Abstract: A switch that includes a sensor device capable of transmitting data related to a sensor signal of at least one sensor of the sensor device to an external unit through wireless communication.

Abstract: A rotor for a radial compressor is provided. An axial shaft of the radial compressor includes longitudinal axial shaft segments. The rotor includes rotor discs, which are placed adjacent to one another, and which extend along a longitudinal axis of the radial compressor. The rotor discs include the respective axial shaft segments and impellers. A coupling means is provided to couple the rotor discs with one another. The coupling means permits reversible axial splitting of the axial shaft into the respective axial shaft segments.

Abstract: There is described an alarm system (1) comprising: a carrier unit (10; a base unit (30) having an in-output (31) for coupling to a communication network (P); an alarm monitoring station (100) coupled to that communication network (P); wherein the carrier unit (10) comprises a transmitter (20) and an alarm switch (13) coupled to an alarm input (23) of the transmitter (20). By operating the alarm switch (13), the base unit (30) is wirelessly activated by the carrier unit (10). Accordingly, the base unit (30) makes connection with the communication network (P) and selects the access number of the alarm monitoring station (100). In accordance with the invention, the transmitter (20) comprises a microphone input (24) coupled to a microphone (14). Speech signals from the user are wirelessly transmitted by the transmitter (20) to the base unit (30), which transmits these speech signals via the communication network (P) to the alarm monitoring station (100).

Abstract: An electroacoustic transducer of the electret type, comprising a case (101) having an opening (102) via which the interior of the case communicates with the surroundings; a backplate (105) and a diaphragm (107) arranged opposite the backplate in the case, the surface of the backplate being provided at least partly with an electret material (106) and at least a part of the surface of the diaphragm being provided with an electrically conductive layer (110); and an annular element (109) for securing the circumference of the diaphragm to the inside wall of the case. According to the invention, the parasitic capacity between the backplate (105) and the annular element (109) is eliminated in that the backplate and the annular element are both electrically connected with the case and thereby have the same potential as the case. This also provides production-technical advantages.