数字电压表设计毕业设计论文

摘要

数字电压表（Digital V oltmeter）简称DVM，它是采用数字化测量技术，把连续的模拟量（交直流输入电压）转换成不连续、离散的数字形式并加以显示的仪表。与此同时，由DVM扩展而成的各种通用及专用数字仪器仪表，也把电量及非电量测量技术提高到崭新水平。本章重点介绍单片A/D 转换器以及由它们构成的基于单片机的数字电压表的工作原目前，由各种单片A/D 转换器构成的数字电压表，已被广泛用于电子及电工测量、工业自动化仪表、自动测试系统等智能化测量领域，示出强大的生命力理。本设计是基于AT89C51单片机的一种电压测量电路,该电路A/D 转换采用ADC0804。测量范围为直流或交流电压有效值0～200V ，并在四位LED数码管上显示。测量最小分辨率为0.019V，本课题主要由A/D转换电路、数据处理及显示控制等三个模块组成。控制系统采用AT89C51单片机，A/D转换采用ADC0804。

关键词：DVM,A/D转换,AT89C51,ADC0804

Abstract

Digital voltmeter (Digital V oltmeter) referred to as DVM, it is the use of digital measuring technology, the continuous analog (DC input voltage) into a non continuous, discrete digital form and the instrument display. At the same time, extended from DVM various general and special digital instrumentation and become, to improve power and non power measurement technology to a new level. This chapter focuses on the monolithic A/D converter and composed by them based on single chip microcomputer digital voltage meter works at present, digital voltage meter is composed of various monolithic A/D converter, which has been widely used in electronic and electrical measurement, industrial automation instrument, automatic test system of intelligent measurement field, showing strong vitality of science. The design is a voltage measuring circuit based on AT89C51 single chip microcomputer, the circuit of A/D conversion using ADC0804. The measuring range of AC or DC voltage effective value was 0 ～200V, and in the four LED digital tube display. Measuring the minimum resolution of 0.019V, this thesis mainly consists of A/D conversion circuit, data and display of three modules control and processing. Control system adopts AT89C51 single-chip, A/D conversion using ADC0804.

Keywords : DVM, A / D conversion , AT89C51, ADC0804

目录

1绪论 (1)

1.1数字电压表的发展综述 (1)

1.2 国内外研究现状 (2)

1.3课题的任务及意义 (2)

1.3.1课题的任务 (2)

1.3.2课题的意义 (2)

1.4毕业设计内容 (3)

1.4.1毕业设计主要工作 (3)

1.4.2毕业设计论文构架 (3)

2系统设计 (4)

3各模块功能详述 (6)

3.1输入电路部分 (6)

3.1.1输入衰减电路 (6)

3.1.2量程选择 (7)

3.2保护电路 (7)

3.2.1继电器 (7)

3.2.2 继电器电路图 (9)

3.2.3 二极管的选择 (11)

3.2.4 继电器的选择 (11)

3.2.5 声光报警模块 (12)

3.3真有效值转换电路 (12)

3.3.1真有效值转换的原理 (13)

3.3.2真有效值转换器AD736应用电路 (15)

3.4A/D转换电路 (16)

3.5信号调理电路设计 (19)

4芯片介绍 (20)

4.1.1AD736各管脚功能 (20)

4.1.2AD736工作原理 (21)

4.1.1典型应用电路 (23)

4.1.2注意事项 (25)

4.2 AT89C51 概述： (25)

4.2.1简单概述 (25)

4.2.2主要功能特性 (25)

4.2.3 AT89C51的引脚介绍 (26)

4.3 ADC0804的简介 (29)

4.3.1 ADC0804的逻辑结构 (29)

4.3.2 ADC0804的引脚 (30)

4.3.3 ADC0804应用说明 (31)

5数字电压表的软件设计 (32)

5.1程序设计 (32)

5.2软件测试 (33)

结论 (34)

致谢 (35)

附录 (36)

附录一：原理图 (36)

附录二：主要程序 (37)

参考文献 (53)