基于半波激励的磁调制传感器设计与验证

基于磁调制传感器的工作原理,创新性的提出了通过采用半波激励信号简化设计双磁芯磁调制传感器的方法.传统磁调制传感器是在环形磁芯一次绕组中通以完整的方波、正弦波或锯齿波作为激励信号,然后提取磁芯二次绕组中感应信号的二次谐波来对被测直流信号进行检测的,此二次谐波反映被测直流信号的大小与方向.笔者通过实验发现,若通以半波激励,可反映被测直流信号的谐波由二次谐波变为一次谐波,此时相敏检波电路参考信号无需倍频,因而在器件中可省去倍频电路.分别采用方波、正弦波和锯齿波及其相应的半波作为激励信号进行了实验分析,结果表明,半波激励可以获得更为理想的检测波形,能更好地反映被测电流的大小,提高传感器的灵敏度.

Design and verification of magnetic modulation sensors based on semiwave excitation signal

On the basis of the working principle of magnetic modulation sensor,we proposed a method to simplify the magnetic modulation sensor with dual core differential structure by using a half wave excitation signal. Com-pared to those using full wave excitation signal,the signal in test port changes from second harmonic into fundamen-tal harmonic when using a half wave excitation signal. As a result,frequency multiplication circuit can be omitted since the reference signal frequency does not need to be doubled in Phase-sensitive detection circuit in this case. To verify the above design,full wave of square wave,sine wave,sawtooth wave and their half waves were used as the ex-citation signal in the experiment,respectively. The results show that all the half wave excitation signals can realize more symmetrical and ideal detection wave in comparison with the corresponding full wave signals. Therefore ,half wave excitation is more conductive to measure the current and simultaneously increase the sensitivity of the magnet-ic modulation sensor.