Liaisons Electroniques-mecaniques Lem Sa

Liaisons Electroniques-mechaniques Lem S.a.

Pierre Cattaneo

Pascal Morel

Claude Gudel

Marc Schaerrer

Guy Vuillermoz

Bernard Richard

Fr&eacute;d&eacute;ric Cattaneo

Rene Chuat

An electrical current sensor comprises a magnetic circuit with an air-gap, a magnetic field sensor positioned in the air-gap, and a secondary coil surrounding a branch of the magnetic circuit. The magnetic circuit comprises at least two parts () that are assembled together, a branch portion () of each part being insertably received in a central cavity of the secondary coil in an axial direction (A). The air-gap () is arranged between overlapping branch portions of each magnetic field circuit part.

Current sensor

An open-loop current sensor comprising a magnetic circuit having an air gap, a magnetic field detector disposed in the air gap, and a primary conductor having one or more turns surrounding the magnetic circuit, the current to be measured flowing in the primary conductor, the sensor being characterised in that the turns of the primary conductor are disposed close to the air gap, on each side of the air gap.

Open-loop electric current sensor and a power supply circuit provided with such sensors

The invention concerns an electric current pick-up shoe compensating fluxes generated in a magnetic circuit (,) by respectively a primary current and a compensating current circulating in a secondary coil. Said secondary coil (,) comprises at its surface a layer of spires (,) forming a protective winding connected to a fixed electric potential (,), such that the effect of leakage capacities between the primary current conductor (,) and the secondary coil (,) winding (,) are practically eliminated.

Electric current pick-up shoe

Plane sheets which have the same shape as the magnetic circuit and are relatively movable along their contact surface are arranged in a stack. The stack is grasped and part of the circuit is bent out of alignment with the plane of the sheets to enable a coil to be placed on a portion of the circuit which is next to the air gap, whereafter said part is bent back into alignment with said sheets.

Method for mounting an electrical coil on a magnetic circuit with an air

Electrical current sensor

An electric current sensing device for measuring a primary current of relatively high intensity. The device includes a magnetic circuit that is coupled with a primary conductor and with a measuring coil that is connected to a current source through an associated control circuit. The magnetic circuit includes an air gap which accommodates a magnetic field detector that is electrically connected to an input of the control circuit for controlling a magnetic field compensating current that is supplied to the measuring coil. The device also includes a printed circuit that is arranged to both minimize electromagnetic interference between the measuring current circuit and the control circuit input, and improves heat dissipation of the printed circuit, thus optimizing the size ratio of the maximum primary current to the bulk of the device and improving performance of the same.

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Collonges-sous-Saleve, France

Pierre Cattaneo