本课题设计的开关电源主要是针对电力系统操作的直流电源。该系统以四个MOSFET作为功率开关器件，构成全桥式开关变换器，采用脉宽调制(PWM)技术，PWM控制信号由集成控制器UC1525A产生。从输出实时采样电压反馈信号，构成闭环系统，以控制输出电压的变化。控制电路和主电路之间通过光电耦合器进行隔离，并设计了软启动、过流保护电路和过压保护电路。
本文先介绍了开关变换器和开关电源的概念，DC-DC变换器的基本手段和分类，DC-DC变换器主回路使用的元件及其特性以及DC-DC变换器发展历程、现状和趋势；而后说明了开关电源主回路——全桥式变换器的工作原理，包括全桥式变换器的变压器设计方法；然后给出了开关电源PWM控制芯片的引脚说明和开关电源驱动电路；最后分析了磁性元件的特性，变压器，电感的设计和MOSFET开关器件的选型。
开关电源高频化是其发展的方向，高频化使开关电源小型化，并使开关电源进入更广泛的应用领域，特别是在高新技术领域的应用，推动了高新技术产品的小型化、轻便化。另外开关电源的发展与应用在节约能源、节约资源及保护环境方面都具有重要的意义。
要求准确的翻译，无语法错误，谢谢
This topic design's switching power supply is mainly aims at the electrical power system operation the direct-current power supply. This system takes the power switch component by four MOSFET, constitutes the entire bridge-type switch converter, uses the pulse-duration modulation (PWM) technology, the PWM control signal by the integrated controller UC1525A production. From the output real-time sampling voltage feedback signal, the constitution closed-loop system, controls the output voltage the change. Between the control circuit and the main circuit carries on the isolation through the electro-optical coupler, and has designed the soft start, the overflow protection circuit and the overvoltage protection electric circuit
This article introduced the first switch converter and switching power supply's concept, the DC-DC converter's essential method and the classification, the DC-DC converter main return route uses part and characteristic as well as DC-DC converter development process, present situation and tendency; Then explained the switching power supply main return route - - entire bridge-type converter's principle of work, including entire bridge-type converter's transformer design method; Then has given the switching power supply PWM control chip pin explanation and the switching power supply driving circuit; Ultimate analysis magnetic elements' characteristic, transformer, inductance design and MOSFET switch component's shaping.
The switching power supply high frequency is its development direction, high frequency causes the switching power supply miniaturization, and causes the switching power supply to enter the more widespread application domain, specially in the high technology and new technology domain's application, promoted the high-tech product miniaturization, facilely. Moreover switching power supply's development and the application are saving the energy, the nurse resources and the protection environment aspect have the vital significance
参考知识1
The issue of switching power supply design is the main power system operations against the DC power supply. The system as a power to the four MOSFET switching device, a full-bridge converter, a PWM (PWM) technology, PWM control signals generated by the integrated controller UC1525A. Real-time sampling from the output voltage feedback signal, a closed-loop system to control the output voltage changes. And the control circuit between the main circuit through Optocoupler in isolation, and to design a soft start, overcurrent protection circuits and over-voltage protection circuit.
This article first introduced the converter and the concept of switching power supply, DC-DC converters and the basic means of classification, DC-DC converters using the main circuit components and characteristics of the DC-DC converters and development process, the status and trends; then Description of the main circuit switching power supply - full-bridge converter works, including full-bridge converter transformer design and then gives a switching power supply PWM control chip and pin that drives switching power supply circuits; final analysis The characteristics of the magnetic components, transformers, inductors in the design and selection of MOSFET switches.
High-frequency switching power supply is the direction of their development, so that high-frequency switching power supply of small, and switching power supply into a wider range of applications, particularly in the application of high-tech fields, and promote the high-tech products of small, lightweight Of. Also switching power supply in the development and application of energy conservation, resource conservation and environmental protection are of great significance.