多通道测量的等精度频率计

Equal Precision Frequency Meter with Multichannel Measurement

介绍一种基于等精度测量的数字频率计的设计方案,该频率计在每个不同测频范围内保持精度不变,且对于幅度值较小的高低频信号能够准确测出.采用多通道的放大整形电路,故能在较宽的频率和幅度范围内对频率、周期、占空比、两路信号的时间间隔等参数进行测量.又结合STM32单片机强大的数据处理能力,将基准频率提高以获取更高的测量精度,还增加软件滤波使测量结果更为稳定.仿真和实验结果表明其测量精度高,有较高的稳定性.

This paper mainly introduces a kind of design schemes based on the accuracy of measurement of digital frequency meter. Not only could the digital frequency meter keep constant accuracy in the range of different frequency measurement,but also small amplitude of the low and high frequency signals can be measured accurately by it. Due to the adoption of the multichannel amplifying and shaping circuit,the frequency,the cycle,the duty cycle and the time interval of the two signals can be measured in a wide range of frequency and amplitude range. With the powerful data processing ability,the reference frequency can be improved to obtain higher measurement accuracy by STM32 single chip microcomputer. In addition,the software filter can make the measurement results more stable. Through the simulation and experiment,the results show that he proposed frequency meter has high accuracy and high stability.