High-power LED options include the choice of brand, product line, a product specifications, including the choice of optical, electrical and thermal parameters.
The choice of product brands
LED product chain: the front-end products, LED chip, the package\\ s patented technology, the majority lies in the hands of several international famous companies. China\\ s enterprises to change this Bureau, also need to swear a longer eye of efforts and we look forward to that day. According to the National Swimming Center, LED architectural landscape lighting project, the importance of the LED industry status quo, the great merit ED chip select Lumileds, Cree, Osram, and other international famous brand products.
The choice of product line
The LED is a development of very rapid production of high-tech! The single LED power and luminous flux very quickly, and a corresponding decline in the price per watt per lumen is also very rapid. As the application of engineering to choose a relatively mature technology and applications, \\ yL were lower than the high capacity, purpose, and, for example,: Lumileds what the company\\ s reble Cree with XLamp. Osram, Goededragon, these products provide us with room for choice.
The choice of the main parameters of the LED light source
LED chips in the package when both the optical design, in the case of \"the scope of the lamps in order to distinguish the second optical design of the lamp, where we have no LED package known as the light source.
(1) the choice of electrical parameters
(1) single LED rated current, rated power, the power LED Rated II for current the following specifications: 200,250,300,350, 500 700 1000. 1500mA and so on.
In the maturity of the technology under the premise appropriate to mention the sound of a single LED rated current can reduce the number of lamps to reduce system cost,
But should not choose a single power-too products, cooling difficulties, easy to cattle production light failure, shortened life span, the technology is mature and to a lesser degree, the application with less experience. Single 700ma, lOOOmA lamps are already on the market.
Select the product of a higher luminous efficiency, reduce the cost per lumen luminous flux of.
According to the international market, we identified a select 350mA LED as a light source.
â'¡ LED peak forward current Ifm
Forward peak current Ifm and LED rated current of a certain proportion of the different brands and different products Department of series of proportion may be different, this ratio is 1. 5,2, and so on.
The â'§ reverse leakage current Ir
Forward voltage is equal to 5v, the general reverse leakage current Ir ≤ 5YA.
â'£ forward mainly as voltage V r: Rated -1. For the current R: Vf2. 2-3.0: G: Vf3. 0-3 5;: Vf, 3. 0-3.
â'¥ reverse operating voltage Vr
To â'¥ maximum reverse voltage Vrm
The â'¦ allow power Pm
â'§ antistatic ability
The â'¨ accelerated aging test conditions
(2) optical parameter selection
CD.t wavelength: k: fi22 429nm G :520-525nm B :465-470nm.
â'¡ LED single tube lumen K ing: at 25 ℃, 350mA, steady work, R ≥ 35, Im; the G ≥ 60Im; B ≥ 15 Im
â'¢ the width of the half-wavelength: R-20 ~ 25nm, the G-35 ~ 40nm, B-25 --- 30nm. Color purity: ≥ 97% of the R, G, ≥ 75% B ≥ 95%.
â'£ the light angle
(5) light distribution curve: typical LED packaging with light curve shown in Figure 4-24.
â'¥ LED brightness uniformity
â'¦ color temperature
The main consideration to maintain the balance of the camera color temperature when shooting the TV. For large public buildings in a major event, you may need television, began broadcasting scene screen in the summer is also the end of completely dark, while the sky is relatively bright. In this case, you need to select the color temperature of 5600. K.
(3) thermal parameters
â' allow small for the junction temperature: generally select Tj ≥ 125
â'¡ maximum operating case temperature (Max CaseTemperature)
â'¢ the PN junction to the package therm al resistance of the base :: R, G, B, Select, ℃ / w value, the greater the heat the worse, the light fades, the more serious.
The R ≤ 12 0C / W; G. B ≤ 10 0C / W.
â'£ work environment temperature
(4) Service life: ≥ 50 000 hours, the light fades and y is less than the initial value of 300.
4.6 4 LFD Lamp Selection
(1) lamp structure
â' lighting material and shape: lighting material and shape should be coordinated with the building shape and external decorating material.
â'¡ shell of protection: IP55
Three anti-treatment: anti-corrosion, moisture, dust.
(2) lamp electrical parameters
(1) Input voltage: like DC24V:
(2) the input current
(3) efficiency (electric)
(4) rated power
(3) lighting optical parameter selection
A luminaire efficiency (optical)
2 light decline:
Light distribution curve: I hope that the asymmetric distribution of light, rectangular optical cross-section.
(4) lamp thermal parameters
Device case temperature:
(2) ambient temperature,
3 fixtures thermal resistance:
(4) low temperature life.
(5) Lamp life: the theory of LED life of more than 100,000 hours. But with the power and the LED chip life is far less than this figure. - General election ≥ 30,000 hours.
没有评论:
发表评论