Digital High-power Exposure Machine Light Source Driving Circuit

In the modern information times, the electronic products which always based on printed circuit board (PCB) account for approximately 80% of the global market. The circuit line image map conversion between backplane and PCB using optical exposure is important in manufacturing PCB. And the exposure light source has a direct impact on the quality and yield of PCB product. With the high luminous efficacy, high luminance, and long lifetime, now metal halide lamp (MHL) becomes the perfect choice of exposure light source. The performance and stability of the exposure light source largely depend on its drive circuit's performance and stability. Therefore, researches on the drive circuit of high-power exposure light source has a strong theoretical and practical significance.Based on the introduction to the development and classification of traditional electric light source, the development process of ballast is reviewed, the basic working principle of ballast as well as the characteristics of metal halide lamp electronic ballast are analyzed. The volt-ampere characteristics of gas discharge is deeply researched, after which the working principle and start-up characteristics of MHL are studied. Introduction to different controlling strategies for different time segment is also given. On the base of previous analysis, the power factor correction, the basic topology options, the controlling strategies, the methods of avoiding acoustic resonance and the ignition circuits modules of high power exposure machine light source drive circuits system are discussed and designed in this dissertation.In a comprehensive analysis of high-power exposure machine light source drive circuit system, a two-level electronic ballast of MHL based on Infineon 16-bit XC164CM is designed to realize digital control of an 8 kW high-power exposure machine light source drive circuit. Experiments show that the system is correct and feasible.