A combined low frequency and high frequency current sensor , comprising: a powdered core bead body composed of a ferromagnetic, ferrite, or magnetic oxide material having a generally toroidal shape with a radial thickness extending between a circumferential periphery and an inner periphery surrounding a centralized circular aperture through which passes a current carrying power wire , and an air cavity formed in the powdered core bead body with sidewalls substantially perpendicular to the circumferential periphery and extending radially inwardly for a distance less than the radial thickness forming a bottom of the cavity separated from the inner periphery of the powdered core bead body surrounding the centralized circular aperture by a remaining thickness of the powdered core bead body forming a shielding bridge portion , configured to provide a magnetic shield for the air cavity from variations in magnetic flux due to variations in distance of the power wire from the inner periphery of the powdered core bead body to enable measurement of magnetic flux in the air cavity; a magnetic flux-density sensing device embedded in the air cavity in the powdered core bead body , having a magnetic field sensing surface oriented substantially perpendicular to the circumferential periphery of the powdered core bead body , configured to measure magnetic flux through the magnetic flux-density sensing device in response to current signals in the power wire ; and a low frequency voltage sensor having an input terminal coupled to an output connection of the magnetic flux-density sensing device , configured to sense a variation of the magnetic flux in the powdered core bead body , sensed by the magnetic flux-density sensing device and to output an indication of an over-current fault in the power wire . a powdered core bead body composed of a ferromagnetic, ferrite, or magnetic oxide material having a generally toroidal shape with a radial thickness extending between a circumferential periphery and an inner periphery surrounding a centralized circular aperture through which passes a current carrying power wire , and an air cavity formed in the powdered core bead body with sidewalls substantially perpendicular to the circumferential periphery and extending radially inwardly for a distance less than the radial thickness forming a bottom of the cavity separated from the inner periphery of the powdered core bead body surrounding the centralized circular aperture by a remaining thickness of the powdered core bead body forming a shielding bridge portion , configured to provide a magnetic shield for the air cavity from variations in magnetic flux due to variations in distance of the power wire from the inner periphery of the powdered core bead body to enable measurement of magnetic flux in the air cavity; a magnetic flux-density sensing device embedded in the air cavity in the powdered core bead body , having a magnetic field sensing surface oriented substantially perpendicular to the circumferential periphery of the powdered core bead body , configured to measure magnetic flux through the magnetic flux-density sensing device in response to current signals in the power wire ; and a low frequency voltage sensor having an input terminal coupled to an output connection of the magnetic flux-density sensing device , configured to sense a variation of the magnetic flux in the powdered core bead body , sensed by the magnetic flux-density sensing device and to output an indication of an over-current fault in the power wire . <EOS>