DC-DC电源设计_精品.doc

摘 要 开关稳压电源具有外围电路简单、电源效率高等优点,在各种电子产品中得到了广泛的应用，而DC-DC变换器则是开关稳压电源的重要分支。本系统是DC-DC升压式可调的开关稳压电源，它由时基电路NE555构成一个低频振荡器，输出周期性脉冲控制开关元件的通断，并以此控制电感上磁能和电能的互相转换，在电感两端产生一自感应电压，此自感电压与电源电压串联起来一起向负载提供电流，此电路输出的电压大于电源电压，为一升压式开关电源。通过调节可调电阻 ，可以改变NE555的振荡周期，同时也改变了输出波形的占空比，从而改变电感的储能大小，最终改变了输出电压值 。在主电路后面为了方便直观的看出电路的输出结果，因此另外设计了由数模转换ADC0804控制的单片机显示电路。 关键词：DC-DC变换器，NE555，数模转换ADC0804 Abstract switch-regulated power supply,which has many advantages such as simplicity of its peripheral circuit and high efficiency of its power supply,has been widely applied in all kinds of electronic products,and Dc-Dc changer/converter is its main branch .This system is a Dc-Dc booster-adjustable switch-regulated power supply,in which the time-base circuit NE555 composes the low-prequency??oscillator and output period ic impulse to control the cut-in and cut-off of the switching elements,and by this control the exchanging between magnetic and eletrical energy on the indultion .on the ends of induction comes into being self-induction voltage ,which is concatenated with supply voltage ,and they together provide the load with electricity .The voltage output through the circuit is bigger than the supply voltage .Its a booster switch power supply .By adjusting , it is posssible to adjust the resistance and?change the oscillating period of NE555 acessible at the same time ,change the duty ratio of ?the output wave from .As a result, change the stored energy of induction and to make it convient and intuitionistic to read the output result of the circui,t .Inaddition MCU controlled by a digital-analog conversion ADCO804 is designed? behind the main circuit to show the circuit . Keywords:DC-DC converter,NE555, digital-analog conversion ADC0804目 录 第1章　引言 1 第2章 升压变换器工作原理 3 2.1 概述 3 2.2 升压变换器的工作原理 3 第3章 升压变换器电路设计 6 3.1主电路设计换器 6 3.1.1 Boost变的能量传输分析 6 3.1.2 主电路参数设计 15 3.2 控制电路 16 3.2.1 555震荡电路 16 3.2.2 本系统的控制电路 17 第4章 显示电路设计 18 4.1单片机电路 18 4.1.1 AT89S52简介 18 4.1.2 震荡电路 20 4.1.3 四位八段共阳数码管 21 4.2 模数转换ADC0804的应用 22 4.3 分压电