Design And Analysis Of Driving Power For LED Headlamp

LED(Light Emitting Diode)are more widely applied in the field of lighting with the lack of global energy supplement and serious environmental pollution.It was identified as the most promising and largest market in the next 10 years,will gradually take place of incandescent,fluorescent and compact and energy-saving fluorescent lamps,become the next generation of mainstream new lighting source.LED is a new type of green light source,and it has so much advantages,such as: high luminous efficiency,high reliability,long service life,less power consumption,a varity of irradiance color,small dimension,easy-controlled,green environmental protection and operate security and so on.It involved core fields include LED display,LED traffic lights,LED interior lighting,architectural lighting,street lamps,lighting plants and automobile lamps etc.But now the current market LED headlight power supply price is too high,performance is not stable,the input voltage range is too narrow,does not meet the EMC(electromagnetic compatibility)design standards and other issues restricted the promotion of LED automobile lamp,aiming at the above problems,this paper selects the PT4121 chip LED lamp with high performance,to design the peripheral circuit complete,suitable for application of LED drive circuit.The main contents are as follows:(1)The use of PT7201 design SM-3018 LED headlights that a wide input voltage was within the scope of 12-48 V and the electrical efficiency of more than 88% and the rated power was 18 W,and the design electric circuit accomplished PCB’s placement and routing by the using of Altium designer software.According to samples tested and analyzed,the lamp has a high optical efficiency and stability characteristic,and the product has been put into use in the market.(2)Using analog dimming technology to control the potential of PT4121 DIM pin in the SM-3018 circuit design,has achieved a design electric circuit of SM-5045 A and SM-5045 B automobile headlamp that a set of drivers has control over light intensity,and the product has been put into use in the market.mass production.The product in the12-48 V input voltage range,can be strong and weak light switch,and can ensure the consistency of light type.The test results show that the lamp has high stability and opticalcoherence,and has high performance price ratio in the design of dimming circuit.(3)On the basis of the SM-3018 driving scheme we did the filter design for input section,completed a design electric circuit of SM-6056 automobile headlamp which complies with the electromagnetic compatibility EMC standard,and the product has been put into use in the market.The effect of the product is more than 100LM/W,the sample test verifies the correctness of the theoretical analysis and the reliability of the scheme.