Abstract: An electro-acoustic communications unit (10) such as a mobile telephone and a telephone handset or headset. The unit has a receiver transducer (12) generating sound signals from a first side (15) of the transducer, and the sound signals are output from the unit through one or more openings (17) in the housing (11). The transducer (12) is secured to a structure of the unit with its first side facing away from that structure. The transducer can thereby be placed at any desired location in the unit including in particular other structures than the housing wall, and a volume in the housing is included in the sound path from the transducer to the user's ear. The telephone can thus be very compact and still be leak-tolerant.

Abstract: An electric miniature motor having a stator of magnetic soft material and a permanent magnet rotor. The stator has a low electrical conductivity at least in the direction of the rotor shaft to dampen eddy currents in the stator material caused by rotation of the rotor. The magnetizable material of the stator is composed of ring-shaped elements with two sections having their respective diameters so that the elements may be joined co-axially to a tubular stator. This provides the same eddy current damping properties as with a stator composed of segments, but the stator is much cheaper. The coils are formed as flat coils on a flexible foil which are arranged along the internal side of the stator.

Abstract: A telephone handset, a cordless telephone or a mobile telephone (4) comprising a transducer (2) provided as a circular capsule (2), which along a ring-shaped front side by means of a ring-shaped gasket is connected to an inner wall of an earcap plane or an earpiece (10), which in front of the front side of the transducer diaphragm has a number of apertures (14), and where a number of acoustic connections (16) to an interior cavity (6) and occurring leakages of the handset or the telephone are provided in said earcap plane or earpiece (10) in such a manner, that said connections (16) are positioned outside the ring-shaped gasket (12) and preferably outside the circumference of the transducer (2) but inside a diameter determined by the ear represented by a standardized measuring ear, that is inside a diameter of preferably 25 mm.

Abstract: A contact device consisting of a helical spring which is adapted from SMD mounting, and which is formed with a base portion adapted to be positioned on and attached to a contact face by soldering or gluing, and with a top portion adapted for handling with a tool preferably associated with an SMD apparatus. This provides the possibility of achieving a generally better and less expensive contacting between components, such as acoustic transducers, batteries or the like and printed circuit boards by means of simple features. Constructing the contact device as a screw or helical spring provides a great safeguard against transfer of laterally directed forces or moments from the contact face which destroy the contact face and/or the solder connection with the printed circuit.

Abstract: An electrodynamic acoustic transducer has its diaphragm with a coil retained with respect to the magnetic system in discrete points along the periphery of the diaphragm, while the rest of the periphery of the diaphragm is not fixed. The diaphragm has tongues at its periphery which are thicker than the rest of the diaphragm, and which are retained between two ring-shaped engagement faces, which, in the preferred embodiment, are formed by a magnetic system which is arranged symmetrically on both sides of the diaphragm. The diaphragm has a flat coil with spiral wound windings, and the diaphragm with coil and termination is supplied integrally with a web of sheet or a film roll comprising a large number of diaphragms, making the diaphragm useful for mounting in the transducer by tape automated bonding.

Abstract: An electromagnetic transducer has a moving coil, a diaphragm and a magnet system enclosed within protecting covers. It includes an inset placed between the magnet system and the front cover. The inset is made of a non-magnetic, electrically insulating material and is provided with an aperture.