Abstract: A system for passive damping of mechanical vibrations generated by a vibrating structure supported by a support, including a transducer interposed between the vibrating structure and the support to transform mechanical energy of vibrations into electrical energy.

Abstract: A system for passive damping of mechanical vibrations generated by a vibrating structure supported by a support, including a transducer interposed between the vibrating structure and the support to transform mechanical energy of vibrations into electrical energy.

Abstract: An electrical power production system including a plurality of generator assemblies having: at least one piezoelectric generator for generating electrical power in response to a mechanical force applied onto said first generator, an actuator for applying a mechanical force onto the generator when said actuator is biased, a rotatable cam having a cam surface, a follower means for following the cam surface, a lever connected to the follower means, said lever being mounted as a lever arm and engaging with the actuator so as to bias said actuator when the cam is rotated and the cam surface exerts a mechanical force on the follower means, a rotatable wheel rotated by a power source and coupled to the cams so that setting said rotatable wheel in rotation at a rotation speed causes the rotation of said cams at another rotation speed, which is greater than that of said rotatable wheel.

Abstract: An apparatus for converting wave energy into electrical energy including a float element excited at a defined frequency by the waves. A power extraction system collaborates with the float element to convert mechanical energy into electrical energy, the mechanical energy coming from the movement of the float element excited by the waves. The power extraction system takes the form of a frequency amplifier made up of at least two piezoelectric motors each composed of at least one piezoelectric post excited at a frequency higher than that of the float, and a member for activating said piezoelectric motors acting on the piezoelectric motors so as to squash said piezoelectric posts. Each piezoelectric motor has a mechanical amplification device connected to rollers and includes a) jaws able to apply mechanical stress to the posts, b) a lever acting on the jaws with a proximal end connected to said jaws and a distal end connected to a roller in contact with the member so as to activate said piezoelectric motor.

Abstract: An electrical power production system including a plurality of generator assemblies having: at least one piezoelectric generator for generating electrical power in response to a mechanical force applied onto said first generator, an actuator for applying a mechanical force onto the generator when said actuator is biased, a rotatable cam having a cam surface, a follower means for following the cam surface, a lever connected to the follower means, said lever being mounted as a lever arm and engaging with the actuator so as to bias said actuator when the cam is rotated and the cam surface exerts a mechanical force on the follower means, a rotatable wheel rotated by a power source and coupled to the cams so that setting said rotatable wheel in rotation at a rotation speed causes the rotation of said cams at another rotation speed, which is greater than that of said rotatable wheel.

Abstract: An apparatus for converting wave energy into electrical energy including a float element excited at a defined frequency by the waves. A power extraction system collaborates with the float element to convert mechanical energy into electrical energy, the mechanical energy coming from the movement of the float element excited by the waves. The power extraction system takes the form of a frequency amplifier made up of at least two piezoelectric motors each composed of at least one piezoelectric post excited at a frequency higher than that of the float, and a member for activating said piezoelectric motors acting on the piezoelectric motors so as to squash said piezoelectric posts. Each piezoelectric motor has a mechanical amplification device connected to rollers and includes a) jaws able to apply mechanical stress to the posts, b) a lever acting on the jaws with a proximal end connected to said jaws and a distal end connected to a roller in contact with the member so as to activate said piezoelectric motor.

Abstract: An acoustic antenna includes an array of elementary submarine transducers, each elementary transducer including, between a counterweight and a horn, at least one ceramic. Each elementary transducer is mounted on a printed circuit so that the printed circuit is clamped between the ceramic and counterweight thereof. The printed circuit includes conductors for connection to electrodes of the respective ceramic for individual control of the elementary transducers. The weight of each element of the elementary transducer is set to minimize cross-talk between channels.

Abstract: A fiber Bragg grating hydrophone includes a fluid chamber (1) and an optical fiber (2) in which a Bragg grating (3) is integrated, the optical fiber extending through the fluid chamber such that the Bragg grating is positioned inside the latter. The fluid chamber is filled with a compressible fluid and is defined by a rigid casing (4) including two end surfaces (28a, 28b) that are rigidly connected to the optical fiber. At least one of the two end surfaces of the rigid casing includes an opening (5a, 5b) closed by a deformable diaphragm (6a, 6b) that is rigidly connected to the optical fiber and that can be deformed in reaction to a difference in the pressures applied to the surfaces thereof, thereby modifying the length of the optical fiber as measured by a variation in the wavelength of a luminous flux extracted from the optical fiber.

Abstract: A Bragg grating fiber hydrophone, includes a fluid chamber and an optical fiber in which a Bragg grating is integrated, the optical fiber passing through the fluid chamber along a longitudinal axis such that the Bragg grating is positioned inside the latter. The fluid chamber is filled with a compressible fluid and is defined by a casing including two ends connected to the optical fiber. The casing includes at least one portion formed by an extensible and compressible tube extending along the longitudinal axis. The portion formed by an extensible and compressible tube includes an outer end coinciding with one of the two casing ends and can be longitudinally deformed by a difference in the pressures applied on the walls thereof, which results in a variation of the length of the optical fiber as measured by a variation in the wavelength of a luminous flux extracted from the optical fiber.

Abstract: A fiber Bragg grating hydrophone includes a fluid chamber (1) and an optical fiber (2) in which a Bragg grating (3) is integrated, the optical fiber extending through the fluid chamber such that the Bragg grating is positioned inside the latter. The fluid chamber is filled with a compressible fluid and is defined by a rigid casing (4) including two end surfaces (28a, 28b) that are rigidly connected to the optical fiber. At least one of the two end surfaces of the rigid casing includes an opening (5a, 5b) closed by a deformable diaphragm (6a, 6b) that is rigidly connected to the optical fiber and that can be deformed in reaction to a difference in the pressures applied to the surfaces thereof, thereby modifying the length of the optical fiber as measured by a variation in the wavelength of a luminous flux extracted from the optical fiber.

Abstract: A Bragg grating fiber hydrophone, includes a fluid chamber and an optical fiber in which a Bragg grating is integrated, the optical fiber passing through the fluid chamber along a longitudinal axis such that the Bragg grating is positioned inside the latter. The fluid chamber is filled with a compressible fluid and is defined by a casing including two ends connected to the optical fiber. The casing includes at least one portion formed by an extensible and compressible tube extending along the longitudinal axis. The portion formed by an extensible and compressible tube includes an outer end coinciding with one of the two casing ends and can be longitudinally deformed by a difference in the pressures applied on the walls thereof, which results in a variation of the length of the optical fiber as measured by a variation in the wavelength of a luminous flux extracted from the optical fiber.

Abstract: An acoustic antenna requiring the fewest possible number of assembly operations, which operations can be easily automated. The acoustic antenna includes an array of elementary transducers (15), each elementary transducer including, between a counterweight (10) and a horn (9), at least one ceramic (8), all the elementary transducers being mounted on a common printed circuit (7, 16) for electrical connection between the transducers and for positioning the transducers relative to one another, and at least one connector (26, 27) fixed to this printed circuit, each of the transducers being mounted in such a way that the printed circuit is clamped between the ceramic(s) thereof and the counterweight thereof.

Abstract: The invention relates to a seismic acquisition device in a marine environment. The device comprises a Janus Helmholtz (12) transducer which is able to operate at a large depth of immersion and to sound waves in a wide frequency band, a calculator (13) to program at will the frequency band and the form of the sound waves emitted by the transducer, a power amplifier (14) that can control the transducer in order to provide the emitted sound waves with predetermined power levels, an impedance adapter (16) placed between the transducer (12) and the amplifier to enable wide band and power adaptation, and a receiver (18) to capture the seismic waves reflected by the different layers of the sea bed.

Abstract: A transducer includes one or more electro-acoustic motors located on a same internal plane or as a peripheral ring of a flexible envelope to which they are interdependent by at least one-of their ends by an assembling device and to which they transmit their vibrations, the flexible envelope being in contact with the liquid and constituting the acoustic waves emitting surface. The flexible envelope is shaped such that the amplitude of the vibrations is increased in a range of very low frequency. The envelope includes at least one orifice allowing the liquid to enter the whole internal cavity delimited by the envelope and a baffle made up of alveolar material that resists the immersion pressure and fills most of the cavity volume. The external surface of the baffle is at a constant distance from that of the interior of the envelope and is interdependent to the assembling device of the acoustic motors.

Abstract: An electro-acoustic transducer comprises two transducer units each having first and second ends, a tubular supporting member disposed between the two transducer units, and a pair of oppositely disposed supporting components between which the transducer units and tubular member are disposed. One of the transducer units is compressively clamped between one of the supporting components and one end of the tubular member, and the other of the transducer elements is compressively clamped between the other of the supporting components and the other end of the tubular member.

Abstract: This invention relates to a device for maintaining the gas contained in a submerged enclosure in pressure equilibrium with the outside, comprising a plurality of deformable bags which are immersed at the same time as said enclosure which are filled with gas compressed to different pressures and which communicate with said enclosure via a manifold on which they are connected by automatic three-way valves.