Hybrid ferrite-amorphous planar fluxgate

A new planar fluxgate is presented. The primary coil consists on a spiral grown on a ferrite disc in order to increase the magnetic field produced by the driving current and also to compensate for superimposed external magnetic fields. Two metallic spirals in opposite phase have been mounted over this coil as the secondary winding. They detect the signal induced by two stripes of ferromagnetic amorphous metal. The fluxgate shows a wide dynamic range and a good linear behaviour up to 50 kHz, with a maximum sensitivity of 12.7 V/T