Abstract:
An operating frequency setting unit outputs an ultrasonic emitting command to a variable oscillator circuit in an operating frequency setting mode to cause a detector to emit an ultrasonic wave a plurality of times while varying the frequency thereof. At this time, emission or reflected waveform data are inputted via a band pass filter to detect a resonance frequency of a system including the piezoelectric element of the detector and an LPG tank on the basis of the difference between attenuation characteristics of waveforms. The detected resonance frequency is registered in a memory part as an operating frequency. Thus, it is possible to provide a general purpose ultrasonic sensor usable for any one of a plurality of vessels having any wall thickness and material when an object is detected while the detector is mounted on the outside face of a vessel.
Abstract:
A vibrating mechanism comprised of piezoelectric elements which vibrate at a high frequency when a voltage is applied to them. The piezoelectric elements are mounted on a rib so that their free ends extend from the rib. When the piezoelectric elements are energized the free ends vibrate with a "wing-flapping" motion. Weights may be attached to the free ends of the piezoelectric element to increase the inertial component of vibration. In the preferred embodiment of the invention, the piezoelectric elements are prestressed. The invention will be an inexpensive substitute for other vibratory devices.
Abstract:
A self-exciting vibratory device for producing vibration signals in a housing includes actuator means (12) attached to housing (16), sensor means (14) attached to housing (16) and electronics module (18) connecting actuator means (12) and sensor means (14). Actuator means (12) creates vibration signals within housing (16). Sensor means (14) senses the vibration signals created by actuator means (12). Electronics module (18) amplifies and phase shifts the vibration signals sensed by sensor means (14) and containing resonant modes of vibration of housing (16). Electronics module (18) then supplies these amplified, phase shifted signals to actuator means (12) to enhance the vibration of housing (16) at the dominant mode of vibration of housing (16).
Abstract:
Ultrasonic vibrators, attached to the back of a mirror, are vibrated according to an A.C. signal pattern which is selected from various A.C. signal patterns for the removal of water, frost and/or ice from the surface of the mirror. Further included is a temperature detecting device attached to the back of the mirror for inhibiting operation of the ultrasonic vibrators when the temperature of the mirror exceeds a predetermined temperature, to thus avoid thermally-induced damage to the mirror.
Abstract:
An acoustic imaging system coupled to an acoustic medium to define an imaging surface. The acoustic imaging system includes an array of piezoelectric acoustic transducers formed at least in part from a thin-film piezoelectric material, such as PVDF. The array is coupled to the acoustic medium opposite the imaging surface and formed using a thin-film manufacturing process over an application-specific integrated circuit that, in turn, is configured to leverage the array of piezoelectric actuators to generate an image of an object at least partially wetting to the imaging surface.
Abstract:
A novel mode of ultrasonic oscillation is generated in a Langevin ultrasonic transducer comprising a metal block, a metal block provided with a supporting means protruding in a ring shape on its side surface, and polarized piezoelectric elements fixed between these metal blocks, by connecting the ultrasonic transducer to a base via the supporting means, whereby supporting the ultrasonic transducer on the base in a restrained state, and applying to the piezoelectric elements a voltage having such frequency that the ultrasonic transducer generates an ultrasonic oscillation with back-and-forth motion in a direction perpendicular to plane surfaces of the piezoelectric elements which has no oscillation node within the ultrasonic transducer; this novel ultrasonic oscillation mode is utilized for performing ultrasonic machining methods as well as for ultrasonic transmission method.
Abstract:
The present invention relates a power ultrasound device for fluids processing. An ultrasonic resonator comprises: an exciter section having a longitudinal axis and dimensioned to be resonant in a direction along the longitudinal axis when the exciter section is energized with high frequency vibrations; and a radiator section having a connection stub and coupled to the exciter section through the connection stub, wherein the radiator section is configured to receive the vibrations from the exciter section and transmit the vibrations as acoustic waves, wherein an axial length of the exciter section is less than a half-wavelength, wherein the connection stub completes the half-wavelength when coupled to the excited section to allow the ultrasonic resonator operate in resonance at design frequency. The radiator section includes a radiator body having at least three sides to provide a plurality of external radiating surfaces, and two opposite faces having a plurality of orifices formed therein, wherein walls of the orifices are configured to provide a plurality of internal radiating surfaces, and wherein the internal and the external surfaces are configured to transmit the vibrations as acoustic waves.
Abstract:
A system for processing biological or other samples includes an array of transducer elements that are positioned to align with sample wells in a microplate. Each transducer element produces ultrasound energy that is focused towards a well of the microplate with sufficient acoustic pressure to cause inertial cavitation. In one embodiment, the transducers are configured to direct ultrasound energy into cylindrical wells. In other embodiments, the transducer elements are configured to direct ultrasound energy into non-cylindrical wells of a microplate.