半桥式开关电源设计

半桥式开关电源设计

摘要

随着电子技术的高速发展,电子系统的应用领域越来越广,电子设备的种类也越来越多,电子设备与我们的工作、生活的关系日益密切。近年来,随着功率电子器件(如IGBT、MOSFET)、PWM技术以及电源理论的快速发展,新一代的电源电路开始逐步取代传统的电源电路。该电源电路具有体积小，控制灵活方便，输出特性好、纹波小、负载调整率高等显著优点。

由于开关电源中的功率调整管工作在开关状态，具有功耗小、效率高、稳压范围宽、温升低、体积小等突出优点，因此在通信设备、数控装置、仪器仪表、视频音响、家用电器等电子电路中得到广泛应用。开关电源的高频变换电路形式很多, 常用的变换电路有推挽、全桥、半桥、单端正激式和单端反激式等形式。本论文采用双端驱动集成电路——TL494输的PWM脉冲控制器设计音响设备供电电源，利用BJT管作为开关管，可以提高电源变压器的工作效率，有利于抑制脉冲干扰，同时还可以减小电源变压器的体积。

关键词：TL494，PWM，半桥式电路，开关电源

Design of Half Bridge Switching Power Supply

ABSTRACT

With the rapid development of electronic technology, electronic systems, more and more extensive applications, the types of electronic equipment, more and more electronic equipment and people work and live closer and closer. In recent years, with the power electronic devices (such as IGBT, MOSFET), PWM switching power supply technology and development of the theory, a new generation of power began to gradually replace the traditional power supply circuits. The circuit is small, flexible to control the output characteristics of a good, ripple, load adjustment rate and so on.

Switching power supply in the power adjustment control work in the off state, with low power consumption, high efficiency, wide voltage range, low temperature rise, and other outstanding advantages of small size, the communication equipment, CNC equipment, Instrumentation, video audio, home appliances so widely used in electronic circuits. High frequency converter switching power supply so many forms of commonly used with push-pull converter, full bridge, half bridge, single-ended forward and the form of single-ended flyback. In this thesis, two-side driver IC - TL494 PWM pulse output of the controller design car audio power supply in use as a switch MOSFET, can improve the efficiency of the power transformer, is conducive to impulse noise suppression, but also can reduce the size of the power transformer.

KEY WORDS:TL494, PWM, Half bridge circuit, Switching power

目录

前言 (1)

第1章开关电源基础技术 (2)

1.1 开关电源概述 (2)

1.1.1 开关电源的工作原理 (2)

1.1.2 开关电源的构成 (3)

1.1.3 开关电源的特点 (4)

1.2 开关电源典型结构 (4)

1.2.1 串联开关电源结构 (4)

1.2.2并联开关电源结构 (5)

1.2.3 正激式结构 (6)

1.2.4 反激式结构 (7)

1.2.5 半桥型结构 (8)

1.2.6 全桥型结构 (9)

1.3 开关电源的技术指标 (10)

第2章半桥变换电路 (12)

2.1 半桥变换电路工作原理 (12)

2.2 半桥变换电路的应用 (13)

2.3 半桥变换电路中应注意的问题 (14)

2.3.1 偏磁问题 (15)

2.3.2 用作桥臂的两个电容选用问题 (15)

2.3.3直通问题 (16)

2.3.4 半桥电路的驱动问题 (17)

2.4 双极结型晶体管 (17)

2.4.1结构和定义 (17)

2.4.2 三极管的特性曲线 (19)

第3章脉宽调制芯片TL494应用分析 (23)

3.1 TL494管脚图 (23)

3.2 TL494内部电路介绍 (23)