Industry news

2016August

LED lighting several major problems

From: www.szbako.com Data:06/08/2016

1 core problem: I studied
cooling light effect problem of the large power of a light source packaging manufacturers to provide integrated light source module, the power module 20w-200w chip is the same, but the optical efficiency of 20W module is as high as 94lm/w (Re Guangxiao), the optical efficiency of 50W module for 82lm/w (hot) and the optical efficiency of 100W module is as high as 70lm/w (thermal effect) the optical efficiency of 200W module is as high as 57lm/w (hot), this is actually the heat at work, I tested the same module, in the premise of good heat dissipation, the optical efficiency of 20W module is as high as 105lm/w (Leng Guangxiao), is say, if the heat design is very good, so the optical efficiency of 200W module is up to 105lm/w, then B (90lm/w) made of energy-efficient LED lighting costs should be below 12RMB/w, how much do you want for a tile, see the user happy. . With what kind of technologies will achieve cooling effect so ideal, I suggest you go to look at, but the cost is not high, to be meaningful, if energy

second: the most difficult problem: small
as we all know, a few years ago the statistical data show that China in the total number of months for street lamp 24 million, this figure is now 30 million lamp, tunnel lamp and lamp number roughly equal, because the average number of 1km tunnel lights roughly equivalent to 10km on average road lamp number, this number allowed to never mind, I want to say, so many lights are replaced by LED lamps, light is this is a piece of aluminum can not afford a astronomical calculation, according to a 10KG lamp, so long is about 600 thousand tons, why not put the I high pressure sodium lamp run off, the LED lights change up? This is a small problem, the premise is: good heat dissipation, energy saving indicators can not fall, how you come to try. 3 is not a problem: the driver of the power supply
from the development of the power supply, efficiency and reliability are already quite good, why should it as a problem to say. Yes, its price is a difficult problem. From now on the market power, good performance a bit, about the price of 3 yuan /w. Of course, there are between 2-3 yuan /W, the price is about weak light source price of 1 /2, in the cost of LED lighting as the second factor, if the use of non isolated house, cost down, but safety and, we cannot themselves to R & D and production of power? This is also too embarrassed. Have the company launched the AC drive LED light source, my friend told me that the life of the light source is not good, it is best not to consider. I haven't tested the LED light source, so they can't comment. 4 additional problems: continuous tone light
LED is a very easygoing guy, can be hungry, can also support, drive current size are not picky, to eat how much current is how much light. This longevity the LED for dimming control demand. The increase of course is a good thing, can make people more lazy, energy-saving targets can also be raised, however, increases the function, the reliability of the system decreased, increased costs, owners on the one hand, shouting lamp price is too high, on the other hand but increase the function of automatic continuous dimming, really is life difficult, more difficult to do led, led to do good even more difficult. 5. The LED ten big problems:
everyone is in awe of the problem: Zebra
what is zebra, must be to look at the pictures, text is not a very good explanation, but can find on the Internet to see

because the phenomenon is still no better solution, so, the experts say: This is inherent in the phenomenon of the white light illumination. Some people say that the role of experts is to say that the fans confused. The basis of these two statements is: experts have not yet made clear what this phenomenon is. Previously said, the higher the evenness of the road, the more serious the phenomenon of zebra stripes. I to different city business and meet high pressure sodium lighting effect is very uniform sections, I love took illuminance meter measuring about uniformity. The test results show that: illumination of the pavement evenness between 0.35-0.4. Two of those uniformity of up to 0.6 above the road looks very bad, this photo shows the section of the uniform illumination degrees up to 0.61. In fact,, whether it is white lighting or sodium light illumination, zebra now are not natural, can through the superb optical design in order to remedy, which may need to be a change of coordinates and standards to guide designers to make a surrender of the design.



this is for the street lights, I am now LED street lamps are not optimistic about the majority of the factory, the street lamp product line is too immature 6 problems six: life LED

lamps and lanterns in the end is how long? This problem may be the industry's most difficult to say clearly. Some people take light 50000 hours for something, but the 50 thousand hour is calculated. Straw hat and closed piranha LED life can be said clearly, 3528MT closed led also can say clearly, because their life is not so long, laboratory to do two or three years to results, but 1-3W high power light source that is not clear, the Cree and OSRAM has been done about 30000 hours, attenuation of still less than 30%, it is estimated that in the light of life (30% depreciation) is 50000 hours, but this is almost. But in the end how long the life of LED is suitable? My point is that we should design different life span according to the occasion of the lamps and lanterns. Such as used in the lighting time of the day for more than 18 hours (tunnels, underground garage, etc.) occasions need 5 million hours of life, and road lighting lamp life of 30000 hours is enough. This means that the LED street lamp used to use more than 3 years, I dare say, now go LED street lamp after 3 years is not skill, because the LED street lamp in 3 years after the lamp light efficiency will be more than 150LM/W, than it is now twice as high, the time must to changing light, the same for 8-10 hours a day lighting, 20000 hours!! What is your design LED lamps and lanterns, the junction temperature written but the fact of the matter is that is inextricably linked with the life span of led the key technical index of because of the finished product is affected by many factors. Most of them can't reach 3 million hours of seven of the ten big problems:
Daobubai problem: junction temperature of the temperature
LED, how many people can understand? If you really want to say, then get a professional testing agencies to identify what can be such a large test who will do? Money not to say, time is too long, also requires a lot of, irritated irritated dead, in fact, temperature to the amount of digital soldier is not important, the key is cooling channel design is not reasonable, if cooling channel design reasonable, usually junction temperature is not more than 75 degrees Celsius, the junction temperature is completely acceptable too, as recommended by the industry alliance 65 degrees Celsius remains to be deliberate, remember last year, when a friend asked me: my light body temperature is not high, the hands can not hot, but light mask is very hot. This is how to return a responsibility? Obviously, this is a typical case of cooling channel design unreasonable, the junction temperature has more than 140 degrees Celsius, the heat from a smooth outside of infrared radiation emitted, my idea is to use a single source power above 1.5W, the thermal conductivity of aluminum substrate should be selected 2.2W/m.k, 3w/m.k is the best. The thermal conductivity of thermal grease will of course, above 3W/m.k, reflow soldering is not less than, but also have sufficient cooling area, if using integrated power source module, then at least to use heat, if you have efficient cooling technology other words, but it is good in the cost of eighth problem:
for LED lighting business license, the cost is the survival of the bottleneck to a certain extent, the cause of LED lighting is high two sources: the first is the light source. Two is the drive power supply. The cost of this second source accounted for more than 65% of the cost of the entire lighting lamps and lanterns, we analyze the some low bid company, found them both source accounted for the cost ratio is about 50%, the proportion of down is the main way to three: one is own package source (low), the second is the low quality of the light source (deceptive), the third is to increase driving power supply (low light efficiency) as a result, their lamps and lanterns to the competitiveness. For example, there are a company in Shenzhen, with us about orders when quoted price is the lamps and lanterns of 15 yuan /W, hear the offer, I almost fainted in the past, so that the user wants to know why my lamp prices than they were as high as more than 50%, let's second home in two days the lamp with sent directly in the past to PK, is the natural result of high quality, the user understand the truth in a price of a cargo. We use the OSRAM light source, they use the CREE chip, the layman is not clear, this is not all imported it? In fact, the gap to a large, the so-called light source, is only has a good package can be directly used in the manufacture of lamps and lanterns of the original, and the chip is can not be directly applied to the lamp manufacture parts, like this is the computer source code, only after some of the follow-up process to use. Last year industry alliance held in Harbin standard to promote the meeting, released such data: the same chip, different closure manufacturers light efficiency difference of 53%, chips of different, the same packaging manufacturers, light efficiency gap is 27% and I see the package of light source and the national famous brand of high power light source, there is a big gap compared to, as long as there are two problems: a passing fast light decay, one is color is not correct, greenish yellowish. So, I advocate the domestic packaging companies can set up a joint research organization, to package the block level up so
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