一种低纹波输出非标准正弦电流有效值转换电路

摘要

The article first introduces the methods currently used for the current rms conversion, analyses of the characteristics of each method and sets up a typical application circuit with AD637 chip,as a core. By analysing the entering the Rectangular wave signal,the higher levels of output ripple are found,and the output contains a large error. Based on the AD637 typical application circuit, a Sallen-Key filter circuit-based nonstandard sinusoidal current RMS conversion circuit was set up,and by optimizing the parameters of the filter circuit,the output ripple decreases less than 1% of the typical application circuit to improve nonstandard sinusoidal current signal RMS conversion accuracy.%首先介绍了目前用于电流有效值转换的方法，分析了每种方法的特点，并以AD637芯片为核心搭建了典型应用电路，通过输入方波信号，发现其输出纹波含量较高，输出结果含有较大误差。在AD637典型应用电路的基础上搭建了基于Sallen-Key滤波电路的非标准正弦电流有效值转换电路，并通过优化滤波电路的参数，使得输出纹波含量降低为典型应用电路的10%以下，提高了非标准正弦电流信号有效值转换的精度。