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A LED is a long-lived light source, but certain mechanisms can cause slow loss of efficiency of the device or sudden failure. The wavelength of the light emitted is a function of the band gap of the semiconductor material used; materials such as gallium arsenide , and others , with various trace doping elements , are used to produce different ...
Dimming a multicolor LED source to match the characteristics of incandescent lamps is difficult because manufacturing variations, age, and temperature change the actual color value output. To emulate the appearance of dimming incandescent lamps may require a feedback system with color sensor to actively monitor and control the color.
Often more than half of the emitted light is reflected back at the LED-package and package-air interfaces. The reflection is most commonly reduced by using a dome-shaped (half-sphere) package with the diode in the center so that the outgoing light rays strike the surface perpendicularly , at which angle the reflection is minimized.
A 230-volt LED filament lamp, with an E27 base. The filaments are visible as the eight yellow vertical lines. An assortment of LED lamps commercially available in 2010: floodlight fixtures (left), reading light (center), household lamps (center right and bottom), and low-power accent light (right) applications An 80W Chips on board (COB) LED module from an industrial light luminaire, thermally ...
Assessment of Advanced Solid State Lighting.National Academies Press. 2013. doi:10.17226/18279. ISBN 978-0-309-27011-3.; Kho, Mu-Jeong, Javed, T., Mark, R., Maier, E., and David, C. (2008) 'Final Report: OLED Solid State Lighting: Kodak European Research' MOTI (Management of Technology and Innovation) Project, Judge Business School of the University of Cambridge and Kodak European Research ...
Simple LED (Light Emitting Diode) circuit diagram. In electronics, an LED circuit or LED driver is an electrical circuit used to power a light-emitting diode (LED). The circuit must provide sufficient current to light the LED at the required brightness, but must limit the current to prevent damaging the LED.
Detail view of an LED display with a matrix of red, green and blue diodes The 1,500-foot (460 m) long LED display on the Fremont Street Experience in Downtown Las Vegas, Nevada, is currently the largest in the world. A LED display is a flat panel display that uses an array of light-emitting diodes (LEDs) as pixels for a video display.
InGaN blue LED (380–405 nm) Spectrum of a white-light LED where GaN or InGaN blue source pumps Ce:YAG phosphor. Indium gallium nitride (InGaN, In x Ga 1−x N) is a semiconductor material made of a mix of gallium nitride (GaN) and indium nitride (InN). It is a ternary group III/group V direct bandgap semiconductor.