LED key performance indicators
LED performance indicators are a core part of the whole , only by understanding its performance indicators in order to understand the depth of the LED street lighting, for future product development and sales can also be handy, but also take into the LED industry must understand something , let me now come to we carried out a detailed analysis in :
(1) LED colors : LED color is a very important indicator , is related to each LED lighting products to be labeled , the current LED colors are red, green , blue , cyan , yellow, white , warm white , amber and other colors, designs and orders in our time this parameter is that it must not be forgotten ( especially beginners ) because the colors are different, the relevant parameters have changed a lot.
(2) LED current : LED ‘s forward limit (IF) in the current multi- 20MA, and the LED light failure current is not greater than the IF / 3, about 15MA and 18MA .. LED luminous intensity only within a certain range of the IF into proportional , when the iF> 20MA , the brightness enhancement has been unable to use the inner eye points out , so the LED current general election in the 17-19MA so reasonable. previously for ordinary low-power LED (0.04-0.08W) between the LED, but except for some Piranha LED ( some around in 40MA ratings ) in addition to the continuous development of technology , high power LED are also emerging as 0.5W LED (IF = 150MA), 1W LED (IF = 350MA), 3W LED (IF = 750MA) there are other more specifications, I will not be introduced , and you can check it yourself LED manual .
(3) LED voltage : we usually refer to the forward voltage of the LED , that LED anode connected to the positive power supply , negative to negative power . Voltage relationship with color , red, yellow, green voltage is 1.8 – between 2.4v . White, blue , green voltage is between 3.0-3.6v , the same number of LED ‘s voltage may be some differences , according to the manufacturer’s prevail in the outside temperature , VF will fall.
(4) LED reverse voltage VRm: the maximum allowed plus reverse voltage. Exceeds this value, light emitting diodes may be damaged breakdown
(5) LED color temperature : K to indicate the absolute temperature , about a standard blackbody heating, the temperature rises to a certain extent, starting from the dark red color – light red – orange – white – blue , gradual change , a light source and a blackbody the same color , we called the absolute temperature of the blackbody at the color temperature of the light source .
In fact due to the correlated color temperature of the light source is a light color close to blackbody radiation , the performance of the light source color evaluation value , not a precise color contrast , the color temperature value with the same second light source , the light -colored appearance may still some differences . Only Feng color temperature light source can not understand the color capability of the object , or an object under the light source to reproduce the colors . Different correlated color temperature of lighting conditions .
LED performance indicators are a core part of the whole , only by understanding its performance indicators in order to understand the depth of the LED street lighting, for future product development and sales can also be handy, but also take into the LED industry must understand something , let me now come to we carried out a detailed analysis in :
(1) LED colors : LED color is a very important indicator , is related to each LED lighting products to be labeled , the current LED colors are red, green , blue , cyan , yellow, white , warm white , amber and other colors, designs and orders in our time this parameter is that it must not be forgotten ( especially beginners ) because the colors are different, the relevant parameters have changed a lot.
(2) LED current : LED ‘s forward limit (IF) in the current multi- 20MA, and the LED light failure current is not greater than the IF / 3, about 15MA and 18MA .. LED luminous intensity only within a certain range of the IF into proportional , when the iF> 20MA , the brightness enhancement has been unable to use the inner eye points out , so the LED current general election in the 17-19MA so reasonable. previously for ordinary low-power LED (0.04-0.08W) between the LED, but except for some Piranha LED ( some around in 40MA ratings ) in addition to the continuous development of technology , high power LED are also emerging as 0.5W LED (IF = 150MA), 1W LED (IF = 350MA), 3W LED (IF = 750MA) there are other more specifications, I will not be introduced , and you can check it yourself LED manual .
(3) LED voltage : we usually refer to the forward voltage of the LED , that LED anode connected to the positive power supply , negative to negative power . Voltage relationship with color , red, yellow, green voltage is 1.8 – between 2.4v . White, blue , green voltage is between 3.0-3.6v , the same number of LED ‘s voltage may be some differences , according to the manufacturer’s prevail in the outside temperature , VF will fall.
(4) LED reverse voltage VRm: the maximum allowed plus reverse voltage. Exceeds this value, light emitting diodes may be damaged breakdown
(5) LED color temperature : K to indicate the absolute temperature , about a standard blackbody heating, the temperature rises to a certain extent, starting from the dark red color – light red – orange – white – blue , gradual change , a light source and a blackbody the same color , we called the absolute temperature of the blackbody at the color temperature of the light source .
In fact due to the correlated color temperature of the light source is a light color close to blackbody radiation , the performance of the light source color evaluation value , not a precise color contrast , the color temperature value with the same second light source , the light -colored appearance may still some differences . Only Feng color temperature light source can not understand the color capability of the object , or an object under the light source to reproduce the colors . Different correlated color temperature of lighting conditions .
Color temperature
8000-8500k northern skies
Overcast 6500-7500k
5500k midday summer sun
Metal halide lamp 4000-4600k
Afternoon sunlight 4000k
Cool Camp Light 4000-5000k
High-pressure mercury lamp 3450-3750k
Warm Camp Light 2500-3000k
Halogen 3000k
Tungsten 2700k
HPS 1950-2250k
Candle light 2000k
8000-8500k northern skies
Overcast 6500-7500k
5500k midday summer sun
Metal halide lamp 4000-4600k
Afternoon sunlight 4000k
Cool Camp Light 4000-5000k
High-pressure mercury lamp 3450-3750k
Warm Camp Light 2500-3000k
Halogen 3000k
Tungsten 2700k
HPS 1950-2250k
Candle light 2000k
Different color temperature light source , the light color is also different :
The light source color temperature of different light colors are different, there is less color temperature 3000k warm feeling , to sedate atmosphere ; color temperature 3000k-5000k color temperature for the middle , there is a refreshing feeling ; color temperature 5000k over a cold feeling. ( 6 ) : luminous intensity (I, Intensity): Unit Candela , that cd. The direction of the light source unit in a given solid angle is defined as the light flux emitted in this direction ( fat ) light intensity ( degree ) , luminous intensity point light source for the purposes of , or the size of the illumination light compared to the distance comparison small occasions . This quantity is to show light in the convergence space launch capability . It can be said , the luminous intensity of the light in the end is to describe how ” bright” , because it is capable of converging optical power and a common description . The greater the light intensity , the light source look brighter , while under the same conditions after the irradiation by the light source , the brighter the object is , therefore , described earlier flashlight are using this parameter . LED is now also used to describe this unit , such as an LED is 15000 , the unit is mcd, 1000mcd = 1cd, so 15000mcd is 15cd. The reason for LED milli cd (mcd) rather than directly to a cd that is because in the past the first LED is dark , such as 1984 ‘s standard 5mm LED the luminous intensity before 0.005cd, so only use mcd said, now very powerful LED , but still follow the original argument. Said luminous intensity with a “Brightness” The disadvantage is that if two identical die LED, moderate convergence is high luminous intensity . Therefore, buy LED when not blindly pursue high I value , but also the irradiation angle . Many high I value of the LED emission efficiency is not improved to achieve its own , but the irradiation angle of the lens extended narrowing to achieve, which although useful for the LED street lighting , but the viewing angle is limited. In addition , the same die LED, 5mm in diameter than 3mm in I value more than twice as large , but only 10mm diameter 1/ 4 because the larger the lens the better convergence characteristic .
(7) LED luminous flux (F, Flux): Unit lumens, ie lm. Light emitted in a unit time is called the amount of light Luminous source . Again, the amount of the light source , the light source is to describe the size of the total , equivalent to the optical power . Light flux is larger, more light emitted for the isotropic light ( i.e. the sources of light emitted in all directions with the same density ) , then F = 4πI. That is, if the light source I is 1cd, the total flux is 4π = 12.56 lm. Comparison with mechanical units , luminous flux equivalent pressure, and luminous intensity equivalent pressure . To appear brighter spot is irradiated , not only to improve the luminous flux, but also to increase the converging means , in fact, reduced area , so as to obtain greater strength . You know, the amount of flux is artificial , for other animals may not be the same, but not completely natural thing, because this definition is based entirely on the response of the human eye comes to light . Human eye to different colors of light feeling is different, and this feeling determines the luminous flux and optical power conversion relationship . Most sensitive to the human eye yellow green 555nm , 1W = 683 lm, that is , 1W convert all the power of the light wavelength of 555nm , is 683 lumens. This is the maximum light conversion efficiency , but also scaling value , because the human eye is most sensitive to light of 555nm . For other colors of light , such as red 650nm , 1W only about 73 lumens of light , this is because the human eye is not sensitive to red light causes. For white light , depending on the situation, because a lot of different spectral structure of the light is white . Such as LED white light, white light and sun on television on very different, different spectra .
Lumen White LED now commonly enumerated , for your reference : 0.06W → 3-5LM, 0.2W → 13-15LM, 1W → 60-80LM.
(8) LED illumination (E, Illuminance): Unit Lux namely lx ( formerly called lux). 1 Lumen uniformly distributed on the surface of one square meter of the illumination generated .
We usually use this parameter was not a lot, we are not here for a detailed description .
( 9 ) CRI:
Color rendering light on the object itself known the extent of color , that is, the degree of color fidelity ; light color rendering index is to show that it represents an object in a light color than the reference light ( sunlight ) lighting color deviation , can more fully reflect the color characteristics of the light source . High color rendering light source on the color performance is better, we have seen it close to the color of natural color, low color rendering light source color performance is poor, we have seen the color deviation is also larger . International Commission on Illumination CIE color rendering index of the sun set at 100 , all kinds of color rendering index varies , such as: high pressure sodium lamp CRI Ra = 23, fluorescent tube CRI Ra = 60 ~ 90. Chromogenic in two ways:
Faithful color : performance material can be properly need to use the original color rendering index (Ra) of high light , its value is close to 100 , the color is best .
Color effects : To clearly emphasize a particular color , showing the lives of U.S. law can be used to add color to enhance the color effect
( 10 ) Glare : Vision has an extremely bright object or strong brightness and contrast , you can cause visual discomfort known as glare, glare is an important factor affecting the quality of lighting .
(11) LED life :
LED in the general description, can all be used more than 50,000 hours , and some manufacturers claim that their LED can operate 100,000 hours. The main problem is in this regard , LED is not a simple operation is no longer just that it’s rated life of the lamp can not be measured by conventional methods to calculate . In fact, the test LED life, no one has been waiting for it to stay next stop functioning. However, there are other ways to measure the LED life. The reason why LED lasting, because it does not produce the problem of filament fuse . LED does not directly stop working , but it will over time gradually degraded . It is predicted that high-quality LED after 50,000 hours of continuous operation, but also to maintain the initial light intensity more than 60% . Assumption that LED has reached its rated life , in fact it may still be light, but the light is very weak Bale. To extend the service life of LED , it is necessary to reduce or completely dissipate the heat generated by the LED chip . Heat is the main reason for the LED stops functioning . Life of the LED and the LED chip and LED driver related , I will become the LED experts << secret by improving the application of article >> LED life for a detailed explanation .
(12) LED Beam Angle: LED light-emitting angle is, its light scattering angles , mainly by diode production plus scattering agent to control , there are three main categories: ( 1 ) high directivity . Generally pointed epoxy package , or package with a metal reflector cavity , and does not add scattering agent . Angle 5 ° ~ 20 ° or less , with a high directivity , can be used for local illumination light source or the light detector associated to form an automatic detection system. ( 2 ) standard . Typically used for light , the luminous angle of 20 ° ~ 45 °. ( 3 ) the scattering type . This is a large angle light -emitting angle is 45 ° ~ 90 ° or more, a large amount of scattering agent .
The light source color temperature of different light colors are different, there is less color temperature 3000k warm feeling , to sedate atmosphere ; color temperature 3000k-5000k color temperature for the middle , there is a refreshing feeling ; color temperature 5000k over a cold feeling. ( 6 ) : luminous intensity (I, Intensity): Unit Candela , that cd. The direction of the light source unit in a given solid angle is defined as the light flux emitted in this direction ( fat ) light intensity ( degree ) , luminous intensity point light source for the purposes of , or the size of the illumination light compared to the distance comparison small occasions . This quantity is to show light in the convergence space launch capability . It can be said , the luminous intensity of the light in the end is to describe how ” bright” , because it is capable of converging optical power and a common description . The greater the light intensity , the light source look brighter , while under the same conditions after the irradiation by the light source , the brighter the object is , therefore , described earlier flashlight are using this parameter . LED is now also used to describe this unit , such as an LED is 15000 , the unit is mcd, 1000mcd = 1cd, so 15000mcd is 15cd. The reason for LED milli cd (mcd) rather than directly to a cd that is because in the past the first LED is dark , such as 1984 ‘s standard 5mm LED the luminous intensity before 0.005cd, so only use mcd said, now very powerful LED , but still follow the original argument. Said luminous intensity with a “Brightness” The disadvantage is that if two identical die LED, moderate convergence is high luminous intensity . Therefore, buy LED when not blindly pursue high I value , but also the irradiation angle . Many high I value of the LED emission efficiency is not improved to achieve its own , but the irradiation angle of the lens extended narrowing to achieve, which although useful for the LED street lighting , but the viewing angle is limited. In addition , the same die LED, 5mm in diameter than 3mm in I value more than twice as large , but only 10mm diameter 1/ 4 because the larger the lens the better convergence characteristic .
(7) LED luminous flux (F, Flux): Unit lumens, ie lm. Light emitted in a unit time is called the amount of light Luminous source . Again, the amount of the light source , the light source is to describe the size of the total , equivalent to the optical power . Light flux is larger, more light emitted for the isotropic light ( i.e. the sources of light emitted in all directions with the same density ) , then F = 4πI. That is, if the light source I is 1cd, the total flux is 4π = 12.56 lm. Comparison with mechanical units , luminous flux equivalent pressure, and luminous intensity equivalent pressure . To appear brighter spot is irradiated , not only to improve the luminous flux, but also to increase the converging means , in fact, reduced area , so as to obtain greater strength . You know, the amount of flux is artificial , for other animals may not be the same, but not completely natural thing, because this definition is based entirely on the response of the human eye comes to light . Human eye to different colors of light feeling is different, and this feeling determines the luminous flux and optical power conversion relationship . Most sensitive to the human eye yellow green 555nm , 1W = 683 lm, that is , 1W convert all the power of the light wavelength of 555nm , is 683 lumens. This is the maximum light conversion efficiency , but also scaling value , because the human eye is most sensitive to light of 555nm . For other colors of light , such as red 650nm , 1W only about 73 lumens of light , this is because the human eye is not sensitive to red light causes. For white light , depending on the situation, because a lot of different spectral structure of the light is white . Such as LED white light, white light and sun on television on very different, different spectra .
Lumen White LED now commonly enumerated , for your reference : 0.06W → 3-5LM, 0.2W → 13-15LM, 1W → 60-80LM.
(8) LED illumination (E, Illuminance): Unit Lux namely lx ( formerly called lux). 1 Lumen uniformly distributed on the surface of one square meter of the illumination generated .
We usually use this parameter was not a lot, we are not here for a detailed description .
( 9 ) CRI:
Color rendering light on the object itself known the extent of color , that is, the degree of color fidelity ; light color rendering index is to show that it represents an object in a light color than the reference light ( sunlight ) lighting color deviation , can more fully reflect the color characteristics of the light source . High color rendering light source on the color performance is better, we have seen it close to the color of natural color, low color rendering light source color performance is poor, we have seen the color deviation is also larger . International Commission on Illumination CIE color rendering index of the sun set at 100 , all kinds of color rendering index varies , such as: high pressure sodium lamp CRI Ra = 23, fluorescent tube CRI Ra = 60 ~ 90. Chromogenic in two ways:
Faithful color : performance material can be properly need to use the original color rendering index (Ra) of high light , its value is close to 100 , the color is best .
Color effects : To clearly emphasize a particular color , showing the lives of U.S. law can be used to add color to enhance the color effect
( 10 ) Glare : Vision has an extremely bright object or strong brightness and contrast , you can cause visual discomfort known as glare, glare is an important factor affecting the quality of lighting .
(11) LED life :
LED in the general description, can all be used more than 50,000 hours , and some manufacturers claim that their LED can operate 100,000 hours. The main problem is in this regard , LED is not a simple operation is no longer just that it’s rated life of the lamp can not be measured by conventional methods to calculate . In fact, the test LED life, no one has been waiting for it to stay next stop functioning. However, there are other ways to measure the LED life. The reason why LED lasting, because it does not produce the problem of filament fuse . LED does not directly stop working , but it will over time gradually degraded . It is predicted that high-quality LED after 50,000 hours of continuous operation, but also to maintain the initial light intensity more than 60% . Assumption that LED has reached its rated life , in fact it may still be light, but the light is very weak Bale. To extend the service life of LED , it is necessary to reduce or completely dissipate the heat generated by the LED chip . Heat is the main reason for the LED stops functioning . Life of the LED and the LED chip and LED driver related , I will become the LED experts << secret by improving the application of article >> LED life for a detailed explanation .
(12) LED Beam Angle: LED light-emitting angle is, its light scattering angles , mainly by diode production plus scattering agent to control , there are three main categories: ( 1 ) high directivity . Generally pointed epoxy package , or package with a metal reflector cavity , and does not add scattering agent . Angle 5 ° ~ 20 ° or less , with a high directivity , can be used for local illumination light source or the light detector associated to form an automatic detection system. ( 2 ) standard . Typically used for light , the luminous angle of 20 ° ~ 45 °. ( 3 ) the scattering type . This is a large angle light -emitting angle is 45 ° ~ 90 ° or more, a large amount of scattering agent .
Source from:http://www.lighting-ledlight.com/
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