Magnetic transducer and current transducer for measuring an electrical current

The invention concerns a current transducer for measuring a current flowing through a cable, comprising at least one magnetic field sensor and an electronic circuit. The current transducer comprises a head (40) with at least two ferromagnetic cores (46) optimized to reduce the effects of external magnetic fields. The current transducer optionally comprises a magnetic transducer comprising a magnetic field sensor and an electronic circuit. The electronic circuit comprises at least one current source (2), a transformer (3), a fully differential preamplifier (4) coupled to the transformer (3), a phase sensitive detector (6) coupled to the preamplifier (4) and a logic block (5, 5a) configured to operate the magnetic field sensor(s) to provide an AC output voltage. The magnetic field sensor(s) is preferably either a Hall element (1) or an AMR sensor (19) or a flux-gate sensor.