Abstract: The resolver with variable magnetic coupling comprises a stator constituted by first and second stacks of laminations disposed coaxially around a rotor having an axis of rotation, and spaced apart along said axis. The rotor is constituted by first and second stacks of laminations spaced apart from each other along the axis of rotation of the rotor and in register with the first and second stator stacks of laminations, respectively. The first and second rotor stacks of laminations are angularly offset from each other and each couples magnetically with the stator via an outer peripheral surface that defines at least two regularly spaced-apart lobes, thus enabling a resolver to be produced that is of low cost and that provides very good accuracy.

Abstract: A linear motor comprising a first portion having: a primary magnetic circuit comprising N.sub.e slots alternating with N.sub.d teeth, with N.sub.e =N.sub.d, a multiphase electrical winding having 2P poles being placed inside said slots and, at an instant t when fed with AC, producing an undulated magnetic field of length l and of P periods along the length l of the magnetic circuit covering the N.sub.e slots and the N.sub.d teeth; and a second portion, disposed facing the first portion and separated therefrom by a plane air gap, said second portion having a length L=l+x, where x is the length of relative displacement between the two portions relative to each other, said second portion constituting a secondary magnetic circuit; wherein, facing said air gap, said secondary magnetic circuit comprises a series of teeth and slots along its entire length L, wherein said first portion comprises, along said air gap, and fixed to the primary magnetic circuit at the end of its teeth and its slots, a series of 2N.sub.

Abstract: A homopolar reluctant sensor comprises a magnetic material rotor including a cylindrical body having at a first end a laminated part comprising the same number of lobes as there are sensor pole pairs and at a second end a ring and a magnetic material stator comprising a cylindrical portion provided with an excitation coil energized by an alternating supply, a first ring having notches and defining with said laminated part a first airgap and a smooth second ring defining with said rotor ring a second airgap. The stator notches are provided with a winding such that the voltage induced therein is sinusoidal and free of harmonics. The envelope of this voltage represents, apart from a phase-shift, the position of the rotor relative to the stator.

Abstract: A sensor for measuring the angular position of a rotor relative to a stator has firstly a rotor made of a magnetic material and including 2 p lobes, where p is an integer. A stator is positioned around the rotor. The stator is made of a magnetic material and includes a number of teeth equal to 2n.p, where n is the number of phases of the sensor. Each tooth is surrounded both by an excitation first winding and by reception second winding. The excitation windings are connected together in series and disposed on the teeth such that the windings on two circumferentially adjacent teeth produce magnetic flux in opposite directions. The set of said excitation windings are powered by an alternative current or voltage. The reception windings of the same phase and offset by 180 electrical degrees are connected together in series. The envelope of the signal at the terminals of each of the pairs of reception windings represent the angle of rotation of the rotor relative to the stator, to within a scaling factor.