Ultrasonic transmitting and receiving circuit and ultrasonic flowmeter

Abstract

The utility model provides an ultrasonic transceiver circuit and an ultrasonic flowmeter. The circuit comprises a controller, an adjusting circuit and a transducer pair, the controller is connected with the input end of the adjusting circuit and used for sending an initial excitation signal to the adjusting circuit. The output end of the adjusting circuit is connected with the transmitting end transducer in the transducer pair, and the adjusting circuit is used for adjusting the intensity of the initial excitation signal and outputting a variable excitation signal; a transmitting end transducer in the transducer pair is used for transmitting an ultrasonic signal according to the variable excitation signal; a receiving end transducer in the transducer pair is used for receiving the ultrasonic signal and converting the received ultrasonic signal into an initial echo signal; and the controller is also used for controlling the adjusting circuit to adjust the intensity of the initial excitation signal according to the initial echo signal. The circuit is used for adjusting the intensity of the excitation signal, and the metering accuracy of the ultrasonic flowmeter is improved.

Description

Technical Field

[0001] This application relates to flow measurement technology, and more particularly to an ultrasonic transceiver circuit and an ultrasonic flow meter. Background Technology

[0002] An ultrasonic flow meter is a non-contact flow measurement instrument with advantages such as high accuracy, good stability, and ease of operation, and has a wide range of applications. The principle of an ultrasonic flow meter is that after receiving an excitation electrical signal, the transducer at the transmitting end generates an ultrasonic signal due to the inverse piezoelectric effect. This ultrasonic signal is transmitted through the flow channel to the receiving transducer, where it is converted into an echo electrical signal by the piezoelectric effect. Flow rate can be measured based on this echo electrical signal. Generally speaking, all other things being equal, the stronger the echo electrical signal, the more accurate the detection.

[0003] In existing technologies, ultrasonic flow meters often use excitation signals of fixed intensity. However, the velocity of sound varies in different application environments, which leads to significant differences in the echo electrical signals measured by the ultrasonic flow meter when the excitation intensity is constant. This results in inaccurate measurements and greatly reduces the metering accuracy of the ultrasonic flow meter. Utility Model Content

[0004] This application provides an ultrasonic transceiver circuit and an ultrasonic flow meter, which are used to adjust the intensity of the excitation signal and improve the measurement accuracy of the ultrasonic flow meter.

[0005] On the one hand, this application provides an ultrasonic transceiver circuit, including: a controller, an adjustment circuit, and a transducer pair;

[0006] The controller is connected to the input terminal of the adjustment circuit and is used to send an initial excitation signal to the adjustment circuit.

[0007] The output terminal of the adjustment circuit is connected to the transmitting transducer in the transducer pair, and is used to adjust the intensity of the initial excitation signal and output a variable excitation signal.

[0008] The transmitting transducer in the transducer pair is used to transmit ultrasonic signals according to the variable excitation signal;

[0009] The receiving transducer in the transducer pair is used to receive the ultrasonic signal and convert the received ultrasonic signal into an initial echo signal.

[0010] The controller is further configured to control the adjustment circuit to adjust the intensity of the initial excitation signal based on the initial echo signal.

[0011] Optionally, the adjustment circuit includes: a driver chip and a control module;

[0012] The control module is used to send control signals to the driver chip under the control of the controller;

[0013] The input terminal of the driver chip is connected to the controller, the output terminal of the driver chip is connected to the transmitter transducer, and the input terminal of the driver chip is connected to the control module; the driver chip is used to boost the initial excitation signal under the control of the control signal to obtain a variable excitation signal.

[0014] Optionally, the control module includes: a boost module and a selection control module;

[0015] The input terminal of the boost module receives a power signal, and the output terminal of the boost module is connected to the control terminal of the driver chip; the boost module is used to boost the power signal and output a control signal.

[0016] The selection and control module is connected to the controller and the boost module, and is used to control the boost process under the control of the controller, thereby controlling the strength of the control signal.

[0017] Optionally, the boost module includes: a boost chip, a first resistor, a second resistor, a third resistor, a fourth resistor, a first inductor, and a first diode; the boost chip includes an input pin, an enable pin, an output pin, and a feedback pin.

[0018] The input pin of the boost chip receives a power signal;

[0019] One end of the first resistor is connected to the input pin of the boost chip, and the other end of the first resistor is connected to the enable pin of the boost chip and one end of the second resistor; the other end of the second resistor is grounded.

[0020] One end of the first inductor is connected to the input terminal of the boost chip, and the other end of the first inductor is connected to the output terminal of the boost chip;

[0021] One end of the first diode is connected to the other end of the first inductor, and the other end of the first diode is connected to the transmitter transducer.

[0022] One end of the third resistor is connected to the transmitter transducer, and the other end of the third resistor is connected to one end of the fourth resistor and the feedback pin of the boost chip; the other end of the fourth resistor is grounded.

[0023] The control module and the fourth resistor are connected in parallel.

[0024] Optionally, the number of the selection and control modules is multiple, and each selection and control module includes: a first transistor, a fifth resistor, and a sixth resistor;

[0025] One end of the fifth resistor is connected to one end of the fourth resistor, and the other end of the fifth resistor is connected to the input terminal of the first transistor.

[0026] The control terminal of the first transistor is connected to one end of the sixth resistor, and the other end of the sixth resistor receives the selection enable signal sent by the controller;

[0027] The output terminal of the first transistor is grounded.

[0028] Optionally, the circuit further includes: a switching module; the switching module includes a first output channel, a second output channel, a first input channel, and a second input channel;

[0029] The input terminals of the first output channel and the second output channel are connected to the output terminal of the adjustment circuit; the output terminal of the first output channel and the input terminal of the first input channel are connected to the first transducer in the transducer pair; the output terminal of the second output channel and the input terminal of the second input channel are connected to the second transducer in the transducer pair; the output terminals of the first input channel and the second input channel are connected to the controller.

[0030] The switching module is used to connect the first output channel and the second input channel when the first transducer is used as a transmitting transducer and the second transducer is used as a receiving transducer; or, when the second transducer is used as a transmitting transducer and the first transducer is used as a receiving transducer, it connects the second output channel and the first input channel.

[0031] Optionally, the circuit further includes: an amplifier circuit;

[0032] The input terminal of the amplifier circuit is connected to the transducer of the receiving terminal, and the output terminal of the amplifier circuit is connected to the controller, which is used to amplify the initial echo signal to obtain an amplified echo signal.

[0033] Optionally, the amplification circuit includes: an operational amplifier, an eleventh resistor, a twelfth resistor, a thirteenth resistor, a fourteenth resistor, a fifteenth resistor, a first capacitor, a second capacitor, a third capacitor, and a fourth capacitor;

[0034] One end of the eleventh resistor and one end of the first capacitor receive a bias voltage, the other end of the first capacitor is grounded, the other end of the eleventh resistor is connected to one end of the twelfth resistor, one end of the second capacitor and one end of the thirteenth resistor, the other end of the second capacitor and the other end of the thirteenth resistor are grounded, and the other end of the twelfth resistor is connected to the non-inverting input of the operational amplifier.

[0035] One end of the fourteenth resistor is connected to the inverting input of the operational amplifier, and the other end of the fourteenth resistor is connected to one end of the third capacitor, while the other end of the third capacitor is grounded.

[0036] One end of the fifteenth resistor and one end of the fourth capacitor are connected to the inverting input of the operational amplifier, the other end of the fifteenth resistor and the other end of the fourth capacitor are connected to the output of the operational amplifier, and the output of the operational amplifier is connected to the controller.

[0037] Optionally, the amplification circuit further includes: a filter resistor, a first coupling capacitor, a second coupling capacitor, and a filter capacitor;

[0038] One end of the first coupling capacitor is connected to the receiving transducer, and the other end of the first coupling capacitor is connected to the inverting input of the operational amplifier.

[0039] One end of the filter resistor is connected to the output terminal of the operational amplifier, the other end of the filter resistor is connected to one end of the filter capacitor, and the other end of the filter capacitor is grounded.

[0040] One end of the second coupling capacitor is connected to the other end of the filter resistor, and the other end of the second coupling capacitor is connected to the controller.

[0041] On the other hand, this application provides an ultrasonic flow meter, including the ultrasonic transceiver circuit as described above.

[0042] In the ultrasonic transceiver circuit and ultrasonic flow meter provided in this application, the controller adjusts the intensity of the initial excitation signal based on the received echo signal and outputs a variable excitation signal to the transmitting transducer. Under the same environment, the stronger the excitation signal, the stronger the echo signal converted by the receiving transducer. Therefore, by controlling the intensity of the echo signal, the consistency of the echo signal intensity under different environments can be improved, which is beneficial for processing and analyzing the echo signal, thereby improving the measurement accuracy of the ultrasonic flow meter. Attached Figure Description

[0043] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0044] Figure 1 The diagram below exemplarily illustrates the structure of the ultrasonic transceiver circuit provided in an embodiment of this application;

[0045] Figure 2 The diagram above exemplarily illustrates the structure of the control module provided in an embodiment of this application;

[0046] Figure 3 The diagram above exemplarily illustrates the structure of the driver chip provided in an embodiment of this application;

[0047] Figure 4 The diagram above exemplarily illustrates the structure of the switching module provided in an embodiment of this application;

[0048] Figure 5 The diagram above illustrates a schematic representation of the amplification module provided in an embodiment of this application.

[0049] The accompanying drawings illustrate specific embodiments of this application, which will be described in more detail below. These drawings and descriptions are not intended to limit the scope of the concept in any way, but rather to illustrate the concept of this application to those skilled in the art through reference to particular embodiments. Detailed Implementation

[0050] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numbers in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this application. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this application as detailed in the appended claims.

[0051] An ultrasonic flow meter is a non-contact flow measurement instrument with advantages such as high accuracy, good stability, and ease of operation, and has a wide range of applications. The principle of an ultrasonic flow meter is that after receiving an excitation electrical signal, the transducer at the transmitting end generates an ultrasonic signal due to the inverse piezoelectric effect. This ultrasonic signal is transmitted through the flow channel to the receiving transducer, where it is converted into an echo electrical signal by the piezoelectric effect. Flow rate can be measured based on this echo electrical signal. Generally speaking, all other things being equal, the stronger the echo electrical signal, the more accurate the detection.

[0052] In existing technologies, ultrasonic flow meters often use excitation signals of fixed intensity. However, the velocity of sound varies in different application environments, which leads to significant differences in the echo electrical signals measured by the ultrasonic flow meter when the excitation intensity is constant. This results in inaccurate measurements and greatly reduces the metering accuracy of the ultrasonic flow meter.

[0053] In this application, a module refers to a functional module or a logical module. It can be in software form, where its function is implemented by a processor executing program code; or it can be in hardware form. "And / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A alone, A and B simultaneously, or B alone. The character " / " generally indicates that the preceding and following related objects have an "OR" relationship.

[0054] The technical solutions of this application are illustrated below with specific embodiments. These specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described again in some embodiments.

[0055] Figure 1 This is a schematic diagram of the ultrasonic transceiver circuit provided in an embodiment of this application. Figure 1 As shown, the ultrasonic transceiver circuit 100 provided in this application embodiment may include: a controller 10, an adjustment circuit 20, and a transducer pair 30;

[0056] The controller 10 is connected to the input terminal of the adjustment circuit 20 and is used to send an initial excitation signal to the adjustment circuit 20;

[0057] The output of the adjustment circuit 20 is connected to the transmitter transducer in the transducer pair 30 to adjust the intensity of the initial excitation signal and output a variable excitation signal.

[0058] The transducer is connected to the output of the transmitting transducer in the 30 and the adjustment circuit 20, and is used to transmit ultrasonic signals according to the variable excitation signal;

[0059] The receiver transducer in transducer pair 30 is used to receive ultrasonic signals and convert the received ultrasonic signals into initial echo signals.

[0060] The controller 10 is also used to control the adjustment circuit 20 to adjust the intensity of the initial excitation signal based on the initial echo signal.

[0061] In a specific implementation, the controller 10 sends an initial excitation signal to the adjustment circuit 20, the adjustment circuit 20 adjusts the intensity of the initial excitation signal, and outputs a variable excitation signal to the transmitting transducer in the transducer pair 30; the transmitting transducer emits an ultrasonic signal according to the variable excitation signal; the receiving transducer in the transducer pair 30 receives the ultrasonic signal and converts the received ultrasonic signal into an initial echo signal, wherein the echo signal is an electrical signal; according to the initial echo signal, the controller 10 controls the adjustment circuit 20 to adjust the intensity of the initial excitation signal after the next initial excitation signal is sent, thereby sending an excitation signal of a new intensity to the transmitting transducer.

[0062] For example, controller 10 can be a microcontroller unit (MCU).

[0063] In this embodiment, the controller, based on the received echo signal, controls the adjustment circuit to adjust the intensity of the initial excitation signal and outputs a variable excitation signal to the transmitting transducer. Under the same environment, the stronger the excitation signal, the stronger the echo signal converted by the receiving transducer. Therefore, by controlling the intensity of the echo signal, the consistency of the echo signal intensity under different environments can be improved, which is beneficial for processing and analyzing the echo signal, thereby improving the measurement accuracy of the ultrasonic flow meter.

[0064] Figure 2 This is a schematic diagram of the control module provided in an embodiment of this application. Figure 3 This is a schematic diagram of the structure of the driver chip provided in an embodiment of this application. Figure 2 and Figure 3 As shown, the adjustment circuit 20 may include: a driver chip U1 and a control module 21;

[0065] Control module 21 is used to send the control signal BOOST to drive chip U1 under the control of controller 10;

[0066] The input terminal of the driver chip U1 is connected to the controller 10, the output terminal of the driver chip U1 is connected to the transmitter transducer, and the input terminal of the driver chip U1 is connected to the control module 21. The driver chip U1 is used to boost the initial excitation signal CHO-OUT under the control of the control signal to obtain the variable excitation signal Fire-Up / Down.

[0067] In a specific implementation, the low-intensity initial excitation signal CHO-OUT issued by the controller 10 can be converted into a variable excitation signal Fire-Up / Down by the driver chip U1. The voltage intensity of the variable excitation signal Fire-Up / Down can be consistent with the control signal BOOST. Therefore, under the control of the controller 10, the control module 21 adjusts the intensity of the output control signal BOOST, thereby adjusting the voltage intensity of Fire-Up / Down.

[0068] For example, the control module 21 includes: a boost module 211 and a selection control module 212;

[0069] The input terminal of the boost module 211 receives the power signal VIN, and the output terminal of the boost module 211 is connected to the control terminal of the driver chip U1; the boost module 211 is used to boost the power signal VIN and output the control signal BOOST.

[0070] The selection control module 212 is connected to the controller 10 and the boost module 211, and is used to control the boost process under the control of the controller, thereby adjusting the strength of the control signal BOOST.

[0071] In a specific implementation, the boost module 211 can boost the power signal VIN and convert it into the control signal BOOST. The selection and control module 212 can control the boost process under the control of the controller 10, thereby controlling the strength of the variable excitation signal.

[0072] For example, the boost module 211 includes: a boost chip U4, a first resistor R1, a second resistor R3, a third resistor R2, a fourth resistor R7, a first inductor L1, and a first diode D1; the boost chip U4 includes an input pin IN, an enable pin EN, an output pin LX, and a feedback pin FB.

[0073] The input pin IN of the boost chip U4 receives the power supply signal VIN;

[0074] One end of the first resistor R1 is connected to the input pin IN of the boost chip U4, and the other end of the first resistor R1 is connected to the enable pin EN of the boost chip U4 and one end of the second resistor R3; the other end of the second resistor R3 is grounded.

[0075] One end of the first inductor L1 is connected to the input terminal of the boost chip U4, and the other end of the first inductor L1 is connected to the output terminal of the boost chip U4.

[0076] One end of the first diode D1 is connected to the other end of the first inductor L1, and the other end of the first diode D1 is connected to the transmitter transducer.

[0077] One end of the third resistor R2 is connected to the transmitter transducer, and the other end of the third resistor R2 is connected to one end of the fourth resistor R7 and the feedback pin FB of the boost chip U4; the other end of the fourth resistor R7 is grounded.

[0078] The control module 212 and the fourth resistor R7 are connected in parallel.

[0079] In its implementation, the boost converter chip U4, the first resistor R1, the second resistor R3, the third resistor R2, the fourth resistor R7, the first inductor L1, and the first diode D1 form a boost circuit that converts the lower power supply signal VIN into a higher voltage control signal BOOST. The boost converter chip U4 does not operate when its enable pin EN receives a low level, and operates when it receives a high level. To ensure the normal operation of the boost converter chip U4 and avoid unnecessary power consumption, the first resistor R1 and the second resistor R3 are selected to provide a specific high level to the enable pin EN of the boost converter chip U4. The resistance ratio of the first resistor R1 and the second resistor R3 needs to meet certain requirements (e.g., R3 / R1 > 30). When the boost converter chip U4 is operating normally, the first resistor R1 pulls the enable pin EN of the boost converter chip U4 high. When the boost converter chip U4 has no input signal, i.e., when the boost converter chip U4 is not operating, the second resistor R3 pulls the enable pin EN of the boost converter chip U4 down. Therefore, the enable pin EN of the boost chip U4 has a fixed level at all times to avoid abnormal phenomena. The voltage divider output voltage BOOST is determined by the ratio of the third resistor R2 and the fourth resistor R7. The third resistor R2 and the fourth resistor R7 can use resistance values ​​between 10kΩ and 1MΩ to reduce power consumption under low load. The control signal BOOST = VFB * (R2 / R7` + 1). The selection module 212 is connected in parallel with the fourth resistor R7. The resistance value R7` after parallel connection of the selection module 212 can be adjusted through the selection module 212, thereby adjusting the voltage value of the control signal BOOST.

[0080] The first inductor L1 serves as the boost inductor, and the first diode D1 serves as the rectifier diode. Specific specifications can be selected based on actual production needs. Specifically, a suitable first inductor L1 needs to be selected to match the boost chip U4 to obtain appropriate ripple current and improve power quality. Furthermore, the inductor's saturation current must be greater than its peak current under full load. The first inductor L1's DC resistance (DCR) and core loss must be sufficiently low to meet efficiency requirements; for example, an inductor L1 with a DCR of less than 10mΩ can be used. The first diode D1 can be a Schottky diode with low forward voltage drop and fast reverse recovery performance. The maximum rectified current of the first diode D1 must be higher than the maximum input current, and the average operating current must be higher than the maximum output current.

[0081] For example, there can be multiple selection and control modules 212. Taking the first selection and control module as an example, the first selection and control module includes: a first transistor Q3, a fifth resistor R4 and a sixth resistor R18;

[0082] One end of the fifth resistor R4 is connected to one end of the fourth resistor, and the other end of the fifth resistor R4 is connected to the input terminal of the first transistor Q3.

[0083] The control terminal of the first transistor Q3 is connected to one end of the sixth resistor R18, and the other end of the sixth resistor R18 receives the first selection and control enable signal 9V-CLT sent by the controller 10.

[0084] The output of the first transistor Q3 is grounded.

[0085] In the specific implementation, the first transistor Q3 is turned on when the selection enable signal is enabled. At this time, the fifth resistor R4 is grounded. The fourth resistor R7 and the fifth resistor R4 are connected in parallel and together with the third resistor R2 adjust the voltage value of the control signal BOOST. When the selection enable signal is not enabled, the fifth resistor R4 is in a high resistance state. After being connected in parallel with the fourth resistor R7, the resistance value R7` is still the same as the resistance value of the fifth resistor R4.

[0086] The second selection and control module includes the second transistor Q1, the seventh resistor R5 and the eighth resistor R8, and receives the second selection and control enable signal 12V-CLT; the third selection and control module includes the third transistor Q2, the ninth resistor R6 and the tenth resistor R17, and receives the second selection and control enable signal 18V-CLT. The working principle of these modules will not be described in detail here.

[0087] For example, the first transistor, the second transistor, and the third transistor can be selected from transistors or MOSFETs, etc., without limitation.

[0088] In some embodiments, the control signal BOOST can be controlled by controlling a single selection control module 212.

[0089] Assuming VFB = 0.6V, and R2 = 120kΩ, to make the control signal BOOST 6V, then R7 = 0.6V * 120 / (6 - 0.6) ≈ 13.3kΩ. At this point, the control signal BOOST is at its default value, and the control enable signals received by the three control modules are all disabled.

[0090] To make the BOOST control signal 9V, R7` = R7 / / R4 = 0.6V * 120 / (9 - 0.6) ≈ 8.57kΩ, 1 / 8.57 = 1 / 13 + 1 / R4, R4 ≈ 25.14kΩ. A general-purpose resistor of 22kΩ is chosen for R4, and the output BOOST is approximately 9.411V. At this time, 9V-CTL is high. 12V-CTL and 18V-CTL are both disabled.

[0091] To achieve a 12V output boost, R7' = R7 / / R5 = 0.6V * 120 / (12 - 0.6) ≈ 6.32kΩ, 1 / 6.32 = 1 / 13 + 1 / R4, R4 ≈ 12.28kΩ. A 12kΩ general-purpose resistor is chosen for R5, resulting in an output boost of approximately 12.14V. At this point, the 12V-CTL is high. Both the 9V-CTL and 18V-CTL are disabled.

[0092] To achieve an output voltage boost of 18V, R7' = R7 / / R5 = 0.6V * 120 / (18 - 0.6) ≈ 4.14kΩ, then 1 / 4.14 = 1 / 13 + 1 / R4, R4 ≈ 6.074kΩ. A general-purpose resistor of 6.2kΩ is chosen for R6, resulting in an output boost of approximately 17.75V. At this point, the 18V-CTL is high. The 9V-CTL and 12V-CTL are both disabled.

[0093] In other embodiments, the control signal BOOST can also be controlled by coordinating multiple control modules 212.

[0094] For example, assuming R2 = 120k, R7 = 13k, R4 = 22k, R5 = 12k, R6 = 6.2k, and VFB = 0.6V.

[0095] When both 9V-CTL and 12V-CTL are enabled and at a high level, R7` = R7 / / R4 / / R5 = 1 / (1 / 13+1 / 22+1 / 12)k ≈ 4.86kΩ, and the control signal BOOST = 0.6V*(120 / 4.86+1) ≈ 15.41V; when both 9V-CTL and 18V-CTL are enabled, R7` = R7 / / R4 / / R6 = 1 / (1 / 13+1 / 22+1 / 6.2)k ≈ 3.53kΩ, and the control signal BOOST = 0.6V*(120 / 3.53+1) ≈ 21V; when both 12V-CTL and 18V-CTL are enabled, R7` = R7 / / R4 / / R6 = 1 / (1 / 13+1 / 22+1 / 6.2)k ≈ 3.53kΩ, and the control signal BOOST = 0.6V*(120 / 3.53+1) ≈ 21V; When all CTLs are enabled, R7` = R7 / / R4 / / R5 / / R6 = 1 / (1 / 13+1 / 12+1 / 6.2)k≈3.11k, and the control signal BOOST = 0.6V*(120 / 3.11+1)≈23.75V; when 9V-CTL, 12V-CTL, and 18V-CTL are enabled simultaneously, R7` = R7 / / R4 / / R5 / / R6 = 1 / (1 / 13+1 / 22+1 / 12+1 / 6.2)k≈2.72k, and the control signal BOOST = 0.6V*(120 / 2.72+1)≈27.07V.

[0096] Therefore, when three selector control modules 212 are set, a total of eight voltage values ​​between 6V and 27V can be generated through the control combination between them: four single-channel control modules and four multi-channel control modules.

[0097] It should be noted that in practical applications, other resistance values ​​of R4, R5, and R6 can be selected, or the number of control modules 212 can be adjusted to achieve different BOOST adjustment ranges.

[0098] Figure 4 This is a schematic diagram of the switching module provided in an embodiment of this application. Figure 1 and Figure 4 As shown, in one possible implementation, the circuit further includes: a switching module 40; the switching module 40 includes a first output channel S1A, a second output channel S1B, a first input channel S2B, and a second input channel S1B;

[0099] The input terminals of the first output channel S1A and the second output channel S1B are connected to the output terminal of the adjustment circuit 20. The output terminal of the first output channel S1A and the input terminal of the first input channel S2B are connected to the first transducer P1 in the transducer pair. The output terminal of the second output channel S1B and the input terminal of the second input channel S1B are connected to the second transducer P2 in the transducer pair. The output terminals of the first input channel S2B and the second input channel S1B are connected to the controller 10.

[0100] The switching module 40 is used to turn on the first output channel S1A and the second input channel S1B when the first transducer P1 is used as the transmitting transducer and the second transducer P2 is used as the receiving transducer; or, when the second transducer P2 is used as the transmitting transducer and the first transducer P1 is used as the receiving transducer, it turns on the second output channel S1B and the first input channel S2B.

[0101] In its implementation, each transducer in a transducer pair can function as both a transmitter and a receiver. Therefore, for each transducer pair, the switching module 40 is equipped with two transmission channels: a first output channel S1A and a second output channel S1B, and two receiving channels: a first input channel S2B and a second input channel S1B. Based on the transducer's state, the switching module 40 activates the corresponding transmission and receiving channels, sending the variable excitation signal Fire-Up / Down to the transmitter transducer and sending the initial echo signal receive-up / down obtained by the receiver transducer to the controller 10.

[0102] The switching module 40 can be a switching chip U2. The IN1 and IN2 pins of the switching chip U2 receive the switching enable signal EN-up / down sent by the controller. The switching chip U2 operates when the switching enable signal EN-up / down is enabled, and does not operate when the switching enable signal EN-up / down is disabled. The D1 pin of the switching chip U2 receives the variable excitation signal Fire-Up / Down, and the D2 pin receives the initial echo signal receive-up / down. The EN and VDD pins of U2 receive the BOOST voltage as power supply. Resistors R9 and R10 are used to protect the switching chip U2, and the grounded capacitor C9 acts as an energy storage filter.

[0103] In one possible implementation, the circuit further includes: an amplifier circuit 50;

[0104] The input terminal of the amplifier circuit 50 is connected to the transducer at the receiving end, and the output terminal of the amplifier circuit 50 is connected to the controller 10. It is used to amplify the initial echo signal receive-up / down to obtain the amplified echo signal CHO-IN.

[0105] In a specific implementation, the amplifier circuit 50 can amplify the initial echo signal receive-up / down and send the resulting amplified echo signal CHO-IN to the controller 10 so that the controller 10 can better process and analyze the data based on the amplified echo signal CHO-IN.

[0106] Figure 5 This is a schematic diagram of the amplifier circuit provided in an embodiment of this application. Figure 5 As shown, the amplifier circuit 50 includes: operational amplifier U3, eleventh resistor R24, twelfth resistor R25, thirteenth resistor R26, fourteenth resistor R11, fifteenth resistor R12, first capacitor C66, second capacitor C33, third capacitor C10, and fourth capacitor C8.

[0107] One end of the eleventh resistor R24 ​​and one end of the first capacitor C66 receive the bias voltage VCC-RX. The other end of the first capacitor C66 is grounded. The other end of the eleventh resistor R24 ​​is connected to one end of the twelfth resistor R25, one end of the second capacitor C33, and one end of the thirteenth resistor R26. The other end of the second capacitor C33 and the other end of the thirteenth resistor R26 are grounded. The other end of the twelfth resistor R25 is connected to the non-inverting input of the operational amplifier U3.

[0108] One end of the fourteenth resistor R11 is connected to the inverting input of the operational amplifier U3, and the other end of the fourteenth resistor R11 is connected to one end of the third capacitor C10, while the other end of the third capacitor C10 is grounded.

[0109] One end of the fifteenth resistor R12 and one end of the fourth capacitor C8 are connected to the inverting input of the operational amplifier U3, and the other end of the fifteenth resistor R12 and the other end of the fourth capacitor C8 are connected to the output of the operational amplifier U3.

[0110] In the specific implementation, operational amplifier U3, eleventh resistor R24, twelfth resistor R25, thirteenth resistor R26, fourteenth resistor R11, fifteenth resistor R12, first capacitor C66, second capacitor C33, third capacitor C10, and fourth capacitor C8 form a non-inverting negative feedback amplifier circuit, which can amplify the initial echo signal receive-up / down into an amplified echo signal CH0-IN. CH0-IN = A * receive-up / down, and the amplification factor A = 1 + R12 / R11. In practical applications, controller 10 can obtain a high signal-to-noise ratio amplified echo signal CH0-IN by adjusting the amplification factor of the excitation signal strength.

[0111] Among them, one end of the eleventh resistor R24 ​​and one end of the first capacitor C66 receive the bias voltage, and the other end of the first capacitor C66 is grounded. The eleventh resistor R24, the twelfth resistor R25, the second capacitor C33, the thirteenth resistor R26, the second capacitor C33, the thirteenth resistor R26, and the twelfth resistor R25 provide 1 / 2*VCC-RX voltage to the non-inverting input terminal of the operational amplifier U3, which can make the operational amplifier U3 work in the optimal state, thereby ensuring the integrity of the waveform of the amplified echo signal CH0-IN.

[0112] The control terminal of operational amplifier U3 can be connected to one end of the sixteenth resistor R13. The other end of the sixteenth resistor R13 receives the amplification enable signal MCU_OPA_EN sent by controller 10. Controller 10 controls operational amplifier U3 to operate or not operate through the amplification enable signal MCU_OPA_EN. The power input terminal of operational amplifier U3 receives power VCC_RX. A fifth capacitor C12 is provided at the power input terminal of operational amplifier U3 to ground, thereby maintaining the voltage stability of the power input terminal of operational amplifier U3 and effectively improving the reliability and stability of the circuit.

[0113] For example, the amplifier circuit 50 further includes: a filter resistor R14, a first coupling capacitor C14, a second coupling capacitor C13, and a filter capacitor C15;

[0114] One end of the first coupling capacitor C14 is connected to the receiving transducer, and the other end of the first coupling capacitor C14 is connected to the inverting input of the operational amplifier U3.

[0115] One end of the filter resistor R14 is connected to the output terminal of the operational amplifier U3, and the other end of the filter resistor R14 is connected to one end of the filter capacitor C15. The other end of the filter capacitor C15 is grounded.

[0116] One end of the second coupling capacitor C13 is connected to the other end of the filter resistor R14, and the other end of the second coupling capacitor C13 is connected to the controller.

[0117] In the specific implementation, the first coupling capacitor C14 and the second coupling capacitor C13 can pass AC and block DC, thereby removing DC bias; the filter resistor R14 and the filter capacitor C15 form a low-pass filter circuit, which can filter the signal output by the operational amplifier U3. The cutoff frequency is F = 1 / (2*π*R14*C15), which can effectively improve the signal quality of the amplified echo signal CH0-IN, and help improve the metering accuracy of the flow meter.

[0118] In this embodiment, the controller, based on the received echo signal, controls the adjustment circuit to adjust the intensity of the initial excitation signal and outputs a variable excitation signal to the transmitting transducer. Under the same environment, the stronger the excitation signal, the stronger the echo signal converted by the receiving transducer. Therefore, by controlling the intensity of the echo signal, the consistency of the echo signal intensity under different environments can be improved, which is beneficial for processing and analyzing the echo signal, thereby improving the measurement accuracy of the ultrasonic flow meter.

[0119] This application also provides an ultrasonic flow meter, including the ultrasonic transceiver circuit as described above.

[0120] Other embodiments of this application will readily occur to those skilled in the art upon consideration of the specification and practice of the utility models disclosed herein. This application is intended to cover any variations, uses, or adaptations of this application that follow the general principles of this application and include common knowledge or customary techniques in the art not disclosed herein. The specification and examples are to be considered exemplary only, and the true scope and spirit of this application are indicated by the following claims.

[0121] It should be understood that this application is not limited to the precise structure described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of this application is limited only by the appended claims.

Claims

1. An ultrasonic transceiver circuit, characterized in that, include: Controller, adjustment circuit and transducer pair; The controller is connected to the input terminal of the adjustment circuit and is used to send an initial excitation signal to the adjustment circuit. The output terminal of the adjustment circuit is connected to the transmitting transducer in the transducer pair, and is used to adjust the intensity of the initial excitation signal and output a variable excitation signal. The transmitting transducer in the transducer pair is used to transmit ultrasonic signals according to the variable excitation signal; The receiving transducer in the transducer pair is used to receive the ultrasonic signal and convert the received ultrasonic signal into an initial echo signal. The controller is further configured to control the adjustment circuit to adjust the intensity of the initial excitation signal based on the initial echo signal.

2. The circuit according to claim 1, characterized in that, The adjustment circuit includes: a driver chip and a control module; The control module is used to send control signals to the driver chip under the control of the controller; The input terminal of the driver chip is connected to the controller, the output terminal of the driver chip is connected to the transmitter transducer, and the input terminal of the driver chip is connected to the control module; the driver chip is used to boost the initial excitation signal under the control of the control signal to obtain a variable excitation signal.

3. The circuit according to claim 2, characterized in that, The control module includes: a boost module and a selective control module; The input terminal of the boost module receives a power signal, and the output terminal of the boost module is connected to the control terminal of the driver chip; the boost module is used to boost the power signal and output a control signal. The selection and control module is connected to the controller and the boost module, and is used to control the boost process under the control of the controller, thereby controlling the strength of the control signal.

4. The circuit according to claim 3, characterized in that, The boost module includes: a boost chip, a first resistor, a second resistor, a third resistor, a fourth resistor, a first inductor, and a first diode; the boost chip includes an input pin, an enable pin, an output pin, and a feedback pin. The input pin of the boost chip receives a power signal; One end of the first resistor is connected to the input pin of the boost chip, and the other end of the first resistor is connected to the enable pin of the boost chip and one end of the second resistor; the other end of the second resistor is grounded. One end of the first inductor is connected to the input terminal of the boost chip, and the other end of the first inductor is connected to the output terminal of the boost chip; One end of the first diode is connected to the other end of the first inductor, and the other end of the first diode is connected to the transmitter transducer. One end of the third resistor is connected to the transmitter transducer, and the other end of the third resistor is connected to one end of the fourth resistor and the feedback pin of the boost chip; the other end of the fourth resistor is grounded. The control module and the fourth resistor are connected in parallel.

5. The circuit according to claim 4, characterized in that, The number of the selection and control modules is multiple, and each selection and control module includes: a first transistor, a fifth resistor, and a sixth resistor; One end of the fifth resistor is connected to one end of the fourth resistor, and the other end of the fifth resistor is connected to the input terminal of the first transistor. The control terminal of the first transistor is connected to one end of the sixth resistor, and the other end of the sixth resistor receives the selection enable signal sent by the controller; The output terminal of the first transistor is grounded.

6. The circuit according to claim 1, characterized in that, The circuit also includes: an amplifier circuit; The input terminal of the amplifier circuit is connected to the transducer of the receiver, and the output terminal of the amplifier circuit is connected to the controller. It is used to amplify the initial echo signal to obtain an amplified echo signal.

7. The circuit according to claim 6, characterized in that, The amplifier circuit includes: an operational amplifier, an eleventh resistor, a twelfth resistor, a thirteenth resistor, a fourteenth resistor, a fifteenth resistor, a first capacitor, a second capacitor, a third capacitor, and a fourth capacitor; One end of the eleventh resistor and one end of the first capacitor receive a bias voltage, the other end of the first capacitor is grounded, the other end of the eleventh resistor is connected to one end of the twelfth resistor, one end of the second capacitor and one end of the thirteenth resistor, the other end of the second capacitor and the other end of the thirteenth resistor are grounded, and the other end of the twelfth resistor is connected to the non-inverting input of the operational amplifier. One end of the fourteenth resistor is connected to the inverting input of the operational amplifier, and the other end of the fourteenth resistor is connected to one end of the third capacitor, while the other end of the third capacitor is grounded. One end of the fifteenth resistor and one end of the fourth capacitor are connected to the inverting input of the operational amplifier, the other end of the fifteenth resistor and the other end of the fourth capacitor are connected to the output of the operational amplifier, and the output of the operational amplifier is connected to the controller.

8. The circuit according to claim 7, characterized in that, The amplifier circuit further includes: a filter resistor, a first coupling capacitor, a second coupling capacitor, and a filter capacitor; One end of the first coupling capacitor is connected to the receiving transducer, and the other end of the first coupling capacitor is connected to the inverting input of the operational amplifier. One end of the filter resistor is connected to the output terminal of the operational amplifier, the other end of the filter resistor is connected to one end of the filter capacitor, and the other end of the filter capacitor is grounded. One end of the second coupling capacitor is connected to the other end of the filter resistor, and the other end of the second coupling capacitor is connected to the controller.

9. The circuit according to any one of claims 1-8, characterized in that, The circuit further includes: a switching module; the switching module includes a first output channel, a second output channel, a first input channel, and a second input channel; The input terminals of the first output channel and the second output channel are connected to the output terminal of the adjustment circuit; the output terminal of the first output channel and the input terminal of the first input channel are connected to the first transducer in the transducer pair; the output terminal of the second output channel and the input terminal of the second input channel are connected to the second transducer in the transducer pair; the output terminals of the first input channel and the second input channel are connected to the controller. The switching module is used to connect the first output channel and the second input channel when the first transducer is used as a transmitting transducer and the second transducer is used as a receiving transducer; or, when the second transducer is used as a transmitting transducer and the first transducer is used as a receiving transducer, it connects the second output channel and the first input channel.

10. An ultrasonic flow meter, characterized in that, Includes the ultrasonic transceiver circuit as described in any one of claims 1-9.

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