节能型恒流开关电源的设计 ——毕业设计.doc

摘 要 开关电源因其高效节能引起社会各方面的重视，现已成为通用开关电源、专用开关电源及特种开关电源优选集成电路。多年来对开关电源的核心单元—控制电路实现集成化是开关电源的发展方向之一，在这过程中，更小体积，更少电磁污染，具有可靠的过电压及过电流保护电路的技术也在飞速发展，特别是在驱动LED恒流开关电源方面，发展尤其突出，因此具有很大研究价值。 白光LED是节能、环保、高效、长寿命的国际公认的下一代照明光源。随着白光LED技术的成熟，它将被更广泛低地应用到各个领域。与传统光源不同，白光LED需要专用恒流电源驱动才能使其高效持续地工作。本毕业（论文）设计的目的就是针对LED照明应用的电源。LED照明通常用多个发光二极管组成点阵光源，为使光源发光均匀则需供电电源提供恒定电流进行驱动。 在论文中，首先阐述了节能型恒流开关电源的工作原理，根据方案设计技术参数，给出了整体电路设计的理论依据；然后根据设计要求提出了整体电路的实现架构，并且阐述了整体电路工作原理和子电路的性能要求。在整个电路的设计上，主要介绍了输入整流与滤波、变压器、功率开关管、控制器、保护电路、电流电压反馈网络、输出整流续流与滤波、稳压恒流输出模块。 最后，本论文在整体电路原理分析和子电路设计的基础之上，应用Multisim仿真软件对子电路模块和整体电路进行功能仿真验证，仿真结果满足要求，进一步验证理论分析和设计的正确性，也是设计理论与实践相结合的一次有价值的尝试。 关键词： 开关电源， 恒流， LED Abstract Switching power supply is paid much attention for its high efficiency and low power consumption. Now it is popular used in general switching power supply, special-purpose switching power supply, special switching power supply. Core unit-control circuit integration of the switching power supply has been one of switching power supply development for many years. A smaller volume, the less EMI, over current and over voltage protection circuit technology has been developing in this process. Especially in the constant current LED driver switching power supply, particularly in the development and therefore have great research value. White LED has been regarded as the next generation of light source because of its power saving high efficiency long life，low pollution and low radioactivity. With the maturating of white LED technology, it will be applied in many regions. Different from the traditional sources, the need for constant current white LED drive power to continue its efficient work. The graduate (paper) is designed for the purpose of the power LED lighting applications. LED lighting is usually formed by a number of dot-matrix LED light source, in order for the uniform LED light source would provide constant current power supply to drive. In the paper, first of all on the energy-saving constant switching power supply works