Resecrch And Improvement Of The Electromagnetic Noise Of The LED Drive Circuit

LED lighting as one of the four major industries of the current hot, and itsdevelopment and its rapid LED driver technology has matured. Electromagneticnoise, the LED drive power that exist within the constraints of the root causes ofthe widely used light bulbs. Therefore. LED driver power supply noise pollutionis becoming increasingly important.Compared with the traditional linear power supplies, switching powersupply with high efficiency, small size, light weight advantage. However, due tothe switching power supply at high frequency, which produces a transient pulsecontains the emission of electromagnetic interference (EMI), high-frequencyharmonics. EMI not only affects the switching power supply, electromagneticcompatibility (EMC) performance, but also affect the cost of switching powersupply. This study focused on several EMI in the form of a typical switchingpower supply, namely, conduction disturbance (including differential mode andcommon mode noise), and radiation interference.Start from the basic principles of the LED drive power, focus on the LED driverpower supply sources of noise pollution, and to address the problem do thefollowing work:First introduced the LED drivers drive power facing the problem ofelectromagnetic compatibility. Including the basic components and themodulation mode switching power supply source of electromagnetic noise of theLED bulbs and its harmonic source of analysis and discussion of relevantstandards and switching power supply LED lights in the ElectromagneticCompatibility electromagnetic harassment inhibition.Followed by experiment and simulation tools to do the research and analysis onthe characteristics of the noise signal. For the problem of a LED driver powersupply systems encountered during normal working electromagnetic disturbancetest and diagnostics.To rectify the last power line filtering technology of the equipment, conduction through the LED drive power harassment test and radiationharassment test objectives to improve the LED driver power supply noisepollution problems, the same frequency conducted disturbances values reducedby about3dB, the same frequency conducted disturbances values decrease byabout2dB improved anti-jamming capability of the LED bulbs, and to meetelectromagnetic compatibility requirements. The entire article at the end of thearticle summary outlines the main research work. Need to be studied in thefuture directionPCB electromagnetic compatibility design and rectification technology, andspecific corrective projects and the actual transformation of design examples, theas given in the LED drive power system electromagnetic compatibility researchconclusions and the specific design of experiments for electromagneticcompatibility design staff some frame of reference.