Design Of 70W LED Explosion Lamp Driver Circuit

With the development trend of green lighting and national attention for theunderground work, energy saving lamp is more and more favored. LED is a solid coldlight source, it has advantage that saving energy, environmental protection, long lifeand so on . Thus LED lighting is widely used in coal mine application field andplayed an irreplaceable role.LED have many advantages, but LED light has high requirements for current，LED luminous is determined by current which is flowing it , if the current is toostrong for a long time, it will cause LED luminous decrease, conversely , the currentis too weak ,it will cause LED brightness is not meet requirement . As the LEDluminous performance by the drive power and environmental constraints and flamesafety lamp install in bad environment places, the lamp life and safety must be better.While LED driver is an important influence factors for the lamp life , LED lamp drivepower still have many troubles that efficiency is low, power factor is too small, outputcurrent is not stability, the life is not long and so on , all these weaknesses have makea problem which limited LED lighting devices to application future more. Soresearching a stability, efficiency, power factor, waterproof , dustproof and standardLED driver design has an important practical significance.This paper introduce the topics background and research significance for highpower LED drive power , indicate the difficult points for LED drive power designing,give main technology such like active power factor correction, Flyback converter. Onthe analysis of the LED driver , designing a 70W LED power supply which is mainlyinvolves the EMI filter design, Flyback converter, active power factor correction,reliability design and so on. This paper adopts two levels of the scheme that involvepower factor correction and DC-DC converter. because the Boost power factorcorrection technique have many advantages , its control circuit is simply，the firstlevel using active power factor correction to realize the calibration, it is used toprovide stability voltage for later level ,to improve the harmonic interference ability,have a stable output voltage, The secondary level is adopted Flyback converter torealize. Limited pressure constant current feedback part adopts LM321 to attaincurrent feedback. This paper firstly introduces the development history and trend of LED, at the same time discuss the present situation of LED driver power development.Secondly analysis the Power factor correction principle, fly back converter workingtheory, the original edge control way for chip feedback and secondrary feedbackdesign. On the base of these theory，then introduces a 70W LED drive power designwith the two stage circuit . One is active power factor design which is based on theNCP1608 chip, another is Flyback convert design which is based on TOP258EN chip.Giving the detailed parameters design for two converters and concluding the debugproblems. Finally analysis the driver power supply reliability of explosion-proof LEDlamp and proposed solutions.This paper test the 70W LED lamp drive power prototype，at the same time givethe key point wave and make analysis. The test results show that driver supply canwork normally in a wide range of input voltage, test result show out character is 47V,1.5A, the PF value is 0.95, efficiency can arrive 87 percent, circuit has simpleperformance, low cost and power supply can work stably , the experimental resultsshow that the program is feasible.