Hong Kong Academy of Sciences Lu Ming: LED street lamp life standard is set at 50,000 hours is unreasonable
——Interview with Dr. Lu Ming, Director of LED Lighting Group, ASTRI
Reporter: Gao Gong LED Zeng Cong
On September 23, 2009, the Hong Kong Academy of Science and Technology's project promotion meeting was held in Shenzhen. At the meeting, the Academy of Sciences released its own LED street light. According to the introduction, this high-brightness LED street light "embodies the best high-brightness LED of today. Lighting technology, while reducing power consumption, its brightness is not inferior to the general street lights." Gaogong LED reporter interviewed Dr. Lu Ming, Director of LED Lighting Group of ASTRI on the performance of the street lamp.
Â
Dr. Lu Ming, Director of LED Lighting Group, ASTRI, Hong Kong
The key parameters of LED street lights developed by ASTRI are as follows:
   High-tech LED : Can your LED street lights be used for the main road now, and what factors are considered in the design?
   Lu Ming : Our street lights are not used on the main road now. It is not that we can't do it, but we have to develop something that really saves energy. At present, the high-efficiency sodium lamp has a very good light efficiency under high-power conditions. We are prepared to wait for some supporting technologies to further improve its performance, such as light efficiency and electronic control efficiency, so that it can be used more than 12 meters. Many companies now claim that they can do more than 12 meters based on market considerations, but from a development perspective, we will be a bit conservative.
   The important point now is that the standard of LED road lighting has not yet come out. Although the local standards of Guangdong have come out, they are very controversial. When the national standards have not yet been settled, these are matters that are vital to people, how the driving methods, color temperature, etc. will affect people. The application time of LED lighting is not long, and the related research has not reached a very At the point of implementation, we would rather spend a certain amount of effort in places where the risk is relatively low.
   Regarding the LED street light standard, we are not a standard setting unit, but we will pass the information to the standard setting unit through various channels, so that it is not an exclusive specification. To establish a standard to ensure the safety of passers-by, the direct use of the main road now, the risk is still relatively large.
   High-tech LED : Your power factor is greater than 0.95. Many companies in Shenzhen's “Ten Cities and Ten Thousand†pilots can achieve 0.98. How do you see this problem?
   Lu Ming : It should be said that the enterprises that enter the “Ten Cities and Ten Thousand Cities†are quite good enterprises. Our technology is not just to serve those companies, but to develop a technology platform to assist companies in Hong Kong and the Pearl River Delta. There are two ways to do this. One is to make our products perfect, and the other is to make your products meet the standards and meet the production efficiency. We hope to help those companies that do not meet the standards to cross this threshold. As for some aspects of excellence, we can help it improve.
High-tech LED : The effect of your LED street light is 60lm/W. There is no room for improvement. What factors have you considered?
   Lu Ming : We are using CREE chips. At present, the company's laboratory efficiency can be as high as 160 lm/W, but the mass production is only about 90 lm/W. A 90 lm/W light source is placed inside the fixture, minus the loss of light distribution, loss of electrical control, and heat loss, leaving approximately 68 lm/W. We can also buy 110 lm/W components, but consider the price/performance issue.
   At present, many of the fine LED street lamps built by many domestic enterprises are based on the purpose of propaganda, but you have to make a road. When you are tens of thousands of kilometers, you must consider its benefits and social costs. At present, you really earned by LED street lights. There are not many companies that make money. Our goal is to provide solutions that meet the standards while at the same time bringing market impact.
   High-tech LED : The operating temperature of the LED street lamp of ASTRI is 55 °C? How many degrees can your PN junction temperature do?
   Lu Ming : Under normal operating conditions, the operating temperature of the PN junction is lower than 55 °C. Our nominal 55 °C is the temperature of the lead line, and the temperature difference between the pin and the outer casing is about 5 °C. In fact, 55 ° C is a common concept, to correctly express the LED temperature, you need to use the concept of thermal resistance, because the ambient temperature is not the same, the temperature of the chip will also change.
   High-tech LED : The life standard of ASTRI LED street light is 30,000 hours. The standard of “Ten Cities and Ten Thousand Miles†is 50,000 hours. Is your product not meeting the requirements of “Ten Cities and Ten Thousand Cities�
   Lu Ming : First of all, our products are not aimed at “Ten Cities and Ten Thousand Citiesâ€. In addition, as far as the current technology is concerned, it is difficult to achieve 50,000 hours. Because the life of the whole lamp includes several parts: light source, electronic control, and so on. According to the US military standards, the general Power Supply can achieve 30,000 hours is already very good. At present, many companies claim that they can do 50,000 hours, but according to the daily light for 10 hours, 50,000 hours is 13.7 years, no one in the market has done such a long time experiment.
   I think the ENERGY STAR standard is relatively reasonable. The ENERGY STAR standard requires 25,000 hours for outdoor use and 30,000 hours for indoors. National standards, when many companies fail to reach or have no way to test, the value of this standard is worthy of our reflection.
COB LED Track Light,Recessed LED Light,LED Jewelry Cabinet Light
Brilliant Electronic Systems Technology Co., Ltd. , http://www.yichen-flashlight.com