摘要: 随着电子技术不断的发展、数字电路应用领域的扩展，人们对数控恒定电流元件的需求越来越大。本文对基于单片机控制的数控恒流源进行研究设计。由单片机程控设定数字信号，通过D/A转换器（AD5320）输出模拟量和控制输出功率管的基极，来实现输出不同大小的稳定电流。单片机系统还需对恒流源进行实时监控，输出电流经过电流/电压转换后，通过A/D转换芯片（MAX1241），把模拟量转化为数字量，再经单片机对信号进行处理。通过数字量形式的反馈环节，使输出电流更加稳定，这样构成稳定的压控电流源。最终利用Proteus进行仿真实现。56783

毕业论文关键词：电压控制,AT89S52,数控电源

ABSTRACT: With the development of electronic technology and digital circuit applications, There is an increasing demand of numerical control constant current device.In this paper, the numerical control constant current source based on single chip microcomputer is studied 、designed、 and  simulated by Proteus software. The system set up the digital signal by single chip microcomputer,  analog output through D/A converter (AD5320) and control the output power tube base, to achieve different stable output current. Single chip microcomputer system still need to real-time monitoring of constant current source. The system get the output current through the current / voltage conversion.  The analog quantity  become into the digital,dealing with single chip microcomputer,by the A/D conversion chip (MAX1241). The output current is more stable through the feedback digital form.Finally, Such a stable voltage controlled current source is implemented using Proteus simulation.

KeyWords：Voltage-controlled,AT89S52,Numerical controlled source

目  录

1　前言 6

2.　设计任务 6

2.1　设计要求 6

2.2　设计思路与理论分析 6

2.3　系统介绍 7

3　硬件设计 7

3.1　供电模块 7

3.1.1　各种稳压电源的设计 8

3.1.2　负载电源模块 9

3.2　恒流源模块 9

3.3　单片机模块 10

3.3.1　AT89S52芯片介绍 10

3.3.2　AT89S52硬件电路设计 11

3.4　键盘模块 12

3.5　液晶显示模块 13

3.5.1　显示器简介 13

3.5.2　LCD硬件显示电路 14

3.6　A/D模块 14

3.6.1　MAX1241芯片简介 15

3.6.2　A/D模块电路 16

3.7　D/A模块 16

3.8　存储模块 17

3.8.1　芯片24C02C 17

3.8.2　存储模块电路 17

4　软件设计 18

4.1　C语言简介 18

4.2　系统软件设计 18

4.2.1　主程序设计 18

4.2.2　中断程序设计 19

5　软件仿真与调试，