Abstract:
An automatically reversing, self-cleaning electric switch preferably for use in miniature, electronic aggregates such as hearing aids comprises a box (1) manufactured from electrically insulating material with a pushing rod (2) also from electrically insulating material mounted in the upper part of the box, a U-formed spring (4) fastened in a hollow space within the pushing rod (2) and spring legs (5, 6) which depending on the position of the pushing rod may rest against one or more end terminals (7, 8, 9) mounted in the lower part of the box for disconnecting or connecting a current through the switch. The resilient force of the U-formed spring causes the pushing rod (2) to revert automatically to a centre or zero position when no outer force is applied to the rod and a self-cleaning effect is obtained through the spring legs (5, 6) resting slidingly against the terminals (7, 8, 9).
Abstract:
The micromechanically produced microphone consists of a housing (1) wherein a transducer element (2) is placed and which has a sound inlet (3) on one side of the transducer element and a pressure compensation hole (4) on the other side. In order to protect the microphone against humidity, dust and dirt, which partly or totally will be able to destroy its characteristics, a sealing acoustic membrane (6, 7) is placed on each side of the transducer element. The transducer element can for example be a capacitive transducer with external bias or an electret based transducer. The microphone, which can be produced in very small dimension, is among other things suitable for use in hearing aids.
Abstract:
A microelectronic position sensor, e.g. for use in hearing aids and the like, for volume control, function shifts or change of another adjustable parameter of the apparatus, consists of a rotor (1) having an integral permanent magnet (2) and which is freely rotatable in both directions through 360 C and mounted on a stator (3) having an integral integrated circuit (4) which is provided with a number of magnet sensitive sensors to read, via the Hall effect, the instantaneous position of the permanent magnet (2) relative to the stator (3). By means of the circuit (4) the position indication read is converted to digital codes for a computer which is incorporated into the hearing aid, said computer converts the code signal received to a function signal for the apparatus.
Abstract:
The invention concerns a Switched MAGFET ( MAG netic field sensitive F ield E ffect T ransistor). A preferred SMAGFET embodiment consists of a MAGFET structure with two equal sized drain contacts (3, 4), a gate area consisting of two equal sized and electrically isolated gate regions G1 and G2 (5, 6) separated by a third isolated gate region Gc (7) placed along the symmetry line of the device and slightly overlapping G1 and G2. The SMAGFET has a common source (1). By varying the gate voltage on Gc (with reference to the common source contact), the magnetic sensitivity of the SMAGFET may be controlled. By applying a first voltage on Gc, exchange of carriers from the channels beneath G1 and G2 is blocked. In case of an applied magnetic field, this will prevent Lorentz deflected carriers to cross symmetry line and redistribute the drain currents, i.e. the magnetic field sensitivity is virtually zero as the drain currents will remain unaffected by the magnetic induction. By changing the voltage at Gc to a second level, exchange of carriers from channels beneath G1 and G2 may take place. In case of an applied magnetic field, this will allow Lorentz deflected carriers to cross symmetry line and redistribute the drain currents.
Abstract:
An electromechanical pulse generator having a purely mechanical mode of operation for microelectronic equipment, e.g. volume control in hearing aids, consisting of a housing formed by a fixed base portion (7) in which a shaft (3) is fixedly mounted and a timing wheel (1) is rotatably mounted around the shaft, said timing wheel having the form of a downward facing open cylinder and being fixedly connected to a casing which forms an external handle. The inner cylinder surface of the timing wheel (1) is provided with grooves (12) engaging with the protrusion (13) of a circular carrier (5) rotatably mounted around the shaft (3). A U-shaped contact spring (6) has members (6', 6'') which are individually imparted an oscillating movement between contact pairs A-B-C and A-D-E, respectively, by the turn of the timing wheel (1) in one or the other direction via the carrier which can only move over a pre-determined circular section, so as to generate digital pulse trains. A locking device (4, 10, 15) prevents the carrier (5) from moving beyond the pre-determined circular section and causes the protrusion (13) to continuously engage with the grooves (12) by the turn of the timing wheel (1).