Second harmonic magnetic field detection circuit with means to rectify the sensed signal

摘要

A magnetic field sensing circuit using three windings on a magnetic sensor with one winding using a locally generated excitation voltage, a second winding providing an output induced by the excitation voltage and a third winding both providing external magnetic field sense signals and serving as a feedback winding. The induced excitation voltage is used to generate a signal indicative of the flux in the core for the ultimate purpose of logically switching the sense winding so as to rectify it and supply it back to the third winding as a feedback signal for counteracting the flux in the sensor due to the external field being sensed.