In general, most of the LED used for lighting is white. LED lighting depends largely on the inventions of the blue LED chip and the emitting efficiency. Realization of white LED is mainly in two ways. One is using the LED chips and the phosphor, the other is to use LED chips whose color is RGB3. The key is to take the first way. Using the blue phosphors are generally that a yellow phosphor is coated on the LED chip. when the blue light Emitted from the LED chip encounter the fluorescent phosphor, part of the light is converted into yellow light,the yellow and blue light of this part of the conversion mix together, it becomes a white light. By adjusting the amount of phosphor ,the color temperature of the white LED can be controlled, so the light color have already been decided in the production, the latter can not be adjusted. At the same time, for the mixing the blue light and yellow light, then because of lack of the red and green components, resulting in poor color. Thus, the red and green phosphor can be mixed in the blue LED chip or the RGB phosphors can be mixed in the ultraviolet LED chip to improve its color. Taking advantage of RGB3 color LED chips lies in that the RGB can adjust various color, so which can not only produce the white light, but also produce various other colors of light. However, the quantity of LED chips is increasingly used, the costs will rise. Three features of the LED: |
(1) Thermal characteristics
Although the LED fever rarely, but because multiple pieces of several watts of the LED need to be used in the LED lighting, so which will produce very high heat. Although the LED efficiency is relatively high, but the high-rate support run in the tiny currents. High current, high temperature, the efficiency is low. In addition, the phosphor type of the LED, when the wavelength is converted,the energy will be lost, thereby the heat is generated. Continuous high temperature will cause that the life of the LED chip, phosphor, encapsulating resin is reduced. Therefore, in order to maintain the advantage of "high efficiency", "long life" of the LED, it is necessary to control the LED junction temperature.
(2) electric characteristics
LED power supply is significantly different from the incandescent, fluorescent. Incandescent lamp can be connected directly to 220V AC. Although the ballasts and switch are attached on the fluorescent, but 220V AC is also used. While the power supply of the LED requires the DC constant current, it is necessary to convert 220V AC to DC. The efficient of the Power is not high,which will directly affect the efficiency of the entire lighting, thus what is very important that increasing power efficiency is to improve the efficiency of LED lighting.
There are two main methods for adjusting the LED light,. One is to change the constant current, the other is to change the pulse modulation. LED is the recombination of electrons and holes to emit light, the light beam depends on the current. Current is small, and the beam is basically proportional to the current, when the LED current increases, the heat increases, resulting in low luminous efficiency, and the current is not proportional to the beam.
In the method of changing the pulse duty cycle, the Talbot-Plateau effect (after repeatedly receiving the momentary flash, the human eye will experience the average brightness at repeated time), we can change the brightness according to the pulse duty cycle.
(3) Optical properties Compared with incandescent and fluorescent lamps, the lighting efficiency of an LED light is relatively small, so the multiple pieces LED need to be used. Meanwhile, because the emitting area of the LED is small, if the brightness is high, the vertigo is easily occurred when the human eye look. To reduce the brightness, use the diffusion plate. However, for the use of the diffusion plate, then light diverge in all directions, reducing the efficiency of light.
LED, the light distribution of incandescent, fluorescent varies. The so-called light distribution is the direction of the light and the direction of the luminous intensity. Even if the same light beam, if the distribution of light distribution is different, the illuminance distribution will be different. Sometimes appear the irradiation intensity of where originally intend to be irradiated decreased, but the rest of the illuminance increases.
To reduce the waste of light, the light distribution must be controlled, a lens and mirror should be used. LED itself has a small light-emitting area, the light emission is limited in the hemisphere, light distribution is symmetrical and rotationally etc., plus lenses and mirrors, can constitute a good source. Other properties in the light source ~ the spectrum. The LED luminous spectrum focuses on a specific wavelength of a very narrow range, which does not emit infrared radiation. Therefore, when do not want to heat up the irradiated object, the use of LED is better. However, LED itself may have a fever, we need to pay attention to prevent the thermal conductivity. Also note, fir the phosphor type of the LED, the color temperature is changed as the temperature changes.
Meanwhile,there are a large number of excellent manufacturer engaging in manufacturing and researching the LED light,of which the lead lighting is just one,lead Lighting adopts high brightness SMD as the light source of the LED tube and highly integrated and high brightness COB as the light source of the LED flood light, which fully guaranteed stability and soft light of the LED tube light and octahedron breadth and brightness irradiation range of the LED flood light, while the low voltage constant current driver convert the AC into DC so that improve energy efficiency of the LED tube light and LED flood light and reduce the waste heat energy and stroboscopic effect exciting the human eye, the most important is that the LED lighting without adding mercury and other heavy metals harmful to our body and pollution the environment, that’s why the LED light is famous for energy-saving and environmental protection ,login www.ledclan.com to learn more features and uses of the LED tube light and surf www.lead-lighting.com to know more awesome LED floodlights and other LED lighting.
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effect, AC, Incandescent lamp, LED flood light, LED lighting, LED tube light, lighting efficiency, phosphors, Plateau, RGB,