Abstract: An autonomous device for measuring at least one characteristic of a fluid circulating in a conduit in a flow direction comprises a permanent magnetic field source, a magneto-electric converter and a processing circuit capable of using the electric charges supplied by the converter to supply a measurement of a characteristic of its environment. The source and the converter are placed in a stator and a rotor forming the device. The autonomous device further comprises attachment means allowing the stator to be fixedly placed in the conduit or at one end of the conduit, in a configuration in which the axis of rotation of the rotor is parallel to the flow direction. A control system may employ at least one such autonomous device.

Abstract: A magneto-electric converter capable of converting a variation in magnetic field into a potential difference between two electrical terminals includes a support layer comprising two electrical terminals; a stack disposed on the support layer of a first layer made from a magnetostrictive material defining the reference plane and of a second layer made from a piezoelectric material having a polarization axis in the plane defined by the second layer, parallel to the reference plane; the second layer comprising electrodes; and a means for electrical connection of the electrodes to the electrical terminals.

Abstract: An electrical generator comprises a converter including two electrical terminals for converting a variation in a magnetic field into a potential difference between the terminals. The generator includes a stack of a first layer comprising an anisotropic magnetostrictive material defining a reference plane and a second layer comprising a piezoelectric material. The first layer has at least one preferential axis of deformation in the reference plane and the second layer has a polarization axis parallel to the reference plane, the preferential axis of deformation of the first layer being aligned to within 15° with the polarization axis of the second layer. The generator includes a source that generates the magnetic field, the strength of which is insufficient to magnetically saturate the material of the first layer. The source and converter are able to rotate with respect to each other so as to vary the orientation of the magnetic field.