Lem International Sa

Fabien Millet

Dominik Schläfli

Stéphan Trombert

Thomas Guillemin

Fluxgate current transducer including a control circuit and a fluxgate measuring device comprising a fluxgate magnetic field detector, the fluxgate magnetic field detector comprising a saturable soft magnetic core surrounded by an excitation coil, the control circuit comprising an excitation coil drive circuit connected to the excitation coil and a controller connected to the excitation coil drive circuit configured to generate an alternating excitation current Ito alternatingly saturate the soft magnetic core. The controller is in the form of a FPGA (Field Programmable Gate Array) comprising at least one input comprising a 1 bit sigma delta analog-to-digital converter (ADC) connected to the excitation coil to receive a measurement signal output by the excitation coil.

Fluxgate current transducer

An open-loop electrical current transducer for measuring an electrical current flowing in a primary conductor, includes a magnetic circuit core with an air-gap, and a magnetic field sensing device positioned at least partially in the air-gap, the magnetic field sensing device including a circuit board, a first magnetic field detector in the form of an ASIC mounted on the circuit board, and a second magnetic field detector in the form of a conductive pick-up coil formed on two or more layers in or on the circuit board. The outputs of the first and second magnetic field detectors are connected to a signal processing circuit generating an output signal representative of the electrical current, the output of the ASIC representing a low frequency (LF) channel and the output of the pick-up coil representing a high frequency (HF) channel.

Current transducer

A current transducer comprising a housing including a base and a cover, a magnetic circuit mounted within a cavity of the base, the magnetic circuit comprising a magnetic core and a least one coil wound around the magnetic core, and an electric circuit comprising a first circuit board mounted within the housing, the first circuit board comprising a signal processing circuit connected to the magnetic field detector and to the coil. The transducer further comprises a second circuit board comprising one or more power amplifiers mounted thereon, the second circuit board being integrated within an inner side of a metallic support substrate forming an outer layer of said cover, the metallic support substrate fixed to the housing base to cover the cavity therein with the second circuit board forming an inner side of the cover facing the first circuit board, the first and second boards interconnected electrically by electrical interconnections.

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Bons-en-Chablais, France

Fabien Millet