基于sg3525的半桥式开关电源变换器.doc

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**工业大学本科毕业设计说明书
摘 要
电力电子及开关电源技术因应用需求不断向前开展，新技术的出现又会使许多应用产品更新换代，还会开拓更多更新的应用领域。要求电子元件体积更小，耗能更低。开关电源作为电子设备中不可或缺的组成局部也在不断的改进，高频化、高效率、高可靠、低耗、低噪声、抗干扰和模块化等，成了开关电源的开展方向，这也标志着这些技术将不断地开展而变得越来越成熟和稳定，同时实现高效率用电和高品质用电的相互结合。
脉宽调制器SG3525具有欠压锁定、系统故障关闭、软起动、延时PWM驱动等功能，因而得到广泛应用。
本设计介绍了一种基于SG3525的半桥式开关电源变换器，对其各电路工作原理进展了分析，并设计了过流保护电路。为了提高效率，辅助电源采用了UC3843为主控芯片的反激变换器。为了减低输入电磁干扰，输入端设置了EMI滤波电路。对各参数进展了计算，通过实物制作与调试证明了方案的可行性。
该电源构造简单，思路清晰，运行稳定性好，有效降低了本钱。
关键词半桥SG3525过流保护
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Abstract
Technology for power electronics and switching power supply is going aheadcontinuously in practice．The emergence of new technology will make replacement inmany application products as well as open up more and more new fields．At the same timeponents are required to have the smaller volume and lower losses，as an importantparts of electronic devices power supply is getting some improvements，for high-frequency，for high efficiency，for high reliability，for low losses，for small noise，for anti-interference，for module and so on．These are being a development direction for power supply，which show that these technologies will bee more mature and stable，it will achieve thebinability between high-efficiency and high quality to use electric energy.
The pulse width modulator SG3525 has been used in various areas for its functions such as locking for the lack of pressure, closing system fault, soft starting, delaying PWM drive and so on.
**工业大学本科毕业设计说明书
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