简易数字毫伏表的设计(完整论文)

目录

摘要 ................................................................. I Abstract ............................................ 错误!未定义书签。第一章引言 . (1)

第二章系统设计思想 (2)

2.1测量方案 (2)

2.2 输出部分中各模块的方案选择 (2)

2.3 最终整体方案设计 (2)

2.4 总体设计方案 (3)

第三章系统的硬件设计 (5)

3.1 系统硬件的主要组成部分与理论分析计算 (5)

3.1.1系统硬件部分 (5)

3.1.2理论分析与公式计算 (5)

3.2 系统各模块单元的理论分析与实际电路设计 (6)

3.2.1测量部分 (6)

3.2.2输出部分 (9)

3.2.3毫伏表的基本电路部分 (14)

3.2.4稳压电源部分电路设计 (14)

第四章系统的软件设计 (16)

4.1主流程图 (16)

4.2软件子流程图 (17)

4.2.1测量部分 (17)

4.2.2输出部分软件流程图 (18)

第五章调试（系统测试）过程 (19)

5.1测试仪器与设备 (19)

5.2 测试过程 (19)

5.2.1分模块调试： (19)

5.2.2整机系统调试： (19)

5.3结果分析 (19)

总结 (21)

结束语 .............................................. 错误!未定义书签。参考文献 (23)

简易数字交流毫伏表设计

摘要

本系统分电压测量和信号产生输出两大部分，电压测量部分以模拟电路为主，配合放大模块、A/D转化模块、显示模块；通过凌阳单片机进行数据处理，在误差允许范围内显示测量电压值。信号产生以直接数字式频率合成器(Direct Digital Frequency Synthesis,简称DDS或DDFS)为核心，经过AT89S52对DDS芯片内部进行控制，使之输出标准正弦波形，利用编程实现频率预置、步进，达到电压输出频率的可调节步进。通过调试与测量完成了题目的基本部分和全部发挥部分的要求并有自己的创新。

此系统以FPGA为核心，辅以必要的外围电路（包括信号调理、AD转换、DA 转换、输入输出和电源模块），采用模块化的设计理念，利用VHDL语言进行编程，具有良好的扩展性和移植性。本系统具有交流电压测量和交流电压输出两大功能。交流电压测量时，将外部输入电压信号经信号调理模块调节到AD电路输入范围，经AD转换后送入FPGA核心模块计算电压的有效值，实现毫伏表的功能，并将结果在LCD显示；交流电压输出时，利用FPGA 的高速数据并行处理的能力，根据DDS原理，经DA输出稳定的频率可调的正弦波电压。经测试，交流电压测量的误差控制在±5%以内，较好地实现了题目的基本要求和发挥要求，同时交流信号输出的频率高达10MHz。

本文是简易数字交流毫伏表的一个新型设计方法的尝试。也符合了利用单片机实现队数据进行较为精确测量的新趋势。

关键词：AT89S52单片机,毫伏表，频率合成器

Design of simple digital communication millivoltmeter

ABSTRACT

This system voltage measurement and signal output of two parts, the voltage measurements of analog amplifier module, cooperate, A/D conversion module, display module, Through the sunplus microcontroller, within the permitted error display measuring voltage. With Digital signals directly to the Digital Frequency synthesizer (as some bio-synthesis, referred to as DDFS) as the core of DDS or, on DDS chip inside AT89S52 control, using standard output waveform, programming, preset, step Frequency voltage output reached Frequency adjustable step. Through measuring and testing the basic topic completed and all play a part of the requirements and have their own innovation.

This system works based on the FPGA with some outer circuits, which include signal processing, A/D converter, D/A convention, input/output and source modules. This system is designed by the principle of module and VHDL program. So it has the advantages of expansibility and replantation. This system has the functions of measuring and supplying alternate current. When the outer input signal is measured, it is send to the A/D circuit through the signal processing module. Then through the A/D converter, the signal is send to the core of the FPGA module to calculate the virtual value of the voltage. Then the function of milli-voltage meter is realized and the result can be displayed on the LCD. When outputting the source, with the help of the FPGA's parallel processing ability and the principle of DDS, it can output stable frequency-adjustable sine wave voltage. Through the measurement, the error of the result is in the range of ±5%.So it realizes the basic requirement and the superior requirement well. And the frequency of the sine wave voltage is up to 10 MHz.

This simple digital communication is a new design of millivolt table method. With the lakers using single chip computer is accurate measurement data of the new trend. KEYWORDS：AT89S52 ，Millivoltmeter , DDS