Reliable bearing trust, a new era of LED light engine

The LED light engine (light engine) is a combination of LED packages (components) or LED arrays (modules), LED drives, and other brightness, thermal, mechanical and electrical components. The device is directly connected to the branch circuit through a conventional connector matched with the LED lamp, and the LED lamp is designed without using a standard lamp holder.

This definition seems to be complete, but it can be confusing.

Professor Mao Yu Hai to the LED light engine summed up a more popular definition, that is, LED + constant current drive power source installed on a piece of aluminum substrate.

As a Chinese LED network of experts, Professor Mao Yu Hai has been renowned in the industry, and there is a long list of flash Titles: the Cornell University electrical engineering college associate professor, senior member of Institute of electrical and electronics engineers, Professor of electrical engineering at Tsinghua University, China Electronics Association, American IEEE senior member, visiting professor of Stanford University, vice director of the Institute Tsinghua University radio electronics research. At present, added: Philae photoelectric chairman.

Is not the entire LED lamps can also be called a light engine? Yu Hai pointed out that, of course, can not be. Just as the whole car can not be called the engine, the engine is the power assembly of the car, but not equal to the car, but also with the shell to become a car. The reason why the need for light engine products, because all the lights have a wide range of appearance. Some lamps can even be called works of art.

Take the incandescent light, it can be said that it is only the simplest form of a light bulb, at most plus a candle light or a small Christmas lights. But it has a variety of shapes. Especially the crystal lamp is a wide range of Arts and crafts, extremely gorgeous. But LED must also be equipped with an extremely complex constant current drive source that works like an incandescent lamp (with 220V). If the LED as a light engine, it can also be connected to the 220V like incandescent light (of course, also need to match the radiator). On the one hand, it contributes to standardization, on the other hand, it can greatly facilitate the design of the shell (and radiator).

Interpretation of technical difficulties of LED light engine

The driver constant current source to do LED light board, the first difficulty is not enough space.

The bulb for example: if the common constant current source switches on LED aluminum substrate, a total of more than and 30 components, including large inductance, transformer and the capacitor element, more light, more components, poor reliability. Therefore, the switching constant current source is not available.

In this case, the linear constant current power supply can be used to solve the problem.

But at the same time, Yu Hai said that the use of ordinary linear constant current source is not a viable light engine program. Although the utility model solves the problem of occupied space, the efficiency of the linear flow source is low, especially when the power is high.

Although no matter where the power supply, its heat is always to scattered into space through the radiator, but when the power supply and the lamp board together, the power consumed power will become heat directly to the lamp board, will increase the lamp board required dispersed heat, which will increase the junction temperature of high LED to reduce the life.

This also extends the light engine second technical difficulties - heat.

To 10 watt LED bulb lamp, for example, assuming that the power efficiency of 85% (linear constant current source of high voltage, low efficiency), that is to drive the LED power of 8.5 watts, the power supply itself consumes a power of 1.5 watts.

It is assumed that the luminous efficiency of LED is 30%, that is, the power of the 70% is changed into heat. Now coupled with the power of the 1.5W, it becomes a power of 7.8W, will increase the heat of 19.2. The power supply is integrated into the aluminum substrate, so that the junction temperature of the LED is increased by 15.8% (because there is a scatter to the radiator). It is assumed that the junction temperature of LED is 85 DEG C, and the junction temperature of LED will be increased to about 98.4 DEG C, which will reduce the life of LED.

In this case, only the extremely high efficiency linear constant current source can realize the optical engine. Efficient driving reduces overall heat.

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