TL494的微机开关电源设计.doc

论文
基于TL494的微机开关电源设计
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[1]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。
微机的电源通常采用脉宽调制式开关稳压电源,这种电源具有功耗小、转换效率高、工作可靠、保护完善和稳压范围宽等特点,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、单端正激和单端反激等形式。本课题介绍了一种基于PWM[2]技术的半桥式微机开关稳压电源,它是通过用双端驱动集成电路——TL494输的PWM脉冲控制主开关的导通来控制直流输出的。本文给出了微机开关稳压电源的交流输入整流滤波电路、辅助电源电路、PWM控制及驱动电路,多路直流输出电路、自动稳压控制电路的详细设计方法及设计思路,并附有详细的电路图。
关键词:IGBT,PWM,开关电源,驱动电路,整流
DESIGN OF A PUTER SWITCHING
POWER SUPPLY BASED ON TL494
ABSTRACT
With the development of switching power supply in the field puter , correspond, aviation and astronautics , instrument appearance and electrical production etc, the demand of the production are increasing as people need ,and people have brought forward higher request to aspect such as the power efficiency , bulk factor, and reliability. The switch power not only volume is small but also efficiency is height, weight makes light, which are substituting the inefficient, both stupid and serious linearity power in many aspects step by step.
With the electric power electronic technology development, especially high efficiency device of IGBT and the MOSFET rapid development, the switching power’s performance develop various and its cost is ing cheaper and cheaper, people could accept the new switching power. The information technology development also set a higher request to the power source technology, thus promoted the switching power technology development.
The puter power usually adopts pulse width modulation switching power supply. This subject introduces a kind of PWM technology based on half bridge type puter switching power supply. It is through the use of drive IC TL494 control of the pulse of PWM switch conduction to control dc output. In this paper the puter switching power supply filter circuits, auxiliary power, PWM contr