A parametric current sensor with feedback loop

Abstract This paper considers a sensor for detecting currents from dc to high frequency without disturbing the circuit current through contact. The current sensor is based on the phenomenon of parametric oscillation and uses the fact that the parametric oscillation voltage is amplitude‐modulated by the magnetic field of the measured current. An examination is made of the previous current sensor circuit with open‐loop construction, and the new circuit construction is closed‐loop and with feedback circuit. In this way, the current‐detecting characteristics are improved greatly, and it was confirmed that a high‐performance current sensor is obtained.