毕业设计_基于单片机的rlc测试仪设计论文.doc

毕业设计（论文） 基于单片机的RLC测试仪设计 Design of RLC Instrument Based on SCM 长 春 工 程 学 院 摘 要 随着电子技术的发展，产品智能化、数字化已成为人们追求的一种趋势，尤其对电子设备的精密度和稳定度最为关注。现在使用的RLC测试仪大都是硬件电路往往比较复杂，体积比较庞大，不便携带，而且价格比较昂贵基于单片机的RLC测试仪利用单片机的运算和控制功能，方便地实现对R、L、C参数测量。可在硬件结构不变的情况下，同时用软件程序代替一些硬件测量电。能够很好的完成对RLC参数的测量。体积更小、功能强大、便于携带的RLC测试仪Abstract With the develop of electronic technology,the products’intelligentize and digitized has become a trend which is pursued by human ， Especially for electronic equipment precision and stability .The RLC testers now are used mostly hardware circuits ,which are complex, large volume comparison, inconvenience to carry, and price is more expensive and inconvenient for beginners. Therefore, the design of the RLC tester based on AT89C51 SCM is necessary. using the SCM’s operation and control functions to realize the measure of the R, L, C parameters expediently. In the case of the hardware structure remain unchangable, using a software program to replace some hardware measuring circuit,which can complete the measure of RLC parameters very well. The design improves the results’measuring accuracy by using the interpolation algorithm effectively, at the same time through a filtering method to avoid reading the beat, making it more convenient to read the measuring results. The design is conformed to the social development, developed a cheap and simple, automatic conversion range and smaller size, and portable RLC Tester. Key word : Single chip micro RLC measuring meter Interpolation algorithm Digital filtering 目 录 1 引言 1 1.1 课题设计目的意义 1 1.2 课题设计内容 1 1.3 技术要求 1 1.4 拟解决关键问题 2 1.5 课题的来源 2 1.6 课题的范围 2 2 总体方案设计 2 2.1 方案一 2 2.2 方案二 4 2.3 方案选择 4 2.4 系统原理框图 4 3 硬件设计 5 3.1 测电阻Rx的RC振荡电路 5 3.2 测量电容Cx的RC振荡电路 6 3.3 测量电感Lx的电容三点式振荡电路 7 3.4 模拟开关 8 3.5 89C81单片机 11 3.6 LED数码管显示器 19 4 软件设计 21 4.1 主程序流程图 21 4.2 频率的测量方法和误差分析 21 4.3 稳定读数 24 5 总结 25 参考文献 26 致 谢 27 附 录 28  1 引言 1.1 课题的目的和意义 现在我们所使用过的RLC测试仪最典型的就是万用表，但是万用表在使用过程中如果操作不当