Abstract: A method of making magnetic circuit (1) with coil having an electric coil (2) and a magnetic core (3), the coil (2) comprising a conducting wire (6) and an end plate (4) and connector (5) being arranged at respective ends of the coil (2). The coil is mounted on the magnetic core (3) which is formed of a tore-shaped magnetic wire.

Abstract: The invention concerns a sensor including a magnetic circuit coupled with a primary conductor, a secondary winding coupled with the magnetic circuit, a damping resistor, a magnetic field detector arranged in an air gap of the magnetic circuit and a powering device supplying the secondary winding with a current tending to compensate the magnetic field in the air gap. A measuring resistor is connected in series to the secondary winding and an auxiliary resistor of same value as the damping resistor is connected to the secondary winding and the measuring resistor common connection point. A difference amplifier set is arranged for measuring the voltage at the secondary winding terminals and applying, to the auxiliary resistor, a voltage equal and in opposite direction to the one occurring at the secondary winding terminals.

Abstract: The invention concerns an electric current pick-up shoe compensating fluxes generated in a magnetic circuit (1) by respectively a primary current and a compensating current circulating in a secondary coil. Said secondary coil (5) comprises at its surface a layer of spires (12) forming a protective winding connected to a fixed electric potential (13), such that the effect of leakage capacities between the primary current conductor (4) and the secondary coil (5) winding (6) are practically eliminated.

Abstract: 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.

Abstract: A current supply device for supplying a direct current, a sinusoidal current or a pulsed current to a load, the device having a conductor portion arranged for being connected in series with the load, the conductor portion being coupled with a magnetic circuit having at least one air-gap, a magnetic field detector device being arranged in the air-gap and being connected to a measuring or control circuit for producing an output signal representing the current supplied by the current supply device.

Abstract: For forming a cylindrical coil (3) on a rectilinear arm of a magnetic circuit (1) having a very small air-gap (2), a wire guide member (6) has a wire inlet portion (8), a wire outlet portion (9) and an elongated intermediary portion (11) arranged for effecting a rotary movement about the axis (4) of the coil (3) and a reciprocating movement in the axial direction of the coil (3). The intermediary portion of the wire guide member has, over a length at least equal to that of the coil to be formed, a height smaller than the length of the air-gap so that it can move through the air-gap in the longitudinal and in the transverse directions.

Abstract: A direct current of high intensity having alternating current components superposed thereon is flowing in a conductor 1 through a magnetic circuit 5, 6. Two measuring coils 7, 8 are arranged inside opposite air-gaps of the magnetic circuit and are connected in an electric measuring circuit in series with each other and in parallel to voltage dividers 12, 13 and 14, 15. The alternating current components induce voltages in the coils 7 and 8 which add up, the sum thereof appearing across the series-connection of resistors 13, 15. This voltage is integrated by an integrating circuit 10 and then filtered in a band-pass filter 11. The magnetic circuit 5, 6 is screened by lateral screening members 30, 31 so that the remaining field lines of a lateral parasitic magnetic field produce in the magnetic circuit flux portions which are approximately equal and which are added to the useful flux in one air-gap and are substracted from the useful flux in the other air-gap.

Abstract: 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.

Abstract: The magnetic circuit (1) is made in a single piece or consists of a stack of identically-shaped sheets. The height (H) of the air gap (2) is greater than the thickness (E) of a coil (5), enabling said coil to be inserted through the air gap. This structure is easily assembled during the mass production of current sensors which use such circuits.

Abstract: A current measuring device includes first and second current transformers, having each a magnetic core, a primary conductor or winding and a secondary winding coupled with the magnetic core, the primary windings or conductors being connected to carry the current to be measured. The secondary windings of the first and second transformers have an equal number of turns and are connected in series with each other, and arranged so that the currents induced in the secondary windings by the current to be measured flow in the same direction. A current generator has an output connected to the secondary winding of the first current transformer for feeding to the same a current comprising a magnetizing current component capable of driving the corresponding core, alternately, in opposite states of saturation.

Abstract: In the present current intensity transformer device, a magnetic circuit having an air-gap provided with a Hall cell, is coupled with a conductor for the current to be measured and with a measuring winding. An electric measuring circuit provides a first voltage which is a function of the magnetic field in the air-gap, and a second voltage which is a function of the current in the measuring winding. Both voltages are added together to provide a measure of variable currents, such as pulse currents or periodic currents of a strongly asymmetrical wave form, as well as direct currents or low frequency alternating currents with superposed strong high frequency undulation.