Hi everyone . I've been wanting to understand how the fluxgate or zeroflux technology used in magnetometers or current sensors works for a few weeks. it seems that there is no single method for their realization but there is more than one. This is what leaves me disconcerted. For example, there are those who use a square wave and others instead use an amplifier that reproduces a signal equal to that of the detection coil and then sends it to the compensation coil to reset the flux. there must necessarily be a minimum of flow otherwise how can there be induction ?.