LED is a solid light source, when it is coupled with a positive voltage across the semiconductor in the minority carrier and majority carrier complex occurs, release the excess energy will cause the photon emission.
Using different materials, different colors can be made of light-emitting diodes. As a new light source, in recent years,glue stick major companies and research institutions in the ascendant on the LED so that light efficiency can be greatly improved, Lumiled company has research and development and production of optical efficiency to achieve 90Lm / W white LED, has reached the incandescent level.
LED drive power status quo.
Standard Electric is undergoing a revolution. For the protection of energy and address global warming considerations, the United States and other countries, some states began to prohibit the use of inefficient incandescent bulbs. Have a variety of new technologies are being used to replace incandescent bulbs, including compact vacuum fluorescent (CFL) is the main alternative. Although this CFL incandescent lamp consumes only 20%,glue gun but they contain toxic substances mercury. In contrast, LED lamps can provide more efficient and more environmentally friendly solution.
The first commercial application of LED in the seventies of last century, but its light output is very low, the application was limited to light and calculator displays and other fields. Now, can produce high-power white light LED can be improved continuously in terms of efficiency, prices are declining, it has become the mainstream lighting applications to be considered one of the options. Expected that with LED technology, the luminous efficiency by 2012 will reach 150 lumens / watt, 1000 lumens will be less than $ 5 cost (source: OIDA), when the LED is expected to become a major source of indoor lighting.
2008 Beijing Olympics through the shape of many specific products and new technology for the Green Olympics, Scientific Olympics and Humanity Olympics made a perfect interpretation of such concepts. LED display products, in the 2008 Beijing Olympic Games a wide range of applications, it is light flashes for the 2008 Beijing Olympic Games has added gorgeous splendor.
Recent Olympic Games, LED display screen are the main Olympic venues essential facilities. 2008 Beijing Olympic Games stadiums were built and rebuilt numerous, unprecedented scale, a large number of Olympic venues are used LED display Zuowei live games played and points display equipment, display products in full color, high resolution, digital, etc. based. Can be said that the 2008 Beijing Olympic Games LED display products used to technical standards and from the number of applications has reached a new milestone, of which many domestic LED display products manufacturing enterprises play an important role.
Through the global LED technology leader in the material, process and packaging technology, efforts to improve, high brightness LED light-emitting efficiency and performance has been significantly improved, in addition to the traditional backlight and display panel market, high-brightness LED start to indoor and outdoor general lighting, automotive interior and exterior lighting, lighting, traffic lights and other new applications. These are harbingers of LED drive power will have a broad application prospects.
Problems.
Shine at the same time LED, LED drive power supply is the development of LED industry chain protection, LED power supply quality products directly to the reliability constraints of the LED, so gradual improvement in the LED industry chain Today, LED driver power supply maturity is also crucial. LED power supply for enterprises, 2009, 100W power supply so the market will increase greatly improved. 100W LED light source from around compared with traditional light sources have a more prominent cost-effective, and soon an industrial scale of the LED lamps and landscape lighting markets. LED is sensitive to the characteristics of semiconductor devices, but also has negative temperature characteristics, so in the application process needs to be stable working conditions and protection, resulting in the drive concept.
LED drive power requirements of devices on the near-stringent, LED unlike ordinary incandescent bulbs, can be connected directly 220V AC mains. 2 to 3 volts LED is low voltage drive, we must transform the circuit design complexity, different uses LED lights, be equipped with different power adapter. Foreign clients on the international market efficiency of the LED drive power conversion, efficient power, constant current accuracy, power life, electromagnetic compatibility requirements are very high, to design a good power supply must be taken into account these factors, because the power in the entire fixture like the role as important as the human heart.
In 2009, although the financial crisis, a great impact on the world economy, but Europe and the international market demand for high-power LED power supply is still very large, the corresponding exports of high-end LED products less affected by the financial crisis. LED application products in China in 2008 the output value has more than 45 billion yuan RMB, LED street demonstration and application, LED full color screen display, solar LED, landscape lighting, consumer electronics, backlighting, signals, instructions and other applications are still the major application areas.
However, in the context of a prosperous market, LED product quality varied, the requirements of the drive power chaos, LED products on the market development trend in full swing, the LED drive power to businesses, are facing several challenges. The first is the overall life of driver circuit, especially in key components such as capacitors at high temperature directly affects the life of the power of life. Followed by the LED drive higher conversion efficiency should be challenging, especially in high-power LED driver is especially true, because all is not as light output power is dissipated as heat, low power conversion efficiency, energy saving effect of the LED play. Third, the major light is high efficient LED dimming on, while ensuring the high and low brightness color characteristics constant. At the same time to reduce costs, smaller power now (1 ~ 5W) applications, the constant current drive power is close to the proportion of the cost of 1 / 3 the cost is close to the source, to a certain extent affected the marketing.