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

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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.


Turning heat to electricity

Turning heat to electricity... efficiently

Physics / General Physics

created Nov 18, 2009 | popularity 4.8 / 5 (65) | comments 9

(PhysOrg.com) -- In everything from computer processor chips to car engines to electric powerplants, the need to get rid of excess heat creates a major source of inefficiency. But new research points the way ...


Solar LED lamps

Solar Cells with LEDs Provide Inexpensive Lighting

Technology / Energy

created Nov 09, 2009 | popularity 4.4 / 5 (17) | comments 2

(PhysOrg.com) -- Of the 1.5 billion people in developing countries who do not have electricity, many rely on kerosene lamps for light after the sun goes down. But now, researchers from Denmark have designed ...


NEC's "Tele Scouter"

Two Retinal Imaging Display Devices at Prototype Stage

Electronics / Consumer & Gadgets

created Oct 30, 2009 | popularity 4.9 / 5 (28) | comments 9

(PhysOrg.com) -- NEC and Brother are both developing wearable prototype devices that use Retinal Imaging Display (RID) technology to project images directly on the wearer's retina. NEC's gadget is designed ...


Lighter, cheaper, LED light bulbs are starting to enter the marketplace

Technology / Energy

created Oct 22, 2009 | popularity 3.8 / 5 (13) | comments 6

Just when you were finally warming up to the idea of swapping out your old light bulbs with compact fluorescent ones, you may soon find a new alternative at your local hardware store.


Researchers create molecular diode

Nanotechnology / Nanophysics

created Oct 22, 2009 | popularity 4.5 / 5 (6) | comments 0

(PhysOrg.com) -- Recently, at Arizona State University’s Biodesign Institute, N.J. Tao and collaborators have found a way to make a key electrical component on a phenomenally tiny scale. Their single-molecule diode is described ...


Researchers create molecular diode

Researchers create molecular diode

Nanotechnology / Nanophysics

created Oct 13, 2009 | popularity 4.4 / 5 (12) | comments 0

Recently, at Arizona State University's Biodesign Institute, N.J. Tao and collaborators have found a way to make a key electrical component on a phenomenally tiny scale. Their single-molecule diode is described ...


Atomtronic transistor and diode could advance quantum computing

Physics / Quantum Physics

created Oct 09, 2009 | popularity 4.6 / 5 (24) | comments 5

(PhysOrg.com) -- What if atoms could be used to perform the functions currently the province of electronic devices? The goal of atomtronics is to do just that by creating analogues to the common items found in electronic ...


Super-thin flexible OLED from Sony

Super-thin flexible OLED from Sony

Electronics / Consumer & Gadgets

created Oct 07, 2009 | popularity 4.7 / 5 (29) | comments 11

(PhysOrg.com) -- Sony is showing off prototypes incorporating its super-thin, flexible OLED technology at the CREATEC JAPAN 2009 IT and electronics trade show in Makuhari Messe (Chiba) in Japan.


Greenlighting a greener world

Greenlighting a greener world (w/ Video)

Technology / Engineering

created Sep 02, 2009 | popularity 3.3 / 5 (4) | comments 0

Just a few years ago, most conversations Christian Wetzel had about his research began with a quick explanation of LEDs.


LG to Launch 15-inch OLED TV

LG to Launch 15-inch OLED TV

Electronics / Consumer & Gadgets

created Sep 01, 2009 | popularity 4.7 / 5 (20) | comments 5

(PhysOrg.com) -- The Korean company, LG Electronics, the second largest television manufacturer in the world, has announced it will launch a 15-inch organic display TV set in early September. The announcement, ...


Ultrathin light-emitting diodes create new classes of lighting and display systems

Ultrathin light-emitting diodes create new classes of lighting and display systems

Technology / Engineering

created Aug 20, 2009 | popularity 4.8 / 5 (11) | comments 3

(PhysOrg.com) -- A new process for creating ultrathin, ultrasmall inorganic light-emitting diodes (LEDs) and assembling them into large arrays offers new classes of lighting and display systems with interesting ...


New material for nanoscale computer chips

New material for nanoscale computer chips

Nanotechnology / Nanomaterials

created Aug 17, 2009 | popularity 5 / 5 (4) | comments 2

Nanochemists from the Chinese Academy of Sciences and Nano-Science Center, Department of Chemistry at University of Copenhagen have developed nanoscale electric contacts out of organic and inorganic nanowires. ...


Liquid-OLED Offers More Light-Emitting Possibilities

Liquid-OLED Offers More Light-Emitting Possibilities

Physics / General Physics

created Aug 14, 2009 | popularity 4.8 / 5 (17) | comments 1

(PhysOrg.com) -- As organic light-emitting diodes (OLEDs) are poised to go mainstream in the near future, scientists continue to explore new twists on the technology. Recently, researchers have fabricated ...


LED Lamp with E27 Edison screw.

LED light bulbs yield big savings in energy

Technology / Energy

created Aug 13, 2009 | popularity 4.8 / 5 (20) | comments 42

One way the United States could slash its electricity use, dependence on fossil fuels and emissions of heat-trapping gases is really quite simple: better light bulbs.