Ultrasonic flowmeter device

Abstract

The ultrasonic flowmeter device provided by this application includes: an ultrasonic flow conversion module connected to an ultrasonic transducer and a main control module, which is used to output an excitation voltage signal under the control of the main control module to drive the ultrasonic transducer to emit ultrasonic signals and calculate the flow rate based on the ultrasonic echo signals; an excitation voltage adaptive module connected to the ultrasonic flow conversion module and the main control module, which is used to collect the excitation voltage signal sent by the ultrasonic flow conversion module and send it to the main control module, so that the main control module outputs a control signal according to the voltage value of the excitation voltage signal; the excitation voltage adaptive module is also used to adjust the output first voltage according to the control signal output by the main control module, and the first voltage is used to provide the working voltage of the channel switching module, and the first voltage is greater than or equal to the voltage value of the excitation voltage signal. This application can adaptively adjust the working voltage of the high-channel switching module according to the excitation voltage signal, improving the applicability to the measurement of different pipe diameters.

Description

Technical Field

[0001] This application relates to the field of testing, and particularly to an ultrasonic flowmeter device. Background Art

[0002] Ultrasonic flowmeters are widely used in civil and industrial measurements. The ultrasonic measurement scheme is as follows: The ultrasonic flow conversion module periodically applies voltage excitation to the ultrasonic transducer to cause a pair of ultrasonic transducers to generate excitation waveforms and echo signals; the ultrasonic flow conversion module receives and processes the echo signals to complete the acquisition of flow data.

[0003] Currently, if an ultrasonic flowmeter is to be adapted to different pipe diameters, it is necessary to consider the matching of the circuit parameters of the peripheral boost circuit and signal processing circuit in different pipe diameter application scenarios, as well as the corresponding matching of the main control circuit board. At the same time, for flow measurement of different pipe diameters, the larger the pipe diameter, the higher the requirement for the echo amplitude of the ultrasonic signal required for measurement, and thus the higher the voltage of the excitation signal required, and an additional lithium battery needs to be added.

[0004] However, the above scheme has a large design difficulty and low applicability of the ultrasonic flowmeter. Summary of the Invention

[0005] This application provides an ultrasonic flowmeter device to improve the applicability of the ultrasonic flowmeter.

[0006] The ultrasonic flowmeter device provided by this application includes: a main control module, an ultrasonic flow conversion module, an excitation voltage adaptive module, a channel switching module, and an ultrasonic transducer; wherein, the ultrasonic flow conversion module is connected to the ultrasonic transducer and the main control module, and is used to output an excitation voltage signal under the control of the main control module to drive the ultrasonic transducer to emit ultrasonic signals and calculate the flow based on the ultrasonic echo signals; the excitation voltage adaptive module is connected to the ultrasonic flow conversion module and the main control module, and is used to collect the excitation voltage signal sent by the ultrasonic flow conversion module and send it to the main control module, so that the main control module outputs a control signal according to the voltage value of the excitation voltage signal; the excitation voltage adaptive module is connected to the channel switching module, and is further used to adjust the output first voltage according to the control signal output by the main control module, and the first voltage is used to provide the working voltage of the channel switching module, and the first voltage is greater than or equal to the voltage value of the excitation voltage signal.

[0007] This application automatically adjusts the output voltage through the excitation voltage adaptive module, so that the working voltage of the channel switching module is greater than or equal to the voltage value of the excitation voltage signal, improving the applicability to different pipe diameter measurements and reducing the design difficulty.

[0008] Furthermore, the excitation voltage adaptive module includes: an excitation voltage sampling module, an adaptive voltage output module, and a boost circuit module; the excitation voltage sampling module is connected to the ultrasonic flow conversion module and the main control module, and is used to collect the excitation voltage signal sent by the ultrasonic flow conversion module and send it to the main control module, so that the main control module outputs a corresponding control signal; the adaptive voltage output module is connected to the main control module and the boost circuit module, and is used to select a feedback resistor to provide to the boost circuit module according to the control signal output by the main control module; the boost circuit module is used to output a first voltage based on the feedback resistor.

[0009] The above settings further provide the operation process of the excitation voltage adaptive module for adaptively adjusting the output voltage.

[0010] In a feasible manner, the excitation voltage sampling module includes: a first triode and a second triode; the base of the first triode is connected to the acquisition control signal sent by the main control module; the emitter of the first triode is grounded; the collector of the first triode is connected to the base of the second triode; the emitter of the second triode is connected to the excitation voltage signal sent by the ultrasonic flow conversion module; the collector of the second triode is connected to the main control module.

[0011] The above settings provide a hardware control circuit for the excitation voltage sampling module. The excitation voltage sampling module, under the acquisition control signal of the main control module, cooperates with the on-off characteristics of the first triode and the second triode to achieve the acquisition of the voltage signal.

[0012] In a feasible manner, the excitation voltage sampling module further includes: a first current-limiting resistor, a second current-limiting resistor, a first voltage-dividing resistor, a second voltage-dividing resistor, and a first filter capacitor; the first end of the first current-limiting resistor is connected to the acquisition control signal sent by the main control module; the second end of the first current-limiting resistor is connected to the base of the first triode; the first end of the second current-limiting resistor is connected to the collector of the first triode; the second end of the second current-limiting resistor is connected to the base of the second triode; the first end of the first voltage-dividing resistor is connected to the collector of the second triode; the second end of the first voltage-dividing resistor is connected to the first end of the second voltage-dividing resistor; the first end of the second voltage-dividing resistor is connected to the voltage detection port of the main control module; the second end of the second voltage-dividing resistor is grounded; the first end of the first filter capacitor is connected to the voltage detection port of the main control module, and the second end of the first filter capacitor is grounded.

[0013] The above settings further improve the hardware control circuit of the aforementioned excitation voltage sampling module, realize the protection of the first triode and the second triode through the current-limiting resistor, and improve the stability of the acquired voltage signal through the filter capacitor.

[0014] In a feasible approach, the adaptive voltage output module includes: a multi-channel analog switch and multiple feedback resistors; the common pins of the multi-channel analog switch are respectively and correspondingly connected to the feedback resistors one by one; the output pins of the multi-channel analog switch are all connected to the feedback port of the boost circuit module; the control pins of the multi-channel analog switch are connected to the selection control signal sent by the main control module; the multi-channel analog switch is configured to select and connect the corresponding feedback resistor to the output pin based on the selection control signal.

[0015] The above setting provides a hardware control circuit for the adaptive voltage output module. Under the selection control signal of the main control module, the adaptive voltage output module uses the multi-channel analog switch to realize the selection of the feedback resistor.

[0016] In a feasible approach, the boost circuit module includes: a boost power supply chip, a first NMOS transistor, and a first PMOS transistor; the gate of the first NMOS transistor is connected to the boost control signal of the main control module; the source of the first NMOS transistor is grounded; the drain of the first NMOS transistor is connected to the gate of the first PMOS transistor; the source of the first PMOS transistor is connected to the power supply of the boost circuit module; the drain of the first PMOS transistor is connected to the input pin of the boost power supply chip U1; the feedback port of the boost power supply chip is connected to the output pin of the adaptive voltage output module, and the output port of the boost power supply chip is connected to the channel switching module.

[0017] The above setting provides a hardware control circuit for the boost circuit module. Under the boost control signal of the main control module, the boost circuit module cooperates with the first NMOS transistor and the first PMOS transistor to realize the power-on of the boost circuit module; the boost circuit module cooperates with the selected feedback resistor to provide an adaptively adjusted working voltage for the channel switching module.

[0018] Furthermore, the boost circuit module further includes: a third current-limiting resistor, a first protection resistor, and a first filtering module; the first end of the third current-limiting resistor is connected to the boost control signal of the main control module; the second end of the third current-limiting resistor is connected to the gate of the first NMOS transistor; the first protection resistor is connected between the gate and the source of the first PMOS transistor; the first filtering module is connected between the drain of the first PMOS transistor and the input pin of the boost power supply chip.

[0019] The above setting further improves the hardware control circuit of the aforementioned boost circuit module, realizes the protection of the first NMOS transistor and the first PMOS transistor through the current-limiting resistor and the protection resistor, and improves the stability of the power supply voltage of the boost circuit through the filtering module.

[0020] In a feasible manner, the boost circuit module further includes: a first resistor; a first end of the first resistor is connected to a feedback pin of the boost power supply chip, and a second end of the first resistor is connected to an overvoltage protection pin of the boost power supply chip.

[0021] The above-mentioned first resistor is used to jointly determine the output voltage value of the boost circuit module with the aforementioned feedback resistor.

[0022] In a feasible manner, the boost circuit module further includes: a first energy storage inductor, a second energy storage module; a first end of the second energy storage inductor is connected to an input pin of the boost power supply chip; a second end of the first energy storage inductor is connected to a switch control pin of the boost power supply chip; an output pin of the boost power supply chip is connected to the second energy storage module, and the second energy storage module is used to enable the boost power supply chip to stably output a first voltage.

[0023] In the above setting, the first energy storage inductor is used to periodically store energy and release energy, thereby periodically charging and discharging the second energy storage module, so that the boost circuit module stably outputs a voltage.

[0024] In a feasible manner, the ultrasonic flow conversion module includes: an ultrasonic flow measurement chip, a high-speed crystal oscillator, and a low-speed crystal oscillator; a remote communication interface of the ultrasonic flow measurement chip is connected to the main control module; the low-speed crystal oscillator is connected to a low-frequency crystal oscillator pin of the ultrasonic flow measurement chip, and the high-speed crystal oscillator is connected to a high-frequency crystal oscillator pin of the ultrasonic flow measurement chip, and is used to provide an external clock signal for the ultrasonic flow measurement chip.

[0025] The above setting introduces the structural composition of the ultrasonic flow conversion module. An ultrasonic flow conversion chip with a relatively high integration degree is adopted to ensure operation stability; a working mode of the cooperation of the low-frequency crystal oscillator and the high-frequency crystal oscillator is adopted, and the high-frequency crystal oscillator is switched on only when it is needed for work to reduce the power consumption of the chip.

[0026] Further, the ultrasonic flow conversion module further includes: a first external capacitor, a second external capacitor, a third external capacitor, and a second filtering module; both ends of the first external capacitor are connected to a first group of charge pump pins of the acoustic wave flow measurement chip; both ends of the second external capacitor are connected to a second group of charge pump pins of the acoustic wave flow measurement chip; both ends of the third external capacitor are connected to a third group of charge pump pins of the acoustic wave flow measurement chip; the second filtering module is connected to a voltage stabilizing pin of the acoustic wave flow measurement chip.

[0027] In the above setting, three capacitors are externally connected to the ultrasonic flow conversion chip, realizing the function of adjusting the excitation voltage within a certain range, and ensuring that the ultrasonic amplitude meets the application requirements in different pipe diameter application scenarios.

[0028] Further, the ultrasonic flow measurement chip has four input power pins, and a third filtering module is connected between the external power supply and the input power pins.

[0029] The above settings enhance the stability of the power supply for a single chip connected to multiple input power pins, thereby enhancing the operating stability of the chip.

[0030] Furthermore, the ultrasonic flow measurement chip has a reference voltage output pin and two reference voltage input pins; the reference voltage output pin is connected to the fourth filtering module, which is used to output the initial reference voltage generated inside the ultrasonic flow measurement chip, and after being filtered by the fourth filtering module, the reference voltage is obtained; the reference voltage is connected to each reference voltage input pin, and at least one reference voltage input pin is connected to a fifth filtering module.

[0031] The fourth filtering module and the fifth filtering module in the above settings are used to ensure the stability and anti-interference ability of the internal reference voltage of the chip.

[0032] The ultrasonic flowmeter device provided by this application includes: a main control module, an ultrasonic flow conversion module, an excitation voltage adaptive module, a channel switching module, and an ultrasonic transducer; among them, the ultrasonic flow conversion module is connected to the ultrasonic transducer and the main control module, and is used to output an excitation voltage signal under the control of the main control module to drive the ultrasonic transducer to emit ultrasonic signals and calculate the flow rate based on the ultrasonic echo signals; the excitation voltage adaptive module is connected to the ultrasonic flow conversion module and the main control module, and is used to collect the excitation voltage signal emitted by the ultrasonic flow conversion module and send it to the main control module, so that the main control module outputs a control signal according to the voltage value of the excitation voltage signal; the excitation voltage adaptive module is connected to the channel switching module, and is also used to adjust the output first voltage according to the control signal output by the main control module, and the first voltage is used to provide the operating voltage of the channel switching module, and the first voltage is greater than or equal to the voltage value of the excitation voltage signal. By automatically adjusting the output voltage through the excitation voltage adaptive module in this application, the operating voltage of the channel switching module is greater than or equal to the voltage value of the excitation voltage signal, improving the applicability to different pipe diameters measurement and reducing the design difficulty. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] The drawings here are incorporated into the specification and form a part of this specification, showing embodiments consistent with this application, and are used together with the specification to explain the principles of this application.

[0034] Figure 1 It is an application scenario of an ultrasonic flowmeter device provided by this application;

[0035] Figure 2 It is a schematic structural diagram of an ultrasonic flowmeter device provided by this application;

[0036] Figure 3 It is a schematic structural diagram of another ultrasonic flowmeter device provided by this application;

[0037] Figure 4 A circuit diagram of an excitation voltage sampling module provided for this application;

[0038] Figure 5 A circuit diagram of an adaptive voltage output module provided for this application;

[0039] Figure 6 A circuit diagram of a boost circuit module provided for this application;

[0040] Figure 7 A circuit diagram of an ultrasonic flow conversion module provided for this application.

[0041] Through the above-mentioned drawings, specific embodiments of this application have been shown, and there will be more detailed descriptions hereinafter. These drawings and textual descriptions are not intended to limit the scope of the concept of this application in any way, but to illustrate the concept of this application to those skilled in the art by referring to specific embodiments. Specific Embodiments

[0042] Here, the exemplary embodiments will be described in detail, and their examples are shown in the drawings. When the following description refers to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this application. On the contrary, they are merely examples of devices and methods consistent with some aspects of this application.

[0043] Flow measurement is an indispensable part of modern scientific measurement. The design and implementation of ultrasonic meters can provide strong support for fluid measurement. Since ultrasonic flowmeters are non-contact meters, they do not cause changes to the fluid in the pipeline, the measurement results are not affected by the fluid temperature and density, do not cause wear to the pipeline, have high accuracy, have almost no requirements for the fluid medium, and also have an extremely wide range ratio, making them widely promoted and used in civil and industrial measurements.

[0044] Ultrasonic measurement requires periodic voltage excitation of ultrasonic transducers. A pair of ultrasonic transducers will generate excitation waveforms and echo signals under voltage excitation, and the ultrasonic flow conversion module receives and processes the signals to complete the acquisition of flow data. For flow measurements with different pipe diameters, the larger the pipe diameter, the higher the requirement for the echo amplitude of the ultrasonic signal required for measurement, and thus the higher the voltage of the excitation signal required.

[0045] However, in current ultrasonic measurement solutions, when applied to different pipe diameter application scenarios, due to the existence of the peripheral boost circuit and signal processing circuit, the circuit parameters in different pipe diameter application scenarios are also different, so all main control circuit boards need to correspond one by one, and the universality of all pipe diameter scenarios cannot be achieved.

[0046] The ultrasonic flowmeter device provided by this application aims to solve the above technical problems in the prior art.

[0047] This application can be specifically applied to flow measurement schemes such as Figure 1 shown. An ultrasonic flowmeter refers to a flowmeter developed based on the principle that the propagation speed of ultrasonic waves in a flowing medium is equal to the vector sum of the average flow velocity of the measured medium and the velocity of sound waves in a stationary medium. As Figure 1 shown, the ultrasonic flowmeter is a multi-channel ultrasonic flowmeter, specifically it can be a dual-channel ultrasonic flowmeter or a four-channel ultrasonic flowmeter. This ultrasonic flowmeter detects the fluid flowing through it and calculates and outputs the flow data of the fluid. Multiple pairs of ultrasonic transducers are distributed on the inner wall of the fluid pipeline to detect the flow velocity at multiple points in the pipeline, and then the weighted integration method is used to calculate the flow rate. The multi-channel ultrasonic flowmeter has strong adaptability to changes in the flow pattern distribution, high measurement accuracy, and can be used for large-diameter pipelines and pipe channels with complex flow pattern distributions.

[0048] Among them, the ultrasonic flow conversion module is used to generate an excitation voltage signal to drive the ultrasonic transducer to complete the reception and processing of measurement data; the excitation voltage signal is transmitted to the ultrasonic transducer through the channel switching module, and it is required that the working voltage of the channel switching module is greater than or equal to the voltage value of the excitation voltage signal. Figure 1 The voltage regulation module shown is used to regulate the working voltage of the channel switching module for ultrasonic measurement.

[0049] The following uses specific embodiments to elaborate in detail on the technical solution of this application and how the technical solution of this application solves the above technical problems. These several specific embodiments below can be combined with each other, and the same or similar concepts or processes may not be repeated in some embodiments. The embodiments of this application will be described below in conjunction with the accompanying drawings.

[0050] Figure 2 FIG. is a schematic structural diagram of an ultrasonic flowmeter device provided by this application, including: a main control module, an ultrasonic flow conversion module, an excitation voltage adaptive module, a channel switching module, and an ultrasonic transducer. Among them, the ultrasonic flow conversion module is connected to the ultrasonic transducer and the main control module, and is used to output an excitation voltage signal under the control of the main control module to drive the ultrasonic transducer to emit ultrasonic signals and calculate the flow rate based on the ultrasonic echo signals. The excitation voltage adaptive module is connected to the ultrasonic flow conversion module and the main control module, and is used to collect the excitation voltage signal emitted by the ultrasonic flow conversion module and send it to the main control module, so that the main control module outputs a control signal according to the voltage value of the excitation voltage signal; the excitation voltage adaptive module is connected to the channel switching module, and is also used to adjust the output first voltage according to the control signal output by the main control module, and the first voltage is used to provide the working voltage of the channel switching module, and the first voltage is greater than or equal to the voltage value of the excitation voltage signal.

[0051] Specifically, the main control module is mainly composed of a main control MCU chip and its peripheral application circuits. The main control MCU chip needs to have functions such as Serial Peripheral Interface (SPI) communication, voltage detection, and logic level control. Its peripheral circuits are composed of basic resistor-capacitor components, crystal oscillators, etc. For example, a central processing unit is built based on a main control chip of the STM32L476VET6 model (or other models of MCU chips), and is designed into a main board control unit in cooperation with corresponding resistor-capacitor components and crystal oscillators. The circuit structure of the main control module in this application is not limited. This main control module needs to be able to perform logic control on other modules, detect voltage signals, and perform SPI communication.

[0052] Specifically, the ultrasonic flow conversion module is a complete ultrasonic flow converter, mainly used to measure and calculate the flow rate of an ultrasonic flowmeter based on time of flight. The ultrasonic flow conversion module is mainly composed of a driver for ultrasonic transducers, an analog switch, a programmable gain amplifier and an offset-stable comparator, a central processor for calculating the flow rate, a clock control unit, etc.; its main function is to drive the ultrasonic transducers and measure and calculate the flow rate of the ultrasonic flowmeter based on time of flight, and transmit the processed data to the main control module through SPI communication.

[0053] Furthermore, the channel switching module is used to implement the function of freely switching and connecting between the ultrasonic flow conversion module and each channel. The excitation voltage signal output by the ultrasonic flow conversion module is transmitted to the corresponding ultrasonic transducer through the channel switching module. To ensure normal signal transmission, it is required that the working voltage of the channel switching module is greater than or equal to the voltage value of the excitation voltage signal. Specifically, the channel switching module is implemented by using an analog switch chip in cooperation with corresponding software logic control. Its switching process is controlled by the main control module. Since it is not the key content of this application, it will not be elaborated here.

[0054] The ultrasonic transducer is connected to the rear end of the channel switching module. The piezoelectric circuit part for generating ultrasonic signals is installed on the inner wall of the pipeline and can transmit and receive ultrasonic signals. For the ultrasonic transducer, better impedance consistency, smaller parasitic capacitance, shorter startup time, and larger ultrasonic signal amplitude are all helpful to improve the measurement stability of the entire ultrasonic flowmeter.

[0055] The excitation voltage adaptive module samples the excitation voltage signal sent by the ultrasonic flow conversion module and sends it to the voltage detection port of the main control module for voltage detection. According to the detected voltage value, the main control module controls the excitation voltage adaptive module to output a first voltage greater than or equal to the voltage value of the excitation voltage signal. The first voltage serves as the operating voltage of the channel switching module and has adjustable adaptability, which is beneficial to improving the applicability of the ultrasonic flowmeter in metering different pipe diameters. In addition, there is no need to redesign and adjust the cooperation of other peripheral circuits and the circuit parameters of each module chip, greatly reducing the design difficulty.

[0056] Figure 3 FIG. 4 is a schematic structural diagram of another ultrasonic flowmeter device provided by the present application. The excitation voltage adaptive module includes: an excitation voltage sampling module, an adaptive voltage output module, and a boost circuit module. The excitation voltage sampling module is connected to the ultrasonic flow conversion module and the main control module, and is configured to collect the excitation voltage signal sent by the ultrasonic flow conversion module and send it to the main control module, so that the main control module outputs a corresponding selection control signal; the adaptive voltage output module is connected to the main control module and the boost circuit module, and is configured to select a feedback resistor to provide to the boost circuit module according to the selection control signal output by the main control module; the boost circuit module is configured to output a first voltage according to the feedback resistor.

[0057] Specifically, the excitation voltage sampling module samples the excitation voltage signal sent by the ultrasonic flow conversion module and sends it to the voltage detection port of the main control module for voltage value detection. The adaptive voltage output module determines the output voltage value of the boost circuit according to the detected voltage value, ensuring that the output voltage of the boost circuit is greater than or equal to the voltage value of the excitation voltage signal. Further, the boost circuit module can be implemented by using a low-power boost power supply chip (such as TPS61096A), in cooperation with the design of the power circuit switch circuit and the adjustment of the feedback loop resistor to achieve the switching function of the power supply and the variable output function of the output voltage. The switching logic control and the switching of the loop feedback resistor are controlled by the main control module.

[0058] Next, the function implementation of the excitation voltage sampling module will be introduced with reference to the circuit diagram.

[0059] Figure 4 FIG. 5 is a circuit diagram of an excitation voltage sampling module provided by the present application. Exemplarily, the excitation voltage sampling module includes: a first triode Q5 and a second triode Q3; the base of the first triode Q5 is connected to the acquisition control signal sent by the main control module; the emitter of the first triode Q5 is grounded; the collector of the first triode Q5 is connected to the base of the second triode Q3; the emitter of the second triode Q3 is connected to the excitation voltage signal sent by the ultrasonic flow conversion module; the collector of the second triode Q3 is connected to the main control module. Figure 4In the example, the first triode Q5 is an NPN-type triode; the second triode Q3 is a PNP-type triode.

[0060] Specifically, TDC-ST-PWR-CTL is the acquisition signal of the main control module; FIRE-UP is the excitation voltage signal output by the ultrasonic flow conversion module. When TDC-ST-PWR-CTL is set to a high level, this high-level signal makes the first triode Q5 conduct forward; the base of the second triode Q3 is grounded and conducts when at a low level; then FIRE-UP enters the voltage detection port of the main control module, which can be an I / O port with voltage detection function. Conversely, when TDC-ST-PWR-CTL is set to a low level, this low-level signal makes the first triode Q5 cut off, then the second triode Q3 cuts off, and FIRE-UP is not collected by the voltage detection port of the main control module. The above process of collecting and detecting the excitation voltage signal is controllable, that is, it is only detected at the beginning of the flowmeter measurement, reducing unnecessary power consumption.

[0061] Further, referring to Figure 4 , the excitation voltage sampling module further includes: a first current-limiting resistor R16, a second current-limiting resistor R15, a first voltage-dividing resistor R12, a second voltage-dividing resistor R13, a first filter capacitor C33; the first end of the first current-limiting resistor R16 is connected to the acquisition control signal TDC-ST-PWR-CTL issued by the main control module; the second end of the first current-limiting resistor R16 is connected to the base of the first triode Q5; the first end of the second current-limiting resistor R15 is connected to the collector of the first triode Q5; the second end of the second current-limiting resistor R15 is connected to the base of the second triode Q3; the first end of the first voltage-dividing resistor R12 is connected to the collector of the second triode Q3; the second end of the first voltage-dividing resistor R12 is connected to the first end of the second voltage-dividing resistor R13; the first end of the second voltage-dividing resistor R13 is connected to the voltage detection port of the main control module; the second end of the second voltage-dividing resistor R13 is grounded; the first end of the first filter capacitor C33 is connected to the voltage detection port of the main control module, and the second end of the first filter capacitor C33 is grounded.

[0062] Specifically, when TDC-ST-PWR-CTL is set to a high level, after the high-level signal passes through the first current-limiting resistor R16, it acts on the base of the first triode Q5, making the first triode Q5 conduct forward. Then, the base of the second triode Q3 is connected to the ground terminal and is at a low level, so the second triode Q3 conducts. After FIRE-UP passes through the first voltage-dividing resistor R12 and the second voltage-dividing resistor R13, it enters the I / O port with voltage detection function of the main control module for voltage detection. The main control module controls the adaptive voltage output circuit and the boost circuit according to the detection result, and outputs a voltage value greater than or equal to the detection result.

[0063] Among them, the first filter capacitor C33 is used to filter out the interference from the outside to the voltage detection. In addition, corresponding filtering processing is performed on the software code, and the accuracy of voltage detection is ensured by taking the average value through multiple measurements.

[0064] Next, the functional implementation of the adaptive voltage output module will be introduced in combination with the circuit diagram.

[0065] Figure 5 This is a circuit diagram of an adaptive voltage output module provided by this application. As Figure 5 shown, the adaptive voltage output module includes: a multi-channel analog switch U5 and multiple feedback resistors. The common pins of the multi-channel analog switch U5 are respectively connected to the feedback resistors one by one; the output pins NO of the multi-channel analog switch U5 are all connected to the feedback port of the boost circuit module; the control pin IN of the multi-channel analog switch is connected to the selection control signal MCU-IN sent by the main control module; the multi-channel analog switch U5 is used to select and connect the corresponding feedback resistor to the output pin based on the selection control signal.

[0066] Specifically, as Figure 5 shown, the multi-channel analog switch U5 is a four-channel analog switch. There are four feedback resistors: the first feedback resistor R21, the second feedback resistor R22, the third feedback resistor R23, and the fourth feedback resistor R28, which are respectively connected to the common pins COM1, COM2, COM3, and COM4 one by one. The first control pin IN1, the second control pin IN2, the third control pin IN3, and the fourth control pin IN4 respectively input the first selection control signal MCU-IN1, the second selection control signal MCU-IN2, the third selection control signal MCU-IN3, and the fourth selection control signal MCU-IN4. The first output pin NO1, the second output pin NO2, the third output pin NO3, and the fourth output pin NO4 are all connected to the feedback port (the FB pin in the following Figure 6 ) of the boost circuit module, that is, the Rfb2-Select network as Figure 5 shown.

[0067] When the control signal MCU-IN1 is set to a high level, the first feedback resistor R21 is selected to be connected to the Rfb2-Select network; when the control signal MCU-IN2 is set to a high level, the second feedback resistor R22 is selected to be connected to the Rfb2-Select network. And so on, according to the selection control signal output by the main control module, the corresponding feedback resistor is selected to be connected to the feedback port of the boost circuit module, and different feedback resistors will cause the first voltage output by the boost circuit module to change accordingly, thereby realizing the adjustability of the output voltage of the boost circuit module.

[0068] Furthermore, as Figure 5As shown, VDD-1636 is the power supply voltage of the multi-channel analog switch U5 and is also the first voltage output by the boost circuit module. Figure 5 Filter capacitors C62 and C63 are also exemplarily provided to filter VDD-1636, ensuring the stability and anti-interference ability of the power supply voltage.

[0069] Next, the function realization of the boost circuit module will be introduced in conjunction with the circuit diagram.

[0070] Figure 6 The figure is a circuit diagram of a boost circuit module provided by this application. The boost circuit module includes: a boost power supply chip U1, a first NMOS transistor Q2, and a first PMOS transistor Q1.

[0071] The gate of the first NMOS transistor Q2 is connected to the boost control signal ADG-1636-PWR of the main control module; the source of the first NMOS transistor Q2 is grounded; the drain of the first NMOS transistor Q2 is connected to the gate of the first PMOS transistor Q1; the source of the first PMOS transistor Q1 is connected to the power supply Main-PWR of the boost circuit module; the drain of the first PMOS transistor Q1 is connected to the input pin VIN of the boost power supply chip U1; the feedback port FB of the boost power supply chip U1 is connected to the output pin NO of the adaptive voltage output module, and the output port VOUT of the boost power supply chip U1 is connected to the channel switching module.

[0072] Specifically, the boost circuit module is designed based on a low-power boost power supply chip U1, and a corresponding power switch function circuit is designed in cooperation with the input pin VIN. The specific control process is as follows: when the boost control signal ADG-1636-PWR is set to a high level by the main control module, its gate-source voltage is greater than its own conduction voltage threshold value, and the first NMOS transistor Q2 conducts; the gate of the first PMOS transistor Q1 is grounded, and its gate-source voltage reaches its conduction threshold value, and the first PMOS transistor Q1 conducts, and the power supply Main-PWR is connected to the input pin VIN, that is, the boost power supply chip U1 is powered on and in a working state.

[0073] If a boost power supply chip with a large working power consumption is selected to design the boost circuit: it can also achieve the purpose of supplying power to the channel switching module, but its own static power consumption is large, resulting in excessive power consumption of the overall circuit.

[0074] Further, refer to Figure 6, the boost circuit module further includes: a third current-limiting resistor R7, a first protection resistor R4, and a first filtering module; a first end of the third current-limiting resistor R7 is connected to the boost control signal of the main control module; a second end of the third current-limiting resistor R7 is connected to the gate of the first NMOS transistor Q2; the first protection resistor R4 is connected between the gate and the source of the first PMOS transistor Q1; the first filtering module is connected between the drain of the first PMOS transistor Q1 and the input pin of the boost power supply chip U1.

[0075] Specifically, when the boost control signal ADG-1636-PWR is set to a high level by the main control module, this high level acts on the gate of the first NMOS transistor Q2 through the third current-limiting resistor R7, playing a current-limiting and protecting role. The first protection resistor R4 is connected between the gate and the source of the first PMOS transistor Q1, discharging the static electricity between the gate and the source in time, avoiding the generation of high voltage due to the equivalent capacitance between the gate and the source poles of the static electricity, resulting in misoperation or even breakdown. Exemplarily, the first filtering module can be composed of, for example Figure 6 as shown by the filter capacitors C14, C15, and C18.

[0076] Further, referring to Figure 6 , the boost circuit module further includes: a first energy storage inductor L and a second energy storage module. A first end of the second energy storage inductor L is connected to the input pin VIN of the boost power supply chip U1; a second end of the first energy storage inductor L is connected to the switch control pin SW of the boost power supply chip U1; the output pin VOUT of the boost power supply chip U1 is connected to the second energy storage module, and the second energy storage module is used to make the boost power supply chip U1 stably output the first voltage VDD-1636.

[0077] Exemplarily, Figure 6 the second energy storage module in

[0078] is composed of a first capacitor C6, a second capacitor C7, a third capacitor C8, and a fourth capacitor C16. One ends of the first capacitor C6, the second capacitor C7, the third capacitor C8, and the fourth capacitor C16 are connected together and grounded, and the other ends are connected together and connected to the output pin VOUT of the boost power supply chip U1.

[0079] Further, referring to Figure 6, the boost circuit module further includes: a first resistor R5; a first end of the first resistor R5 is connected to the feedback pin FB of the boost power supply chip U1, and a second end of the first resistor R5 is connected to the overvoltage protection pin VOSNS of the boost power supply chip U1. Among them, the feedback pin FB is connected to the Rfb2-Select network, that is, connected to the feedback resistor selected by the aforementioned adaptive voltage output module.

[0080] Specifically, the value of the first voltage VDD-1636 is related to the first resistor R5 and the feedback resistors (R21, R22, R23, R28), and the feedback resistors are defined as R fb2 , and its calculation formula is

[0081]

[0082] Among them, V FB is a fixed value, R5 is a fixed value, when R fb2 changes, the output voltage VDD-1636 also changes accordingly, so as to realize the adaptive output of the voltage. Among them, the higher the output voltage VDD-1636, the greater the power consumption.

[0083] Next, in combination with the circuit diagram, the function realization of the ultrasonic flow conversion module will be introduced.

[0084] Figure 7 This is a circuit diagram of an ultrasonic flow conversion module provided by this application. As Figure 7 shown, the ultrasonic flow conversion module includes: an ultrasonic flow measurement chip U2, a high-speed crystal oscillator Y2, and a low-speed crystal oscillator Y1; the remote communication interface (INTN, MISO, SCK, MOSI, SSN) of the ultrasonic flow measurement chip U2 is connected to the main control module; the low-speed crystal oscillator Y1 is connected to the low-frequency crystal oscillator pins (XIN_32MHZ and XOUT_32MHZ) of the ultrasonic flow measurement chip U2, and the high-speed crystal oscillator Y2 is connected to the high-frequency crystal oscillator pins (XIN_4MHZ and XOUT_4MHZ) of the ultrasonic flow measurement chip U2, and is used to provide an external clock signal for the ultrasonic flow measurement chip.

[0085] Specifically, Y1 is a low-speed 32.768kHz crystal oscillator, which mainly provides a timing function for the ultrasonic flow measurement chip U2. This clock is the basis of the monitor, including a measurement rate generator and a task sequencer, and it has been running when using the normal low-power mode. Refer to Figure 7, the capacitors C13 and C12 are the load capacitors required for the low-speed crystal oscillator Y1 (generally with capacitance values between 6 pF and 15 pF), which are used to improve the anti-interference ability of the crystal oscillator; the resistor R6 connected in parallel across the low-speed crystal oscillator Y1 serves to invert the output signal of the crystal oscillator by 180 degrees and feedback it to the input pin XIN_32MHZ of the low-frequency crystal oscillator to form negative feedback, and at the same time plays a role in current limiting to prevent the output of the inverter inside the crystal oscillator from overdriving the crystal oscillator and damaging the crystal oscillator. Its resistance value can be taken between 100 kΩ and 20 MΩ, and the crystal oscillator can start normally, but it will affect the pulse width ratio.

[0086] Y2 is a high-speed ceramic crystal oscillator, generally a 4M or 8M ceramic crystal oscillator. During normal operation, it is only turned on when a high-speed crystal oscillator is needed to reduce the power consumption of the ultrasonic flow measurement chip U2. The parallel-connected resistor R18 is the same as the resistor R6 connected across Y1. The high-speed crystal oscillator Y2 is used for front-end processing and is only activated when needed. It is recommended to use a ceramic oscillator for the high-speed crystal oscillator Y2 because compared with quartz, the advantage of a ceramic resonator is its short establishment time and power consumption savings. On the other hand, the clock needs to be periodically calibrated relative to a standard quartz (LSO quartz), so there is no advantage in using a quartz oscillator.

[0087] The above settings introduce the structural composition of the ultrasonic flow conversion module. An ultrasonic flow conversion chip with a relatively high integration level is adopted to ensure the operating stability; a mode of cooperative operation of a low-frequency crystal oscillator and a high-frequency crystal oscillator is adopted, and the high-frequency crystal oscillator is only switched on when work is needed to reduce the power consumption of the chip.

[0088] Furthermore, Figure 7 The remote communication interface (INTN, MISO, SCK, MOSI, SSN) in is connected to the remote communication port of the main control module and is used to transmit the flow data information in the ultrasonic flow conversion module to the main control module. After the ultrasonic transducer excitation and echo signal information processing are completed in the ultrasonic flow conversion module, an interrupt trigger signal at this moment is sent to the main control module through the interruption of the GP40-INTN signal to initiate the remote communication with the main control module.

[0089] During a measurement cycle, after the front-end and back-end processing of all information is completed and after the last data processing within a measurement cycle is completed, the ultrasonic flow conversion module automatically issues an interrupt GP40-INTN signal to initiate data interaction with the main control MCU. Among them, the GP40-SSN signal is active low. When the remote communication is in an idle state, the GP40-SSN signal is set to high level to disable the remote communication; and it is necessary to set the initial state of the remote communication port of the main control module to be consistent with the idle states of the signals of the remote communication interface (INTN, MISO, SCK, MOSI, SSN) of the ultrasonic flow measurement chip U2 to prevent unnecessary sink current loss from the main control module to the remote communication interface of the ultrasonic flow measurement chip U2 in the communication idle state.

[0090] Further, referring to Figure 7 , the ultrasonic flow conversion module further includes: a first external capacitor C34, a second external capacitor C35, a third external capacitor C36, and a second filtering module; both ends of the first external capacitor C34 are connected to the first group of charge pump pins (CHP_C1_P and CHP_C1_M) of the acoustic wave flow measurement chip; both ends of the second external capacitor C35 are connected to the second group of charge pump pins (CHP_C2_P and CHP_C2_M) of the acoustic wave flow measurement chip; both ends of the third external capacitor C36 are connected to the third group of charge pump pins (CHP_C3_P and CHP_C3_M) of the acoustic wave flow measurement chip; the second filtering module is connected to the regulated voltage pin (VCC_CHP) of the acoustic wave flow measurement chip.

[0091] The above-mentioned first external capacitor C34, second external capacitor C35, and third external capacitor C36 are external capacitors for the internal charge pump circuit of the ultrasonic flow measurement chip U2 (the reference charge pump provides a configurable voltage based on the reference voltage; the power charge pump has three stages to multiply), realizing the function of adjusting the excitation voltage within a certain range and ensuring that the ultrasonic amplitude meets the application requirements in different pipe diameter application scenarios. Specifically, due to the high integration of the ultrasonic flow measurement chip U2 itself, only three ceramic capacitors need to be externally connected to realize the function of adjusting the excitation voltage between 6V and 18V.

[0092] In the example as shown in Figure 7 , the second filtering module is composed of capacitors C25, C26, and C27 connected in parallel. These three capacitors are the output capacitors (the withstand voltage value needs to be greater than or equal to 18V) of the excitation voltage signals (FIRE-Up and FIRE-Down) of the ultrasonic flow measurement chip U2, and the capacitance value generally takes dozens of microfarads (μF) to ensure the stability and anti-interference ability of the output excitation voltage.

[0093] Further, the ultrasonic flow measurement chip has four input power pins VCC, and a third filtering module is connected between the externally supplied power supply GP40-VCC and the input power pin VCC.

[0094] In the example as Figure 7 shown, the four input power pins VCC correspond to four groups of third filtering modules, which are respectively composed of five filtering capacitors C1, C2, C3, C4 and C5 in parallel, composed of five filtering capacitors C20, C21, C22, C23 and C24 in parallel, composed of five filtering capacitors C37, C38, C39, C46 and C49 in parallel, and composed of five filtering capacitors C40, C41, C42, C44 and C45 in parallel. The capacitance values of these four groups of third filtering modules include levels of microfarad (μF), nanofarad (nF), and picofarad (pF), and are mainly used to filter out the power supply ripple and noise of the working voltage of the ultrasonic flow measurement chip U2. Among them, the μF-level capacitors are mainly for low-frequency power supply interference, and the nF and pF levels are mainly for high-frequency power supply interference, ensuring the power quality of the working power supply of U2.

[0095] The above setting for connecting multiple input power pins to a single chip enhances the stability of the chip's power supply, and further enhances the working stability of the chip.

[0096] Further, the ultrasonic flow measurement chip has a reference voltage output pin VDD18_OUT and two reference voltage input pins VDD18_IN; the reference voltage output pin VDD18_OUT is connected to a fourth filtering module, which is used to output the initial reference voltage VDD18_OUT generated inside the ultrasonic flow measurement chip, and after being filtered by the fourth filtering module, the reference voltage VDD18 is obtained; the reference voltage VDD18 is connected to each reference voltage input pin VDD18_IN, and at least one reference voltage input pin VDD18_IN is connected to a fifth filtering module.

[0097] Among them, the initial reference voltage VDD18_OUT is the power supply reference generated inside the ultrasonic flow measurement chip U2, and is used as the reference voltage of the offset stable comparator inside the chip. The stability of this voltage directly affects the stability and accuracy of flow measurement. Therefore, in the example as Figure 7 shown, the fourth filtering module is composed of capacitors C50, C51, C52, C53, C54, C55, C56, C57 and C60 in parallel, and also includes a current limiting resistor R20 to generate a stable and high-precision reference voltage VDD18.

[0098] In the example as Figure 7In the shown example, the two groups of fifth filtering modules are respectively composed of capacitors C28, C29, C30, C31 and C32 in parallel, and capacitors C43, C47, C48, C58 and C61 in parallel. The capacitance values of these two groups of fifth filtering modules are at the levels of μF, nF, and pF, and are mainly used to filter out the power supply ripple and noise of the working voltage of the ultrasonic flow measurement chip U2. Among them, the μF-level capacitors are mainly for low-frequency power supply interference, and the nF and pF levels are mainly for high-frequency power supply interference, ensuring the stability and anti-interference ability of the internal reference voltage of the chip.

[0099] It should be noted that the number of capacitors in the foregoing filtering module of this application is not limited, as long as the filtering requirements of each module of the ultrasonic flowmeter can be met. Reducing the number of filtering capacitors, the ultrasonic flowmeter can still perform measurement, but the reference inside the ultrasonic flow conversion chip in the transducer excitation module may become unstable, the zero offset of the circuit becomes larger, and the flight time error measured by the ultrasonic flow measurement chip U2 is relatively large, affecting the overall measurement accuracy.

[0100] In the example as Figure 7 shown, it also includes filtering capacitors C9, C17 and C19, which are used to filter out power supply interference, and the capacitance values are at the levels of μF, nF, and pF respectively. The resistor R19 and the capacitor C59 are used to disable the temperature acquisition function of the measurement chip.

[0101] Referring to Figure 7 , COMP-IN and RECEIVE-SIG are the lead-out points of the ultrasonic echo signal, which are used to amplify the echo signal. The resistors R1, R2, R3 and the capacitors C10, C11 form an external filter for the programmable gain amplifier (PGA) circuit inside the ultrasonic flow measurement chip U2. This external filter can effectively reduce the PGA noise. This external filter is only effective at high amplification multiples. Therefore, in the case of small-diameter pipes, the PGA amplification multiple is small, and this part of the circuit is not enabled. The recommended resistance value is within 10k, and the capacitance value is within 10nF. The corresponding parameter values can be adjusted according to the actual circuit.

[0102] If the PGA peripheral loop compensation circuit is removed: the gain amplification function still exists, but when performing gain amplification with a large multiple, the amplified signal is easily interfered by noise, and the loop of the internal PGA circuit becomes unstable, resulting in the loss or error of the measurement data.

[0103] Referring to Figure 7, FIRE UP and FIRE DOWN are the upstream excitation and downstream excitation respectively, which are mainly used to drive the piezoelectric transducer at the back end to generate ultrasonic signals. Resistors R8, R9, R10, and R11 are serial matching resistors connected between the ultrasonic flow measurement chip U2 and the ultrasonic transducer, and need to be connected to the external ultrasonic transducer. Resistor R11 is located between the upstream excitation and the transducer; resistor R8 is located between the downstream excitation and the transducer; resistor R10 is located between the receiving upstream pin and the transducer; resistor R9 is located at the point between the receiving downstream pin and the transducer. During operation, the receiving pin is internally switched to ground, so the receiving transducer is in parallel with the matching resistor. Therefore, ideally, the external resistor and the impedance of the receiving transducer are in the same order of magnitude to obtain the maximum acoustic power of the receiving transducer. Exemplarily, the designed range of the resistance value can be 330Ω to 1KΩ. In actual application, the resistance value is selected according to the self-impedance of the selected transducer to achieve the maximum acoustic power.

[0104] The task of the ultrasonic flow measurement chip U2 is to process the whole process: drive the excitation piezoelectric transducer, generate ultrasonic pulses, measure the time offset amplitude of the receiving transducer, and optionally perform a complete post-processing of the flow calculation. The flow velocity at a given cross-sectional area is a measure of the actual flow rate through the valve element, and the flow rate is obtained by integrating the flow rate over time.

[0105] The ultrasonic flow measurement chip U2 is a complete ultrasonic flow converter used to measure and calculate the flow rate of a time-of-flight-based ultrasonic flowmeter. Specifically, it includes a driver for the piezoelectric transducer, an analog switch, a programmable gain amplifier and an offset-stable comparator, a central processor for calculating the flow rate, a clock control unit, and most importantly, a measurement rate control and task sequencer unit. As a completely autonomous system, the task sequencer manages the entire measurement sequence independently of the external central processor. With the help of its internal central processor, it autonomously manages the entire measurement sequence. It outputs the time-of-flight information, and the time information can be converted into flow calibration information. It covers the complete ultrasonic flow measurement task, but does not touch all other tasks of the central microcontroller. Therefore, there is high flexibility in choosing the central microcontroller during the design process, and even a central microcontroller used for, for example, mechanical instruments can be selected.

[0106] The internally integrated PGA circuit and internal charge pump circuit can effectively and reliably amplify the signal amplitude and flexibly adjust the excitation voltages of each level, making it applicable to application scenarios with different pipe diameters. There is no need to build a PGA circuit and a charge pump voltage multiplier circuit externally, which enhances the anti-interference ability and stability of the entire circuit module, and the zero-offset value of the entire circuit module is small, laying a solid foundation for achieving good measurement accuracy. The design of using low-frequency and high-frequency crystal oscillators in cooperation switches different crystal oscillator sources in different working states, which can effectively reduce the working power consumption value and meet the low-power requirements for subsequent battery-powered occasions. As a completely autonomous system, the task sequencer manages the entire measurement sequence independently of the external central processor and does not require the external central processor to manage the task sequence. It can independently complete the measurement and processing of all flow data, and finally transmit the data results to the external central processor in the form of SPI communication, making the selection requirements for the external central processor simple and reducing the software code work.

[0107] If the ultrasonic flow measurement chip U2 with a high integration level is not selected and only a time conversion chip is selected: the conversion of ultrasonic flow can still be completed, but a signal conditioning circuit and flow data processing logic need to be added additionally, which will increase the overall power consumption value of the circuit, significantly increase the design cost, and the development task of software code.

[0108] This application is designed with an excitation voltage adaptive module, which can detect the ultrasonic transducer excitation signal sent by the ultrasonic flow conversion module and automatically adjust the output of the system working voltage with this excitation signal as a reference. Since the power supply voltage of the external circuit needs to be greater than or equal to the excitation voltage to complete the measurement task normally, with different excitation voltages, the external voltage needs to cover the maximum value of the excitation voltage. Without the voltage adaptive output function, there will be a large amount of energy waste at low excitation voltages.

[0109] If the adaptive voltage output circuit and the excitation voltage sampling circuit are removed: ultrasonic measurement can still be carried out, but when used in different pipe diameter occasions, the excitation voltages of the ultrasonic flow conversion module are different. If voltage adaptive output is not supported, the output voltage value of the boost circuit must be greater than the maximum value of the excitation voltage. Due to the conversion efficiency problem of the boost circuit, this will undoubtedly increase the working power consumption of the circuit and reduce the applicable occasions for battery power supply.

[0110] In addition, when there is no fluid in the pipeline or any ultrasonic transducer is damaged, the ultrasonic echo signal cannot be received. At this time, in order to limit time and current, an overtime window can be set accordingly to remind of an empty pipe or ultrasonic transducer failure, and automatically close the relevant measurement tasks and enter the standby low-power mode, reducing power consumption while promptly prompting the failure.

[0111] When actually performing ultrasonic measurements, the channel switching circuit cooperates with the corresponding software control strategy to reasonably control the excitation time and excitation interval of each channel, so that it is in a low-power state for most of a measurement cycle, which can effectively reduce the operating power consumption of the channel switching circuit, thereby reducing the operating power consumption of the overall circuit.

[0112] In actual application, the power supply part of the entire ultrasonic flowmeter can be powered by a lithium battery or an external DC power supply. The power supply is converted into a stable working voltage value that meets the main control chip and ultrasonic flow conversion module through a power conversion chip. The power supply scheme is more common than the design application and is not described in detail. After the entire metering scheme obtains the normal working voltage, each circuit module operates normally.

[0113] When the ultrasonic flowmeter is powered by a battery, low power consumption becomes particularly important. When the ultrasonic metering solution has a high power consumption, in order to ensure the normal service life of the ultrasonic flowmeter, the number of lithium batteries required will increase directly, and the volume occupied by multiple lithium batteries will also increase accordingly. The appearance of the ultrasonic flowmeter is not attractive, and the cost will also increase significantly accordingly.

[0114] In addition, since the channels cannot be completely physically isolated from each other, the channels will crosstalk when they are excited in sequence, affecting the stable transmission of the excitation signal to the ultrasonic transducer, which in turn affects the ultrasonic echo signal detection and data analysis, and ultimately affects the measurement accuracy and stability of the ultrasonic flowmeter; and the unreasonable layout and wiring of the circuit board leads to the instability of the ultrasonic measurement signal, thus affecting the stability of the ultrasonic measurement of the entire board. When the actual PCB board is laid out and wired, the layout and wiring design of the PCB board is optimized, the sensitive signal lines are differentially processed with equal length, and the corresponding ground plane shielding design is made to enhance the anti-interference ability of the sensitive signal to achieve the best circuit application effect.

[0115] The ultrasonic flowmeter device provided by the present application includes: a main control module, an ultrasonic flow conversion module, an excitation voltage adaptive module, a channel switching module, and ultrasonic transducers. Among them, the ultrasonic flow conversion module is connected to the ultrasonic transducers and the main control module, and is used to output an excitation voltage signal under the control of the main control module to drive the ultrasonic transducers to emit ultrasonic signals and calculate the flow rate based on the ultrasonic echo signals. The excitation voltage adaptive module is connected to the ultrasonic flow conversion module and the main control module, and is used to collect the excitation voltage signal emitted by the ultrasonic flow conversion module and send it to the main control module, so that the main control module outputs a control signal according to the voltage value of the excitation voltage signal. The excitation voltage adaptive module is also connected to the channel switching module, and is further used to adjust the output first voltage according to the control signal output by the main control module. The first voltage is used to provide the operating voltage of the channel switching module, and the first voltage is greater than or equal to the voltage value of the excitation voltage signal. By automatically adjusting the output voltage through the excitation voltage adaptive module in the present application, the operating voltage of the channel switching module is greater than or equal to the voltage value of the excitation voltage signal, which improves the applicability to different pipe diameters and also reduces the design difficulty.

[0116] Those skilled in the art will readily conceive of other embodiments of the present application after considering the specification and practicing the invention disclosed herein. The present application is intended to cover any variations, uses, or adaptations of the present application, which follow the general principles of the present application and include known common knowledge or conventional technical means in the technical field not disclosed in the present application. The specification and embodiments are only regarded as exemplary, and the true scope and spirit of the present application are pointed out by the following claims.

[0117] It should be understood that the present application is not limited to the exact structure already described and shown in the drawings, and various modifications and changes can be made without departing from its scope. The scope of the present application is only limited by the appended claims.

Claims

1. An ultrasonic flowmeter device, characterized in that, it includes: a main control module, an ultrasonic flow conversion module, an excitation voltage adaptive module, a channel switching module, and ultrasonic transducers; wherein, the ultrasonic flow conversion module is connected to the ultrasonic transducers and the main control module, and is configured to output an excitation voltage signal under the control of the main control module to drive the ultrasonic transducers to emit ultrasonic signals and calculate the flow rate based on the ultrasonic echo signals; the excitation voltage adaptive module is connected to the ultrasonic flow conversion module and the main control module, and is configured to collect the excitation voltage signal emitted by the ultrasonic flow conversion module and send it to the main control module, so that the main control module outputs a control signal according to the voltage value of the excitation voltage signal; the excitation voltage adaptive module is connected to the channel switching module, and is further configured to adjust and output a first voltage according to the control signal, where the first voltage is used to provide the operating voltage of the channel switching module, and the first voltage is greater than or equal to the voltage value of the excitation voltage signal; the excitation voltage adaptive module includes: an excitation voltage sampling module, an adaptive voltage output module, and a boost circuit module; the excitation voltage sampling module is connected to the ultrasonic flow conversion module and the main control module, and is configured to collect the excitation voltage signal emitted by the ultrasonic flow conversion module and send it to the main control module, so that the main control module outputs a corresponding selection control signal; the adaptive voltage output module is connected to the main control module and the boost circuit module, and is configured to select a feedback resistor to provide to the boost circuit module according to the selection control signal; the boost circuit module is configured to output the first voltage according to the feedback resistor.

2. The device according to claim 1, characterized in that, the excitation voltage sampling module includes: a first triode and a second triode; the base of the first triode is connected to the acquisition control signal emitted by the main control module; the emitter of the first triode is grounded; the collector of the first triode is connected to the base of the second triode; the emitter of the second triode is connected to the excitation voltage signal emitted by the ultrasonic flow conversion module; the collector of the second triode is connected to the main control module.

3. The device according to claim 2, characterized in that, the excitation voltage sampling module further includes: a first current limiting resistor, a second current limiting resistor, a first voltage dividing resistor, a second voltage dividing resistor, and a first filter capacitor; the first end of the first current limiting resistor is connected to the acquisition control signal emitted by the main control module; the second end of the first current limiting resistor is connected to the base of the first triode; the first end of the second current limiting resistor is connected to the collector of the first triode; the second end of the second current limiting resistor is connected to the base of the second triode; the first end of the first voltage dividing resistor is connected to the collector of the second triode; the second end of the first voltage dividing resistor is connected to the first end of the second voltage dividing resistor; the first end of the second voltage dividing resistor is connected to the voltage detection port of the main control module; the second end of the second voltage dividing resistor is grounded; The first end of the first filter capacitor is connected to the voltage detection port of the main control module, and the second end of the first filter capacitor is grounded.

4. The device according to claim 1, wherein, the adaptive voltage output module includes: a multi-channel analog switch and a plurality of feedback resistors; the common pins of the multi-channel analog switch are respectively connected to the feedback resistors in one-to-one correspondence; the output pins of the multi-channel analog switch are all connected to the feedback port of the boost circuit module; the control pin of the multi-channel analog switch is connected to the selection control signal sent by the main control module; the multi-channel analog switch is used to select and connect the corresponding feedback resistor to the output pin based on the selection control signal.

5. The device according to claim 1, wherein, the boost circuit module includes: a boost power supply chip, a first NMOS transistor, and a first PMOS transistor; the gate of the first NMOS transistor is connected to the boost control signal of the main control module; the source of the first NMOS transistor is grounded; the drain of the first NMOS transistor is connected to the gate of the first PMOS transistor; the source of the first PMOS transistor is connected to the power supply of the boost circuit module; the drain of the first PMOS transistor is connected to the input pin of the boost power supply chip; the feedback port of the boost power supply chip is connected to the output pin of the adaptive voltage output module, and the output port of the boost power supply chip is connected to the channel switching module.

6. The device according to claim 5, wherein, the boost circuit module further includes: a third current limiting resistor, a first protection resistor, and a first filtering module; the first end of the third current limiting resistor is connected to the boost control signal of the main control module; the second end of the third current limiting resistor is connected to the gate of the first NMOS transistor; the first protection resistor is connected between the gate and the source of the first PMOS transistor; the first filtering module is connected between the drain of the first PMOS transistor and the input pin of the boost power supply chip.

7. The device according to claim 6, wherein, the boost circuit module further includes: a first resistor; the first end of the first resistor is connected to the feedback pin of the boost power supply chip, and the second end of the first resistor is connected to the overvoltage protection pin of the boost power supply chip.

8. The device according to claim 6, wherein, the boost circuit module further includes: a first energy storage inductor and a second energy storage module; the first end of the second energy storage module is connected to the input pin of the boost power supply chip; the second end of the first energy storage inductor is connected to the switch control pin of the boost power supply chip; the output pin of the boost power supply chip is connected to the second energy storage module, and the second energy storage module is used to make the boost power supply chip stably output the first voltage.

9. The device according to claim 1, wherein, the ultrasonic flow conversion module includes: an ultrasonic flow measurement chip, a high-speed crystal oscillator, and a low-speed crystal oscillator; the remote communication interface of the ultrasonic flow measurement chip is connected to the main control module; The low-speed crystal oscillator is connected to the low-frequency crystal oscillator pin of the ultrasonic flow measurement chip, and the high-speed crystal oscillator is connected to the high-frequency crystal oscillator pin of the ultrasonic flow measurement chip, for providing an external clock signal to the ultrasonic flow measurement chip.

10. The device according to claim 9, wherein, the ultrasonic flow conversion module further includes: a first external capacitor, a second external capacitor, a third external capacitor, and a second filtering module; both ends of the first external capacitor are connected to the first group of charge pump pins of the acoustic wave flow measurement chip; both ends of the second external capacitor are connected to the second group of charge pump pins of the acoustic wave flow measurement chip; both ends of the third external capacitor are connected to the third group of charge pump pins of the acoustic wave flow measurement chip; the second filtering module is connected to the voltage stabilizing pin of the acoustic wave flow measurement chip.

11. The device according to claim 9, wherein, the ultrasonic flow measurement chip has four input power pins, and a third filtering module is connected between the external power supply and the input power pins.

12. The device according to claim 9, wherein, the ultrasonic flow measurement chip has a reference voltage output pin and two reference voltage input pins; the reference voltage output pin is connected to a fourth filtering module, for outputting the initial reference voltage generated inside the ultrasonic flow measurement chip, and after being filtered by the fourth filtering module, obtaining the reference voltage; the reference voltage is connected to each reference voltage input pin, and at least one reference voltage input pin is connected to a fifth filtering module.

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