[[alternative]]Design and Implementation of Xenon Lamp Electronic Ballast Based on Microcontroller

碩士電機工程學系[[abstract]]近年來節能問題已成為世界主流，其中照明用電也是很重要的一環，所以高照度、低功耗的氙燈，逐漸受到重視。目前大多數的氙燈電子式安定器皆使用全橋式反流器，由於此種電路架構除控制複雜外，其元件數量亦多；而傳統半橋式反流器則有分壓不均、中性點偏移等問題，因此為了克服上述的缺點，本文提出以直流12 V為電源，利用雙輸出繞組返馳式轉換器(Flyback converter)作為主要電源轉換電路，提供後級高壓點火電源及兩組穩定的直流電源，後級則使用半橋式反流器(Half-Bridge Inverter)提供低頻交流方波電源至燈管，此種方式可大幅降低元件數量及避開音頻共振問題。此外，為了簡化控制電路的複雜性，使用微控制器作為核心，對燈管電壓、燈管電流及電池電壓進行回授控制，實現定功率控制、點火高壓保護、電池保護及LCD顯示等功能。最後本文實際研製一12 V/35 W之氙燈電子式安定器，並分別以模擬及實驗驗證電路的可行性及穩定性，由實驗結果顯示當氙燈進入穩態後，其整體系統效率可達85 %。[[abstract]]In recent years, the issue of energy saving has become global mainstream including illumination electricity. Therefore, the xenon lamp with high-illumination and low-power is getting important. A full-bridge inverter is mostly applied in electronic ballasts of xenon lamp; nevertheless, there are some demerits within this frame such as complicated controlling and more components required; while, traditional half-bridge inverters have problems of uneven partial pressure and the neutral point voltage offset. In order to overcome the shortcomings mentioned above, this paper presents the xenon lamp electronic ballast with DC 12 V source as input, and uses the flyback converter with two output coils as the main power circuit which supplies a high voltage and stable power for second series circuit. The second series circuit is a half-bridge inverter supplying xenon lamp with low frequency square wave of AC power to reduce components and avoid acoustic resonance phenomena. To simplify the control of circuit, the microcontroller is used as the base to feedback the lamp voltage, lamp current and battery voltage which achieved constant power control, high voltage protection, battery protection and LCD display. Eventually, this paper actually implements a 12 V/35 W electronic ballast of xenon lamp. Through the simulations and experiments, we have verified the feasibility and stability of the ballast and proved that the system efficiency could reach up to 85 % when the xenon lamp is in steady-state