A Research Into LED Driving Circuits

With the development of semiconductor lighting, LED is already a research hotspot, and is showing tremendous potential and bright prospect. LED is well applied to general lighting, landscape lighting, auto lighting, house decoration, information display, portable electronic devises and display back-lighting. Due to the high cost, LEDs don't share a popular market, but the performance of LEDs is much better than the other light sources. With the advancement of technology, the cost of LEDs will eventually be acceptable to most users, and then LEDs will have great market competitive power. Now huge manpower and financial resources are invested to research LED, and the focus are enhancing the performance and reducing the cost.The electrical and optical characteristics are introduced at first. Then, a LED miner's lamp and a high power constant current system for driving LEDs are designed, using the technology of electronics and switching power supply. The latest HB-LED, the specialized chip for LED driving and the chip for Li-Ion charging regulation are employed to design the LED miner's lamp, and the electrical and optical performance of the lamp are tested. It can be seen that the miner's lamp based on LED is better in lighting, working for longer time, of longer lifetime, smaller in size, and maintenance free, which holds great advantage compared to traditional miner's lamp. It is a revolutionary product in the coal mine industry.A high power LED driving system is designed mainly employing the technology of switching power supply. In the system, low power LEDs are used to form an LED array and the driving circuits is based on the Cuk Topology. The system is novel in structure, adaptive and giving considerations to both cost and reliability. The design procedure is stated in detail, and the system is verified by experiments.At last, the proposals to improve the miner's lamp and the LED driving system are given, and the development of LED and its driving technology is expected.