Abstract: A method for determining a characteristic data set (“fingerprint”) for a sound signal, the sound signal itself is searched through for characteristic locations, and these characteristics locations are used for producing a characteristic data set. For this the frequency spectrum is evaluated over a time interval, subdivided into frequency bands, and averaged over each frequency band into a value. The fingerprint then consists of data that has been obtained from these values after possible further averagings, wherein only data is included which belongs to certain time segments.

Abstract: The piezoelectric motor (6) comprises a stator (1) and a runner (4) which form a gap (7) as well as comprising a piezoelectric transducer (3) which is connected to the stator (1) or the runner (4) and which with the stator (1) or the runner (4) forms a resonator (1,3;4,3), wherein the resonator (1,3; 4,3) may be excited in a main oscillation direction (H), characterised in that the stator (1) comprises an engagement surface (1a) facing the runner (4), or the runner (4) an engagement surface which faces the stator (1), and that the stator (1) or the runner (4) comprises an elastic advance element (5) which bridges the gap (7) between the stator (1) and the runner (4) in a manner such that the advance element (5) at least temporarily lies on the engagement surface (1a). The advance element (5) comprises a first part-section (5c) as well as a second part-section (5d), wherein the part-sections (5c, 5d) have a different resonant frequency.

Abstract: A piezoelectric drive having an excitation piezoelement (10) and a resonator (2). The resonator is coupled to the piezoelement and is in interactive connection with a body (3) to be driven. The resonator (2) has a mass distribution that is designed such that, as a result of an excitation oscillation by the piezoelement (10), the resonator (2) begins to asymmetrically oscillate in several directions dependent on the frequency of the excitation oscillation. The asymmetric oscillations, via the interactive connection, displace the body to be driven into a directed movement.

Abstract: A continuous flow heater has an elastic, flexible or rigid pipe (10) which is movably mounted and a heat source (6). When a liquid flowing through the pipe is heated in the pipe interior (1), undesired scale tends to be deposited on the interior of the pipe walls. To prevent or remove this deposit, the pipe (10) is moved and/or deformed by an internal overpressure or by application of external forces, causing the deposits to be detached from the pipe inner walls and carried away by the fluid flow. The overall pipe (10) can have an inner pipe (2), inner insulating layers (3-5), a filament (6) and external insulating layers (7-9).