Improved transducer for reproducing and/or recording sound, comprising a membrane onto which is provided a one-piece or multipart piezo-electric element, characterized in that the membrane is composed of two or several layers of which at least one layer is made of polymer, and the shape of the perimeter of the piezo-electric element differs from the shape of the perimeter of the membrane.

A transducer for measuring the pressure of a fluid has a housing having a fluid contact region, a cavity divided from the third fluid contact region by a dividing wall, and an aperture through the dividing wall. A sensor component is located in the cavity and has a substrate carrying a pressure sensor. A rigid support block is mounted on the substrate and includes a surface facing the dividing wall off the housing. A spigot from this surface extends into the aperture of the dividing wall. A pass...

A transducer for detecting a shaft dynamic behavior. The transducer comprises an arcuate sensor member supported between an inner member and an outer member. At least one strain gage is attached to a surface of the arcuate sensor member to detect a surface strain caused by a shaft dynamic behavior. The inner member, outer member and arcuate sensor member are substantially coplanar. The inner member comprises a means for attaching the transducer to a mounting surface. The inner member may also co...

A transducer, in particular suitable for hearing aids, comprising a coil, two spaced magnet elements, a membrane, and an E-shaped armature, a middle leg of the E-shaped armature extending through the coil and the two magnet elements and being coupled with the membrane by means of a connecting element, limiting means being provided for limiting the maximum deflection of the middle leg of the E-shaped armature, which limiting means cooperate with the end of the middle leg of the E-shaped armature.

A transducer, in particular suitable for hearing aids, comprising a coil, two spaced magnet elements, a membrane, and a U-shaped armature, a first leg of the U-shaped armature extending through the coil and the two magnet elements and being coupled with the membrane by means of a connecting element, limiting means being provided for limiting the maximum deflection of the first leg of the armature, which limiting means are disposed on the connecting element.

First and second units have similar, preferably substantially identical, constructions. Each unit is preferably cylindrical and has an outer electrically conductive shell preferably made from a metal. A dielectric material, preferably a ceramic, abuts the inner surface of the electrically conductive shell in each unit. A conductive coating is disposed on the inner surface of the dielectric material in each unit. In this way, each unit defines a capacitor with the shell and the conductive coating...

A transducer for use in a hybrid optical and radio communications system includes a zero electrical power photodetector and a radio antenna. The photodetector is electrically connected to the radio antenna so that, in use, optical signals are received and radio signals are transmitted by the transducer without the use of electrical power. The transducer can thus be remotely sited at locations in communications systems not having a supply of electrical power. In a first embodiment the photodetect...

A force transducer in which a deflectable seismic mass is supported on a frame by support means is disclosed. The seismic mass at rest includes a plane and when the seismic mass is deflected by any force the mass always retains the plane parallel to the rest position. Any deflection of the seismic mass is purely topographically translational movement with no rotational movement allowed. The invention allows three identical structures to be etched onto a flat semiconductor wafer and yet can be us...

A transducer apparatus and method for generating sonic sound waves having a far field wavefront amplitude pattern in a Bessel or Gaussian distribution is disclosed. The transducer includes a piezoelectric element having uniformly poled dipoles formed therein. An unpoled backing body having the same dielecctric constant as the piezoelectric element contacts and is attached to the piezoelectric element. An indentation shaped to produce a beam amplitude distribution of a predetermined function is f...

A transducer having an energy conversion medium for converting changes in applied mechanical energy into corresponding changes in thermal energy and a pyroelectric material in thermal energy transfer relationship with the energy conversion medium for producing an electrical output substantially in response to the converted thermal energy. Such transducer is particularly useful as a hydrophone in detecting low frequency sound waves emitted by, or reflected from, underwater objects.