Abstract:
An apparatus for use as an output device of a user interface to an information processing system includes at least one device (15;20) for generating a synthetic jet flow.
Abstract:
A loudspeaker arrangement comprises an acoustic enclosure (101) which is divided into at least two subchambers (103, 105). An audio radiator (109) is mounted in a first subchamber (103) of the at least two subchambers (103, 105) such that it radiates outwardly of the acoustic enclosure (101). A port (107) is included for pneumatically connecting the first subchamber (103) and the second subchamber (105). The system is designed such that a Helmholtz frequency of the first subchamber (103) and the port (107) is at least five times higher than a resonance frequency of the audio radiator (109). The loudspeaker arrangement may provide an improved trade-off between sound pressure levels, audio quality and size and may in particular provide improved low frequency performance without introducing disadvantages typically associated with conventional ported speaker and passive radiator designs.
Abstract:
An illumination device (1) comprising: at least one light emitting device (5); and a suspension structure (2), suspending the at least one light emitting device (5) in a desired position. Further, the illumination device (1) has a transducer (6), adapted to generate pressure waves at a drive frequency; wherein the suspension structure (2) is utilized as a flow guiding structure (7), having a first end adapted to receive the pressure waves from the transducer, and a second end adapted to generate a pulsating net output flow towards the at least one light emitting device (5), thereby cooling the at least one light emitting device (5). By utilizing the suspension structure itself as flow guiding structure cooling can be integrated in a cost efficient way. Further, no additional space is required to accommodate the flow guiding structure.
Abstract:
A cooling device comprising at least one transducer (1) having a membrane adapted to generate pressure waves at a working frequency, characterized by a first and a second cavity (3, 4), said transducer being arranged between said first and second cavities, such that said membrane forms an fluid tight seal between said cavities, each cavity having at least one opening (7, 8) adapted to emit a pulsating net output fluid flow, wherein said cavities and openings are formed such that, at said working frequency, a first harmonic fluid flow emitted by said opening(s) (7) of a first one of said cavities is in anti-phase with a second harmonic fluid flow emitted by said opening(s) (8) of a second one of said cavities, so that a sum of harmonic fluid flow from said openings is essentially zero. With this design, sound reproduction at the working frequency is largely cancelled due to the counter phase of the outlets resulting in a close to zero far-field volume velocity.
Abstract:
A device (30) for adapting an audio input signal (V1n) to a transducer unit (20) comprises: • mapping means (10) for mapping input signal components from a first audio frequency range onto a second audio frequency range so as to produce a mapped audio signal (VM), wherein the second audio frequency range is narrower than the first audio frequency range, and wherein the transducer unit (20) has a maximum efficiency at the second audio frequency range, • filter means (31) for filtering the input signal (V1n) so as to produce a filtered input signal (V1n') having a third audio frequency range, and • combination means (32) for combining the mapped audio signal (VM) and the filtered input signal (V1n') so as to produce a transducer signal (VT). The first audio frequency range is preferably contained in the second audio frequency range, while the third audio frequency range may be adjacent the first audio frequency range. The second audio frequency range preferably extends within 5% of the Helmholtz frequency of the transducer unit (20).