Two-wire ultrasonic transmitter
First Claim
1. An instrument for sensing level of a material comprising:
- a transducer and means for mounting said transducer in proximity to a material, the level of which is being sensed;
a drive circuit connected to said transducer and including means for periodically energizing said transducer to transmit an energy pulse to be reflected off of a surface of the sensed material;
an amplifier circuit connected to said transducer and including amplifier means for developing an analog signal having a magnitude corresponding to reflected energy received by said transducer;
a detector circuit connected to said amplifier circuit for determining if said analog signal has a level above a select threshold, representing receipt of a return echo pulse; and
a control circuit operatively coupled to said drive circuit, said amplifier circuit and said detector circuit and including level determining means for determining a time difference between a first time when said drive circuit energizes said transducer and a second time when said analog signal is above said threshold, said time difference representing level, and amplifier control means for energizing said amplifier circuit for a select minimum time duration commencing subsequent to energization of said transducer and terminating after receipt of a return echo pulse.
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0 Petitions
Accused Products
Abstract
A two-wire ultrasonic transmitter senses level of a material and controls current of power supplied thereto to a magnitude representing sensed level The transmitter comprises a transducer mounted in proximity to a material, the level of which is being sensed. A power supply circuit receives power for operating the instrument. A drive circuit is connected to the transducer and the power supply circuit and periodically energizes the transducer to transmit an energy pulse to be reflected off of a surface of the sensed material. An amplifier circuit is connected to the transducer and develops an analog signal having a magnitude corresponding to reflected energy received by the transducer. A control circuit is operatively coupled to the drive circuit and the amplifier circuit and determines time difference between a first time when the drive circuit energizes the transducer and a second time when the analog signal is above the threshold, the time difference representing level, and energizes the amplifier circuit for a select minimum time duration commencing subsequent to energization of the transducer and terminating after receipt of a return echo pulse A current control circuit is coupled to the control circuit for controlling current received by the power supply circuit to a magnitude representing sensed level.
48 Citations
20 Claims
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1. An instrument for sensing level of a material comprising:
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a transducer and means for mounting said transducer in proximity to a material, the level of which is being sensed; a drive circuit connected to said transducer and including means for periodically energizing said transducer to transmit an energy pulse to be reflected off of a surface of the sensed material; an amplifier circuit connected to said transducer and including amplifier means for developing an analog signal having a magnitude corresponding to reflected energy received by said transducer; a detector circuit connected to said amplifier circuit for determining if said analog signal has a level above a select threshold, representing receipt of a return echo pulse; and a control circuit operatively coupled to said drive circuit, said amplifier circuit and said detector circuit and including level determining means for determining a time difference between a first time when said drive circuit energizes said transducer and a second time when said analog signal is above said threshold, said time difference representing level, and amplifier control means for energizing said amplifier circuit for a select minimum time duration commencing subsequent to energization of said transducer and terminating after receipt of a return echo pulse. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. A two wire ultrasonic transmitter for sensing level of a material and controlling current of power supplied thereto to a magnitude representing sensed level, comprising:
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a transducer; means for mounting said transducer in proximity to a material, the level of which is being sensed; a power supply circuit for receiving power for operating said transmitter; a drive circuit connected to said transducer and said power supply circuit and including means for periodically energizing said transducer to transmit an energy pulse to be reflected off of a surface of the sensed material; an amplifier circuit connected to said transducer and including amplifier means for developing an analog signal having a magnitude corresponding to reflected energy received by said transducer; a control circuit operatively coupled to said drive circuit and said amplifier circuit and including level determining means for determining a time difference between a first time when said drive circuit energizes said transducer and a second time when said analog signal is above a select threshold, said time difference representing level, and amplifier control means for energizing said amplifier circuit for a select minimum time duration commencing subsequent to energization of said transducer and terminating after receipt of a return echo pulse; and current control means coupled to said level determining means for controlling current received by said power supply circuit to a magnitude representing sensed level. - View Dependent Claims (9, 10, 11, 12, 13, 14, 15, 16, 17, 18)
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19. An ultrasonic transmitter for sensing level of a material and including a transducer self-test mode of operation, comprising:
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a transducer; means for mounting said transducer in proximity to a material, the level of which is being sensed; a drive circuit connected to said transducer and including means for periodically energizing said transducer to transmit a sound energy pulse to be reflected off of a surface of the sensed material; a receive circuit connected to said transducer for developing a signal having a magnitude corresponding to reflected sound energy received by the transducer; and a control circuit operatively controlling said drive circuit and said receive circuit, each said drive circuit and receive circuit normally being disabled by said control circuit, said control circuit including a self-test mode of operation means for periodically enabling the drive circuit for a select time duration to transmit sound energy pulses to be reflected off of a surface of the sensed material and for subsequently enabling the receive circuit and monitoring means for determining if the transducer continues to transmit sound energy pulses subsequent to said select time duration to insure proper operation of the transducer. - View Dependent Claims (20)
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Specification