Controller for ultrasonic sensors
First Claim
1. An apparatus for controlling operation of ultrasonic transducers, comprising:
- a multiplexer adapted for coupling to a plurality of ultrasonic transducers and having a multiplexer output and a selection input for selecting which of the plurality of ultrasonic transducers is coupled to the multiplexer output;
signal processing means for processing the multiplexer output based upon signal processing parameters received from a parameter input and providing a processed output; and
controller means for receiving an input related to a selected transducer, providing a signal to the selection input of the multiplexer whereby the selected transducer is coupled to the multiplexer output, and providing signal processing parameters related to the selected transducer to the signal processing means, the controller means including an interface for coupling to a communication loop and wherein the controller input related to a selected transducer is received over the communication loop.
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Accused Products
Abstract
An ultrasonic transducer for measuring a property of a material within a defined space has a function of a velocity at which ultrasonic signals travel through the defined space includes a controller. The controller is adapted for coupling to a plurality of ultrasonic transducers. The controller include a multiplexer for selecting one of the plurality of ultrasonic transducers, signal processing means for processing an output of the selected ultrasonic transducer and controller means for providing parameters to the signal processing means based upon the selected ultrasonic transducer. The controller couples to a two wire 4-20 mA communication loop. The controller periodically excites the ultrasonic transducer to obtain a measurement. The controller stores power received from the two wire communication loop and excites the transducer using stored power. The controller is capable of providing power which exceeds that available directly from the two wire communication loop for a brief period of time. The controller provides a wet self-test whereby output level of the ultrasonic transducer is monitored while strength of the excitation signal provided to the ultrasonic transducer is decreased. The amount of decrease required for the output signal to pass a threshold level is an indication of the usefulness of the sensor.
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Citations
26 Claims
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1. An apparatus for controlling operation of ultrasonic transducers, comprising:
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a multiplexer adapted for coupling to a plurality of ultrasonic transducers and having a multiplexer output and a selection input for selecting which of the plurality of ultrasonic transducers is coupled to the multiplexer output; signal processing means for processing the multiplexer output based upon signal processing parameters received from a parameter input and providing a processed output; and controller means for receiving an input related to a selected transducer, providing a signal to the selection input of the multiplexer whereby the selected transducer is coupled to the multiplexer output, and providing signal processing parameters related to the selected transducer to the signal processing means, the controller means including an interface for coupling to a communication loop and wherein the controller input related to a selected transducer is received over the communication loop. - View Dependent Claims (2, 3, 4, 5, 6)
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7. An ultrasonic transducer for coupling to a two wire 4-20 mA communication loop, comprising:
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interface means for receiving power from the two wire communication loop and transmitting information related to transducer measurements over the two wire communication loop; an ultrasonic transducing element; means for periodically exciting the ultrasonic transducing element, obtaining a transducer measurement and providing the interface means with information related to a transducer measurement; and means, coupled to the interface means, for storing power received from the two wire communication loop and providing stored power to the means for periodically exciting. - View Dependent Claims (8, 9, 10)
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11. An ultrasonic transducer for measuring a property of a material, comprising:
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an ultrasonic transducing element; means for exciting the ultrasonic transducing element; means for receiving a transducer output signal from the ultrasonic transducing element; means for decreasing strength of an excitation signal provided to the ultrasonic transducing element by the means for exciting; and comparator means for comparing strength of the transducer output signal with a threshold level and producing an output based upon the comparison which is related to a wet self-test. - View Dependent Claims (12, 13, 14)
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15. An apparatus for controlling operation of ultrasonic transducers, comprising:
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a multiplexer adapted for coupling to a plurality of ultrasonic transducers and having a multiplexer output and a selection input for selecting which of the plurality of ultrasonic transducers is coupled to the multiplexer output; signal processing means for processing the multiplexer output based upon signal processing parameters received from a parameter input and providing a processed output; controller means for receiving an input related to a selected transducer, providing a signal to the selection input of the multiplexer whereby the selected transducer is coupled to the multiplexer output, and providing signal processing parameters related to the selected transducer to the signal processing means; interface means for receiving power from a two wire communication loop and transmitting the processed output over the two wire communication loop; means for periodically exciting the selected ultrasonic transducer; and means, coupled to the interface means, for storing power received from the two wire communication loop and providing stored power to the means for periodically exciting. - View Dependent Claims (16, 17, 18, 19, 20)
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21. An apparatus for controlling operation of ultrasonic transducers, comprising:
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a multiplexer adapted for coupling to a plurality of ultrasonic transducers and having a multiplexer output and a selection input for selecting which of the plurality of ultrasonic transducers is coupled to the multiplexer output; signal processing means for processing the multiplexer output based upon signal processing parameters received from a parameter input and providing a processed output; controller means for receiving an input related to a selected transducer, providing a signal to the selection input of the multiplexer whereby the selected transducer is coupled to the multiplexer output, and providing signal processing parameters related to the selected transducer to the signal processing means; means for exciting a selected ultrasonic transducing element and obtaining a transducer output signal; wherein the controller means includes; means for decreasing strength of an excitation signal provided to the ultrasonic transducing element; and comparator means for comparing the strength of the transducer output signal with a reference signal level and producing an output based upon the comparison which is representative of a wet self-test. - View Dependent Claims (22, 23, 24, 25, 26)
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Specification