数字式工频有效值多用表设计

文档编号:ZD531 文档字数:15677,页数:35，有开题报告，任务书，文献综述

摘要：本系统以8051单片机为核心元件进行设计，采用采样保持电路同时对电流和电压信号的瞬时值进行采样。样值经模拟开关选择后送12位A/D转换电路转换成数字信号送CPU处理。在地址译码逻辑转换等方面均应用了可编程逻辑器件，为使计算准确在一个工频周期内采样50个点，根据实测频率来确定采样间隔，然后计算电流、电压的有效值及有功功率、无功功率。由四位数码管显示，通过按键实现不同的测量功能。本系统除能达到设计的所有要求外，还有以下扩展功能，策频、策相，并能策电压、电流、有功功率、无功功率的最大值及最小值和电压总谐波的有效值。
 设计分三个模块：数据采集、数据处理和显示模块。数据信号采集采用可编程运算放大器PGA103，对大、小信号分别进行放大处理，采样控制信号由集成锁相环ADC0809对被测信号 进行64倍频产生；数据处理以单片机8051为核心，对采集信号进行精确控制和严格计算；显示部分又74LS164移位寄存器和数码管构成。
 关键词：数字工频有效值 80C51单片机 数据采集 数据处理 显示模块

 Abstract ：The multi-meter presented here is based on a microprocessor (80C51).All components used are low-cost, high-speed CMOS type. The instantaneous values of the voltage and current can be sampled simulate amorously by two sample-and-hold circuits. The sampled analog signal that can be processed by CPU. The PLD is used for address decoding and logic signal converting. For accuracy calculation .50 points are sampled in a power cycle. The sampling intervals are decided by the measured power frequency.Then,the voltage and current rms valves.active power and reactive power and reactive power are calculated. A 4-place seven-segment LED is used to display the results.The function of the multi-meter can be selected by a keypad.Besides,the functions of the multi-meter can be extended,such as measure ments of frequency,phase,maximum and minimum values of current,voltage,active power and reactive power,and rms values of harmonic voltage.  
 Design branch three modules: Data acquisition 、Data handling and display module. The data signal adopts the programmable to operate amplifier PGA103, To great 、Separately is enlarged the handle to the little signal, The sampling control signal is carried on 64 -fold of frequencies coming into being through integration PLL ADC0809 to fathoms the signal; The data handling takes onboard computer 80C51 as the core, Accurately dominate and rigorously enforce calculation to collecting the signal; Display section but 74LS164's dislocation register and the nixie light constitutes.
 Keywords: figure style workman frequency virtual value；  80C51 signal chip computer；data collect；data processing；display module

目  录
摘要…………………………………………………………………………………………4
Abstract…………………………………………………………………………………… 5
第一章 总体方案设计与论证…………………………………………………………… 6
第二章 硬件模块电路设计……………………………………………………………… 7
2.1数据信号采集……………………………………………………………………… 7
 2.1.1数据采集与控制原理……………………………………………………… 7
 2.1.2 数据采集模块…………………………………………………………………7
2.2 单片机系统数据处理模块……………………………………………………………8
     2.2.1信号频率倍频处理部分……………………………………………………8
     2.2.2数据处理转换部分…………………………………………………………8
2.3  键盘电路设计………………………………………………………………………12
 2.3.1键盘电路原理……………………………………………………………12
 2.3.2 器件说明…………………………………………………………………13
2.4  显示电路设计…………………………………………………………………… 15
 2.4.1 显示模块…………………………………………………………………16
 2.4.2 LED电路显示原理……………………………………………………… 16
第三章 系统实现与理论分析………………………………………………………… 16
3.1采集部分…………………………………………………………………………… 16
3.2数据处理部分……………………………………………………………………… 17
第四章  软件设计………………………………………………………………………18
4.1 主程序流程图与说明………………………………………………………………19
4.2 数据处理……………………………………………………………………………20
4.3 键盘电路…………………………………………………………………………… 23
4.4 显示电路…………………………………………………………………………… 25
总结与体会……………………………………………………………………………… 26
致谢……………………………………………………………………………………… 27
参考文献………………………………………………………………………………… 28
附录……………………………………………………………………………………… 29
附录A 各部分设计电路原理图………………………………………………………… 29
附录B 总电路图………………………………………………………………………… 31
附录C 设计程序………………………………………………………………………… 32
 

相关论文