Abstract: A switching apparatus including an electromagnetic command device fitted with a magnetic circuit made up of a main circuit polarized by a permanent magnet and linked to a depolarizing coil and through a movable circuit integral with a movable support subject to a return spring and acting directly or indirectly on at least one disconnecting pole. The main magnetic circuit has at least two air gaps in series on the path of the magnetic flux generated by the permanent magnet and the movable magnetic circuit includes at least two parts capable of closing the air gaps when the main magnetic circuit and the movable magnetic circuit are joined together and are crossed by the magnetic flux created by the permanent magnetic, thereby carrying out a locking function and creating a multiplication of the locking forces, with an unlocking function being provided by the depolarization coil the counter-flux from which crosses the magnetic circuit and air gaps.

Abstract: Inductive current sensor and electrical apparatus incorporating this sensor. The magnetic circuit of the sensor comprises a separable part carrying the detector element and is made of a material having a permeability lying between 5 and 100. The circuit reduces the influence of spurious gaps and external interference on the current sensor for the electrical apparatus.