Based On HT46R064Control Of The Level Three Type Constant Power Electronic Ballast For Metal Halide Lamp

Metal halide lamp has been called the most ideal one light source, because it has a highluminous efficiency, good color, long life and other characteristics, metal halide lampsbecause of the negative resistance characteristic, started work and must have the support ofballast. The traditional ballast is generally the inductance ballast, the electronic ballast of themost is. Due to the electronic ballast than inductance ballast has a lot of advantages;especially the use of single-chip control circuit of electronic ballast, the simplification of thestructure, performance is more superior, which is the content of this paper.This study is based on He Tai HT46R064MCU control three level type constant powerelectronic ballast for metal halide lamp, a detailed analysis of its control strategy and designthe corresponding software and hardware control circuit. The main contents include:(1) The input part of the electromagnetic interference resistance. Electronic ballast withexternal power grid connection part, external power to the electronic ballast has theinterference effect. The input part of the circuit design of EMI interference resistance circuitand a rectification filter circuit, can effectively improve the EMC effect.(2) The power factor correction circuit. In order to reduce the AC-DC AC circuit inputharmonic current caused by noise and harmonics in electric network caused by" pollution", inorder to ensure the quality of power supply, to improve power grid reliability; at the sametime in order to improve the input power factor, has reached the energy-saving effect must usethe power factor correcting circuit. This paper analyzes the active power factor correctiontechnique of electronic ballast, and to design the AP1661chip as a power factor correctioncircuit diagram, the parameter of the circuit is given and its calculation method.(3) DC/DC BUCK step-down circuit. APFC circuit after adjustment are relatively highDC voltage, using the PMW DC/DC BUCK step-down circuit, needed to obtain approximateconstant current power supply. This design uses peak current control chip IMP3845to realizethe PWM drive control.(4) Full bridge inverter circuit and an ignition circuit. This paper introduces the design ofDC/AC full bridge inverter circuit, the bridge driver IC IR2453, metal halide lamp workprovide a low frequency square wave current, which can effectively avoid the metal halidelamp at high frequency power driven to work often acoustic resonance phenomenon, througha step-up transformer secondary side to generate high amounts to4000volts of high voltagepulse start of metal halide lamp. (5) Trigger and protection circuit. This paper introduces the design of HT46R064basedelectronic ballast controlled by the trigger and the protection circuit, the metal halide lampopen circuit or short circuit, the voltage too high or too high temperature, can effectivelyprotect the electronic ballast.The results show, the design of the electronic ballast power factor of0.996, totalharmonic current of6.8%, the machine efficiency can reach88%, it is proved that the designof the electronic ballast has the advantages of high efficiency, safety, reliability, energy saving,low cost and other advantages, has a good market foreground.