Embodiments include a primary short circuit coupled to a primary side of a transformer and a dampening element, coupled to a transducer coupled to a secondary side of the transformer, configured to dampen a received signal during a portion of a reverberation period.

A method of operating a sound generation mechanism includes determining a temperature of the sound generation mechanism, identifying a resonant frequency of the sound generation mechanism associated with the determined temperature, and communicating an excitation frequency to the sound generation mechanism. The excitation frequency is selected in response to the resonant frequency associated with the determined temperature. The sound generation mechanism is operated to produce one or more sounds.

A vibro-acoustic assembly and related systems and methods for applying a wide range of audio frequencies in one or multiple channels to living beings for wellbeing. The assembly is ergonomic, compact, portable and configured to address physically any area of a user's body while being flexible and easy to use to deliver a wide degree of frequencies/identified targeted programs from a source audio device, such as a smart phone application via wireless transmission.

A gas turbine engine includes an airfoil and a deicing system. The airfoil radially extends from a hub towards a case disposed about a central longitudinal axis of the gas turbine engine. The deicing system includes an acoustic driver assembly arranged to apply acoustic energy to the airfoil to excite a predetermined vibratory mode of the airfoil.

A gas turbine engine includes an airfoil and a deicing system. The airfoil radially extends from a hub towards a case disposed about a central longitudinal axis of the gas turbine engine. The deicing system includes an acoustic driver assembly arranged to apply acoustic energy to the airfoil to excite a predetermined vibratory mode of the airfoil.

Acoustic signal sources include acoustic resonators that include acoustic nonlinear materials. Acoustic signals at higher frequencies are mixed in the nonlinear materials to produce a lower frequency acoustic signal. Resonance provides increased efficiency in producing acoustic signals at difference frequencies corresponding to resonance frequencies. Higher frequency acoustic signals used in nonlinear mixing are preferably at frequencies corresponding to resonance frequencies as well.

The present invention relates to an ultrasonic generator for repelling harmful animals. The invention comprises a columnar ultrasonic wave generating body 18 which has a piezoelectric element 16 and a connecting body 22 and a smaller-diameter connecting body 24 each having a reduced diameter, a diaphragm 28 which is in the form of a speaker horn, and a connecting rod 26 which extends from the ultrasonic wave generating body 18 and connects and fixes the diaphragm 28 to an end thereof. The thickness of the diaphragm 28 gradually decreases from the base 34 connected to the connecting rod 26 toward an outer edge of the diaphragm 28 and one or more undulated portions 36 are formed concentrically on the front face of the diaphragm.

The present invention relates to an ultrasonic generator for repelling harmful animals. The invention comprises a columnar ultrasonic wave generating body 18 which has a piezoelectric element 16 and a connecting body 22 and a smaller-diameter connecting body 24 each having a reduced diameter, a diaphragm 28 which is in the form of a speaker horn, and a connecting rod 26 which extends from the ultrasonic wave generating body 18 and connects and fixes the diaphragm 28 to an end thereof. The thickness of the diaphragm 28 gradually decreases from the base 34 connected to the connecting rod 26 toward an outer edge of the diaphragm 28 and one or more undulated portions 36 are formed concentrically on the front face of the diaphragm.

An ultrasonic transducer including a membrane film and a perforated baseplate. The baseplate can have a conductive surface with a plurality of perforations formed through the baseplate. The membrane film can have a conductive surface and be positioned under tension proximate to the perforations formed through the baseplate. The tension of the membrane film can be controlled to provide a restoring force to counteract the moving mass of the membrane film, and the moving mass of air in the perforations of the baseplate. By selecting the diameter(s) of the perforations of the baseplate, the thickness of the baseplate, the thickness of the membrane film, the tension of the membrane film, and/or the bending stiffness of the membrane film, a wide bandpass frequency response of the ultrasonic transducer centered at an ultrasonic frequency of interest can be obtained and tailored to a desired application.

A gas turbine engine includes an airfoil and a deicing system. The airfoil radially extends from a hub towards a case disposed about a central longitudinal axis of the gas turbine engine. The deicing system includes an acoustic driver assembly arranged to apply acoustic energy to the airfoil to excite a predetermined vibratory mode of the airfoil.