| The thesis focus on Osram 35W xenon lamp, high pressure discharge lamp. The key technology of its electronic ballast is presented based on the introduction of lamp characteristic.Flyback converter is adopted as power topology, and its leakage-inductor energy absorbing circuit is analyzed and designed. To prevent lamp from extinguishing during each bridge commutation, the output capacitance and the secondary inductance of the ignitor transformer is analyzed. Approximation equivalent model is used to analyze the influence of ignitor circuit which is composed of a voltage doubler and a transformer booster. The current auxiliary circuit is analyzed to prolong the lamp's life.Through a comparative study on thecontrol methods of the xenon electronic ballast, microcontroller-based digital-analog mixed method that consists of PIC16C781 and UBA2030T is choosen, which can successfully realize the required complex control functions. A novel constant power control strategy is adopted. Then the software flow charts of constant power control, start-up procedure control and protection control are depicted in detail.At the end of the thesis, a two-stage electronic ballast for the 35W automotive xenon lamp operating in a low frequency square waveform is designed And the design method and simulation result of main circuit are given in the thesis. |
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