The toroidal core was excited by sharp pulse current. The sensor circuit is composed of peak value detector, Butterworth low-pass filter and differential amplifier.
磁芯采用高频脉冲电流励磁，信号处理电路由峰值检波、低通滤波及差动电路构成。
But the possibility of the sudden changes contained in polynomial considerably produces "sharp pulse" when expressing some curves with polynomial, which has greatly reduced precision.
但多项式本身包含突变的可能，使得在用多项式拟合一些曲线时，会表现出大幅“尖脉冲”，对拟合精度影响很大。
The error includes two sides, one is the calculation error about Wheatstone bridge circuit, and another is the effect of the sharp pulse producing when test current is loaded on the sample.
系统误差分析分为两个方面，一是与惠斯顿电桥电路有关的计算误差；二是测试电流脉冲加载时出现的尖脉冲引起的误差。
应用推荐