TV panel

Electronics / Hardware

created Dec 21, 2009 | popularity 4.2 / 5 (11) | comments 8

South Korea's LG Display said Monday it has developed the world's thinnest LCD television panel, measuring 2.6 millimetres (0.1 inches).


At Stanford, nanotubes + ink + paper = equal instant battery (w/ Video)

At Stanford, nanotubes + ink + paper = equal instant battery (w/ Video)

Nanotechnology / Nanomaterials

created Dec 07, 2009 | popularity 4.9 / 5 (27) | comments 3

(PhysOrg.com) -- Stanford scientists are harnessing nanotechnology to quickly produce ultra-lightweight, bendable batteries and supercapacitors in the form of everyday paper.


Using lasers to cool and manipulate molecules

Using lasers to cool and manipulate molecules

Physics / General Physics

created Dec 07, 2009 | popularity 4.8 / 5 (13) | comments 0 feature

(PhysOrg.com) -- "For years, we have been using laser cooling to trap and manipulate atoms," David DeMille tells PhysOrg.com. "This has been very useful for both basic science and many applications. Recent ...



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