Recently, the haze once again sweeping across the country, as the lighting enterprise, we can not change the environment, but can do small thing, so that people not can see only the lights but also the road when going out, Which requires increasing penetration of the LED street lights. Color temperature selection of LED street lights LED packaging process currently used through applying the phosphor with different excitation wavelengths, adjusting the amount or the proportion of phosphor to obtained white LED light source with different color temperature. Different light sources emit different color temperature, low color temperature light source is characterized by energy distribution, the red radiation is relatively more, usually called "warm light; After color temperature increasing, the proportion of blue radiation will be ncreased in the energy distribution, commonly referred to as "cold light." For white LED light, there is a relative more proportion in yellow for the low color temperature, however, there is a relative more proportion in blue for the high color temperature. From the human visual point of view, low color temperature gives a warm, stable feeling, and high color temperature gives a deserted, refreshing feeling. The color temperature of some common light sources In general, LED light sources can be divided into warm white, neutral white and cold white, three categories. The color temperature of traditional street lights are generally warm white light that about 2300K, the human eye vision will obviously feel yellow. LED can be produced different color temperature of the light source through the packaging process, give the road lighting a lot of different options. The relationship between color temperature and light efficiency It is noteworthy that, for the color temperature selection in the early group of LED lights, almost all manufacturers have chosen 6000K, or even more than 6000K, this is why? It turned out that under the technical conditions that the early phosphor, cool white LED light source with a higher light efficiency. Compared to color temperature, people pay more attention to the physical properties of light efficiency. The most important means to improve light efficiency is to improve the excitation efficiency of the phosphor, excitation efficiency of YAG yellow powder is much higher than the orange powder. Higher color temperature can get higher light efficiency, light efficiency of 5500-6500K color temperature can enhance 48.7% than the warm white light source which less than 3500K. LED is energy-saving, entirely because the LED has a higher light efficiency than other light sources, put aside the energy efficiency and talking the energy-saving is meaningless. High light efficiency not only bring higher energy efficiency, but also reduce the cost of lights, making the products more competitive. So most of the LED street light manufacturers select to producing the products with 6000K color temperature in order to pursue high energy-saving rate. In recent years, LED technology is still high-speed developing, the light efficiency of chip continuously improve, energy efficiency rate has also been guaranteed. The contradiction between light efficiency and color temperature is no longer the main contradiction in the application process, and whether the color temperature and environmental conditions are coordinated is the focus should be paid attention. Synthesize technical conditions, climatic conditions, the current environmental conditions and the human eye senses, we propose, color temperature of LED street lights should choose the range of 3000 ~ 5700K. This color temperature will not have a large impact on light efficiency, but also to ensure the penetration of haze, and adapt to our people's visual senses.
