LED street lights have developed into the 21st century and are widely used in urban slow lanes, narrow lanes, residential areas, tourist attractions, parks, squares, private gardens and other public places on one or both sides of the road for road lighting, improving people's nighttime travel. Safety is used to increase the time of people's outdoor activities and improve the safety of life and property. Why are LED street lights so widely used? Compared with other road lighting fixtures, what are the outstanding features of LEDs? Let us compare together below.
1. Lifespan: The LED chip used in LED street lights is a semiconductor diode, and its lifespan is very long. When the luminous flux decays to 80%, its lifespan reaches 50,000 hours. The life of the metal halide lamp is 6000~12000 hours, and the life of the high pressure sodium lamp is 12000 hours.
2. Shock resistance: The basic structure of the LED chip is a piece of electroluminescent semiconductor material, placed on a shelf with leads, and then sealed with epoxy resin around it to protect the internal core wire, so the shock resistance of LED it is good.
3. Light distribution: The color of LED street lights using white LEDs is better than that of high-pressure sodium lamps. At the level of intermediate vision, it is easier for the human eye to distinguish things in a high color temperature environment than in a low color temperature environment. The color rendering of white LEDs is also much better than that of high-pressure sodium lamps. The color rendering index of high-pressure sodium lamps is only about 20, while that of white LEDs can reach 65-80.
4. Dimming: LED street lights can achieve a more perfect dimming function. Due to the large working range of the LED, its light output is directly proportional to the working current, so the method of reducing the current can be used to adjust the light. In addition, since the frequent switching of LED street lights does not cause much damage to the LED, the dimming of the LED can also be obtained by adjusting the pulse width. By adjusting the duty cycle of the voltage and the operating frequency, the luminous intensity of the LED can be effectively adjusted.
5. Illumination angle: In the optical system of the lamp, the luminous flux loss of the LED light source of the LED street lamp is the smallest. Unlike traditional light sources, LEDs are light sources that emit light in half space. High-pressure sodium lamps or metal halide lamps are light sources that emit light in the entire space. It is necessary to change the direction of the outgoing light from one half of the space by 180° to the other half of the space. When we rely on the reflector to complete, the absorption of light by the reflector and the blocking of light by the light source itself are inevitable. However, using LED as a light source will not cause this loss, and the utilization rate of light is higher than that of traditional light sources. Finally, LED light sources do not contain harmful metallic mercury, unlike high-pressure sodium lamps or metal halide lamps that are harmful to the environment when they are scrapped.
