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LED Filament
A LED filament light bulb is a LED lamp which is designed to resemble a traditional incandescent light bulb with visible filaments for aesthetic and light distribution purposes, but with the high efficiency of light-emitting diodes (LEDs). The name comes from their strings of many close-spaced series-connected diodes, which resemble the filaments of incandescent light bulbs much closer than previous bulbs with many LEDs. They are made as direct replacements for conventional incandescent bulbs, as they are made in the same shapes, they use the same bases that fit the same sockets, and they work at the same supply voltage. They may be used for their appearance, similar when lit to a clear incandescent bulb, or for their wide angle of light distribution, typically 300°. They are also more efficient than many other LED lamps. History A LED filament type design light bulb was produced by Ushio Lighting in 2008, intended to mimic the appearance of a standard light bulb. Contempo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
LED Filament Lamp
A light-emitting diode (LED) is a semiconductor device that Light#Light sources, emits light when Electric current, current flows through it. Electrons in the semiconductor recombine with electron holes, releasing energy in the form of photons. The color of the light (corresponding to the energy of the photons) is determined by the energy required for electrons to cross the band gap of the semiconductor. White light is obtained by using multiple semiconductors or a layer of light-emitting phosphor on the semiconductor device. Appearing as practical electronic components in 1962, the earliest LEDs emitted low-intensity infrared (IR) light. Infrared LEDs are used in Remote control, remote-control circuits, such as those used with a wide variety of consumer electronics. The first visible-light LEDs were of low intensity and limited to red. Early LEDs were often used as indicator lamps, replacing small Incandescent light bulb, incandescent bulbs, and in seven-segment displays. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Series Circuit
Terminal (electronics), Two-terminal components and electrical networks can be connected in series or parallel. The resulting electrical network will have two terminals, and itself can participate in a series or parallel Topology (electrical circuits), topology. Whether a two-terminal "object" is an electrical component (e.g. a resistor) or an electrical network (e.g. resistors in series) is a matter of perspective. This article will use "component" to refer to a two-terminal "object" that participates in the series/parallel networks. Components connected in series are connected along a single "electrical path", and each component has the same electric current through it, equal to the current through the network. The voltage across the network is equal to the sum of the voltages across each component. Components connected in parallel are connected along multiple paths, and each component has the same voltage across it, equal to the voltage across the network. The current throug ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Linear Regulator
300px, Block scheme for voltage regulator in an electronic circuit In electronics, a linear regulator is a voltage regulator used to maintain a steady voltage. The resistance of the regulator varies in accordance with both the input voltage and the load, resulting in a constant voltage output. The regulating circuit varies its resistance, continuously adjusting a voltage divider network to maintain a constant output voltage and continually dissipating the difference between the input and regulated voltages as waste heat. By contrast, a ''switching regulator'' uses an active device that switches on and off to maintain an average value of output. Because the regulated voltage of a linear regulator must always be lower than input voltage, efficiency is limited and the input voltage must be high enough to always allow the active device to reduce the voltage by some amount. Linear regulators may place the regulating device in parallel with the load ( shunt regulator) or may place the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Philips
Koninklijke Philips N.V. (), simply branded Philips, is a Dutch multinational health technology company that was founded in Eindhoven in 1891. Since 1997, its world headquarters have been situated in Amsterdam, though the Benelux headquarters is still in Eindhoven. The company gained its royal honorary title in 1998. Philips was founded by Gerard Philips and his father Frederik, with their first products being light bulbs. Through the 20th century, it grew into one of the world's largest electronics conglomerates, with global market dominance in products ranging from kitchen appliances and electric shavers to light bulbs, televisions, cassettes, and compact discs (both of which were invented by Philips). At one point, it played a dominant role in the entertainment industry (through PolyGram). However, intense competition from primarily East Asian competitors throughout the 1990s and 2000s led to a period of downsizing, including the divestment of its lighting and c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Color Rendering Index
A color rendering index (CRI) is a quantitative measure of the ability of a light source to reveal the colors of various objects faithfully in comparison with a natural or standard light source. ''Color rendering'', as defined by the International Commission on Illumination (CIE), is the effect of an illuminant on the color appearance of objects by conscious or subconscious comparison with their color appearance under a reference or standard illuminant. The CRI of a light source does not indicate the apparent color of the light source; that information is given by the correlated color temperature (CCT). The CRI is determined by the light source's spectrum. An incandescent lamp has a continuous spectrum, a fluorescent lamp has a discrete line spectrum; implying that the incandescent lamp has the higher CRI. The value often quoted as "CRI" on commercially available lighting products is properly called the CIE Ra value, "CRI" being a general term and CIE Ra being the interna ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Luminous Flux
In photometry, luminous flux or luminous power is the measure of the perceived power of light. It differs from radiant flux, the measure of the total power of electromagnetic radiation (including infrared, ultraviolet, and visible light), in that luminous flux is adjusted to reflect the varying sensitivity of the human eye to different wavelengths of light. Units The SI unit of luminous flux is the lumen (lm). One lumen is defined as the luminous flux of light produced by a light source that emits one candela of luminous intensity over a solid angle of one steradian. 1\ \text = 1\ \text \times 1\ \text In other systems of units, luminous flux may have units of power. Weighting The luminous flux accounts for the sensitivity of the eye by weighting the power at each wavelength with the luminosity function, which represents the eye's response to different wavelengths. The luminous flux is a weighted sum of the power at all wavelengths in the visible band. Light outside the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Junction Temperature
Junction temperature, short for transistor junction temperature, is the temperature of the actual semiconductor in an electronic device. In operation, it is higher than case temperature and the temperature of the part's exterior. The difference is equal to the amount of heat transferred from the junction to case multiplied by the junction-to-case thermal resistance. Microscopic effects Various physical properties of semiconductor materials are temperature dependent. These include the diffusion rate of dopant elements, carrier mobilities and the thermal production of charge carriers. At the low end, sensor diode noise can be reduced by cryogenic cooling. On the high end, the resulting increase in local power dissipation can lead to thermal runaway that may cause transient or permanent device failure. Maximum junction temperature calculation Maximum junction temperature (sometimes abbreviated TJMax) is specified in a part's datasheet and is used when calculating the necessary case- ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Helium
Helium (from ) is a chemical element; it has chemical symbol, symbol He and atomic number 2. It is a colorless, odorless, non-toxic, inert gas, inert, monatomic gas and the first in the noble gas group in the periodic table. Its boiling point is the lowest among all the Chemical element, elements, and it does not have a melting point at standard pressures. It is the second-lightest and second-most Abundance of the chemical elements, abundant element in the observable universe, after hydrogen. It is present at about 24% of the total elemental mass, which is more than 12 times the mass of all the heavier elements combined. Its abundance is similar to this in both the Sun and Jupiter, because of the very high nuclear binding energy (per nucleon) of helium-4 with respect to the next three elements after helium. This helium-4 binding energy also accounts for why it is a product of both nuclear fusion and radioactive decay. The most common isotope of helium in the universe is helium-4, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thermal Management (electronics)
All electronic devices and Electronic circuit, circuitry generate excess heat and thus require thermal management to improve Reliability engineering, reliability and prevent premature failure. The amount of heat output is equal to the Electric power, power input, if there are no other energy interactions. There are several techniques for cooling including various styles of heat sinks, Thermoelectric cooling, thermoelectric coolers, forced air systems and Computer fan, fans, heat pipes, and others. In cases of extreme low environmental temperatures, it may actually be necessary to heat the electronic components to achieve satisfactory operation. Overview Thermal resistance of devices This is usually quoted as the Thermal resistance in electronics, thermal resistance from p–n junction, junction to case of the semiconductor device. The units are °C/W. For example, a heatsink rated at 10 °C/W will get 10 °C hotter than the surrounding air when it dissipat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Colour Temperature
Color (or colour in Commonwealth English; see spelling differences) is the visual perception based on the electromagnetic spectrum. Though color is not an inherent property of matter, color perception is related to an object's light absorption, emission, reflection and transmission. For most humans, colors are perceived in the visible light spectrum with three types of cone cells ( trichromacy). Other animals may have a different number of cone cell types or have eyes sensitive to different wavelengths, such as bees that can distinguish ultraviolet, and thus have a different color sensitivity range. Animal perception of color originates from different light wavelength or spectral sensitivity in cone cell types, which is then processed by the brain. Colors have perceived properties such as hue, colorfulness (saturation), and luminance. Colors can also be additively mixed (commonly used for actual light) or subtractively mixed (commonly used for materials). If the colors ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phosphor
A phosphor is a substance that exhibits the phenomenon of luminescence; it emits light when exposed to some type of radiant energy. The term is used both for fluorescent or phosphorescent substances which glow on exposure to ultraviolet or visible light, and cathodoluminescent substances which glow when struck by an electron beam ( cathode rays) in a cathode-ray tube. When a phosphor is exposed to radiation, the orbital electrons in its molecules are excited to a higher energy level; when they return to their former level they emit the energy as light of a certain color. Phosphors can be classified into two categories: fluorescent substances which emit the energy immediately and stop glowing when the exciting radiation is turned off, and phosphorescent substances which emit the energy after a delay, so they keep glowing after the radiation is turned off, decaying in brightness over a period of milliseconds to days. Fluorescent materials are used in applications in wh ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
