Design Of 120W LED Driver

With the costs of energy rising,much more stringent global energy laws promulgated andimplementated and high brightness LED luminous efficiency inproved.LED lighting becomes theideal substitute products of the incandescent and fluorescent lamp.Due to the advantages of higheffieiency,longlife,Pollution-free and safety, white LED beeomes popular in the filed of generalillumination.LED driver have effect on LED Shine effect, efficiency and stability of themachine,LED technology change rapidly, the LED driver have become the study hotspot.In this paper,a 120W LED driver is designed according to the practical requirement in thelighting area. Through the comparison of different schemes, I finally determined to usePFC+DC-DC two level scheme. First of all, The power factor correction (PFC)technology isintroduced，three operating modes of the PFC have been detailed analyzed, introduced the basicprinciples of the critical conduction mode(CRM)PFC, Determined using the Boost PFC circuitworking in critical conduction mode.And then giving the key parameters of the main circuit andthe detailed designing of control circuit based on L6562.Secondly, the traditional single-endedforward converter is introduced briefly, discussed several different reset methods，presented theprinciples of the active-clamp forward converter,completed the calculation of the circuitcomponents parameters.Future more,analyzed key technology of main circuit and put forwardimprove measure.Later,in response to the existence problem of the active clamped forwardconverter,put forward two-switch forward topology structure, completed circuitdesigning,Finally,introduced the driver’s electromagnetic compatibility and reliability problems,the factors leading to EMI (Electro Magnetic Interruption)and suppression measures for EMI areanalyzed, also focused on the EMI filter design principle and design principles.In order to makethe noise reduction effect better, this paper gave a two level hybrid EMI filter circuit, and thespecific circuit structure.is provide.Adopting the proposed seheme,a 120W LED driver prototype is designed.The prototype isbuilt and tested,and experimental result verify the effectiveness and feasibility of the proposedapproach.