Design Of High Power Factor Quasi-Resonant LED Driver

In order to cope with global warming and energy crisis, all the countries in the worldattach great importance to the development of energy-saving and environmental products.Lighting is the main way to consume power resources, the use of energy saving LED lamps toreplace traditional lighting, is to represent the general trend. The quality of LED drive is veryimportant to the LED lamp. In response to the national green lighting policy and promote themarket popularity, research on the LED driving power supply characteristics and keytechnology, has certain practical significance.Switching power supply has the advantages of small volume and light weight, is widelyused in LED drive. This paper is aiming at the characteristics of high power LED lighting,two popular techniques of switching power is studied: active power factor correctiontechnology and soft switch technology, through comparative and analysis,found two-stagepower factor correction design scheme is suitable for LED driver.Compared the characteristics of commonly used power factor correction control method,choose BCM peak current control active power factor correction circuit as a pre-stage circuit.Studied how to design inductors of BCM peak current control active power factor correctioncircuit. The control circuit and the feedback network is designed with the TDA4863chip.Analysis the characteristics of commonly isolated topology, choose flyback converter circuitto design back-end circuit. Studied the implementation process and working principle ofquasi-resonant flyback circuit, OB2203chip is used to design the back-end Quasi-resonantflyback circuit. The constant current circuit and EMI filter circuit is studied and designed.Finally a high power factor, high efficiency100watt LED driver is produced. Achievethe output voltage of active power factor correction circuit variable and the output current canbe adjusted. The efficiency with low input voltage is improved and the matching ability of thedriver is enhanced. The waveform power factor and efficiency were tested, the results areideal, achieved the expected target.