With the continuous development of LED technology, promoted the white LED available, lighting industry began the green lighting times. Because LED less energy consumption, low heat radiation, high luminous efficiency, energy saving, environmental protection, is an economic, safe new lighting device, therefore, accelerate a technology to study and improve the luminous efficiency has become the primary problem. High power LED lighting industry should become the main body, wherein the safe, efficient drive research is to promote the application of high power LED key.

High power LED job characteristics

LED is a new type of semiconductor solid cold light source, it is one kind can be converted into electric energy visible light photoelectric device. In general, large power LED power at least above 1W, currently more common 1W,3W,5W,8W and 10W; known as the" green light" LED, is facing the big electric current (300mA ~ 1.4A ), high efficiency (60 ~ 120lm / W ), brightness adjustable direction.

(1) volt-ampere characteristic

High power LED is a low voltage, high current drive, when the LED voltage change is very small, current big changes. When the forward voltage exceeds a certain threshold, what say normally namely turn-on voltage, is approximately proportional to VF, IF.

(2) optical properties

According to LED light-emitting principle, LED brightness with LED current positive change. Control of large power LED light brightness, essence is to control its output luminous flux.

(3) the temperature

LED forward current size also varies with temperature. Once the environment temperature exceeds a certain value, the white light LED allow forward electrical