Abstract: An ultrasonic sensor detects a liquid level. A substrate (707) has an acoustic array (705). An acoustic diversion array (710) can be between a substrate edge (713) and the acoustic array. A sensing region (701) can lay next to the acoustic array opposite the acoustic diversion array. A collimation groove (706) can be in the substrate along a length of the acoustic array next to the liquid level sensing region. Multiple longitudinal folds (801, 802, 803) can run parallel to and between acoustic source and receive arrays. A feed strip (1201, 1202, 1309, 1311) can be used with a bend (1203, 1204) acoustically coupled to the acoustic array and an ultrasonic transducer at another end of the feed strip. The feed strip runs along the entire acoustic array when top fed and runs along part of the acoustic array when fed through a side of a tank (1401).

Abstract: An ultrasonic sensor detects a level of a fluid. A first probe has a first transducer element to transmit an ultrasonic signal through the first probe. A second probe of a helix shape has a second transducer element coiled around the first probe to receive the ultrasonic signal transmitted by the first probe through the fluid. A stabilizing rod and a plurality of stabilizing collets are disposed between the rod and the second probe parallel to both the first probe and the second probe.

Abstract: A touch panel has a substrate having first and second surfaces, and defines a touch surface. A first portion of a touch system includes a first plurality of echelons on the first surface in a first array along a first centerline. Each echelon is formed at an angle to the first centerline, and a first shear transducer assembly on the edge of the substrate that generates a shear wave in a source wave mode in a first direction along the first centerline. A second portion of the touch system includes a second plurality of echelons on the first surface in a second array along a second centerline, each echelon at a second angle to the second centerline. The second centerline is orthogonal to the first. A second shear transducer assembly is mounted on the edge and generates a shear wave in a source wave mode in a second direction along the second centerline. The first sensing mode is different from the second sensing mode.

Abstract: An ultrasonic sensor for detecting the presence or absence of an aerated fluid includes a probe having a first solid portion and a second hollow portion. The probe has a closed end at the hollow portion. The solid portion and the hollow portion define an interface therebetween. A transducer element is mounted to the probe at about the solid portion. The transducer element is configured to transmit an ultrasonic signal through the solid portion into the hollow portion and to receive reflections of the ultrasonic signal to determine the presence or absence of a fluid and/or an aerated fluid.

Abstract: A level sensor includes a substrate having at least one reflective side surface, at least one wave generator on one end of the substrate configured to transmit a wave down the surface of the substrate and a plurality of reflective echelons mounted on the substrate such that each echelon is at an angle relative to reflective side surface. The reflective echelons are configured to convert a wave of a first mode in to a wave of a second mode.

Abstract: An ultrasonic liquid sensor for detecting liquid in a tube having sidewalls includes a first intermediate mounting plate held in physical communication with a first sidewall of the tube, a second intermediate mounting plate held in physical communication with the second sidewall of the tube. The plates are configured to allow the ultrasonic signal to pass therethrough. The sensor also includes a first and a second transducer element. The first and second transducer elements are mounted to the intermediate mounting plates and are configured to receive the ultrasonic signal passing through the sidewalls of the tube as well as the intermediate mounting plates to determine the presence or absence of liquid in the tube. The sensor can be enclosed in a self-contained unit and a support assembly can be used and formed of metal material or non-metal material to interface with the sensor and a secondary circuit.

Abstract: An ultrasonic sensor for detecting the presence or absence of an aerated fluid includes a probe having a first solid portion and a second hollow portion. The probe has a closed end at the hollow portion. The solid portion and the hollow portion define an interface therebetween. A transducer element is mounted to the probe at about the solid portion. The transducer element is configured to transmit an ultrasonic signal through the solid portion into the hollow portion and to receive reflections of the ultrasonic signal to determine the presence or absence of a fluid and/or an aerated fluid.

Abstract: An ultrasonic liquid sensor for detecting liquid in a tube having sidewalls includes a first intermediate mounting plate held in physical communication with a first sidewall of the tube, a second intermediate mounting plate held in physical communication with the second sidewall of the tube. The plates are configured to allow the ultrasonic signal to pass therethrough. The sensor also includes a first and a second transducer element. The first and second transducer elements are mounted to the intermediate mounting plates and are configured to receive the ultrasonic signal passing through the sidewalls of the tube as well as the intermediate mounting plates to determine the presence or absence of liquid in the tube. The sensor can be enclosed in a self-contained unit and a support assembly can be used and formed of metal material or non-metal material to interface with the sensor and a secondary circuit.

Abstract: A circuit for an acoustic wave switch or sensor having a resonant acoustic wave cavity detects a touch or sensed event using a time domain approach. The circuit includes a controller that drives an acoustic wave transducer to generate a resonant acoustic wave in the acoustic wave cavity during a first portion of a sampling cycle. In a second portion of the sampling cycle, the controller monitors the time that it takes for the acoustic wave signal from the transducer to decay to a predetermined level. Based on the decay time, the controller detects a sensed event, such as a touch on the acoustic wave switch/sensor.

Abstract: Certain embodiments provide an acoustic wave touch bar system and method of use. Certain embodiments include a bar having two portions of reduced cross-section forming an acoustic cavity in the portion of the bar between the reduced cross-sections. The system includes an acoustic wave transducer positioned on the acoustic wave cavity, wherein the transducer generates an acoustic standing wave that is substantially trapped in the acoustic cavity. The system also includes a circuit coupled to the transducer and responsive to a change in an output of the transducer to detect a touch on a touch surface of the bar. The circuit may be a programmable and/or adaptive circuit, for example. The circuit may detect a change in an exponentially decaying response of the transducer indicating that the touch surface of the bar has been touched.

Abstract: An acoustic wave switch includes a substrate with an acoustic wave cavity formed therein such that the mass per unit area of the acoustic cavity is greater than the mass per unit area of the substrate adjacent the cavity. A transducer is mounted on the acoustic cavity for generating an acoustic wave that is substantially trapped in the cavity. A touch on the touch surface of the acoustic wave cavity absorbs acoustic wave energy and produces a detectable change in the impedance of the transducer. Various feedback mechanisms can be employed to provide a user with a tactile, audible and/or visual response indicating actuation of the switch by a touch.

Abstract: An individual acoustic wave switch includes a body with a top section having an acoustic wave cavity formed therein and a base section extending downwardly from the top section. An acoustic wave transducer is mounted adjacent to a surface of the acoustic wave cavity opposite the touch surface thereof so as to generate an acoustic wave in the acoustic wave cavity and to pick up a signal representing the acoustic wave energy in the cavity. The acoustic wave switch is readily mounted in an aperture of a substrate through which the base of the switch extends.

Abstract: A circuit for an acoustic wave switch or sensor having a resonant acoustic wave cavity detects a touch or sensed event using a time domain approach. The circuit includes a controller that drives an acoustic wave transducer to generate a resonant acoustic wave in the acoustic wave cavity during a first portion of a sampling cycle. In a second portion of the sampling cycle, the controller monitors the time that it takes for the acoustic wave signal from the transducer to decay to a predetermined level. Based on the decay time, the controller detects a sensed event, such as a touch on the acoustic wave switch/sensor.

Abstract: An acoustic wave switch includes a substrate with an acoustic wave cavity formed therein such that the mass per unit area of the acoustic cavity is greater than the mass per unit area of the substrate adjacent the cavity. A transducer is mounted on the acoustic cavity for generating an acoustic wave that is substantially trapped in the cavity. A touch on the touch surface of the acoustic wave cavity absorbs acoustic wave energy and produces a detectable change in the impedance of the transducer. The acoustic wave switch has a high Q so as to enable a touch to be detected by extremely simple, low-cost circuitry. The acoustic wave switch of the present invention is rugged, explosion proof, operates in the presence of liquids and other contaminants, has a low power consumption and can be incorporated and integrally formed in a wall of a housing for a device.

Abstract: A laminated acoustic wave touch panel is shown and a method of making the panel is described using an adhesive barrier material. The adhesive barrier material is positioned between a substrate in which a shear wave is to propagate and a backplate in order to form a cavity between the substrate and backplate. An adhesive is injected into the cavity to laminate the substrate to the back plate. The use of the barrier material allows the laminated touch panel to be easily manufactured and allows the adhesive to be constrained to a desired area of the panel. The invention envisions the use of similar and dissimilar materials for the substrate and backplate. The velocity of a shear wave at a given frequency is greater in the backplate than in the substrate in the case where the materials are dissimilar and equal for a given frequency when the materials are the same.

Abstract: An acoustic wave touch panel comprising a substrate formed of a first material. The substrate is capable of supporting an acoustic wave for propagation therein. A reflective array upon the substrate is provided for reflecting an acoustic wave to propagate in the substrate. The reflective array is formed in the substrate. An inlay is formed of a second material. The inlay is disposed in the reflective array, wherein the acoustic wave has a velocity of propagation in the second material that is slower than the velocity of propagation of the acoustic wave in the first material.