24v开关电源设计说明

摘要

随着开关电源在计算机、通信、航空航天、仪器仪表及家用电器等方面的广泛应用, 人们对其需求量日益增长, 并且对电源的效率、体积、重量及可靠性等方面提出了更高的要求。开关电源以其效率高、体积小、重量轻等优势在很多方面逐步取代了效率低、又笨又重的线性电源。电力电子技术的发展，特别是大功率器件IGBT和MOSFET的迅速发展，将开关电源的工作频率提高到相当高的水平，使其具有高稳定性和高性价比等特性。开关电源技术的主要用途之一是为信息产业服务，信息技术的发展对电源技术又提出了更高的要求，从而促进了开关电源技术的发展。本次设计采用典型的正激式开关电源结构设计形式，以(RCC)作为控制核心器件，运用脉宽调制的基本原理，并采用辅助电源供电方式为其供电，有利于增大主电源的输出功率。采用场效应管作为开关器件，其导通和截止速度很快，导通损耗小，这就为开关电源的高效性提供保障。同时，电路中辅以过压过流保护电路，为系统的安全工作提供保障，本电路注意改善负载调整率,降低了电磁串扰，达到绿色环保的目的。输出电压可调，使其可适用于不同场合。

关键词高频变压器；场效应管；正激式变换器；脉宽调制

Abstract

With the wide application of switching power supply in the computer, communications, aerospace, instrumentation and electrical appliances and so on, the growing demand for its people, and has put forward higher requirements for power efficiency, volume, weight and reliability.Switching power supply with its high efficiency, small size, light weight and other advantages in many respects gradually replaced the linear power supply, low efficiency, heavy and bulky. The development of power electronic technology, especially the rapid development of the high-power IGBT devices and MOSFET, increasing the working frequency of the switching power supply to a very high level, which has high stability and high performance characteristics. One of the main purposes of switching power supply technology is serves for the information industries, the development of information technology on power technology and put forward higher requirements, so as to promote the development of switch power supply. This design is excited by the switching power supply design of the structure of typical, with (RCC) as the core control device, using the basic principle of pulse width modulation, and auxiliary power supply by way of its power, is conducive to the output power increase of the main power supply. FET used as a switching device, the conducting and closing fast, conduction loss is small, which guarantee the high efficiency switching power supply. At the same time, the circuit with over-voltage and over-current protection circuit, providing security for the safe operation of system, the attention of the circuit to improve load regulation, reducing the electromagnetic crosstalk, to achieve the purpose of environmental protection. The output voltage is adjustable, so that it can be suitable for different occasions

Keywords:High frequency transformer; MOSFET; forward converter; pulse

width modulation

目录

1 诸论 (1)

1.1 开关电源的基本概念 (1)

1.2 开关电源的发展 (1)

1.2.1 开关电源的发展史 (2)

2 电路的比较方案 (3)

2.1 方案一、反激式变换器 (3)

2.2 方案二、半桥变换器 (3)

2.3 方案三、正激式变换器 (4)

3 各部分电路工作原理 (6)

3.1 单相桥式整流电路 (6)

3.1.2 参数计算 (7)

3.2 功率变换电路 (8)

3.2.1 MOS管工作原理 (8)

3.3.1肖特基二极管 (12)

3.4 高频变压器的设计 (13)

3.4.1 变压器的设计 (13)

3.4.2 控制电路工作原理 (16)

3.5 L431的功能 (16)

3.6 短路保护电路 (18)

3.6.1 输入保护器件 (18)

3.6.2输入瞬间电压保护 (18)

4、电路的总结构 (20)

附录 (27)

附录一 (27)

附录二 (29)

参考文献 (30)

致 (31)