Non-magnetic fluid metering circuit

Abstract

The application discloses a non-magnetic fluid metering circuit, comprising a signal acquisition circuit and a controller; the signal acquisition circuit comprises a coil inductance, a rotor and a first capacitor, the coil inductance comprises an external coil inductance and an internal coil inductance; the rotor is located above the coil inductance and rotates based on the flow of the fluid; the controller is connected with the first capacitor and the internal coil inductance; the other end of the first capacitor is connected with the external coil inductance; the controller is used for outputting a PWM signal to the first capacitor and determining the fluid flow based on a voltage signal generated by the internal coil inductance; the controller comprises a radio frequency module and is used for sending a first signal representing the fluid flow to a data concentrator. By starting the signal acquisition circuit and receiving the signal representing the fluid flow through the controller and sending the signal representing the fluid flow to the data concentrator through the controller integrated with the radio frequency function, the number of peripheral circuits and components is reduced, so that the power consumption and cost of the non-magnetic fluid metering instrument are reduced.

Description

Technical Field

[0001] This application relates to the field of instrumentation, and more particularly to a non-magnetic fluid metering circuit. Background Technology

[0002] Currently, there are wireless communication instruments on the market that support non-magnetic fluid measurement and WM-Bus (a wireless communication standard for instruments). There are two main design schemes: the first is to use an MCU (Microcontroller Unit) combined with a non-magnetic fluid measurement chip and an RF chip, which has a higher cost; the second is to use a non-magnetic sensing measurement module combined with an MCU and an RF chip, which has a higher power consumption and more electronic components, and also has a higher cost. Utility Model Content

[0003] In view of this, embodiments of this application provide a non-magnetic fluid metering circuit, which aims to reduce the cost of non-magnetic fluid metering instruments.

[0004] The technical solution of this application embodiment is implemented as follows:

[0005] This application provides a non-magnetic fluid metering circuit, including:

[0006] The signal acquisition circuit includes a coil inductor, a rotor, and a first capacitor. The coil inductor includes an outer coil inductor and an inner coil inductor. The rotor is located above the coil inductor and is used to rotate based on the flow of fluid.

[0007] A controller is connected to a first terminal of the first capacitor and the internal coil inductor; a second terminal of the first capacitor is connected to the external coil inductor; the controller is used to output a pulse width modulation (PWM) signal to the first capacitor and determine the fluid flow rate based on the voltage signal generated by the internal coil inductor.

[0008] The controller includes a radio frequency module for sending a first signal characterizing the fluid flow rate to a data concentrator.

[0009] In some implementations, the signal acquisition circuit further includes an amplification circuit connected to the internal coil inductor and the controller, for amplifying the voltage signal generated by the internal coil inductor and outputting it to the controller.

[0010] In some implementations, the signal acquisition circuit further includes a trigger connected to the controller and the first capacitor for shaping the PWM signal output by the controller.

[0011] In some implementations, a second capacitor is provided between the trigger and the controller.

[0012] In some implementations, the number of internal coil inductors is three, and the three internal coil inductors are connected at a single point and arranged at an angle of 120 degrees.

[0013] In some implementations, the three internal coil inductors are located inside the external coil inductors.

[0014] In some implementations, the non-magnetic fluid metering circuit further includes an antenna and a battery;

[0015] The antenna is connected to the controller and is used to receive the first signal and send the first signal to the data concentrator;

[0016] The battery is connected to the controller and is used to provide power to the controller.

[0017] In some embodiments, the rotor is a circular sheet, the rotor comprising a semi-circular non-metallic region and a semi-circular metallic region.

[0018] In some implementations, the controller further includes a first port for receiving a voltage signal generated by the internal coil inductance, the first port being connected to a pull-up resistor.

[0019] In some implementations, the amplifier circuit includes a first resistor, a second resistor, a transistor, and a third resistor;

[0020] The first end of the first resistor is connected to the internal coil inductance, the second end of the first resistor is connected to the second resistor and the base of the transistor, the emitter of the transistor is connected to the third resistor, and the collector of the transistor is connected to the first port.

[0021] The non-magnetic fluid metering circuit provided in this application includes a signal acquisition circuit and a controller. The signal acquisition circuit includes a coil inductor, a rotor, and a first capacitor. The coil inductor includes an external coil inductor and an internal coil inductor. The rotor is located above the coil inductor and is used to rotate based on the fluid flow. The controller is connected to the first capacitor and the internal coil inductor. The other end of the first capacitor is connected to the external coil inductor. The controller outputs a PWM signal to the first capacitor and determines the fluid flow rate based on the voltage signal generated by the internal coil inductor. The controller includes a radio frequency module for sending a first signal representing the fluid flow rate to a data concentrator. Thus, by activating the signal acquisition circuit and receiving the signal representing the fluid flow rate through the controller, and using the controller with integrated radio frequency signal processing to send the signal representing the fluid flow rate to the data concentrator, the number of peripheral circuits and components is reduced, thereby reducing the power consumption and cost of the non-magnetic fluid metering instrument. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the structure of the non-magnetic fluid metering circuit in an embodiment of this application;

[0023] Figure 2 This is a schematic diagram of the structure of the technical solution related to the application example of this application;

[0024] Figure 3 This is a structural schematic diagram of another related technical solution used in this application example;

[0025] Figure 4 This is a schematic diagram of the structure of a non-magnetic fluid metering scheme, which is an application example of this application.

[0026] Figure 5 This is a circuit diagram of the main control MCU used in the application of this application;

[0027] Figure 6 This is a circuit diagram of a non-magnetic fluid metering device, which is an application example of this application.

[0028] Figure 7 This is a schematic diagram of the rotor used in this application example. Detailed Implementation

[0029] The present application will now be described in further detail with reference to the accompanying drawings and embodiments.

[0030] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.

[0031] Before providing a further detailed description of the embodiments of this application, the terms and concepts used in the embodiments of this application are explained:

[0032] wM-Bus: Wireless Meter-BUS, is a wireless communication protocol used for low-power remote automatic meter reading and monitoring applications. It is a European standard-based wireless communication protocol primarily used for data acquisition and transmission from metering devices such as water meters, electricity meters, and gas meters.

[0033] Non-magnetic sensing metrology: A metrology technology, also known as non-magnetic fluid metrology, distinct from magnetic metrology. In the field of fluid metering, non-magnetic sensing technology was developed in contrast to traditional magnetic sampling. Non-magnetic sensing technology uses a non-magnetized metal sheet instead of a magnet, and its applications typically include mechanical water meters. Magnetic sampling technology relies on a small magnet on the rotating pointer of the indicator dial, as well as external reed switches or Hall effect elements for sampling; while non-magnetic sampling technology uses a non-magnetized metal sheet, such as stainless steel or copper, thus avoiding the use of magnets and significantly reducing interference from external magnetic fields. The core mechanism of non-magnetic sensing technology lies in the energy transfer between the metal sheet and alternating magnetic field lines. When the metal sheet perpendicularly crosses the alternating magnetic field lines, energy is instantly transferred to the metal sheet, causing a significant decrease in the circuit resonance amplitude and triggering a change in circuit resonance. This phenomenon can be accurately captured by the circuit and input into a microcontroller for rotation and direction determination.

[0034] Among related technologies, there are wireless communication instruments that support non-magnetic fluid metering and WM-Bus communication. There are two main design schemes: the first is to use an MCU combined with a non-magnetic fluid metering chip and an RF chip, which has a high cost; the second is to use a non-magnetic sensing metering module combined with an MCU and an RF chip, which has a high power consumption and more electronic components, and also has a high cost.

[0035] In various embodiments of this application, the signal acquisition circuit is activated by the controller and the signal representing the fluid flow rate is received. The controller with integrated radio frequency signal processing function is used to send the signal representing the fluid flow rate to the data concentrator, which reduces the number of peripheral circuits and components, thereby reducing the power consumption and cost of the non-magnetic fluid metering instrument.

[0036] This application provides a non-magnetic fluid metering circuit, such as... Figure 1 As shown, the system includes a signal acquisition circuit 101 and a controller 102. The signal acquisition circuit 101 includes a coil inductor, a rotor, and a first capacitor. The coil inductor includes an external coil inductor and an internal coil inductor. The rotor is located above the coil inductor and is used to rotate based on the fluid flow. The controller 102 is connected to the first capacitor and the internal coil inductor. The other end of the first capacitor is connected to the external coil inductor. The controller 102 is used to output a PWM signal to the first capacitor and determine the fluid flow rate based on the voltage signal generated by the internal coil inductor. The controller 102 includes a radio frequency module 1021, which is used to send a first signal characterizing the fluid flow rate to a data concentrator.

[0037] For example, the signal acquisition circuit 101 may include an external coil inductor and multiple internal coil inductors, with the internal coil inductors forming a mutual inductance relationship with the external coil inductors. Under the PWM signal drive of the controller 102, the first capacitor and the external coil inductor generate LC series resonance, thereby causing the internal coil inductor to generate a periodic magnetic field. Here, the controller 102 may be referred to as a microcontroller, SOC, MCU, or main control MCU; the specific type and name of the controller are not limited in this application embodiment.

[0038] When the fluid drives the rotor to rotate, the metal parts of the rotor periodically enter or leave the magnetic field range of the internal coil inductance, causing changes in magnetic flux. When the metal parts are close to the coil inductance, the magnetic flux is absorbed, the equivalent inductance value decreases, and the induced voltage amplitude decreases; when the metal parts are away from the coil inductance, the magnetic flux passes freely, the equivalent inductance value increases, and the induced voltage amplitude increases. Therefore, as the rotor rotates, the induced voltage value generated by the internal coil inductance changes sequentially. The controller 102 can calculate the rotor rotation direction and speed by the time difference (phase difference) of the induced voltage values ​​generated by multiple internal coil inductances. The direction of the rotor rotation can be used to determine the direction of the fluid, and the flow rate can be determined by the rotor rotation speed and the number of rotations of the rotor per unit volume of fluid. The controller 102 stores data such as the fluid flow rate in the internal Flash memory and sends the fluid flow rate data to the data concentrator via the radio frequency module 1021.

[0039] Here, the data concentrator is a key device widely used in fields such as the Internet of Things, automatic meter reading systems, and industrial automation. Its core function is to centrally collect, process, and forward data from multiple terminal devices (such as various instruments and meters), and act as a data transmission hub to transmit data to a higher-level system (such as a server or control center).

[0040] In practical applications, the rotor is typically made of non-magnetic materials, such as stainless steel or copper sheets, avoiding the interference problems of traditional magnetic sensors that are susceptible to external magnetic fields. This improves the system's anti-interference capability and measurement accuracy. The controller 102 can use a system-on-a-chip (SoC) with integrated radio frequency communication capabilities, such as the AMICCOM A9139M0. This chip is a wireless communication SoC based on the ARM M0 core architecture, supports the wM-Bus wireless communication protocol, has 128KB Flash memory and 16KB SRAM (Static Random Access Memory), and integrates various I / O interfaces, including SPI (Serial Peripheral Interface), UART (Universal Asynchronous Receiver / Transmitter), and supports ADC (Analog-Digital Converter) and PWM functions. By using a SoC with integrated radio frequency communication capabilities, not only can peripheral circuit design be simplified, but hardware costs and power consumption can also be significantly reduced, improving the overall system's economy and reliability. In addition, thanks to the use of low-power wireless communication protocols (such as wM-Bus), the controller 102 can operate for extended periods while ensuring communication quality, making it ideal for remote meter reading and industrial monitoring scenarios.

[0041] It is understood that the solution provided in this application embodiment starts the signal acquisition circuit and receives the signal representing the fluid flow rate through the controller, and sends the signal representing the fluid flow rate to the data concentrator using the controller with integrated radio frequency signal processing function, thereby reducing the number of peripheral circuits and components, and thus reducing the power consumption and cost of the non-magnetic fluid metering instrument.

[0042] To facilitate the controller's acquisition of the induced voltage signal generated by the internal coil inductance, the induced voltage needs to be appropriately amplified.

[0043] Based on this, in some embodiments, the signal acquisition circuit 101 further includes an amplification circuit, which is connected to the internal coil inductor and the controller 102, and is used to amplify the voltage signal generated by the internal coil inductor and output it to the controller 102.

[0044] Here, by introducing an amplifier circuit, the induced voltage of the internal coil inductance is effectively amplified, enhancing the availability of the signal. This reduces the risk of false measurements caused by signal distortion, improves the accuracy of fluid measurement, and ensures the long-term stable operation of the instrument and the reliability of the data.

[0045] In practical applications, where low power consumption is a high priority, transistors and low-power resistors can be used to construct the amplifier circuit; while in high-precision measurement applications, high-gain, low-noise operational amplifier components can be selected to construct the amplifier circuit. This application does not limit the specific circuit structure of the amplifier circuit in its embodiments.

[0046] The PWM waveform output by the controller is usually not a perfectly regular square wave, which can easily affect the accuracy and stability of the induced voltage signal acquisition.

[0047] Based on this, in some embodiments, the signal acquisition circuit 101 further includes a trigger connected to the controller 102 and the first capacitor, for shaping the PWM signal output by the controller 102.

[0048] Here, a flip-flop is a digital logic device used to shape input signals to enhance their stability and driving capability. The flip-flop receives the PWM signal output from controller 102 and shapes it, giving it clearer rising and falling edges. This enhances the driving capability of the PWM signal and removes noise or distortion, facilitating identification and response by subsequent circuits. In practical applications, a single-channel Schmitt trigger inverter of model SN74LVC1G14DBVR can be used as the flip-flop.

[0049] The pins of the trigger may experience voltage fluctuations due to high-frequency noise, causing false triggering.

[0050] Therefore, in some embodiments, a second capacitor is provided between the trigger and the controller 102.

[0051] Here, the second capacitor is used to filter the low-frequency components of the PWM signal output by the controller 102, thereby removing unnecessary DC bias and retaining only the required AC components. This allows the PWM signal output by the controller 102 to be transmitted to the trigger input more purely. By setting the second capacitor, it is possible to effectively prevent trigger malfunctions or signal distortion caused by the DC components in the PWM signal output by the controller 102, thereby improving the stability and signal transmission quality of the entire circuit system.

[0052] In some embodiments, the number of internal coil inductors is three, and the three internal coil inductors are connected at a single point and arranged at an angle of 120 degrees.

[0053] Here, "single-point connection and arrangement at a 120-degree angle" means that the three internal coil inductors share a single connection point and are arranged in a "petal-like" pattern at a 120-degree angle. This arrangement ensures that the three internal coil inductors are evenly distributed in space, thereby improving the ability to sense the direction of fluid movement. In practical applications, when the rotor rotates due to fluid flow, the three internal coil inductors will generate different induced signals due to their different positions. Because the three internal coil inductors are evenly arranged, the induced signals generated by these three internal coil inductors have good phase difference characteristics. The controller 102 can accurately determine the flow rate and direction of the fluid by comparing the induced signals generated by the three internal coil inductors, thereby improving the measurement accuracy and response speed of the non-magnetic fluid metering.

[0054] In some embodiments, the three internal coil inductors are located inside the external coil inductors.

[0055] Here, the three internal coil inductors are arranged inside the external coil inductors, which helps to enhance the efficiency of electromagnetic induction, thereby improving the accuracy of fluid flow measurement.

[0056] In some embodiments, the non-magnetic fluid metering circuit further includes an antenna and a battery;

[0057] The antenna is connected to the controller 102 and is used to receive the first signal and send the first signal to the data concentrator;

[0058] The battery is connected to the controller 102 and is used to provide power to the controller 102.

[0059] Here, the antenna is electrically connected to the controller 102, which supports the WM-Bus communication protocol, and forwards the first signal representing the fluid flow rate provided by the controller 102 to the data concentrator. The battery provides power to the controller 102, ensuring its normal operation. The antenna can be a monopole antenna or a dipole antenna, etc., and the battery can be a lithium battery or a button battery, etc. This application does not limit the specific types of antennas and batteries.

[0060] In some embodiments, the rotor is a circular sheet, and the rotor includes a semi-circular non-metallic region and a semi-circular metallic region.

[0061] Here, compared to traditional magnetic rotors, the circular thin-film rotor avoids the use of magnets, reduces interference with external magnetic fields, and possesses higher structural stability and manufacturing feasibility. The non-metallic regions can be hollowed-out parts of the rotor or filled with non-metallic materials. The metallic regions are composed of highly conductive metallic materials, such as stainless steel or copper. These metallic regions generate strong electromagnetic induction in an alternating magnetic field. In practical applications, when the fluid propels the rotor to rotate at the speed of fluid flow, the non-metallic and metallic regions alternately enter the range of the three internal coil inductors. When a metallic region absorbs the magnetic flux of one internal coil inductor, the magnetic fields of the other internal coil inductors remain unaffected. Therefore, the three internal coil inductors are affected by the rotor's metallic parts at different times. The controller 102 determines the fluid's rotational speed and direction based on the timing of abnormal induced voltages generated by the three internal coil inductors.

[0062] In some embodiments, the controller 102 further includes a first port for receiving a voltage signal generated by the internal coil inductance, the first port being connected to a pull-up resistor.

[0063] Here, the first port is used to receive induced voltage signals from the internal coil inductors. For example, the controller 102 may include three first ports for receiving induced voltage signals from three internal coil inductors.

[0064] In practical applications, a pull-up resistor is a resistor connected between an input pin and the power supply. It maintains the input pin at a stable high level when there is no external signal input. The pull-up resistor prevents the first port from becoming unpredictable due to floating, thus avoiding false triggering or interference with the operation of the controller 102. The pull-up resistor also limits current, protecting the controller 102 from inrush current. By setting a pull-up resistor at the first port of the controller 102, the stability of the received signal can be effectively enhanced, and the impact of noise on the measurement results can be reduced, thereby improving the accuracy and reliability of non-magnetic fluid measurement.

[0065] In some embodiments, the amplifier circuit includes a first resistor, a second resistor, a transistor, and a third resistor;

[0066] The first end of the first resistor is connected to the internal coil inductance, the second end of the first resistor is connected to the second resistor and the base of the transistor, the emitter of the transistor is connected to the third resistor, and the collector of the transistor is connected to the first port.

[0067] For example, the induced voltage from the internal coil inductance is divided by the first and second resistors to provide a stable DC bias voltage to the base of the transistor, enabling the transistor to operate in the amplification region. The induced voltage is then converted into current and input to the base of the transistor. The relationship between the collector current Ic and the base current Ib of the transistor is Ic = β × Ib, where β is the amplification factor of the transistor, typically ranging from tens to hundreds. When an input signal (the induced voltage signal from one of the internal coil inductances) flows into the base of the transistor, the base current changes with the input signal, causing the collector current to change accordingly. The collector current flows from the collector to the emitter, and after passing through the third resistor, it is converted into a voltage signal. The controller 102 receives this voltage signal, enabling precise acquisition of the magnetic field changes of the internal coil inductance, thereby improving the accuracy and reliability of non-magnetic fluid metering. Here, the amplification factor of the transistor can be determined according to the actual situation. The transistor can be a PNP type transistor or an NPN type transistor. This application embodiment does not limit the specific type and amplification factor of the transistor.

[0068] This application provides a non-magnetic fluid metering circuit, including a signal acquisition circuit and a controller. The signal acquisition circuit includes a coil inductor, a rotor, and a first capacitor. The coil inductor includes an external coil inductor and an internal coil inductor. The rotor is located above the coil inductor and rotates based on fluid flow. The controller is connected to the first capacitor and the internal coil inductor. The other end of the first capacitor is connected to the external coil inductor. The controller outputs a PWM signal to the first capacitor and determines the fluid flow rate based on the voltage signal generated by the internal coil inductor. The controller includes a radio frequency module for sending a first signal representing the fluid flow rate to a data concentrator. Thus, by activating the signal acquisition circuit and receiving the signal representing the fluid flow rate through the controller, and using the controller with integrated radio frequency signal processing to send the signal representing the fluid flow rate to the data concentrator, the number of peripheral circuits and components is reduced, thereby reducing the power consumption and cost of the non-magnetic fluid metering instrument.

[0069] The following section provides a more detailed description of this application with reference to application examples.

[0070] In related technologies, a solution combining an MCU with a non-magnetic fluid metering chip and a radio frequency chip is used, such as... Figure 2As shown, the system includes an antenna 201, an RF chip 202, a battery 203, an MCU 204, and a non-magnetic fluid metering chip 205. The non-magnetic fluid metering chip 205 can be a TI MSP430FW42X series chip or a Mindray N32L436 series chip. These chips have 2-3 dedicated LC oscillation metering I / Os, enabling forward and reverse fluid metering. The RF chip 202 uses a wM-Bus RF communication IC, such as a TI CC1120 series, to achieve both non-magnetic fluid metering and wM-Bus data transmission functions.

[0071] In this solution, the RF chip 202 and MCU 204 are powered by batteries. When not transmitting or receiving data, the RF chip 202 is in a sleep state. The RF chip 202 is turned on only when data transmission or reception is required. Its power consumption is low, but the disadvantage is that the cost is relatively high.

[0072] In related technologies, a solution combining a non-magnetic fluid metering module (also known as a non-magnetic sensing module or a non-magnetic sensing metering module), an MCU, and an RF chip is employed, such as... Figure 3 As shown, the system includes an antenna 301, an RF chip 302, an MCU 303, a non-magnetic fluid metering module 304, and a battery 305. The non-magnetic fluid metering module is a third-party LC fluid metering module, which can utilize the domestic WF5502 module for non-magnetic fluid metering. It is paired with a main control MCU (MCU303), and the RF chip 302 uses a wM-Bus communication IC to form a complete unit that realizes metering, storage, and wM-Bus wireless data transmission functions. In this solution, the metering part is a separate module, requiring a separate battery power supply, and works in conjunction with the MCU303 and RF chip 302. The disadvantages are relatively high power consumption, a large number of required electronic materials, and high cost.

[0073] It can be seen that, as Figure 2 The first scheme shown is similar to... Figure 3 Of the two options shown, the second option has the highest material cost, followed by the first option.

[0074] The structural schematic diagram of the non-magnetic fluid metering scheme provided in the application example of this application is shown below. Figure 4 As shown, it includes: antenna 401, MCU 402 (i.e. controller 102), battery 403, and non-magnetic fluid metering device 404 (i.e. signal acquisition circuit 101). The battery 403 only supplies power to the MCU 402 and does not need to supply power to the non-magnetic fluid metering device 104, which reduces the number of peripheral circuits and components, thereby reducing the power consumption and cost of the non-magnetic fluid metering instrument.

[0075] The circuit diagram of the main control MCU provided in the application example of this application is as follows: Figure 5As shown, the main control MCU (i.e., controller 102) is U1. Pin 25 or pin 26 of U1 is used to output PWM signals. Pins 28, 29, and 30 of the main control MCU have ADC signal acquisition functions, used to receive the induced voltage signals amplified by the three internal coil inductors, respectively. Furthermore, pins 28, 29, and 30 all have internal pull-up resistors. U1 receives the voltage provided by the battery through pin 38, connects to the antenna through pins 8 and 9, sends the modulated signal to the data concentrator through pin 9, and receives the antenna signal through pin 8.

[0076] The circuit diagram of the non-magnetic fluid metering device provided in the application example of this application is as follows: Figure 6 As shown, in this configuration, port 2 of trigger U2 is connected to capacitor C30 (the second capacitor mentioned above) and resistor R16. Port 3 of trigger U2 is grounded along with the other end of resistor R16. Port 4 of trigger U2 is connected to capacitor C32 (the first capacitor mentioned above) and external main coil L9 (the external coil inductor mentioned above). Port 5 of trigger U2 is connected to capacitor C29 and then grounded. Internal mutual inductance coil L2 (one of the three internal coil inductors mentioned above) is connected to resistor R4 (the first resistor mentioned above). The other end of resistor R4 is connected to resistor R8 (the second resistor mentioned above) and then grounded. The other end of resistor R4 is also connected to the base of transistor Q1. The collector of transistor Q1 is connected to capacitor C9 and resistor R3. The other end of capacitor C9 is grounded. The emitter of transistor Q1 is connected to resistor R6 (the third resistor mentioned above). The other end of resistor R6 is connected to resistor R10 and resistor R14 and then grounded. Internal mutual inductance coil L3 (one of the three internal coil inductors mentioned above) is connected to resistor R11. (i.e., the first resistor mentioned above), the other end of resistor R11 is connected to resistor R17 (i.e., the second resistor mentioned above) and then grounded. The other end of resistor R11 is also connected to the base of transistor Q2. The collector of transistor Q2 is connected to capacitor C10 and resistor R9 respectively. The other end of capacitor C10 is grounded. The emitter of transistor Q2 is connected to resistor R15 (i.e., the third resistor mentioned above). The other end of resistor R15 is connected to resistor R10 and resistor R14 in sequence and then grounded. The internal mutual inductance coil L10 (i.e., one of the three internal coil inductors mentioned above) is connected to resistor R19 (i.e., the first resistor mentioned above). The other end of resistor R19 is connected to resistor R21 (i.e., the second resistor mentioned above) and then grounded. The other end of resistor R19 is also connected to the base of transistor Q3. The collector of transistor Q3 is connected to capacitor C33 and resistor R18 respectively. The other end of capacitor C33 is grounded. The emitter of transistor Q3 is connected to resistor R20 (i.e., the third resistor mentioned above). The other end of resistor R20 is connected to resistor R10 and resistor R14 in sequence and then grounded.

[0077] Here, trigger U2 receives the PWM signal output by the main control MCU through capacitor C30. After the waveform is shaped, it is connected to the external main coil L9 through capacitor C32 in a series resonant circuit. L9 generates a magnetic field, which is mutually induced to the internal mutual inductance coils L2, L3, and L10. The induced signals generated by the internal mutual inductance coils L2, L3, and L10 are amplified by transistors Q1, Q2, and Q3 respectively and then input to the main control MCU.

[0078] The schematic diagram of the rotor provided in the application example of this application is as follows: Figure 7 As shown, the rotor is a circular thin sheet, including a semi-circular non-metallic covering area and a semi-circular metallic covering area, covering the outer main coil L9, the inner mutual inductance coil L2, the inner mutual inductance coil L3, and the inner mutual inductance coil L10.

[0079] Based on the above description, it is evident that the technical features and beneficial effects of this application are at least as follows:

[0080] Using an RF SOC as the main control MCU, this chip integrates functions such as RF signal processing, general I / O, interface communication, PWM modulation, and ADC signal sampling. With a small number of external resistor-capacitor logic devices, it can achieve the same functions as the first and second solutions mentioned above, solving the pain points of high power consumption and high cost of related technologies.

[0081] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0082] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of the stated features. In the description of the embodiments of this application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified. It should be noted that "first," "second," etc., are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence.

[0083] It should be understood that the phrase "some embodiments" throughout the specification means that a particular feature, structure, or characteristic related to an embodiment is included in at least one embodiment of this application. Therefore, "some embodiments" appearing throughout the specification does not necessarily refer to the same embodiment. Furthermore, these particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments without conflict.

[0084] In the description of the embodiments of this application, it should be noted that, unless otherwise explicitly specified and limited, the terms "connected" or "linked" should be interpreted broadly. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, an electrical connection, or a connection that allows communication between the components; it can be a direct connection or an indirect connection through an intermediate medium; it can be the internal communication between two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0085] The above description is merely a preferred embodiment of this application and is not intended to limit the scope of patent protection of this application. Any equivalent structural transformations made based on the content of this application's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the scope of patent protection of this application.

Claims

1. A non-magnetic fluid metering circuit, characterized in that, include: The signal acquisition circuit includes a coil inductor, a rotor, and a first capacitor, wherein the coil inductor includes an external coil inductor and an internal coil inductor; The rotor is located above the coil inductance and is used to rotate based on the flow of fluid; A controller is connected to a first terminal of the first capacitor and the internal coil inductor; a second terminal of the first capacitor is connected to the external coil inductor; the controller is used to output a pulse width modulation (PWM) signal to the first capacitor and determine the fluid flow rate based on the voltage signal generated by the internal coil inductor. The controller includes a radio frequency module for sending a first signal characterizing the fluid flow rate to a data concentrator.

2. The circuit according to claim 1, characterized in that, The signal acquisition circuit further includes an amplification circuit, which is connected to the internal coil inductor and the controller, and is used to amplify the voltage signal generated by the internal coil inductor and output it to the controller.

3. The circuit according to claim 1, characterized in that, The signal acquisition circuit also includes a trigger, which is connected to the controller and the first capacitor and is used to shape the PWM signal output by the controller.

4. The circuit according to claim 3, characterized in that, A second capacitor is provided between the trigger and the controller.

5. The circuit according to claim 1, characterized in that, The number of internal coil inductors is three, and the three internal coil inductors are connected at a single point and arranged at an angle of 120 degrees.

6. The circuit according to claim 4, characterized in that, The three internal coil inductors are located inside the external coil inductors.

7. The circuit according to claim 1, characterized in that, The non-magnetic fluid metering circuit also includes an antenna and a battery; The antenna is connected to the controller and is used to receive the first signal and send the first signal to the data concentrator; The battery is connected to the controller and is used to provide power to the controller.

8. The circuit according to claim 1, characterized in that, The rotor is a circular thin sheet, and the rotor includes a semi-circular non-metallic region and a semi-circular metallic region.

9. The circuit according to claim 2, characterized in that, The controller also includes a first port for receiving the voltage signal generated by the internal coil inductance, and the first port is connected to a pull-up resistor.

10. The circuit according to claim 9, characterized in that, The amplifier circuit includes a first resistor, a second resistor, a transistor, and a third resistor; The first end of the first resistor is connected to the internal coil inductance, the second end of the first resistor is connected to the second resistor and the base of the transistor, the emitter of the transistor is connected to the third resistor, and the collector of the transistor is connected to the first port.

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