Communication circuit and water meter device for collecting water meter readings using new magnetic coupling technology

Abstract

This utility model discloses a novel communication circuit and water meter device for acquiring water meter readings using magnetic coupling technology. The communication circuit includes: a first coil and a second coil, a first capacitor to a fourth capacitor, a first switching device, and a first resistor. The first end of the first coil is connected to the second end of the first capacitor, and the first end of the first capacitor is connected to a first data transmission unit. The first end of the second coil is connected to the controlled end of the first switching device and the first end of the second capacitor. The second ends of the first coil and the second coil are connected to a preset voltage or grounded. The second end of the second capacitor is connected to the first end of the second data transmission unit. The first end of the first switching device is connected to the second end of the second data transmission unit and the first end of the third capacitor. The second end of the first switching device is connected to the first end of the fourth capacitor, the first end of the first resistor, and the third end of the second data transmission unit. The second end of the fourth capacitor and the second end of the first resistor are connected and grounded, and the second end of the third capacitor is grounded.

Description

Technical Field

[0001] This utility model relates to the field of water meter communication technology, and in particular to a new type of communication circuit and water meter device for acquiring water meter readings using magnetic coupling technology. Background Technology

[0002] Water meter equipment often experiences communication failures due to oxidation and corrosion of contact connections (such as gold fingers, connectors, and wires) in harsh environments. To solve this problem, technicians proposed contactless communication.

[0003] However, contactless communication can be mainly categorized as follows: based on radio frequency technology, based on electromagnetic induction, based on sound waves, and based on light waves. From a cost perspective, data transmission using coil coupling based on electromagnetic induction is the cheapest. Data transmission based on electromagnetic induction technology is mainly divided into NFC and RFID technologies. However, NFC and RFID technologies constitute a complete and standardized near-field communication protocol system, containing complex communication protocols (such as initialization, anti-collision, and data exchange). To achieve standardized protocols and interoperability with other devices, NFC / RFID must use dedicated integrated chips.

[0004] For IoT water meters, which involve low-data-volume, point-to-point communication between fixed devices, the complex protocols of NFC / RFID (such as card finding and anti-collision) are completely redundant, introducing unnecessary overhead and latency. Currently, there is a need to propose a low-cost, low-power communication circuit. Utility Model Content

[0005] The main purpose of this invention is to provide a new type of communication circuit for acquiring water meter readings using magnetic coupling technology, aiming to propose a low-cost, low-power communication circuit.

[0006] To achieve the above objectives, this utility model proposes a novel magnetic coupling technology communication circuit for acquiring water meter readings, which is applied to water meter equipment. The water meter equipment includes a first data transmission unit and a second data transmission unit. The communication circuit for acquiring water meter readings using the novel magnetic coupling technology includes: A first coil and a second coil, the first coil and the second coil being electromagnetically coupled; The first to fourth capacitors, the first switching device, and the first resistor; The first end of the first coil is connected to the second end of the first capacitor, and the first end of the first capacitor is connected to the first data transmission unit. The first end of the second coil is connected to the controlled end of the first switching device and the first end of the second capacitor; the second ends of the first coil and the second coil are connected to a preset voltage or grounded; the second end of the second capacitor is connected to the first end of the second data transmission unit. The first terminal of the first switching device is connected to the second terminal of the second data transmission unit and the first terminal of the third capacitor, and the second terminal is connected to the first terminal of the fourth capacitor, the first terminal of the first resistor and the third terminal of the second data transmission unit; the second terminal of the fourth capacitor and the second terminal of the first resistor are connected and grounded, and the second terminal of the third capacitor is grounded.

[0007] Optionally, the first switching device is a MOSFET / transistor.

[0008] Optionally, when a preset voltage is applied to the second end of the first coil and the second end of the second coil, the first switching device is a first PMOS transistor / first PNP transistor; If the first switching device is a first PMOS transistor, the source of the first PMOS transistor is connected to the second terminal of the second data transmission unit and the first terminal of the third capacitor, the drain is connected to the first terminal of the fourth capacitor, the first terminal of the first resistor and the third terminal of the second data transmission unit, and the gate is connected to the first terminal of the second coil. If the first switching device is a first PNP transistor, the collector of the first PNP transistor is connected to the second terminal of the second data transmission unit and the first terminal of the third capacitor, the emitter is connected to the first terminal of the fourth capacitor, the first terminal of the first resistor and the third terminal of the second data transmission unit, and the base is connected to the first terminal of the second coil.

[0009] Optionally, when the second end of the first coil and the second end of the second coil are grounded, the first switching device is a first NMOS transistor / first NPN transistor; If the first switching device is a first NMOS transistor, the drain of the first NMOS transistor is connected to the second terminal of the second data transmission unit and the first terminal of the third capacitor, the source is connected to the first terminal of the fourth capacitor, the first terminal of the first resistor and the third terminal of the second data transmission unit, and the gate is connected to the first terminal of the second coil. If the first switching device is a first NPN transistor, the emitter of the first NPN transistor is connected to the second terminal of the second data transmission unit and the first terminal of the third capacitor, the collector is connected to the first terminal of the fourth capacitor, the first terminal of the first resistor and the third terminal of the second data transmission unit, and the base is connected to the first terminal of the second coil.

[0010] Optionally, the communication circuit for acquiring water meter readings using the novel magnetic coupling technology further includes: a first TVS diode; The cathode of the first TVS diode is connected to the controlled terminal of the first switching device, and the anode is connected to the first terminal of the first switching device.

[0011] Optionally, the communication circuit for acquiring water meter readings using the novel magnetic coupling technology further includes: The fifth and sixth capacitors, the second switching device, and the second resistor; The first end of the first coil is connected to the controlled end of the second switching device and the second end of the first capacitor, and the first end of the first capacitor is connected to the first end of the first data transmission unit; The first terminal of the second switching device is connected to the second terminal of the first data transmission unit and the first terminal of the fifth capacitor, and the second terminal is connected to the first terminal of the sixth capacitor, the first terminal of the second resistor and the third terminal of the first data transmission unit; the second terminal of the sixth capacitor and the second terminal of the second resistor are connected to and grounded, and the second terminal of the fifth capacitor is grounded.

[0012] Optionally, the second switching device is a second PMOS transistor / a second PNP transistor; When a preset voltage is applied to the second terminal of the first coil and the second terminal of the second coil, if the second switching device is a second PMOS transistor, the source of the second PMOS transistor is connected to the second terminal of the first data transmission unit and the first terminal of the fifth capacitor, the drain is connected to the first terminal of the sixth capacitor, the first terminal of the second resistor and the third terminal of the first data transmission unit, and the gate is connected to the first terminal of the first coil; or, If the second switching device is a second PNP transistor, the collector of the second PNP transistor is connected to the second terminal of the first data transmission unit and the first terminal of the fifth capacitor, the emitter is connected to the first terminal of the sixth capacitor, the first terminal of the second resistor and the third terminal of the first data transmission unit, and the base is connected to the first terminal of the first coil.

[0013] Optionally, the second switching device is a second NMOS transistor / second NPN transistor; With the second terminal of the first coil and the second terminal of the second coil grounded, if the second switching device is a second NMOS transistor, the drain of the second NMOS transistor is connected to the second terminal of the first data transmission unit and the first terminal of the fifth capacitor, the source is connected to the first terminal of the sixth capacitor, the first terminal of the second resistor and the third terminal of the first data transmission unit, and the gate is connected to the first terminal of the first coil; or, If the second switching device is a second NPN transistor, the emitter of the second NPN transistor is connected to the second terminal of the first data transmission unit and the first terminal of the fifth capacitor, the collector is connected to the first terminal of the sixth capacitor, the first terminal of the second resistor and the third terminal of the first data transmission unit, and the base is connected to the first terminal of the first coil.

[0014] Optionally, the communication circuit for acquiring water meter readings using the novel magnetic coupling technology further includes: a second TVS diode; The cathode of the second TVS diode is connected to the controlled terminal of the second switching device, and the anode is connected to the first terminal of the second switching device.

[0015] This utility model also proposes a water meter device, including a first data transmission unit and a second data transmission unit, and the water meter device further includes a communication circuit for acquiring water meter readings using the novel magnetic coupling technology.

[0016] This utility model discloses a communication circuit and a water meter device for acquiring water meter readings using novel magnetic coupling technology. The communication circuit for acquiring water meter readings using novel magnetic coupling technology is applied to the water meter device, which includes a first data transmission unit and a second data transmission unit. The communication circuit for acquiring water meter readings using novel magnetic coupling technology includes: a first coil and a second coil, which are electromagnetically coupled; a first capacitor to a fourth capacitor; a first switching device; and a first resistor. A first end of the first coil is connected to a second end of the first capacitor, and a first end of the first capacitor is connected to the first data transmission unit. A first end of the second coil is connected to the controlled end of the first switching device and a first end of the second capacitor. The second ends of the first coil and the second coil are connected to a preset voltage or grounded. A second end of the second capacitor is connected to a first end of the second data transmission unit. A first end of the first switching device is connected to a second end of the second data transmission unit and a first end of the third capacitor. The second end of the first switching device is connected to a first end of the fourth capacitor, a first end of the first resistor, and a third end of the second data transmission unit. The second end of the fourth capacitor and the second end of the first resistor are connected and grounded, and the second end of the third capacitor is grounded. This invention achieves data signal transmission or reception using only two coils, four capacitors, one switching device, and one resistor, offering a low-cost advantage compared to NFC / RFID chips. Furthermore, this embodiment is adapted for time interval modulation, exhibiting low power consumption. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of the first structure of the communication circuit for acquiring water meter readings using the novel magnetic coupling technology of this utility model. Figure 2 This is a second structural schematic diagram of the communication circuit for acquiring water meter readings using the novel magnetic coupling technology of this utility model; Figure 3 This is a schematic diagram of the third structure of the communication circuit for acquiring water meter readings using the novel magnetic coupling technology of this utility model; Figure 4 This is a schematic diagram of the fourth structure of the communication circuit for acquiring water meter readings using the novel magnetic coupling technology of this utility model; Figure 5 This is a fifth structural schematic diagram of the communication circuit for acquiring water meter readings using the novel magnetic coupling technology of this utility model; Figure 6 This is a sixth structural schematic diagram of the communication circuit for acquiring water meter readings using the novel magnetic coupling technology of this utility model; Figure 7 This is a seventh structural schematic diagram of the communication circuit for acquiring water meter readings using the novel magnetic coupling technology of this utility model. Figure 8 This is a schematic diagram of the eighth structure of the communication circuit for acquiring water meter readings using the novel magnetic coupling technology of this utility model. Figure 9 This is a ninth structural schematic diagram of the communication circuit for acquiring water meter readings using the novel magnetic coupling technology of this utility model; Figure 10 This is a schematic diagram of the tenth structure of the communication circuit for acquiring water meter readings using the novel magnetic coupling technology of this utility model. Figure 11 This is the eleventh structural schematic diagram of the communication circuit for acquiring water meter readings using the novel magnetic coupling technology of this utility model. Figure 12 This is a schematic diagram of the first structure of the communication circuit for acquiring water meter readings using the novel magnetic coupling technology of this utility model. Figure 13 This is a second structural schematic diagram of the second embodiment of the communication circuit for acquiring water meter readings using the novel magnetic coupling technology of this utility model.

[0019] Explanation of icon numbers:

[0020] The realization of the purpose, functional features and advantages of this utility model will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0021] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0022] It should be noted that all directional indicators (such as up, down, left, right, front, back, etc.) in this utility model embodiment are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicator will also change accordingly.

[0023] In this utility model, unless otherwise explicitly specified and limited, the terms "connection," "fixing," etc., should be interpreted broadly. For example, "fixing" can mean a fixed connection, a detachable connection, or an integral part; it can mean a mechanical connection or an electrical connection; it can mean a direct connection or an indirect connection through an intermediate medium; it can mean the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0024] Furthermore, in this utility model, descriptions involving "first," "second," etc., are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of that feature. Additionally, the technical solutions of the various embodiments can be combined with each other, but only on the basis of being achievable by those skilled in the art. When the combination of technical solutions is contradictory or impossible to implement, such a combination of technical solutions should be considered non-existent and not within the scope of protection claimed by this utility model.

[0025] This invention proposes a novel communication circuit for acquiring water meter readings using magnetic coupling technology, applied to water meter devices. The water meter device includes a first data transmission unit and a second data transmission unit. It should be noted that this invention does not limit the type of water meter device. The water meter device can be an integrated water meter (e.g., the water meter includes a flow sensing chip that outputs flow information to the water meter's control chip or communication chip), or it can be a split-type water meter (e.g., the water meter consists of a main body and a data acquisition device; the main body includes a flow detection sensor and a control communication unit; the flow detection sensor outputs flow data to the control communication unit; the data acquisition device has a controller; wherein the controller and the control communication unit interact via a coupling coil, and can use NFC protocol, RFID protocol, or a custom protocol, etc.).

[0026] The first data transmission unit may include a controller such as an MCU, a SOC, or an FPGA, and the second data transmission unit may include a controller such as an MCU, a SOC, or an FPGA.

[0027] like Figure 1 As shown, in the first embodiment, the communication circuit for acquiring water meter readings using the novel magnetic coupling technology includes: First coil FC1 and second coil FC2 are electromagnetically coupled. The first capacitor C1 to the fourth capacitor C4, the first switching device, and the first resistor R1; The first end of the first coil FC1 is connected to the second end of the first capacitor C1, and the first end of the first capacitor C1 is connected to the first data transmission unit. The first end of the second coil FC2 is connected to the controlled end of the first switching device and the first end of the second capacitor C2; the second ends of the first coil FC1 and the second ends of the second coil FC2 are connected to a preset voltage or grounded; the second end of the second capacitor C2 is connected to the first end of the second data transmission unit. The first terminal of the first switching device is connected to the second terminal of the second data transmission unit and the first terminal of the third capacitor C3. The second terminal is connected to the first terminal of the fourth capacitor C4, the first terminal of the first resistor R1 and the third terminal of the second data transmission unit. The second terminal of the fourth capacitor C4 and the second terminal of the first resistor R1 are connected and grounded. The second terminal of the third capacitor C3 is grounded.

[0028] It is easy to understand that the first coil FC1 and the second coil FC2 are electromagnetically coupled; when an alternating current is applied to either coil, an alternating magnetic field is generated, and the other coil generates an induced voltage under the action of electromagnetic induction; data transmission is achieved through a transmission protocol (NFC protocol, RFID protocol or a self-defined protocol can be used).

[0029] like Figure 1 As shown, the second terminal of the first coil FC1 and the second terminal of the second coil FC2 are connected to a preset voltage or grounded. The preset voltage is determined by the researchers, and this invention does not impose any limitations on it. In this embodiment, the first to third terminals of the second data transmission unit are all GPIO terminals. The GPIO terminal structure (not explained here) includes PMOS and NNMOS transistors to control the level of the GPIO port. Therefore, the first and second terminals of the second data transmission unit are used to pull the port level high / low.

[0030] The first embodiment proposes a communication circuit for acquiring water meter readings using novel magnetic coupling technology. Depending on whether the second terminals of the first coil FC1 and the second coil FC2 are connected to a preset voltage or grounded, it can be divided into two variations. For example... Figure 1 As shown, the coil in the upper circuit is connected to a preset voltage, while the coil in the lower circuit is grounded. It should be noted that whether the coil is connected to a preset voltage or grounded affects the initial voltage of the controlled terminal of the first switching device (when no AC current is applied to the first coil FC1 and the second coil FC2). In the initial state (when no AC current is applied to the first coil FC1 and the second coil FC2), the first switching device needs to be in the off state to ensure that the second terminal of the second data transmission unit is fixed at a low level. Additionally, the first switching device being in the off state also reduces power consumption. Therefore, the type of the first switching device is closely related to whether the second terminal of the first coil FC1 and the second coil FC2 is connected to a preset voltage or grounded. When the second terminal of the first coil FC1 and the second coil FC2 is connected to a preset voltage, the first switching device conducts when its controlled terminal is at a low level and is off when it is at a high level; for example, the first switching device can be a PNP transistor or a PMOS transistor. When the second terminal of the first coil FC1 and the second coil FC2 is grounded, the first switching device conducts when its controlled terminal is at a high level and is off when it is at a low level; for example, the first switching device can be an NPN transistor or an NMOS transistor.

[0031] In this embodiment, the third terminal of the second data transmission unit is used to detect the voltage value at the port. The second data transmission unit determines the corresponding binary data based on the voltage value of the third terminal. For example, a low voltage value at the third terminal corresponds to binary data "0", and a high voltage value at the third terminal corresponds to binary data "1".

[0032] As can be seen from the above, the first to third terminals of the second data transmission unit are GPIO terminals, which can output voltage or ground by boosting the voltage or pulling the level low. This embodiment does not limit the transmitting and receiving ends in the first and second data transmission units (the transmitting end can output pulse signals or AC signals, etc., to induce a voltage at the receiving end). In this embodiment, there are the following four cases: 1. The first data transmission unit is the transmitting end, the second data transmission unit is the receiving end, and the second end of the coil is connected to a preset voltage.

[0033] 2. The first data transmission unit is the transmitting end, the second data transmission unit is the receiving end, and the second end of the coil is grounded.

[0034] 3. The first data transmission unit is the receiving end, the second data transmission unit is the transmitting end, and the second end of the coil is connected to a preset voltage.

[0035] 4. The first data transmission unit is the receiving end, the second data transmission unit is the transmitting end, and the second end of the coil is grounded.

[0036] The second end of the coil is connected to a preset voltage or grounded, which affects the type of the first switching device; the first data transmission unit is a transmitting end or a receiving end, which affects the potential of the first end and the second end of the second data transmission unit.

[0037] In one example, when the first data transmission unit is the transmitter and the second data transmission unit is the receiver, the second data transmission unit determines the corresponding binary data based on the voltage at its third terminal. Accordingly, the voltage levels of the first to third terminals of the second data transmission unit change accordingly. The first terminal (GPIO) is pulled down to ground via an internal NMOS transistor, and the second terminal (GPIO) is pulled up via an internal PMOS transistor to output a voltage level, for example, the second terminal outputs the preset voltage. Figure 2 As shown, this is equivalent to the first terminal of the first switching device being connected to a preset voltage, the second terminal of the second capacitor C2 being grounded, and the first capacitor C1 and the first coil FC1 forming an LC resonant circuit. The frequency value of the data transmission carrier can be changed by changing the value of the first capacitor C1 and the inductance value corresponding to the first coil FC1.

[0038] At this time, if a preset voltage is applied to the second end of the coil, the corresponding first switching device (such as a PMOS transistor or a PNP transistor) will conduct when it is at a low level; if Figure 3As shown, at this time, since the first data transmission unit starts sending data (changing the current flowing through the first coil FC1), a voltage waveform with an amplitude that continuously changes from positive to negative to positive is formed in the second coil FC2. When this voltage waveform is in phase with the preset voltage (the two are added together, pushing up the potential), the potential of the controlled terminal of the first switching device increases, and the first switching device is turned off; when the voltage waveform is out of phase with the preset voltage (the two are subtracted, lowering the potential), the potential of the controlled terminal of the first switching device decreases, and the first switching device is turned on.

[0039] Additionally, if the second terminal of the coil is grounded, the corresponding first switching device (e.g., an NMOS transistor or an NPN transistor) will conduct when the voltage is high; for example... Figure 4 As shown, at this time, since the first data transmission unit starts sending data (changing the current flowing through the first coil FC1), a voltage waveform with an amplitude that continuously changes from positive to negative to positive is formed in the second coil FC2. This voltage waveform is output to the control terminal of the first switching device. When the voltage waveform is positive, the potential of the controlled terminal of the first switching device increases, and the first switching device is turned on; when the voltage waveform is negative, the potential of the controlled terminal of the first switching device is zero, and the first switching device is turned off.

[0040] In another embodiment, when the first data transmission unit is a receiver and the second data transmission unit is a transmitter, the second data transmission unit outputs an AC signal or a pulse signal through its first terminal. Correspondingly, the voltage levels of the first to third terminals of the second data transmission unit change accordingly. The second terminal (GPIO) is pulled down to ground through an internal NMOS transistor, such as... Figure 5 As shown, this is equivalent to the first terminal of the first switching device being grounded. At this time, regardless of whether the first switching device is turned on or off, the level at the third terminal of the second data transmission unit is fixed at a low level. The second capacitor C2 and the second coil FC2 form an LC resonant circuit. The frequency value of the data transmission carrier can be changed by changing the value of the second capacitor C2 and the inductance value corresponding to the second coil FC2.

[0041] It should be explained that when the second data transmission unit is the transmitting end, only the second capacitor C2 and the second coil FC2 are used; this is equivalent to the case when the first data transmission unit is the transmitting end.

[0042] As can be seen from the above, theoretically, both the first and second data transmission units can serve as transmitters. However, based on the electromagnetic coupling of the coils, the polarity (positive and negative) of the induced voltage in the receiving coil alternates periodically. Data transmission can be achieved using pulse width modulation (PWM), time interval modulation (PIT), or a hybrid modulation method. However, PWM changes the amplitude of the induced voltage by altering the pulse width, with the voltage amplitude corresponding to binary numbers "0" and "1" (e.g., 1V corresponds to binary "0", 5V to binary "1"). However, PWM relies on continuous output, resulting in high power consumption and susceptibility to external magnetic field interference, leading to changes in the induced voltage and data distortion.

[0043] Preferably, this embodiment uses time interval modulation. The core of time interval modulation is to first agree on the "correspondence rules between time intervals and binary data", and then transmit information by generating a time interval sequence that conforms to the rules. Assume that a short time interval T1 represents binary data "0". For example, T1 = 100μs (meaning that when the time difference between two adjacent signal events is 100μs, it represents "0"); a long time interval T2 represents binary data "1". For example, T2 = 300μs (meaning that when the time difference between two adjacent signal events is 300μs, it represents "1"). If binary data is output (such as "101"), according to the pre-agreed encoding rules, the data is converted into the corresponding time interval sequence: "1" → T2 = 300μs, "0" → T1 = 100μs, therefore "101" corresponds to "300μs → 100μs → 300μs". The transmitting end generates a signal with "rising edges at specific time intervals" (such as intermittent induction pulses) in the coupling coil: after the first rising edge is triggered, the second rising edge (representing "1") is triggered after an interval of 300μs, the third rising edge (representing "0") is triggered after an interval of 100μs, and finally the fourth rising edge (representing "1") is triggered after an interval of 300μs. The time interval modulation method uses the time difference between two adjacent signals to represent the corresponding binary number, which does not require continuous output signal and has low power consumption.

[0044] However, it should be considered that since a single pulse at the transmitting end corresponds to an induced voltage (with a rising edge) at the receiving end, it is easily affected by external magnetic field interference. External magnetic field interference causes the coil at the receiving end to have an interference voltage (the induced voltage formed in the coil by the external magnetic field interference), which may result in a rising edge of the interference voltage, affecting the judgment of the time interval in the time interval modulation. To address this problem, this invention uses a fourth capacitor C4 and a first resistor R1 in combination to reduce the interference of external magnetic fields. Therefore, preferably, the first data transmission unit is used as the transmitting end and the second data transmission unit is used as the receiving end, and the fourth capacitor C4 and the first resistor R1 are used to reduce the interference of external magnetic fields.

[0045] Specifically, in one example, the first data transmission unit acts as the transmitter, and the second data transmission unit acts as the receiver; the second terminals of the first coil FC1 and the second coil FC2 are connected to a preset voltage or grounded. Due to the output signal of the first data transmission unit, a voltage waveform with amplitude continuously changing from positive to negative to positive is formed in the second coil FC2, with positive and negative intervals; correspondingly, the first switching device switches between on and off states. The following situation exists: when the first switching device is on, the fourth capacitor C4 is charged, and the voltage of the fourth capacitor C4 rises; then the first switching device is off, the fourth capacitor C4 stops charging, and the fourth capacitor C4 begins to slowly discharge through the first resistor R1, the discharge rate being related to the value of the fourth capacitor C4 and the value of the first resistor R1. When the first switching device is turned on again, the fourth capacitor C4 is charged again. This process repeats, as... Figure 6 As shown, as long as the duration of a single off state of the first switching device is less than the discharge rate of the fourth capacitor C4 (the duration of a single off or on state of the first switching device depends on the carrier frequency output from the first data transmission unit to the first coil FC1), the voltage of the fourth capacitor C4 can continue to rise until the voltage of the fourth capacitor C4 is the charging voltage value (e.g., a preset voltage value provided by the second terminal of the second data transmission unit), forming a rising edge; the second data transmission unit detects the voltage value at its third terminal (equivalent to the voltage value of the fourth capacitor C4), and when the voltage value at the third terminal is greater than the set voltage value (the set voltage value is less than the charging voltage value), it is determined to be a valid rising edge; wherein, the values ​​of the set voltage value and the preset voltage are determined by the researchers. During the time interval between two rising edges, the first data transmission unit stops outputting, the first switching device turns off, and the fourth capacitor C4 begins to discharge until the voltage value of the fourth capacitor C4 is less than the set voltage value.

[0046] It should be noted that this invention accumulates the charging charge when the first switching device is turned on using the fourth capacitor C4. Combined with a higher frequency carrier signal (e.g., 8MHz carrier, 1μs pulse width, using 100μs / 200μs intervals to distinguish 0 and 1), and multiple turns of the first switching device within the pulse width, the second data transmission unit detects a rising edge signal (the voltage at the third terminal is greater than a set voltage value, during which a comparator can be used to compare the voltage at the third terminal with the set voltage value). It should be explained that the amplitude of the second coil FC2 changes multiple times within the pulse width. The 8MHz carrier corresponds to a 125ns period, and there are 8 periods within the 1μs pulse width. Figure 6As shown in the figure, the communication circuit for acquiring water meter readings using novel magnetic coupling technology proposed in this embodiment is suitable for time modulation. Specifically, it utilizes a fourth capacitor C4 and a first resistor R1 to perform a successive voltage boosting process, ensuring that the voltage value at the third terminal of the second data transmission unit meets the requirements. Due to the successive voltage boosting process, interference from external magnetic fields can be reduced to some extent. The voltage value of the fourth capacitor C4 corresponding to a single magnetic field interference will be lower than the set voltage value.

[0047] Furthermore, this embodiment uses only two coils, four capacitors, one switching device, and one resistor to achieve data signal transmission or reception, offering a low-cost advantage compared to NFC / RFID chips. In addition, this embodiment allows for time interval modulation, resulting in low power consumption.

[0048] The first capacitor C1 is used to form an LC resonant circuit with the first coil FC1 to select a carrier frequency of a specific frequency. The second capacitor C2 can be used to form an LC resonant circuit with the second coil FC2 (the second data transmission unit is the transmitting end), or it can be used for voltage regulation and filtering. (The second data transmission unit is the receiving end, and the second terminal of the second capacitor C2 is grounded). The third capacitor C3 is used to stabilize the preset voltage value output from the second terminal of the second data transmission unit. The fourth capacitor C4 is used to increase the voltage as the first switching device is turned on / off. The first resistor R1 is used to release the charge in the fourth capacitor C4.

[0049] It is particularly important to emphasize that this utility model provides a communication circuit structure adapted to scenarios where low-cost, low-power communication is performed between the first and second data transmission units based on a time modulation method. The core of time interval modulation is to first agree on the "correspondence rules between time intervals and binary data," and then transmit information by generating a time interval sequence that conforms to the rules. The transmission protocol between the first and second data transmission units is determined by the developers. It is crucial that the transmission protocol of the first and second data transmission units is based on the communication circuit structure proposed in this utility model. Because this circuit structure is suitable for time interval modulation, the first and second data transmission units perform corresponding processing. The main focus of this utility model is the proposed circuit structure. This utility model does not restrict the transmission protocol of the first and second data transmission units; it only needs to satisfy the time interval modulation method. Time interval modulation is a conventional method in this field. The transmission protocols of the first and second data transmission units and the corresponding software programs should not be considered as technical features of the subject matter of this utility model. The aforementioned actions of the first and second data transmission units should be understood as feasible examples of a communication circuit structure adapted to the novel magnetic coupling technology for collecting water meter readings proposed in this utility model, and not as merely the existence of the above content.

[0050] In one example, the first switching device is a MOSFET / transistor.

[0051] It is important to note that in coil communication systems based on time interval modulation, time accuracy is fundamental. Data encoding and decoding rely entirely on the precise measurement of the pulse interval (100μs vs 200μs). Any delay or waveform distortion introduced into the signal path will directly lead to decoding errors and reduce communication reliability. MOSFETs and transistors, as high-speed semiconductor switches, rely on their extremely high switching speeds to ensure the normal operation of the entire system; the switching time of a MOSFET can be as short as a few nanoseconds, and that of a transistor can be as short as tens of nanoseconds. At the receiving end, the high-frequency pulse group signal sensed by the second coil FC2 acts on the control terminal (gate / base) of the first switching device, controlling its rapid switching on and off, thereby converting the voltage on the integrating capacitor into a digital pulse output. High-speed switching ensures that the digital pulse output from the receiving end has a steep edge. A pulse with a steep edge means that its "timing" is very precise, allowing the receiving end MCU's I / O port or timer capture unit to accurately record the rising or falling edge of the pulse, which is a prerequisite for accurate measurement of the pulse interval.

[0052] The second end of the first coil FC1 and the second end of the second coil FC2 are connected to a preset voltage or grounded, depending on the type of the first switching device.

[0053] In one example, when a preset voltage is applied to the second terminal of the first coil FC1 and the second terminal of the second coil FC2, the first switching device is a first PMOS transistor / first PNP transistor; like Figure 7 As shown, if the first switching device is a first PMOS transistor, the source of the first PMOS transistor is connected to the second terminal of the second data transmission unit and the first terminal of the third capacitor C3, the drain is connected to the first terminal of the fourth capacitor C4, the first terminal of the first resistor R1 and the third terminal of the second data transmission unit, and the gate is connected to the first terminal of the second coil FC2. Initially, the voltage at the gate of the first PMOS transistor is a preset voltage, and the first PMOS transistor is turned off. When the voltage at the gate of the first PMOS transistor decreases due to the induced voltage of the second coil FC2, the first PMOS transistor turns on.

[0054] like Figure 8As shown, if the first switching device is a first PNP transistor, the collector of the first PNP transistor is connected to the second terminal of the second data transmission unit and the first terminal of the third capacitor C3, the emitter is connected to the first terminal of the fourth capacitor C4, the first terminal of the first resistor R1 and the third terminal of the second data transmission unit, and the base is connected to the first terminal of the second coil FC2. Initially, the voltage at the base of the first PNP transistor is a preset voltage, and the first PNP transistor is off. When the voltage at the base of the first PNP transistor decreases due to the induced voltage of the second coil FC2, the first PNP transistor turns on.

[0055] In another example, with the second end of the first coil FC1 and the second end of the second coil FC2 grounded, the first switching device is a first NMOS transistor / first NPN transistor; like Figure 9 As shown, if the first switching device is a first NMOS transistor, the drain of the first NMOS transistor is connected to the second terminal of the second data transmission unit and the first terminal of the third capacitor C3, the source is connected to the first terminal of the fourth capacitor C4, the first terminal of the first resistor R1 and the third terminal of the second data transmission unit, and the gate is connected to the first terminal of the second coil FC2. Initially, the voltage at the gate of the first NMOS transistor is zero (grounded), and the first NMOS transistor is turned off. When the voltage at the gate of the first NMOS transistor becomes high (greater than the turn-on voltage of the NMOS transistor) due to the induced voltage of the second coil FC2, the first NMOS transistor turns on.

[0056] like Figure 10 As shown, if the first switching device is a first NMOS transistor, the drain of the first NMOS transistor is connected to the second terminal of the second data transmission unit and the first terminal of the third capacitor C3, the source is connected to the first terminal of the fourth capacitor C4, the first terminal of the first resistor R1 and the third terminal of the second data transmission unit, and the gate is connected to the first terminal of the second coil FC2. Initially, the voltage at the base of the first NPN transistor is zero (grounded), and the first NPN transistor is turned off. When the voltage at the base of the first NPN transistor becomes high (greater than the turn-on voltage of the NPN transistor) due to the induced voltage of the second coil FC2, the first NPN transistor turns on.

[0057] It should be noted that the preset voltage or zero voltage (ground) connected to the second terminal of the second coil FC2 overlaps with the induced voltage in the second coil FC2. The overlapped voltage acts on the controlled terminal of the first switching device (the gate of the MOS transistor, the base of the transistor). This invention uses the positive / negative amplitude stages of the induced voltage to overlap, depending on the type of the first switching device, to turn on the first switching device. For example, for a first PMOS transistor / first PNP transistor, the second terminal of the second coil FC2 is connected to a preset voltage; the voltage obtained by overlapping the negative amplitude of the induced voltage with the preset voltage turns on the first switching device. For a first NMOS transistor / first NPN transistor, the second terminal of the second coil FC2 is grounded; the voltage obtained by overlapping the positive amplitude of the induced voltage with the preset voltage turns on the first switching device.

[0058] However, it's important to note that both MOSFETs and transistors have PN junctions. If this PN junction breaks down due to excessive voltage across it, the MOSFET or transistor will be damaged. For example, if the first switching device is a PMOS / PNP transistor, and the positive amplitude of the induced voltage overlaps with the preset voltage to an excessively large value, it will break down the PN junction between the gate and source of the PMOS transistor, or the PN junction between the base and collector of the PNP transistor. Similarly, if the first switching device is an NMOS / NPN transistor, and the negative amplitude of the induced voltage is excessively large, it will break down the PN junction between the gate and drain of the NMOS transistor, or the PN junction between the base and emitter of the NPN transistor.

[0059] Therefore, as Figure 11 As shown, in one example, the communication circuit for acquiring water meter readings using the novel magnetic coupling technology further includes: a first TVS diode; The cathode of the first TVS diode is connected to the controlled terminal of the first switching device, and the anode is connected to the first terminal of the first switching device. The first TVS diode is used for overvoltage protection.

[0060] The above explains why the first data transmission unit, which is only connected to the first coil FC1 and the first capacitor C1, is more suitable as a transmitter. Although two communication circuits using novel magnetic coupling technology to collect water meter readings can be set between the first and second data transmission units to ensure that both units function as transmitters and receivers, data transmission can be achieved. However, as mentioned earlier, the second data transmission unit can be transformed from a receiver to a transmitter by changing the port states from the first to the third end. Therefore, this invention proposes a second embodiment, such as... Figure 12 As shown, the communication circuit for acquiring water meter readings using the novel magnetic coupling technology also includes: The fifth capacitor C5 and the sixth capacitor C6, the second switching device and the second resistor R2; The first end of the first coil FC1 is connected to the controlled end of the second switching device and the second end of the first capacitor C1, and the first end of the first capacitor C1 is connected to the first end of the first data transmission unit; The first terminal of the second switching device is connected to the second terminal of the first data transmission unit and the first terminal of the fifth capacitor C5. The second terminal is connected to the first terminal of the sixth capacitor C6, the first terminal of the second resistor R2, and the third terminal of the first data transmission unit. The second terminal of the sixth capacitor C6 and the second terminal of the second resistor R2 are connected to and grounded. The second terminal of the fifth capacitor C5 is grounded.

[0061] It is easy to understand that the circuit structure formed by the first capacitor C1, the fifth capacitor C5, the sixth capacitor C6, the second switching device, and the second resistor R2 is the same as the circuit structure of the second capacitors C2 to the fourth capacitor C4, the first switching device, and the first resistor R1 in the first embodiment. Therefore, it has at least all the beneficial effects brought about by the circuit structure scheme in the above embodiments, which will not be elaborated here.

[0062] Based on the above, it can be deduced that, in order to adapt to the communication circuit structure of the novel magnetic coupling technology for collecting water meter readings proposed in this embodiment, the first data transmission unit / second data transmission unit can become a receiving end by lowering the potential of its second terminal and raising the potential of its first terminal; or it can become a transmitting end by lowering the potential of its first terminal and using its second terminal to output pulse signals, AC signals or other types of excitation signals.

[0063] Therefore, the communication circuit for acquiring water meter readings using the novel magnetic coupling technology proposed in this embodiment can realize data interaction between the first data transmission unit and the second data transmission unit; compared with the previous scheme of setting two communication circuits for acquiring water meter readings using the novel magnetic coupling technology, it has the characteristics and advantages of low cost.

[0064] Correspondingly, the type of the second switching device also varies depending on the specific preset voltage / grounding connected to the second terminal of the first coil FC1.

[0065] In one example, the second switching device is a second PMOS transistor / second PNP transistor; When a preset voltage is applied to the second terminal of the first coil FC1 and the second terminal of the second coil FC2, if the second switching device is a second PMOS transistor, the source of the second PMOS transistor is connected to the second terminal of the first data transmission unit and the first terminal of the fifth capacitor C5, the drain is connected to the first terminal of the sixth capacitor C6, the first terminal of the second resistor R2 and the third terminal of the first data transmission unit, and the gate is connected to the first terminal of the first coil FC1; or, If the second switching device is a second PNP transistor, the collector of the second PNP transistor is connected to the second terminal of the first data transmission unit and the first terminal of the fifth capacitor C5, the emitter is connected to the first terminal of the sixth capacitor C6, the first terminal of the second resistor R2 and the third terminal of the first data transmission unit, and the base is connected to the first terminal of the first coil FC1.

[0066] In another example, the second switching device is a second NMOS transistor / second NPN transistor; With the second terminals of the first coil FC1 and the second coil FC2 grounded, if the second switching device is a second NMOS transistor, the drain of the second NMOS transistor is connected to the second terminal of the first data transmission unit and the first terminal of the fifth capacitor C5, the source is connected to the first terminal of the sixth capacitor C6, the first terminal of the second resistor R2 and the third terminal of the first data transmission unit, and the gate is connected to the first terminal of the first coil FC1; or, If the second switching device is a second NPN transistor, the emitter of the second NPN transistor is connected to the second terminal of the first data transmission unit and the first terminal of the fifth capacitor C5, the collector is connected to the first terminal of the sixth capacitor C6, the first terminal of the second resistor R2 and the third terminal of the first data transmission unit, and the base is connected to the first terminal of the first coil FC1.

[0067] In addition, such as Figure 13 As shown, the communication circuit for acquiring water meter readings using the novel magnetic coupling technology also includes a second TVS diode; The cathode of the second TVS diode is connected to the controlled terminal of the second switching device, and the anode is connected to the first terminal of the second switching device. For the same reason as the first TVS diode, the second TVS diode is used for overvoltage protection.

[0068] This utility model also proposes a water meter device, including a first data transmission unit and a second data transmission unit, and the water meter device further includes a communication circuit for acquiring water meter readings using a novel magnetic coupling technology as described in the first embodiment, or the water meter device includes a communication circuit for acquiring water meter readings using a novel magnetic coupling technology as described in the second embodiment.

[0069] The specific structure of the communication circuit for acquiring water meter readings using the novel magnetic coupling technology is described in the first and second embodiments above. Since this water meter device adopts all the technical solutions of all the above embodiments, it has at least all the beneficial effects brought about by the technical solutions of the above embodiments, which will not be elaborated here.

[0070] The above description is only an optional embodiment of the present utility model and does not limit the patent scope of the present utility model. All equivalent structural transformations made under the inventive concept of the present utility model using the contents of the present utility model specification and drawings, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present utility model.

Claims

1. A communication circuit for collecting water meter readings using a novel magnetic coupling technique, characterized in that, Applied to water meter equipment, the water meter equipment includes a first data transmission unit and a second data transmission unit; The communication circuit for acquiring water meter readings using the novel magnetic coupling technology includes: A first coil and a second coil, the first coil and the second coil being electromagnetically coupled; The first to fourth capacitors, the first switching device, and the first resistor; The first end of the first coil is connected to the second end of the first capacitor, and the first end of the first capacitor is connected to the first data transmission unit. The first end of the second coil is connected to the controlled end of the first switching device and the first end of the second capacitor; the second ends of the first coil and the second coil are connected to a preset voltage or grounded; the second end of the second capacitor is connected to the first end of the second data transmission unit. The first terminal of the first switching device is connected to the second terminal of the second data transmission unit and the first terminal of the third capacitor, and the second terminal is connected to the first terminal of the fourth capacitor, the first terminal of the first resistor and the third terminal of the second data transmission unit; the second terminal of the fourth capacitor and the second terminal of the first resistor are connected and grounded, and the second terminal of the third capacitor is grounded.

2. The communication circuit for collecting water meter reading by novel magnetic coupling technology as claimed in claim 1, wherein, The first switching device is a MOSFET / transistor.

3. The communication circuit for collecting water meter reading by novel magnetic coupling technology as claimed in claim 2 wherein, When a preset voltage is applied to the second end of the first coil and the second end of the second coil, the first switching device is a first PMOS transistor / first PNP transistor. If the first switching device is a first PMOS transistor, the source of the first PMOS transistor is connected to the second terminal of the second data transmission unit and the first terminal of the third capacitor, the drain is connected to the first terminal of the fourth capacitor, the first terminal of the first resistor and the third terminal of the second data transmission unit, and the gate is connected to the first terminal of the second coil. If the first switching device is a first PNP transistor, the collector of the first PNP transistor is connected to the second terminal of the second data transmission unit and the first terminal of the third capacitor, the emitter is connected to the first terminal of the fourth capacitor, the first terminal of the first resistor and the third terminal of the second data transmission unit, and the base is connected to the first terminal of the second coil.

4. The communication circuit for collecting water meter reading by novel magnetic coupling technology as claimed in claim 2 wherein, When the second end of the first coil and the second end of the second coil are grounded, the first switching device is a first NMOS transistor / first NPN transistor; If the first switching device is a first NMOS transistor, the drain of the first NMOS transistor is connected to the second terminal of the second data transmission unit and the first terminal of the third capacitor, the source is connected to the first terminal of the fourth capacitor, the first terminal of the first resistor and the third terminal of the second data transmission unit, and the gate is connected to the first terminal of the second coil. If the first switching device is a first NPN transistor, the emitter of the first NPN transistor is connected to the second terminal of the second data transmission unit and the first terminal of the third capacitor, the collector is connected to the first terminal of the fourth capacitor, the first terminal of the first resistor and the third terminal of the second data transmission unit, and the base is connected to the first terminal of the second coil.

5. A communication circuit for collecting water meter readings by novel magnetic coupling technology according to any one of claims 1 to 4, characterized in that, The communication circuit for acquiring water meter readings using the novel magnetic coupling technology also includes: a first TVS diode; The cathode of the first TVS diode is connected to the controlled terminal of the first switching device, and the anode is connected to the first terminal of the first switching device.

6. The communication circuit for collecting water meter reading by novel magnetic coupling technology as claimed in claim 5 wherein, The communication circuit for acquiring water meter readings using the novel magnetic coupling technology also includes: The fifth and sixth capacitors, the second switching device, and the second resistor; The first end of the first coil is connected to the controlled end of the second switching device and the second end of the first capacitor, and the first end of the first capacitor is connected to the first end of the first data transmission unit; The first terminal of the second switching device is connected to the second terminal of the first data transmission unit and the first terminal of the fifth capacitor, and the second terminal is connected to the first terminal of the sixth capacitor, the first terminal of the second resistor and the third terminal of the first data transmission unit; the second terminal of the sixth capacitor and the second terminal of the second resistor are connected to and grounded, and the second terminal of the fifth capacitor is grounded.

7. The communication circuit for collecting water meter reading by novel magnetic coupling technology as claimed in claim 6 wherein, The second switching device is a second PMOS transistor / a second PNP transistor; When a preset voltage is applied to the second terminal of the first coil and the second terminal of the second coil, if the second switching device is a second PMOS transistor, the source of the second PMOS transistor is connected to the second terminal of the first data transmission unit and the first terminal of the fifth capacitor, the drain is connected to the first terminal of the sixth capacitor, the first terminal of the second resistor and the third terminal of the first data transmission unit, and the gate is connected to the first terminal of the first coil; or, If the second switching device is a second PNP transistor, the collector of the second PNP transistor is connected to the second terminal of the first data transmission unit and the first terminal of the fifth capacitor, the emitter is connected to the first terminal of the sixth capacitor, the first terminal of the second resistor and the third terminal of the first data transmission unit, and the base is connected to the first terminal of the first coil.

8. The communication circuit for collecting water meter reading by novel magnetic coupling technology as claimed in claim 6 wherein, The second switching device is a second NMOS transistor / second NPN transistor; With the second terminal of the first coil and the second terminal of the second coil grounded, if the second switching device is a second NMOS transistor, the drain of the second NMOS transistor is connected to the second terminal of the first data transmission unit and the first terminal of the fifth capacitor, the source is connected to the first terminal of the sixth capacitor, the first terminal of the second resistor and the third terminal of the first data transmission unit, and the gate is connected to the first terminal of the first coil; or, If the second switching device is a second NPN transistor, the emitter of the second NPN transistor is connected to the second terminal of the first data transmission unit and the first terminal of the fifth capacitor, the collector is connected to the first terminal of the sixth capacitor, the first terminal of the second resistor and the third terminal of the first data transmission unit, and the base is connected to the first terminal of the first coil.

9. A communication circuit for collecting water meter readings by novel magnetic coupling technology as claimed in any one of claims 6 to 8, wherein, The communication circuit for acquiring water meter readings using the novel magnetic coupling technology also includes: a second TVS diode; The cathode of the second TVS diode is connected to the controlled terminal of the second switching device, and the anode is connected to the first terminal of the second switching device.

10. A water meter apparatus, characterized by, The water meter device includes a first data transmission unit and a second data transmission unit, and further includes a communication circuit for acquiring water meter readings using the novel magnetic coupling technology as described in any one of claims 1 to 5, or... The water meter device further comprises a communication circuit for collecting water meter readings by the new magnetic coupling technology as claimed in any one of claims 6 to 9.

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