مصطلحات : Ambient:The surrounding light level in a given area. It is also the temperature in which a LED light source is expected to operate in. Referring to light, it is the light given off by the Sun, Moon, other light fixtures nearby or even within the same space. Amperage: The strength of an electrical current measured in amperes. The higher the amperage number, the higher the ability to place more devices on a circuit that will be driven by that amperage. Amp: The basic unit of electric current adopted under the System International dUnites; a typical household circuit carries 15 to 50 amps Bulb: A bulb is a light bulb, a flashlight bulb, a MR16 or E27 light bulb. A LED light bulb is a finished product that has the LEDs installed, electrical components installed and is ready to be used by the consumer. A LED light bulb is screwed in place, twisted and locked in place, pressed into sockets or contact terminals. A LED is not a bulb, but a bulb can contain LEDs Bulb Base: The part of the bulb that is used to set it into place and to make contact with electricity. There are many types and sizes. Most common are E26/27, USA and European standard household size, or medium base as it often is called. The 26 or 27 equates to the diameter measurement in millimeters of the threads of a screw-in bulb base. This type of bulb also includes the PAR 20, PAR 30 and PAR38 types, and a few others. There are MR16 and MR11 type base LED bulbs as well as GU10s. Correlated color temperature (CCT) is the measure used to describe the relative color appearance of a white light source. CCT indicates whether a light source appears more yellow/gold/orange or more blue, in terms of the range of available shades of white. CCT is given in kelvins (unit of absolute temperature). See also Chromaticity Chromaticity: Chromaticity tells you what the lamp itself or a neutral surface illuminated by a lamp will look like. Chromaticity sets the tone or atmosphere of a room: warm, cool or something in between. Chromaticity (sometimes called color temperature) is usually measured in Kelvins. It can also be defined by using x and y coordinated against a standard chromaticity scale developed by the Commission Internationale de lÉclairage (CIE). See also CCT. Color Rendering Index (CRI): indicates how well a light source renders colors of people and objects, compared to a reference source. A measurement of the amount of color shift that objects undergo when lighted by a light source as compared with the color of those same objects when seen under a reference light source of comparable color temperature. LED light CRI values generally range from 60(average) to 90(best). High CRI equates to sharper, crisper, more natural colored pictures while at the same time reducing glare. Color Temperature: A measure of the color of a light source relative to a black body at a particular temperature expressed in degrees Kelvin (K). Incandescent lights have a low color temperature (approximately 2800K) and have a red-yellowish tone; daylight has a high color temperature (approximately 6000K) and appears bluish (the most popular fluorescent light, Cool White, ia rated at 4100K). Lamps with color temperatures below 5000K tend to be more yellow/red. Foot-Candle: The unit is defined as the amount of illumination the inside surface of an imaginary 1-foot radius sphere would be receiving if there were a uniform point source of one candela in the exact center of the sphere. Basically, the amount of light that a single candle would provide to a 1ft. radius sphere. Full Spectrum: A light bulb or lamp that produces a light spectrum that covers the entire range of visible light (400-700nm) without gaps in its spectral output. White LEDs are inherently a full spectrum light source. General illumination: is a term used to distinguish between lighting that illuminates tasks, spaces, or objects from lighting used in indicator or purely decorative applications. In most cases, general illumination is provided by white light sources, including incandescent, fluorescent, high-intensity discharge sources, and white LEDs. Lighting used for indication or decoration is often monochromatic, as in traffic lights, exit signs, vehicle brake lights, signage, and holiday lights. Intensity: Is a measure of the time-averaged energy flux or amount of light striking a given area. For bulbs alone this is measured in terms of lumens while for lighting fixtures it is measured in lux (lumens/sq. meter). Kelvin Color Temperature: A measure of the color of a light source relative to a black body at a particular temperature expressed in degrees Kelvin (K). Incandescent lights have a low color temperature (approximately 2800K) and have a red-yellowish tone; daylight has a high color temperature (approximately 6000K) and appears bluish (the most popular fluorescent light, Cool White, is rated at 4100K). Today, the phosphors used in fluorescent lamps can be blended to provide any desired color temperature in the range from 2800K to 6000K. Lamps with color temperatures below 5000K tend to be more yellow/red, lamps rated between 5000 and 6000K are viewed as white, while lamps above 6000K tend to have a blue cast. L.E.D.: LED means light emitting diode. LEDs are a solid state device and do not require heating of a filament to create light. Rather, electricity is passed through a chemical compound that is excited and that generates light. LED Cluster or Array: A group of LEDs set in a square, rectangular or linear pattern, and formatted to be operated at a specific voltage. They will always include two wires called leads. One is positive, the other negative. LED Drivers: are current control devices that replace the need for resistors. LED Drivers respond to the changing input voltage while maintaining a constant amount of current (output power) to the LED as its electrical properties change with temperature. Lumen Maintenance: How well a LED light bulb is able to retain its intensity when compared to new. Typically a high quality LED bulb will retain 70% of its intensity for 40,000-50,000 hours. That means a good quality LED bulb will run 8 hours a day for 13 years at 70% of its new condition. No other artificial light source can do this. Luminous efficacy: is the most commonly used measure of the energy efficiency of a light source. It is stated in lumens per watt (lm/W), indicating the amount of light a light source produces for each watt of electricity consumed. Lumens: The unit of luminous flux in the International System, equal to the amount of light given out through a solid angle by a source of one candela intensity radiating equally in all directions. Used to measure light bulbs as stand alone light sources. Lighting fixtures are measured by lux output which is lumens per square meter. Lux: Typically used to measure the light intensity produced by a lighting fixture. The higher the lux reading the more light the lighting fixture is producing over a given area. Known as lumens per square meter mA: stands for milliamp. 1000mA equals 1.0 amp. All LEDs run on current and current is measured in milliamps. All LED products have a mA rating at which they are to be powered at. Max Rated Temperature: or Operating Temperature is the ambient temperature where the LED light source is installed at and should be maintained at. In most case that is around 40-50° Celsius. That is comparable to 104° F to 122° F. Operating a LED light source beyond the Operating temperature will lower the LEDs life span. Nanometers or nm: Used to measure the wavelengths of light. The lower the wavelength eg. 400nm the bluer and stronger the light source. Longer wavelengths above 600nm are red. Above 680nm, they fall into the InfraRed category, which is colorless to our eyes. White LEDs have no specific wavelength. They are measured by the color of white against the chromaticity scale. Phosphor conversion: is a method used to generate white light with LEDs. A blue or near-ultraviolet LED is coated with a yellow or multichromatic phosphor, resulting in white light. RGB stands for red, green, and blue, the three primary colors of light. When the primaries are mixed, the resulting light appears white to the human eye. Mixing the light from red, green, and blue LEDs is one way to produce white light. The other approach is known as phosphor conversion. SMD/SMT: A type of low profile LED that is surface mounted to a PCB. These type LEDs are very powerful and range in lumen output from 35 up to 170 lumens. With the latest LED technology being applied today, these have shown to have the most promise in delivering light levels and coloring that we are used to having. Those smd LEDs we talk about, use and sell are in the .5 watt, 1 watt, 3 watt and 5 watt power range. When you see a 7 watt or 9 watt LED light, it will contain 1 watt LEDs x 7, or 1 watt LEDs x 9, or 3 watt LEDs x 3. Solid-state lighting (SSL) technology uses semi-conducting materials to convert electricity into light. Task Lighting/Lamp: A LED light used to specifically light a particular area used for work or reading. Typically found in the form of a desk, floor, or clamp-on lamp, it can be a high powered LED light in any form. UV-A: (380–315 nm), also called Long Wave or blacklight because it is invisible to the human eye. Can cause skin irritation and fading of fabrics. UV-B: (315–280 nm), also called Medium Wave radiation. Can cause severe damage to the skin and human eye through exposure. UV-C: (
Posted on: Wed, 12 Nov 2014 05:33:33 +0000