Electromagnetic water meter pressure automatic calibration device circuit

Abstract

The utility model relates to an automatic pressure calibration device circuit of an electromagnetic water meter. The automatic pressure calibration device circuit comprises an MCU microcontroller, a peripheral module, two ADC modules, eight pressure sensor modules, a relay control module, a power supply module, a 485 communication module, a liquid crystal display module, a power supply color indicating lamp, a key module and a color indicating lamp. Eight pressure sensors are calibrated at the same time, efficiency is improved, and time is saved. Pressure calibration of the electromagnetic water meter is facilitated, production efficiency is improved, mechanical strength of worker operation is reduced, time of workers is saved, production cost is reduced, and benefits of enterprises are improved.

Description

Technical Field

[0001] This utility model relates to the field of electromagnetic water meter technology, and more specifically to a circuit for an automatic pressure calibration device for electromagnetic water meters. Background Technology

[0002] The existing calibration of electromagnetic water meter pressure sensors involves using an oil pressure calibration bench operated by workshop workers. Since only one calibration bench and one pressure sensor can be calibrated at a time, the operation is time-consuming and inefficient. It also requires manual tightening and disassembly, and a waiting period for the oil pressure to stabilize before the pressure sensor can be calibrated. The long calibration cycle makes the production and calibration of electromagnetic water meter pressure sensors extremely inconvenient. Summary of the Invention

[0003] To address the problems of existing pressure sensor devices for electromagnetic water meters, this invention aims to provide a simple-to-operate circuit calibration device that simultaneously calibrates eight pressure sensors, improving efficiency and saving time. This facilitates pressure calibration of electromagnetic water meters, improves production efficiency, reduces the mechanical strain on workers, saves worker time, lowers production costs, and increases enterprise profits.

[0004] To solve the above problems, the technical solution of this utility model is as follows: A circuit for an automatic pressure calibration device for an electromagnetic water meter, comprising an MCU microcontroller and peripheral modules, a 2-channel ADC module, an 8-channel pressure sensor module, a relay control module, a power supply module, a 485 communication module, an LCD display module, a power color indicator light, a button module, and color indicator lights, characterized in that:

[0005] The MCU microcontroller and peripheral modules run embedded programs to control the external LCD display, relay operation, ADC data acquisition and conversion, LED color indicator, EEPROM data parameter storage, and data processing for communication with the host computer via 485.

[0006] The two-channel ADC module is used for data processing, which involves acquiring analog voltage signals from pressure sensors and converting them into digital signals by connecting to eight pressure sensor modules.

[0007] The 8-channel pressure sensor module is for connecting external pressure sensors and providing power to the pressure sensors, as well as connecting the terminals to the pressure sensors.

[0008] The relay control module is a microcontroller that uses GPIO pins to control the drive circuit, which in turn controls the relay to engage and disengage, thereby controlling the normally open and normally closed contacts of the relay. The relay contacts then control the opening and closing of an external solenoid valve.

[0009] The power module includes an MCU microcontroller and peripheral modules, a 2-channel ADC module, an 8-channel pressure sensor module, a relay control module, a 485 communication module, an LCD display module, a power color indicator light, a button module, and color indicator lights, providing power and power conversion.

[0010] The 485 communication module is the circuit for connecting this calibration circuit device to the host computer, used for data communication, and for transmitting data and controlling the functions of this device.

[0011] The liquid crystal display module is the liquid crystal module used by this calibration device for displaying pressure information and data.

[0012] The power color indicator light serves as a power supply indicator for this device, used to check the power supply status of the device;

[0013] The button module is an operation button that receives and sends signals through the MCU microprocessor to enable the start and stop control functions of this device.

[0014] The color indicator lights are LEDs that display different colors to indicate the start-up, operation, and abnormal status of the device.

[0015] The beneficial effects of this utility model are:

[0016] This utility model is a circuit calibration device that allows for the simultaneous calibration of eight pressure sensors, improving efficiency and saving time. It facilitates pressure calibration of electromagnetic water meters, improves production efficiency, reduces the mechanical strain on workers, saves worker time, lowers production costs, and increases enterprise profits. Attached Figure Description

[0017] Figure 1 is a circuit block diagram of an embodiment of the present invention.

[0018] Figure 2 is a schematic diagram of the MCU microcontroller and peripheral modules of an embodiment of this utility model.

[0019] Figure 3 is a schematic diagram of the 2-channel ADC module according to an embodiment of the present invention.

[0020] Figure 4 is a schematic diagram of the 8-channel pressure sensor module according to an embodiment of this utility model.

[0021] Figure 5 is a schematic diagram of the relay control module according to an embodiment of the present invention.

[0022] Figure 6 is a schematic diagram of the power module of this utility model embodiment.

[0023] Figure 7 is a schematic diagram of the 485 communication module according to an embodiment of the present invention.

[0024] Figure 8 is a schematic diagram of the liquid crystal display module according to an embodiment of the present invention. Detailed Implementation

[0025] The embodiments of this utility model are described in further detail below with reference to the accompanying drawings. However, these embodiments are not intended to limit this utility model. Any similar principles or variations thereof that adopt this utility model should be included in the protection scope of this utility model. In this utility model, commas indicate a relationship between and.

[0026] Figure 1 shows a block diagram of the circuit in this calibration device. The circuit of an automatic pressure calibration device for an electromagnetic water meter includes an MCU microcontroller and peripheral modules, a 2-channel ADC module, an 8-channel pressure sensor module, a relay control module, a power supply module, a 485 communication module, an LCD display module, a power color indicator light, a button module, and device color indicator lights, etc.

[0027] The purpose of this invention is to provide a circuit device for quickly and efficiently calibrating pressure sensors for electromagnetic water meter manufacturers.

[0028] As shown in Figures 2-8, the automatic pressure calibration device circuit for electromagnetic water meters provided in this embodiment of the present invention provides a circuit scheme for calibrating the pressure sensor of electromagnetic water meters.

[0029] As shown in Figure 2, the MCU microcontroller and peripheral module chip in this example are domestically produced chips. They adopt a low-power design, have stable and reliable performance, and are therefore more energy-efficient and have superior battery life. Pin 14 of the MCU microcontroller chip U10 is connected to one end of resistor R121 and pin 2 of the ferroelectric memory chip U11. The other end of resistor R121 is connected to a 3.3V power supply. Pin 15 of the MCU microcontroller chip U10 is connected to one end of resistor R120 and pin 1 of the ferroelectric memory chip U11. The other end of resistor R120 is connected to a 3.3V power supply. Pin 16 of the MCU microcontroller chip U10 is connected to one end of resistor R123 and pin 5 of the ferroelectric memory chip U11. The other end of resistor R123 is connected to a 3.3V power supply. Pin 19 of the MCU microcontroller chip U10 is connected to pin 3 of the ferroelectric memory chip U11. Pin 20 of the MCU microcontroller chip U10 is connected to one end of resistor R122 and pin 6 of the ferroelectric memory chip U11. Resistor R122... The other end is connected to a 3.3V power supply. Pin 4 of the ferroelectric memory chip U11 is connected to ground (GND). Pins 7 and 8 of the ferroelectric memory chip U11 are connected to a 3.3V power supply. One end of capacitor C118 is connected to ground (GND). Pin 17 of the MCU microcontroller chip U10 is connected to one end of resistor R124. The other end of resistor R124 is connected to one end of resistor R127. Pin 6 of the EEPROM chip U12 is connected to a 3.3V power supply. Pin 18 of the MCU microcontroller chip U10 is connected to one end of resistor R125. The other end of resistor R125 is connected to one end of resistor R126. Pin 5 of the EEPROM chip U12 is connected to a 3.3V power supply. Pin 8 of chip U12 is connected to power supply 3.3V; one end of capacitor C10, the other end of capacitor C10 is connected to ground GND; pin 7 of EEPROM chip U12; pins 1, 2, 3, and 4 of EEPROM chip U12 are simultaneously connected to ground GND; pin 48 of MCU microcontroller chip U10 is connected to pin 3 of passive crystal oscillator Y11; one end of capacitor C117, the other end of capacitor C117 is connected to ground GND; pin 49 of MCU microcontroller chip U10 is connected to pin 1 of passive crystal oscillator Y11; one end of capacitor C116, the other end of capacitor C116 is connected to ground GND; pins 2 and 4 of passive crystal oscillator Y11 are simultaneously connected to ground GND; pin 60 of MCU microcontroller chip U10 is connected to one end of passive crystal oscillator Y10; capacitor C115... One end of capacitor C115 is connected to ground GND. Pin 61 of MCU microcontroller chip U10 is connected to the other end of passive crystal oscillator Y10. One end of capacitor C114 is connected to ground GND. Pin 62 of MCU microcontroller chip U10 is connected to one end of capacitor C113, one end of capacitor C112, the other end of capacitor C113 is connected to the other end of capacitor C112, and ground GND. Pin 66 of MCU microcontroller chip U10 is connected to one end of capacitor C111, one end of capacitor C110, the other end of capacitor C111 is connected to the other end of capacitor C110, and ground GND. Pin 67 of MCU microcontroller chip U10 is connected to one end of capacitor C19, one end of capacitor C18, and one end of capacitor C17. The positive terminal of capacitor C19 is connected to the 3.3V power supply. The other end of capacitor C19 is connected to the other end of capacitor C18, the negative terminal of capacitor C17, and ground GND. Pin 78 of MCU microcontroller chip U10 is connected to one end of resistor R14, pin 2 of the cathode of Schottky diode D14, and pin 9 of program programming port connector J10. The other end of resistor R14 is connected to the 3.3V power supply and pin 1 of program programming port connector J10. Pin 3 of the anode of Schottky diode D14 is connected to ground GND. Pin 79 of MCU microcontroller chip U10 is connected to one end of resistor R15, pin 1 of the cathode of Schottky diode D14, and pin 7 of program programming port connector J10. The other end of resistor R15 is connected to the 3.3V power supply.The following connections are made: 1 pin of the 3.3V programming port connector J10; 80 pin of the MCU microcontroller chip U10; one end of capacitor C11; one end of capacitor C12; pins 1 and 2 of the cathode of Schottky diode D15; pin 4 of the programming port connector J10; one end of resistor R16; one end of resistor R17; the other end of capacitor C11 is connected to the other end of capacitor C12 and ground GND; the other end of resistor R16 is connected to the 3.3V power supply; the other end of resistor R17 is connected to one end of button S10; the other end of button S10 is connected to ground GND; pin 2 of the programming port connector J10 is connected to the 3.3V power supply; pins 8 and 10 of the programming port connector J10 are connected to ground GND.

[0030] As shown in Figure 3, in this example, the two ADC module chips are connected as follows: Pin 2 of ADC module chip U20 is connected to one end of resistor R219, one end of resistor R222, one end of capacitor C236, and pin 2 of ADC module chip U21; the other end of resistor R219 is connected to a 3.3V power supply; the other end of resistor R222 is connected to pin 3 of passive crystal oscillator Y20; the other end of capacitor C236 is connected to ground GND; pin 2 of passive crystal oscillator Y20 is connected to ground GND; pin 4 of passive crystal oscillator Y20 is connected to one end of capacitor C235, one end of capacitor C234, and a 3.3V power supply; the other end of capacitor C235 is connected to the other end of capacitor C234 and ground GND; and pin 3 of ADC module chip U20 is connected to pin 42 of MCU microcontroller chip U10. Pin 4 of ADC module chip U20 is connected to pin 41 of MCU microcontroller chip U10, one end of resistor R221, and the other end of resistor R221 is connected to the 3.3V power supply. Pin 7 of ADC module chip U20 is connected to one end of capacitor C230, the positive terminal of capacitor C231, and the 2.5V power supply REF. The other end of capacitor C230 is connected to the negative terminal of capacitor C231 and ground GND. Pins 8, 9, 10, 20, 22, and 23 of ADC module chip U20 are connected to ground GND. Pin 24 of ADC module chip U20 is connected to the 3.3V power supply. Pin 25 of ADC module chip U20 is connected to capacitor C229. One end of capacitor C229 is connected to the other end of capacitor C228 and ground GND. Pin 26 of ADC module chip U20 is connected to pin 43 of MCU microcontroller chip U10. One end of resistor R218 is connected to the other end of resistor R218 and ground GND. Pin 27 of ADC module chip U20 is connected to pin 44 of MCU microcontroller chip U10. One end of resistor R217 is connected to the other end of resistor R217 and ground GND. Pin 28 of ADC module chip U20 is connected to pin 45 of MCU microcontroller chip U10. One end of resistor R216 is connected to the other end of resistor R216 and ground GND. The positive terminal of capacitor C224 is connected to one end of capacitor C225 and ground GND.3V, the negative terminal of capacitor C224 is connected to the other end of capacitor C225 and ground GND. Pin 3 of ADC module chip U21 is connected to pin 30 of MCU microcontroller chip U10 and one end of resistor R228. The other end of resistor R228 is connected to the 3.3V power supply. Pin 4 of ADC module chip U21 is connected to pin 32 of MCU microcontroller chip U10 and one end of resistor R227. The other end of resistor R227 is connected to the 3.3V power supply. Pin 7 of ADC module chip U21 is connected to one end of capacitor C243, the positive terminal of capacitor C244, and the 2.5V power supply REF. The other end of capacitor C243 is connected to the negative terminal of capacitor C244 and ground GND. Pins 8, 9, 10, 20, 22, and 23 of ADC module chip U21... Pin 24 of ADC module chip U21 is connected to the 3.3V power supply. Pin 25 of ADC module chip U21 is connected to one end of capacitor C242, one end of capacitor C241, and the 3.3V power supply. The other end of capacitor C242 is connected to the other end of capacitor C241 and the GND ground. Pin 26 of ADC module chip U21 is connected to pin 31 of MCU microcontroller chip U10 and one end of resistor R226. The other end of resistor R226 is connected to the 3.3V power supply. Pin 27 of ADC module chip U21 is connected to pin 29 of MCU microcontroller chip U10 and one end of resistor R225. The other end of resistor R225 is connected to the 3.3V power supply. Pin 28 of ADC module chip U21 is connected to pin 33 of MCU microcontroller chip U10 and resistor R224. One end of resistor R224 is connected to the 3.3V power supply. The positive terminal of capacitor C237 is connected to one end of capacitor C238 and the 3.3V power supply. The negative terminal of capacitor C237 is connected to the other end of capacitor C238 and ground GND. One end of resistor R20 is connected to one end of ferrite bead FB51. The other end of resistor R20 is connected to one end of capacitor C20, one end of capacitor C22, pin 3 of Schottky diode D20, and pin 11 of ADC module chip U20. The other end of capacitor C20 is connected to ground GND. Pin 2 of Schottky diode D20 is connected to the 3V power supply.3V. Pin 1 of Schottky diode D20 is connected to ground (GND). One end of resistor R21 is connected to one end of ferrite bead FB52. The other end of resistor R21 is connected to one end of capacitor C21, the other end of capacitor C22, pin 3 of Schottky diode D21, and pin 12 of ADC module chip U20. The other end of capacitor C21 is connected to ground (GND). Pin 2 of Schottky diode D21 is connected to the 3.3V power supply. Pin 1 of Schottky diode D21 is connected to ground (GND). One end of resistor R22 is connected to one end of ferrite bead FB54. The other end of resistor R22 is connected to one end of capacitor C23, one end of capacitor C25, pin 3 of Schottky diode D22, and pin 13 of ADC module chip U20. The other end of capacitor C23 is connected to ground (GND). Schottky diode D22... Pin 2 of the circuit is connected to a 3.3V power supply. Pin 1 of the Schottky diode D22 is connected to ground (GND). One end of resistor R23 is connected to one end of the ferrite bead FB55. The other end of resistor R23 is connected to one end of capacitor C24, the other end of capacitor C25, pin 3 of Schottky diode D23, and pin 14 of ADC module chip U20. The other end of capacitor C24 is connected to ground (GND). Pin 2 of the Schottky diode D23 is connected to a 3.3V power supply. Pin 1 of the Schottky diode D23 is connected to ground (GND). One end of resistor R24 ​​is connected to one end of the ferrite bead FB57. The other end of resistor R24 ​​is connected to one end of capacitor C26, one end of capacitor C28, pin 3 of Schottky diode D24, and pin 15 of ADC module chip U20. The other end of the resistor is connected to ground (GND). Pin 2 of the Schottky diode D24 is connected to the 3.3V power supply. Pin 1 of the Schottky diode D24 is connected to ground (GND). One end of the resistor R25 is connected to one end of the ferrite bead FB58. The other end of the resistor R25 is connected to one end of capacitor C27, the other end of capacitor C28, pin 3 of the Schottky diode D25, and pin 16 of the ADC module chip U20. The other end of capacitor C27 is connected to ground (GND). Pin 2 of the Schottky diode D25 is connected to the 3.3V power supply.3V. Pin 1 of Schottky diode D25 is connected to ground (GND). One end of resistor R26 is connected to one end of ferrite bead FB510. The other end of resistor R26 is connected to one end of capacitor C29, one end of capacitor C211, pin 3 of Schottky diode D26, and pin 17 of ADC module chip U20. The other end of capacitor C29 is connected to ground (GND). Pin 2 of Schottky diode D26 is connected to the 3.3V power supply. Pin 1 of Schottky diode D26 is connected to ground (GND). One end of resistor R27 is connected to one end of ferrite bead FB511. The other end of resistor R27 is connected to one end of capacitor C210, the other end of capacitor C211, pin 3 of Schottky diode D27, and pin 18 of ADC module chip U20. The other end of capacitor C210 is connected to ground (GND). Pin 2 of Schottky diode D27 is connected to a 3.3V power supply, and pin 1 of Schottky diode D27 is connected to ground (GND). One end of resistor R28 is connected to one end of ferrite bead FB513, and the other end of resistor R28 is connected to one end of capacitor C212, one end of capacitor C214, pin 3 of Schottky diode D28, and pin 11 of ADC module chip U21. The other end of capacitor C212 is connected to ground (GND). Pin 2 of Schottky diode D28 is connected to a 3.3V power supply, and pin 1 of Schottky diode D28 is connected to ground (GND). One end of resistor R29 is connected to one end of ferrite bead FB514, and the other end of resistor R29 is connected to one end of capacitor C213, the other end of capacitor C214, pin 3 of Schottky diode D29, and pin 12 of ADC module chip U21. The other end of capacitor C213 is connected to ground GND. Pin 2 of Schottky diode D29 is connected to the 3.3V power supply, and pin 1 of Schottky diode D29 is connected to ground GND. One end of resistor R210 is connected to one end of ferrite bead FB516, and the other end of resistor R210 is connected to one end of capacitor C215, one end of capacitor C217, pin 3 of Schottky diode D210, and pin 13 of ADC module chip U21. The other end of capacitor C215 is connected to ground GND, and pin 2 of Schottky diode D210 is connected to the 3.3V power supply.3V, pin 1 of Schottky diode D210 is connected to ground GND, one end of resistor R211 is connected to one end of ferrite bead FB517, the other end of resistor R211 is connected to one end of capacitor C216, the other end of capacitor C217, pin 3 of Schottky diode D211, and pin 14 of ADC module chip U21, the other end of capacitor C216 is connected to ground GND, pin 2 of Schottky diode D211 is connected to the 3.3V power supply, pin 1 of Schottky diode D211 is connected to ground GND, one end of resistor R212 is connected to one end of ferrite bead FB519, the other end of resistor R212 is connected to one end of capacitor C218, one end of capacitor C220, pin 3 of Schottky diode D212, and pin 15 of ADC module chip U21, capacitor C218... The other end of the resistor R213 is connected to ground (GND). Pin 2 of the Schottky diode D212 is connected to the 3.3V power supply, and pin 1 of the Schottky diode D212 is connected to ground (GND). One end of the resistor R213 is connected to one end of the ferrite bead FB520. The other end of the resistor R213 is connected to one end of capacitor C219, the other end of capacitor C220, pin 3 of the Schottky diode D213, and pin 16 of the ADC module chip U21. The other end of the capacitor C219 is connected to ground (GND). Pin 2 of the Schottky diode D213 is connected to the 3.3V power supply, and pin 1 of the Schottky diode D213 is connected to ground (GND). One end of the resistor R214 is connected to one end of the ferrite bead FB522, and the other end of the resistor R214 is connected to one end of capacitor C221 and capacitor C223. One end of resistor R215 is connected to one end of ferrite bead FB523, and the other end of resistor R215 is connected to one end of capacitor C222, the other end of capacitor C223, pin 3 of ADC module chip U215, pin 18 of ADC module chip U21, and the other end of capacitor C222 is connected to ground GND. Pin 2 of ADC module chip U215 is connected to the 3.3V power supply, and pin 1 of ADC module chip U215 is connected to ground GND.

[0031] As shown in Figure 4, in the 8-channel pressure sensor module of this example, pin 1 of the power chip U50 is connected to one end of capacitor C514, the positive terminal of capacitor C515, and a 3.3V power supply. The other end of capacitor C514 is connected to the negative terminal of capacitor C515 and ground GND. Pin 3 of the power chip U50 is connected to ground GND. Pin 2 of the power chip U50 is connected to one end of capacitor C512, the positive terminal of capacitor C513, and a 2.5V power supply REF. The other end of capacitor C512 is connected to the negative terminal of capacitor C513 and ground GND. Pin 5, the non-inverting input of the operational amplifier chip U51B, is connected to one end of capacitor C50 and one end of resistor R50. The other end of capacitor C50 is connected to ground GND, and the other end of resistor R50 is connected to a 2.5V power supply REF. Pin 6, the inverting input of the operational amplifier chip U51B... One end of resistor R51 is connected to pin 7 of the operational amplifier chip U51B. The other end of resistor R51 is connected to one end of ferrite bead FB50. The other end of ferrite bead FB50 is connected to pin 4 of pressure sensor interface connector JP50 and pin 4 of connector J50. The other end of ferrite bead FB51 is connected to pin 3 of pressure sensor interface connector JP50 and pin 3 of connector J50. The other end of ferrite bead FB52 is connected to pin 2 of pressure sensor interface connector JP50 and pin 2 of connector J50. Pin 1 of pressure sensor interface connector JP50 is connected to pin 1 of connector J50 and ground GND. Pin 3 of the non-inverting input of operational amplifier chip U51A is connected to one end of capacitor C51 and one end of resistor R52. The other end of capacitor C51 is connected to ground GND. Resistor R52... The other end is connected to the power supply REF2.5V. The inverting input pin 2 of the operational amplifier chip U51A is connected to one end of the resistor R53 and the output pin 1 of the operational amplifier chip U51A. Pin 4 of the operational amplifier chip U51A is connected to the ground GND. Pin 8 of the operational amplifier chip U51A is connected to the power supply 3.One end of capacitor C52 is connected to ground (GND). The other end of resistor R53 is connected to one end of ferrite bead FB53. The other end of ferrite bead FB53 is connected to pin 4 of pressure sensor interface connector JP51 and pin 4 of connector J51. The other end of ferrite bead FB54 is connected to pin 3 of pressure sensor interface connector JP51 and pin 3 of connector J51. The other end of ferrite bead FB55 is connected to pin 2 of pressure sensor interface connector JP51 and pin 2 of connector J51. Pin 1 of pressure sensor interface connector JP51 is connected to pin 1 of connector J51 and ground (GND). Pin 5 of the non-inverting input of operational amplifier chip U52B is connected to one end of capacitor C53 and one end of resistor R54. The other end of capacitor C53 is connected to ground (GND). The other end is connected to the power supply REF2.5V. Pin 6 of the operational amplifier chip U52B's inverting input is connected to one end of resistor R55 and pin 7 of the operational amplifier chip U52B's output. The other end of resistor R55 is connected to one end of ferrite bead FB56. The other end of ferrite bead FB56 is connected to pin 4 of pressure sensor interface connector JP52 and pin 4 of connector J52. The other end of ferrite bead FB57 is connected to pin 3 of pressure sensor interface connector JP52 and pin 3 of connector J52. The other end of ferrite bead FB58 is connected to pin 2 of pressure sensor interface connector JP52 and pin 2 of connector J52. Pin 1 of pressure sensor interface connector JP52 is connected to pin 1 of connector J52 and ground GND. Pin 3 of the operational amplifier chip U52A's non-inverting input is connected to one end of capacitor C54 and resistor R56. One end of capacitor C54 is connected to ground GND, the other end of resistor R56 is connected to power supply REF2.5V, pin 2 of the inverting input of operational amplifier chip U52A is connected to one end of resistor R57 and pin 1 of the output of operational amplifier chip U52A, pin 4 of operational amplifier chip U52A is connected to ground GND, and pin 8 of operational amplifier chip U52A is connected to power supply 3.3V; one end of capacitor C55; the other end of capacitor C55 is connected to ground GND; the other end of resistor R57 is connected to one end of ferrite bead FB59; the other end of ferrite bead FB59 is connected to pin 4 of pressure sensor interface connector JP53 and pin 4 of connector J53; the other end of ferrite bead FB510 is connected to pin 3 of pressure sensor interface connector JP53 and pin 3 of connector J53; the other end of ferrite bead FB511 is connected to pin 2 of pressure sensor interface connector JP53 and pin 2 of connector J53; pin 1 of pressure sensor interface connector JP53 is connected to pin 1 of connector J53 and ground GND; pin 5 of the non-inverting input of operational amplifier chip U53B is connected to one end of capacitor C56 and one end of resistor R58; the other end of capacitor C56 is connected to ground GND; resistor R58... The other end is connected to the power supply REF2.5V. Pin 6, the inverting input of operational amplifier chip U53B, is connected to one end of resistor R59 and pin 7, the output of operational amplifier chip U53B. The other end of resistor R59 is connected to one end of ferrite bead FB512. The other end of ferrite bead FB512 is connected to pin 4 of pressure sensor interface connector JP54 and pin 4 of connector J54. The other end of ferrite bead FB513 is connected to pin 3 of pressure sensor interface connector JP54 and pin 3 of connector J54. The other end of ferrite bead FB514 is connected to pin 2 of pressure sensor interface connector JP54 and pin 2 of connector J54. Pin 1 of pressure sensor interface connector JP54 is connected to pin 1 of connector J54 and ground GND. Pin 3, the non-inverting input of operational amplifier chip U53A, is connected to capacitor C57. One end of resistor R510 and the other end of capacitor C57 are connected to ground GND. The other end of resistor R510 is connected to power supply REF2.5V. Pin 2, the inverting input of operational amplifier chip U53A, is connected to one end of resistor R511 and pin 1, the output of operational amplifier chip U53A. Pin 4 of operational amplifier chip U53A is connected to ground GND. Pin 8 of operational amplifier chip U53A is connected to power supply 3.One end of capacitor C58 is connected to ground (GND). The other end of resistor R511 is connected to one end of ferrite bead FB515. The other end of ferrite bead FB515 is connected to pin 4 of pressure sensor interface connector JP55 and pin 4 of connector J55. The other end of ferrite bead FB516 is connected to pin 3 of pressure sensor interface connector JP55 and pin 3 of connector J55. The other end of ferrite bead FB517 is connected to pin 2 of pressure sensor interface connector JP55 and pin 2 of connector J55. Pin 1 of pressure sensor interface connector JP55 is connected to pin 1 of connector J55 and ground (GND). Pin 5 of the non-inverting input of operational amplifier chip U54B is connected to one end of capacitor C59 and one end of resistor R512. The other end of resistor R512 is connected to ground GND. The other end of resistor R512 is connected to power supply REF2.5V. Pin 6, the inverting input of operational amplifier chip U54B, is connected to one end of resistor R513 and pin 7, the output of operational amplifier chip U54B. The other end of resistor R513 is connected to one end of ferrite bead FB518. The other end of ferrite bead FB518 is connected to pin 4 of pressure sensor interface connector JP56 and pin 4 of connector J56. The other end of ferrite bead FB519 is connected to pin 3 of pressure sensor interface connector JP56 and pin 3 of connector J56. The other end of ferrite bead FB520 is connected to pin 2 of pressure sensor interface connector JP56 and pin 2 of connector J56. Pin 1 of pressure sensor interface connector JP56 is connected to pin 1 of connector J56 and ground GND. Operational amplifier chip U54A... The non-inverting input pin 3 of the operational amplifier chip U54A is connected to one end of capacitor C510 and one end of resistor R514. The other end of capacitor C510 is connected to ground GND, and the other end of resistor R514 is connected to power supply REF2.5V. The inverting input pin 2 of the operational amplifier chip U54A is connected to one end of resistor R515 and the output pin 1 of the operational amplifier chip U54A. Pin 4 of the operational amplifier chip U54A is connected to ground GND, and pin 8 of the operational amplifier chip U54A is connected to power supply 3.One end of capacitor C511 is connected to 3V, and the other end of capacitor C511 is connected to ground (GND). The other end of resistor R515 is connected to one end of ferrite bead FB521. The other end of ferrite bead FB521 is connected to pin 4 of pressure sensor interface connector JP57 and pin 4 of connector J57. The other end of ferrite bead FB522 is connected to pin 3 of pressure sensor interface connector JP57 and pin 3 of connector J57. The other end of ferrite bead FB523 is connected to pin 2 of pressure sensor interface connector JP57 and pin 2 of connector J57. Pin 1 of pressure sensor interface connector JP57 is connected to pin 1 of connector J57 and ground (GND).

[0032] As shown in Figure 5, in the relay control module of this example, pins 4 and 5 of relay K70 are connected to ground 24GND; pins 3 and 6 of relay K70 are connected to the anode of Schottky diode D74 and pin 3 of solenoid valve interface connector J70; the cathode of Schottky diode D74 is connected to power supply 24V; pin 1 of relay K70 is connected to the cathode of Schottky diode D70 and power supply PWR+5V; pin 8 of relay K70 is connected to the anode of Schottky diode D70 and the drain pin 3 of MOSFET Q70; the source pin 2 of MOSFET Q70 is connected to ground GND and one end of resistor R71; the gate pin 1 of MOSFET Q70 is connected to one end of resistor R70 and the other end of resistor R71; the other end of resistor R70 is connected to pin 6 of the MCU microcontroller and peripheral module chip; pins 4 and 6 of relay K71 are connected to ground GND and solenoid valve interface connector J70. Pins 1 and 5 are connected to ground (24GND). Pins 3 and 6 of relay K71 are connected to the anode of Schottky diode D75. Pin 1 of solenoid valve interface connector J70 is connected to power supply (24V). Pins 2 and 4 of solenoid valve interface connector J70 are connected to power supply (24V). The cathode of Schottky diode D75 is connected to power supply (24V). Pin 1 of relay K71 is connected to the cathode of Schottky diode D71. Power supply PWR+5V is connected to power supply (PWR+5V). Pin 8 of relay K71 is connected to the anode of Schottky diode D71. Pin 3 of MOSFET Q71 is connected to the drain. Pin 2 of MOSFET Q71 is connected to ground (GND). One end of resistor R73 is connected to the gate of MOSFET Q71. Pin 1 of MOSFET Q71 is connected to one end of resistor R72 and the other end of resistor R73. The other end of resistor R72 is connected to pin 7 of the MCU microcontroller and peripheral module chip. Pin 4 of relay K72 is connected to the gate of MOSFET Q71. Pins 1 and 5 are connected to ground (24GND). Pins 3 and 6 of relay K72 are connected to the anode of Schottky diode D76 and pin 3 of solenoid valve connector J71. The cathode of Schottky diode D76 is connected to the 24V power supply.Pin 1 of relay K72 is connected to the cathode of Schottky diode D72 and power supply PWR+5V. Pin 8 of relay K72 is connected to the anode of Schottky diode D72 and the drain pin 3 of MOSFET Q72. Pin 2 of the source of MOSFET Q72 is connected to ground GND and one end of resistor R75. Pin 1 of the gate of MOSFET Q72 is connected to one end of resistor R74 and the other end of resistor R75. The other end of resistor R74 is connected to pin 8 of the MCU microcontroller and peripheral module chip. Pins 4 and 5 of relay K73 are connected to ground 24GND. Pins 3 and 6 of relay K73 are connected to the anode of Schottky diode D77 and pin 1 of solenoid valve interface connector J71. Pins 2 and 4 of solenoid valve interface connector J71 are connected to power supply 24V. Schottky diode D77... The cathode of relay K73 is connected to a 24V power supply. Pin 1 of relay K73 is connected to the cathode of Schottky diode D73 and the power supply PWR+5V. Pin 8 of relay K73 is connected to the anode of Schottky diode D73 and the drain pin 3 of MOSFET Q73. The source pin 2 of MOSFET Q73 is connected to ground GND and one end of resistor R77. The gate pin 1 of MOSFET Q73 is connected to one end of resistor R76 and the other end of resistor R77. The other end of resistor R76 is connected to pin 9 of the MCU microcontroller and peripheral module chip.

[0033] As shown in Figure 6, in this example, one end of the resettable fuse F30 is connected to the 24V power supply. The other end of the resettable fuse F30 is connected to one end of the varistor R30, the cathode of the TVS diode D31, the positive terminal of the electrolytic capacitor C30, the positive terminal of the electrolytic capacitor C31, one end of the capacitor C32, and one end of the inductor L30. The other end of the varistor R30 is connected to the anode of the TVS diode D31, the negative terminal of the electrolytic capacitor C30, the negative terminal of the electrolytic capacitor C31, the other end of the capacitor C32, one end of the capacitor C33, one end of the capacitor C39, pin 1 of the power module U30, and the anode of the Schottky diode D30. The cathode of the Schottky diode D30 is connected to ground 24GND. The other end of the inductor L30 is connected to the other end of the capacitor C33 and the capacitor C316. One end of capacitor C316 is connected to pin 2 of power module U30. Pin 5 of power module U30 is connected to ground (GND). The other end of capacitor C316 is connected to pin 3 of power module U30. The positive terminals of electrolytic capacitors C34 and C35 are also connected. One end of capacitor C36 is connected to pin 1 and pin 2 of the cathode of ESD diode D32. One end of capacitor C37 is connected to one end of capacitor C38. The cathode of TVS diode D33 is connected to one end of resistor R31. The power supply terminal is PWR+5V. The other end of capacitor C39 is connected to the negative terminals of electrolytic capacitors C34 and C35. The other end of capacitor C36 is connected to pin 3 of the anode of ESD diode D32. The other end of capacitor C37 is connected to one end of capacitor C38. The anode of TVS diode D33 is connected to the light-emitting diode D34. The cathode of LED D34 is connected to ground (GND), the anode of LED D34 is connected to the other end of resistor R31, and one end of inductor L31 is connected to the power supply terminal PWR+5V.The other end of inductor L31 is connected to the positive terminal of electrolytic capacitor C310, one end of capacitor C311, and pin 1 of power supply chip U31. The negative terminal of electrolytic capacitor C310 is connected to the other end of capacitor C311, pin 2 of power supply chip U31, one end of capacitor C312, one end of capacitor C313, one end of capacitor C314, one end of capacitor C315, the anode of TVS diode D35, and ground GND. Pin 3 of power supply chip U31 is connected to the other ends of capacitors C312, C313, C314, and C315, the cathode of TVS diode D35, and the 3.3V power supply.

[0034] As shown in Figure 7, in this example, the 485 communication module has the following connections: one end of resistor R42 is connected to pin 34 of the MCU microcontroller chip U10, and the other end is connected to pin 1 of the 485 communication chip U40; one end of resistor R41 is connected to pin 36 of the MCU microcontroller chip U10, and the other end is connected to pins 2 and 3 of the 485 communication chip U40; one end of resistor R43 is connected to ground (GND); one end of resistor R40 is connected to pin 35 of the MCU microcontroller chip U10, and the other end is connected to pin 4 of the 485 communication chip U40; pin 5 of the 485 communication chip U40 is connected to ground (GND); and pin 6 of the 485 communication chip U40 is connected to the cathode of TVS diode D42. One end of the anode of transistor D40, one end of resistor R46, one end of resistor R44, and the anode of TVS diode D42 are connected to ground (GND). The other end of resistor R46 is connected to a 3.3V power supply. The other end of resistor R44 is connected to pin 4 of connector J40. Pin 7 of 485 communication chip U40 is connected to the cathode of TVS diode D41, the other end of the anode of TVS diode D40, one end of resistor R47, and one end of resistor R45. The anode of TVS diode D41 is connected to ground (GND). The other end of resistor R47 is connected to ground (GND). The other end of resistor R45 is connected to pin 3 of connector J40. Pin 2 of connector J40 is connected to ground (GND). Pin 1 of connector J40 is connected to a 24V power supply. Pin 8 of 485 communication chip U40... One end of capacitor C40 is connected to the 3.3V power supply, and the other end of capacitor C40 is connected to ground GND.

[0035] As shown in Figure 8, in this example, the liquid crystal display module P60 has the following pin connections: pin 1 is connected to one end of capacitor C63; pin 2 is connected to the other end of capacitor C63 and ground GND; pin 3 is connected to the cathode pin 1 of ESD diode D62, the cathode of Schottky diode D63, one end of resistor R60, one end of capacitor C61, one end of capacitor C60, and a 3.3V power supply; the other end of capacitor C61 is connected to the other end of capacitor C60 and ground GND; pin 4 is connected to one end of ferrite bead FB60; the other end of ferrite bead FB60 is connected to the cathode pin 2 of ESD diode D62 and pin 75 of MCU microcontroller chip U10; the anode pin 3 of ESD diode D62 is connected to ground GND; and pin 5... One end of the ferrite bead FB61 is connected to the other end of the ferrite bead FB61. The other end of the ferrite bead FB61 is connected to pin 1 of the cathode of the ESD diode D61 and pin 76 of the MCU microcontroller chip U10. Pin 6 of the LCD module P60 is connected to ground GND. Pin 7 of the LCD module P60 is connected to one end of the ferrite bead FB62. The other end of the ferrite bead FB62 is connected to pin 2 of the cathode of the ESD diode D61 and pin 1 of the MCU microcontroller chip U10. Pin 3 of the ESD diode D61 is connected to ground GND. Pin 8 of the LCD module P60 is connected to one end of the ferrite bead FB63. The other end of the ferrite bead FB63 is connected to pin 1 of the cathode of the ESD diode D60, one end of capacitor C62, the anode of Schottky diode D63, and the other end of resistor R60. Capacitor C62... The other end is connected to ground GND. Pin 9 of LCD module P60 is connected to one end of ferrite bead FB64. The other end of ferrite bead FB64 is connected to pin 2 of the cathode of ESD diode D60 and pin 77 of MCU microcontroller chip U10. Pin 3 of the anode of ESD diode D60 is connected to ground GND. Pin 10 of LCD module P60 is connected to ground GND. Pin 11 of LCD module P60 is connected to one end of resistor R61. The other end of resistor R61 is connected to power supply 3.3V. Pin 12 of LCD module P60 is connected to ground GND.

[0036] As shown in Figure 6, the anode of the red LED D34, the power indicator light, is connected to one end of resistor R31, and the other end of resistor R31 is connected to the power supply PWR+5V. The cathode of the red LED D34 is connected to ground GND.

[0037] As shown in Figure 2, in the button module, one end of button S11 is connected to one end of resistor R19, one end of capacitor C13, and pin 25 of MCU microcontroller chip U10. The other end of resistor R19 is connected to a 3.3V power supply, and the other end of capacitor C13 is connected to ground GND. The other end of button S11 is also connected to ground GND. One end of button S12 is connected to one end of resistor R112, one end of capacitor C14, and pin 26 of MCU microcontroller chip U10. The other end of resistor R112 is connected to a 3.3V power supply, and the other end of capacitor C14 is connected to ground GND. The other end of button S12 is also connected to ground GND. One end of button S13 is connected to one end of resistor R115, one end of capacitor C15, and pin 27 of MCU microcontroller chip U10. The other end of button S14 is connected to a 3.3V power supply. The other end of capacitor C15 is connected to ground GND. The other end of button S14 is connected to one end of resistor R118, one end of capacitor C16, and pin 28 of MCU microcontroller chip U10. The other end of resistor R118 is connected to a 3.3V power supply. The other end of capacitor C16 is connected to ground GND. The other end of button S14 is connected to ground GND.

[0038] As shown in Figure 2, the color indicator lights of the device are as follows: The anode of the white LED D10 is connected to a 3.3V power supply, and the cathode of the white LED D10 is connected to one end of resistor R10. The other end of resistor R10 is connected to pin 21 of the MCU microcontroller chip U10. The anode of the green LED D11 is connected to a 3.3V power supply, and the cathode of the green LED D11 is connected to one end of resistor R11. The other end of resistor R11 is connected to pin 22 of the MCU microcontroller chip U10. The anode of the yellow LED D12 is connected to a 3.3V power supply, and the cathode of the yellow LED D12 is connected to one end of resistor R12. The other end of resistor R12 is connected to pin 23 of the MCU microcontroller chip U10. The anode of the blue LED D13 is connected to a 3.3V power supply, and the cathode of the blue LED D13 is connected to one end of resistor R13. The other end of resistor R13 is connected to the MCU microcontroller chip U10. Pin 24 of the microcontroller chip U10.

Claims

1. A circuit for an automatic pressure calibration device for an electromagnetic water meter, comprising an MCU microcontroller and peripheral modules, a 2-channel ADC module, an 8-channel pressure sensor module, a relay control module, a power supply module, a 485 communication module, an LCD display module, a power color indicator light, a button module, and color indicator lights, characterized in that: The MCU microcontroller and peripheral modules run embedded programs to control the external LCD display, relay operation, ADC data acquisition and conversion, LED color indicator, EEPROM data parameter storage, and data processing for communication with the host computer via 485. The two-channel ADC module is used for data processing, which involves acquiring analog voltage signals from pressure sensors and converting them into digital signals by connecting to eight pressure sensor modules. The 8-channel pressure sensor module is for connecting external pressure sensors and providing power to the pressure sensors, as well as for connecting the pressure sensors to the terminals. The relay control module is a microcontroller that uses GPIO pins to control the drive circuit, which in turn controls the relay to engage and disengage, thereby controlling the normally open and normally closed contacts of the relay. The relay contacts then control the opening and closing of an external solenoid valve. The power module consists of an MCU microcontroller and peripheral modules, a 2-channel ADC module, an 8-channel pressure sensor module, a relay control module, a 485 communication module, an LCD display module, a power color indicator light, and a button module. The color indicator light provides power and power conversion. The 485 communication module is the circuit for connecting this calibration circuit device to the host computer, used for data communication, and for transmitting data and controlling the functions of this device. The liquid crystal display module is the liquid crystal module used by this calibration device for displaying pressure information and data. The power color indicator light serves as a power supply indicator for this device, used to check the power supply status of the device; The button module is an operation button that receives and sends signals through the MCU microprocessor to start and stop the control function of this device; The color indicator lights are LEDs that display different colors to indicate the start-up, operation, and abnormal status of the device.

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