【摘要】 设计了一种软硬件结合的频率实时监测系统。系统主要由信号调节、抗混叠低通滤波、模数转换(ADC)接口、电压比较、ADC、信号处理、ARM管理模块等组成。首先通过变压器、互感器、信号调理电路将220 V交流电转换成5 V内的单极性同频率正弦波和方波。用数字信号处理器(DSP)的脉冲捕获单元测量方波周期进而得到信号频率。将方波锁相倍频后作为高速ADC的采样频率。ADC采集变换后的正弦波,将采样数据用并行口输入DSP进行傅里叶变换,分析出频率特征和谐波。在完成Multisim仿真和实物平台搭建调试后,测量结果的精度、测量速度满足设计要求。更多还原

【Abstract】 A real-time frequency monitoring system based on hardware and software is designed.The system is mainly composed of signal conditioning,anti aliasing low-pass filtering,analog to digital conversion(ADC) interface,voltage comparison,ADC,signal processing,ARM management module,etc.Firstly,through transformer,mutual inductor and signal conditioning circuit,220 V alternating current is converted into monopolar sine wave and square wave with the same frequency within 5 V.The pulse capture unit of digital signal processor(DSP) is used to measure the period of square wave and get the signal frequency.The square wave phase-locked frequency multiplier is used as the sampling frequency of high-speed ADC.ADC collects the converted sine wave,inputs the sampled data into DSP through parallel port for Fourier transform,and analyzes the frequency characteristics and harmonics.After the completion of Multisim simulation and physical platform debugging,and the speed of the measurement results and the accuracy of the measurement meet the design requirements.更多还原