Design circuit of household natural gas leakage and water leakage detection alarm terminal

Abstract

The utility model discloses a design circuit of a household natural gas leakage and water leakage detection alarm terminal. Comprising a multi-stage power supply circuit module, a control unit circuit module, a GSM module remote communication circuit module, a double-leakage detection circuit module, a terminal lighting circuit module and a terminal alarm circuit module. The multi-stage power supply circuit module is connected with the GSM module remote communication circuit module, the double-leakage detection circuit module and the control unit circuit module; the GSM module remote communication circuit module is connected with the control unit circuit module through a UART (Universal Asynchronous Receiver / Transmitter) interface; the GSM module remote communication circuit module is in communication connection with a mobile client through a GSM antenna; the problems that existing natural gas leakage and water leakage detection alarm can only be independently controlled indoors and cannot give an alarm remotely, existing detection terminal detection equipment is single, and detection positioning equipment for local natural gas leakage / water leakage detection affects accurate searching of natural gas leakage / water leakage positioning points, so that the detection efficiency is high are solved. The problem that an existing water leakage detection terminal lacks a lighting function and is not beneficial for maintenance personnel to carry out maintenance under the dark condition is solved.

Description

Technical Field

[0001] This utility model relates to the fields of microcontroller control, sensor use and wireless communication, and in particular to the design circuit of a household natural gas leak and water leakage detection alarm terminal. Background Technology

[0002] Currently, with the continuous development of science and technology and the increasing demands of people for quality of consumption, smart home systems such as smart kitchens and bathrooms, smart water heaters, smart windows, and smart natural gas terminals have emerged.

[0003] However, most natural gas leak and water leakage detection alarms can only be controlled independently indoors and cannot be remotely triggered. This causes a lot of inconvenience for busy office workers. Moreover, the existing detection terminals are limited to either natural gas detection terminals or water leakage detection terminals, making the detection equipment too limited. In addition, existing natural gas leak detection terminals or water leakage detection terminals only have one detection channel and can only achieve local detection and location of natural gas / water leaks, which affects the accurate location of natural gas / water leaks and increases the difficulty of maintenance. At the same time, existing water leakage detection terminals lack lighting functions, which is not conducive to maintenance personnel performing maintenance in the dark. Summary of the Invention

[0004] This utility model provides a design circuit for a household natural gas leak and water leakage detection alarm terminal to overcome the above-mentioned technical problems.

[0005] To achieve the above objectives, the technical solution of this utility model is as follows:

[0006] A circuit design for a household natural gas leak and water leak detection alarm terminal includes a multi-stage power supply circuit module, a control unit circuit module, a GSM module remote communication circuit module, a dual water leak detection circuit module, a dual leak detection circuit module, a terminal lighting circuit module, and a terminal alarm circuit module.

[0007] The multi-stage power supply circuit module includes a primary power supply circuit, a secondary power supply circuit, and a tertiary power supply circuit; the output terminal of the primary power supply circuit is electrically connected to the input terminal of the GSM module remote communication circuit module; the output terminal of the secondary power supply circuit is electrically connected to the input terminal of the dual leakage detection circuit module; and the output terminal of the tertiary power supply circuit is electrically connected to the input terminal of the control unit circuit module.

[0008] The control unit circuit module is electrically connected to the dual water leakage detection circuit module, the dual leak detection circuit module, the terminal lighting circuit module, and the terminal alarm circuit module through the I / O interface, respectively.

[0009] The control unit circuit module is used to generate alarm signals and remote prompt signals based on the water or natural gas leak detection results of the dual water leak detection circuit module or the dual leak detection circuit module, and send them to the terminal alarm circuit module and the GSM module remote communication circuit module respectively; the terminal alarm circuit module is used to sound a buzzer warning based on the received alarm signal; the terminal lighting circuit module is used to provide a light source through the control signals issued by the control unit circuit module when detecting / maintaining natural gas and water leaks.

[0010] One end of the GSM module remote communication circuit module is electrically connected to the control unit circuit module via a UART interface, and the GSM module remote communication circuit module is equipped with a GSM antenna inside. The other end of the GSM module remote communication circuit module is connected to the mobile client via the GSM antenna. The GSM module remote communication circuit module receives remote prompt signals and sends them to the mobile client for remote early warning prompts.

[0011] Furthermore, the primary power supply circuit includes a first power supply chip U2;

[0012] Pin 1 of the first power supply chip U2 is connected to one end of the first capacitor C1. Pin 2 of the first power supply chip U2 is connected to one end of the first resistor R2, one end of the second capacitor C2, one end of the third capacitor C3, and one end of the first diode D1, which are all connected to the output pin of the +12V power supply. The other end of the first diode D1 is connected to pin 1 of the first terminal U1, and pin 2 of the first terminal U1 is grounded. Pin 3 of the first power supply chip U2 is connected to the other end of the first resistor R2 and one end of the second resistor R4. Pin 4 of the first power supply chip U2 is connected to one end of the third resistor R5. The other end of the third resistor R5 is grounded along with the other ends of the second resistor R4, the second capacitor C2, and the third capacitor C3. Pin 5 of the first power supply chip U2 is connected to one end of the fourth capacitor C4, pin 7 of the first power supply chip U2, one end of the second diode D2, one end of the fourth resistor R6, one end of the fifth capacitor C5, one end of the sixth capacitor C6, one end of the seventh capacitor C7, and one end of the fifth resistor R8, with the other end of the fifth resistor R8 grounded; pin 6 of the first power supply chip U2 is connected to the other end of the fourth capacitor C4, pin 8 of the first power supply chip U2 is connected to the other end of the first capacitor C1, one end of the first inductor L1, and the other end of the second diode D2, the other end of the first inductor L1 is connected to the other end of the fourth resistor R6, the other end of the fifth capacitor C5, the other end of the sixth capacitor C6, and the other end of the seventh capacitor C7, and pin 9 of the first power supply chip U2 is grounded.

[0013] Furthermore, the secondary power supply circuit includes a second power supply chip U4;

[0014] Pin 1 of the second power supply chip U4 is connected to one end of the eighth capacitor C10. Pin 2 of the second power supply chip U4 is connected to one end of the sixth resistor R13 and one end of the ninth capacitor C13, which are connected to the output pin of the +12V power supply. Pin 3 of the second power supply chip U4 is connected to the other end of the sixth resistor R13 and one end of the seventh resistor R15. Pin 4 of the second power supply chip U4 is connected to one end of the eighth resistor R16. The other end of the eighth resistor R16, the other end of the seventh resistor R15, and the other end of the ninth capacitor C13 are grounded. Pin 5 of the second power supply chip U4 is connected to one end of the ninth resistor R19, one end of the tenth capacitor C14, pin 7 of the second power supply chip U4, one end of the third diode D3, one end of the tenth resistor R52, and the... One end of capacitor C15 (eleventh), one end of capacitor C16 (twelfth), one end of capacitor C17 (thirteenth), and one end of LED2 (first light-emitting diode) are connected. The other end of resistor R19 (ninth) is grounded. Pin 6 of the second power supply chip U4 is connected to the other end of capacitor C14 (tenth). Pin 8 of the second power supply chip U4 is connected to the other end of capacitor C10 (eighth), one end of inductor L2 (second), and the other end of diode D3 (third). The other end of inductor L2 is connected to one end of resistor R51 (eleventh), capacitor C15 (eleventh), capacitor C16 (twelfth), capacitor C17 (thirteenth), and LED2 (first light-emitting diode). The other end of resistor R51 (eleventh) is connected to the other end of resistor R52 (tenth).

[0015] Furthermore, the three-stage power supply circuit includes a third power supply chip U14;

[0016] Pin 1 of the third power supply chip U14 is grounded to one end of the fourteenth capacitor C27 and one end of the fifteenth capacitor C31. Pin 2 of the third power supply chip U14 is connected to pin 4 of the third power supply chip U14 and the other end of the fifteenth capacitor C31 and outputs a +3.3V voltage. Pin 3 of the third power supply chip U14 is connected to the other end of the fourteenth capacitor C27, the other end of the twelfth capacitor C18 and the other end of the thirteenth capacitor C17.

[0017] Furthermore, the control unit circuit module includes a control chip U7 and a self-test reset button circuit;

[0018] Pin 1 of the control chip U7 is connected to the +3.3V terminal; pin 3 of the control chip U7 is connected to one end of the sixteenth capacitor C18 and one end of the first resonator X1; pin 4 of the control chip U7 is connected to one end of the seventeenth capacitor C19 and the other end of the first resonator X1; the other ends of the sixteenth capacitor C18 and the seventeenth capacitor C19 are grounded; pin 5 of the control chip U7 is connected to one end of the thirteenth resistor R21, pin 1 of the second resonator X2, and one end of the eighteenth capacitor C20; pin 6 of the control chip U7 is connected to the other end of the thirteenth resistor R21. Pin 3 of the second resonator X2 and one end of the nineteenth capacitor C22 are connected; the other end of the eighteenth capacitor C20 is grounded to pin 4 of the second resonator X2, the other end of the nineteenth capacitor C22, and pin 2 of the second resonator X2; one end of the twentieth capacitor C23 is connected to one end of the twenty-first capacitor C24, one end of the twenty-second capacitor C25, and one end of the twenty-third capacitor C26 to the +3.3V terminal; the other end of the twentieth capacitor C23 is grounded to the other end of the twenty-first capacitor C24, the other end of the twenty-second capacitor C25, and the other end of the twenty-third capacitor C26.

[0019] The self-test reset button circuit is connected to pin 7 of the control chip U7;

[0020] The self-test reset button circuit includes a fourteenth resistor R20, a twenty-fourth capacitor C21, and a reset switch SW2. Pin 7 of the control chip U7 is connected to one end of the fourteenth resistor R20, one end of the twenty-fourth capacitor C21, and one end of the reset switch SW2. The other end of the fourteenth resistor R20 is connected to the +3.3V terminal. The other end of the twenty-fourth capacitor C21 and the other end of the reset switch SW2 are grounded. Pin 44 of the control chip U7 is connected to one end of the twenty-fifth resistor R22. The other end of the twenty-fifth resistor R22 is connected to pin 3 of terminal J2. Pins 1 and 2 of terminal J2 are connected to the +3.3V terminal. Pin 4 of terminal J2 is connected to one end of the twenty-sixth resistor R23. The other end of the twenty-sixth resistor R23 is connected to pin 20 of the control chip U7. Pins 5 and 6 of terminal J2 are grounded.

[0021] Furthermore, the dual leakage detection circuit module includes a first MQ-5 sensor interface circuit and a second MQ-5 sensor interface circuit;

[0022] The first MQ-5 sensor interface circuit includes a 27th resistor R46, a 28th resistor R47, and a 25th capacitor C29. One end of the 27th resistor R46, one end of the 28th resistor R47, and one end of the 25th capacitor C29 are connected to pin 42 of the control chip U7. The other end of the 28th resistor R47 and the other end of the 25th capacitor C29 are grounded. The other end of the 27th resistor R46 is connected to pin 3 of the terminal U12. Pin 1 of the terminal U12 is connected to the +5V terminal, and pin 2 of the terminal U12 is grounded.

[0023] The second MQ-5 sensor interface circuit includes a twenty-ninth resistor R48, a thirtieth resistor R49, and a twenty-sixth capacitor C30. One end of the twenty-ninth resistor R48, one end of the thirtieth resistor R49, and one end of the twenty-sixth capacitor C30 are connected to pin 41 of the control chip U7. The other end of the thirtieth resistor R49 and the other end of the twenty-sixth capacitor C30 are grounded. The other end of the twenty-ninth resistor R48 is connected to pin 3 of the terminal U13. Pin 1 of the terminal U13 is connected to the +5V terminal, and pin 2 of the terminal U13 is grounded.

[0024] Furthermore, the dual leakage detection circuit module includes a first water immersion sensor interface circuit and a second water immersion sensor interface circuit;

[0025] The first water immersion sensor interface circuit includes a terminal U8 and a 31st resistor R24; pin 4 of terminal U8 and one end of the 31st resistor R24 ​​are connected to pin 40 of the control chip U7, and the other end of the 31st resistor R24 ​​is grounded to pin 2 of terminal U8; pin 1 of terminal U8 is connected to the +12V terminal, and pin 3 of terminal U8 is connected to the +3.3V terminal. The second water immersion sensor interface circuit includes a terminal U9 and a 32nd resistor R31; pin 4 of terminal U9 and one end of the 32nd resistor R31 are connected to pin 39 of the control chip U7, and the other end of the 32nd resistor R31 is grounded to pin 2 of terminal U9; pin 1 of terminal U9 is connected to the +12V terminal, and pin 3 of terminal U9 is connected to the +3.3V terminal.

[0026] Furthermore, the terminal lighting circuit module includes a water leakage lighting circuit and a natural gas indicator circuit; the water leakage lighting circuit includes a first transistor Q5, and the collector of the first transistor Q5 is connected to one end of the thirty-fourth resistor R33 and one end of the thirty-third resistor R32, and the other end of the thirty-fourth resistor R33 is connected to pin 11 of the control chip U7, the other end of the thirty-third resistor R32 is grounded to the emitter of the first transistor Q5, the source of the first transistor Q5 is connected to one end of the first light-emitting diode LED3, the other end of the first light-emitting diode LED3 is connected to one end of the second light-emitting diode LED6, the other end of the second light-emitting diode LED6 is connected to one end of the thirty-fifth resistor R50, and the other end of the thirty-fifth resistor R50 is connected to the +12V terminal; the natural gas indicator circuit includes a thirty-sixth resistor R36, and one end of the thirty-sixth resistor R36 is connected to the +3.3V terminal, the other end of the thirty-sixth resistor R36 is connected to one end of the third light-emitting diode LED5, and the other end of the third light-emitting diode LED5 is connected to pin 12 of the control chip U7.

[0027] Furthermore, the terminal alarm circuit module includes a second transistor Q4, a thirty-seventh resistor R27, and a thirty-eighth resistor R29; the collector of the second transistor Q4 is connected to one end of the thirty-seventh resistor R27 and one end of the thirty-eighth resistor R29, the other end of the thirty-seventh resistor R27 is connected to pin 25 of the control chip U7, the emitter of the second transistor Q4 is grounded to the other end of the thirty-eighth resistor R29, the source of the second transistor Q4 is connected to one end of the buzzer BUZZER1, and the other end of the buzzer BUZZER1 is connected to the +5V terminal.

[0028] Furthermore, the first power supply chip U2 and the second power supply chip U4 adopt GBI1450SMAR;

[0029] The third power supply chip U14 uses AMS1117-3.3;

[0030] The control chip U7 uses an STM32F103C8T6, and the water immersion sensor uses a KW2.

[0031] The first tertiary tube Q5 and the second tertiary tube Q4 are both S8050.

[0032] The first light-emitting diode LED3 and the second light-emitting diode LED6 are SSL-LX5093UWC / H;

[0033] The third light-emitting diode, LED5, uses 204-10SDRD / S530-A3 / F182-6B.

[0034] The GSM module's remote communication circuit module uses the SIM800C chip.

[0035] This utility model provides a design circuit for a household natural gas leak and water leak detection and alarm terminal, with the following beneficial effects:

[0036] (1) By using a dual water leakage detection circuit module and a dual leak detection circuit module, dual MQ-5 sensors and water immersion sensors are used to monitor natural gas leaks or water leaks at multiple points. This overcomes the problem that the detection and positioning range of local natural gas leaks / water leaks is small, which affects the accurate location of natural gas leaks / water leaks, thereby improving the accuracy of leak detection.

[0037] (2) By using the GSM module remote communication circuit module, the problem of natural gas leak detection not being able to be remotely alerted was solved by utilizing the communication technology of the GSM module.

[0038] (3) The terminal lighting circuit module provides an interface circuit for LED lighting equipment that corresponds to water leakage lighting or natural gas indication, which facilitates the investigation or repair of water leaks in dark environments.

[0039] (4) The design circuit of the household natural gas leak and water leak detection alarm terminal provided by this utility model integrates the terminal circuit structure for natural gas leak and water leak detection, which solves the problem that the existing detection terminals only have either a natural gas detection terminal or a water leak detection terminal, and the detection equipment is too simple. It is more suitable for places such as family kitchens or company canteens, so as to avoid some water or natural gas leaks from occurring, which may endanger personal safety or cause property damage. Attached Figure Description

[0040] 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 some embodiments of this utility model. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0041] Figure 1 This is a schematic diagram of the design circuit of the household natural gas leak and water leakage detection alarm terminal of this utility model;

[0042] Figure 2 This is the circuit schematic diagram of the multi-stage power supply circuit module in this embodiment;

[0043] Figure 3 This is a circuit diagram of the control unit circuit module in this embodiment;

[0044] Figure 4This is a circuit diagram of the dual leakage detection circuit module in this embodiment;

[0045] Figure 5 This is a circuit diagram of the dual leakage detection circuit module in this embodiment;

[0046] Figure 6 This is the circuit diagram of the self-test reset button circuit in this embodiment;

[0047] Figure 7 This is the circuit diagram of the water leakage lighting circuit in this embodiment;

[0048] Figure 8 This is a circuit diagram of the natural gas indicator circuit in this embodiment;

[0049] Figure 9 This is a circuit diagram of the terminal alarm circuit module in this embodiment;

[0050] Figure 10 This is a circuit diagram of the programming circuit in this embodiment;

[0051] Figure 11 This is a circuit diagram of the remote communication circuit module of the GSM module in this embodiment;

[0052] Figure 12 This is a schematic diagram of the SIM card slot connection circuit in this embodiment;

[0053] Figure 13 This is a schematic diagram of the anti-static circuit for the SIM card slot in this embodiment;

[0054] Figure 14 This is a core structural block diagram of the design circuit for the household natural gas leak and water leakage detection alarm terminal in this embodiment. Detailed Implementation

[0055] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0056] This embodiment provides a design circuit for a household natural gas leak and water leak detection alarm terminal, such as... Figure 1 and Figure 14 As shown, it includes a multi-level power supply circuit module, a control unit circuit module, a GSM module remote communication circuit module, a dual water leakage detection circuit module, a dual leakage detection circuit module, a terminal lighting circuit module, and a terminal alarm circuit module.

[0057] The multi-stage power supply circuit module includes a primary power supply circuit, a secondary power supply circuit, and a tertiary power supply circuit; the output terminal of the primary power supply circuit is electrically connected to the input terminal of the GSM module remote communication circuit module; the output terminal of the secondary power supply circuit is electrically connected to the input terminal of the dual leakage detection circuit module; and the output terminal of the tertiary power supply circuit is electrically connected to the input terminal of the control unit circuit module.

[0058] The control unit circuit module is electrically connected to the dual water leakage detection circuit module, the dual leak detection circuit module, the terminal lighting circuit module, and the terminal alarm circuit module through the I / O interface, respectively.

[0059] The control unit circuit module is used to generate alarm signals and remote prompt signals based on the water or natural gas leak detection results of the dual water leak detection circuit module or the dual leak detection circuit module, and send them to the terminal alarm circuit module and the GSM module remote communication circuit module respectively; the terminal alarm circuit module is used to sound a buzzer warning based on the received alarm signal; the terminal lighting circuit module is used to provide a light source through the control signals issued by the control unit circuit module when detecting / maintaining natural gas and water leaks.

[0060] One end of the GSM module's remote communication circuit module is electrically connected to the control unit circuit module via a UART interface, and the GSM module's remote communication circuit module has an internal GSM antenna. The other end of the GSM module's remote communication circuit module is connected to the mobile client via the GSM antenna. The GSM module's remote communication circuit module receives a remote alert signal and sends it to the mobile client for remote early warning. The method by which the control unit circuit module generates alarm and remote alert signals based on the leakage detection results of the dual leakage detection circuit module or dual leak detection circuit module, and the GSM module's remote communication circuit module receives the remote alert signal and sends it to the mobile client for remote early warning, is a known existing technology. Therefore, this embodiment does not modify the computer program and will not be elaborated further.

[0061] In a specific embodiment, such as Figure 2As shown, the primary power supply circuit includes a first power supply chip U2, which adopts a GB11450SMAR. Pin 1 of the first power supply chip U2 is connected to one end of the first capacitor C1. Pin 2 of the first power supply chip U2 is connected to one end of the first resistor R2, one end of the second capacitor C2, one end of the third capacitor C3, and one end of the first diode D1, all of which are connected to the output pin of the +12V power supply. The other end of the first diode D1 is connected to pin 1 of the first terminal block U1, and pin 2 of the first terminal block U1 is grounded. Pin 3 of the first power supply chip U2 is connected to the other end of the first resistor R2 and one end of the second resistor R4. Pin 4 of the first power supply chip U2 is connected to one end of the third resistor R5. The other end of the third resistor R5 is connected to the other end of the second resistor R4 and the other end of the second capacitor C2. The other end of the third capacitor C3 is grounded. Pin 5 of the first power supply chip U2 is connected to one end of the fourth capacitor C4, pin 7 of the first power supply chip U2, one end of the second diode D2, one end of the fourth resistor R6, one end of the fifth capacitor C5, one end of the sixth capacitor C6, one end of the seventh capacitor C7, and one end of the fifth resistor R8, and the other end of the fifth resistor R8 is grounded. Pin 6 of the first power supply chip U2 is connected to the other end of the fourth capacitor C4. Pin 8 of the first power supply chip U2 is connected to the other end of the first capacitor C1, one end of the first inductor L1, and the other end of the second diode D2. The other end of the first inductor L1 is connected to the other end of the fourth resistor R6, the other end of the fifth capacitor C5, the other end of the sixth capacitor C6, and the other end of the seventh capacitor C7, and pin 9 of the first power supply chip U2 is grounded.

[0062] The secondary power supply circuit includes a second power supply chip U4; the second power supply chip U4 adopts GB11450SMAR; pin 1 of the second power supply chip U4 is connected to one end of the eighth capacitor C10; pin 2 of the second power supply chip U4 is connected to one end of the sixth resistor R13 and one end of the ninth capacitor C13, which are connected to the output pin of the +12V power supply; pin 3 of the second power supply chip U4 is connected to the other end of the sixth resistor R13 and one end of the seventh resistor R15; pin 4 of the second power supply chip U4 is connected to one end of the eighth resistor R16; the other end of the eighth resistor R16, the other end of the seventh resistor R15, and the other end of the ninth capacitor C13 are grounded; pin 5 of the second power supply chip U4 is connected to one end of the ninth resistor R19, one end of the tenth capacitor C14, pin 7 of the second power supply chip U4, and the... One end of diode D3, one end of tenth resistor R52, one end of eleventh capacitor C15, one end of twelfth capacitor C16, one end of thirteenth capacitor C17, and one end of first light-emitting diode LED2 are connected; the other end of ninth resistor R19 is grounded. Pin 6 of second power supply chip U4 is connected to the other end of tenth capacitor C14. Pin 8 of second power supply chip U4 is connected to the other end of eighth capacitor C10, one end of second inductor L2, and the other end of third diode D3. The other end of second inductor L2 is connected to one end of eleventh resistor R51, the other end of eleventh capacitor C15, the other end of twelfth capacitor C16, the other end of thirteenth capacitor C17, and the other end of first light-emitting diode LED2. The other end of eleventh resistor R51 is connected to the other end of tenth resistor R52.

[0063] The three-stage power supply circuit includes a third power supply chip U14; the third power supply chip U14 adopts an AMS1117-3.3; pin 1 of the third power supply chip U14 is grounded to one end of the fourteenth capacitor C27 and one end of the fifteenth capacitor C31; pin 2 of the third power supply chip U14 is connected to pin 4 of the third power supply chip U14 and the other end of the fifteenth capacitor C31 and outputs a +3.3V voltage; pin 3 of the third power supply chip U14 is connected to the other end of the fourteenth capacitor C27, the other end of the twelfth capacitor C18, and the other end of the thirteenth capacitor C17.

[0064] In this embodiment, the multi-stage power supply circuit module mainly provides power to the terminal system. The terminal system input is DC 12V, which can be provided by a commercially available 220V to 12V power adapter or a 12V lithium battery. The terminal system integrates three power conversion chips, outputting 3.3V (three-stage power supply circuit), 4V (two-stage power supply circuit), and 5V (one-stage power supply circuit). The 3.3V mainly powers the STM32 microcontroller (control unit circuit module) and the dual leakage detection circuit module, while the 4V mainly powers the GSM module remote control. The communication circuit module is powered by a 5V power supply, primarily supplying power to the dual leak detection circuit module, namely the natural gas detection sensor (MQ-5). The 4V and 5V power supplies utilize Shenzhen Gubang Electronics' GBI1450SMAR (i.e., the first power supply chip U2 and the second power supply chip U4) power conversion chip. This chip can output a maximum current of 5A and has an input voltage range of 4V-40V (suitable for external lithium batteries; the power chip can still operate normally even when the battery voltage drops). The peripheral circuit design of the GBI1450SMAR power supply is a typical BUCK-type circuit design. The 3.3V power supply uses AMS' AMS1117-3.3(U14) power chip, placed after the 5V power supply. This chip can output a maximum current of 1A and has a maximum input voltage of 15V. The two external capacitors are power supply filter capacitors.

[0065] In a specific embodiment, such as Figure 3 As shown, the control unit circuit module includes a control chip U7 and a self-test reset button circuit. The control chip U7 is an STM32F103C8T6. Pin 1 of the control chip U7 is connected to the +3.3V terminal. Pin 3 of the control chip U7 is connected to one end of the sixteenth capacitor C18 and one end of the first resonator X1. Pin 4 of the control chip U7 is connected to one end of the seventeenth capacitor C19 and the other end of the first resonator X1. The other ends of the sixteenth capacitor C18 and the seventeenth capacitor C19 are grounded. Pin 5 of the control chip U7 is connected to one end of the thirteenth resistor R21, pin 1 of the second resonator X2, and one end of the eighteenth capacitor C20. The connection is as follows: pin 6 of control chip U7 is connected to the other end of the thirteenth resistor R21, pin 3 of the second resonator X2, and one end of the nineteenth capacitor C22; the other end of the eighteenth capacitor C20 is grounded to pin 4 of the second resonator X2, the other end of the nineteenth capacitor C22, and pin 2 of the second resonator X2; one end of the twentieth capacitor C23 is connected to the +3.3V terminal to one end of the twenty-first capacitor C24, one end of the twenty-second capacitor C25, and one end of the twenty-third capacitor C26; the other end of the twentieth capacitor C23 is grounded to the other end of the twenty-first capacitor C24, the other end of the twenty-second capacitor C25, and the other end of the twenty-third capacitor C26.

[0066] The self-test reset button circuit is connected to pin 7 of the control chip U7, such as... Figure 6 As shown, the self-test reset button circuit includes a fourteenth resistor R20, a twenty-fourth capacitor C21, and a reset switch SW2. Pin 7 of the control chip U7 is connected to one end of the fourteenth resistor R20, one end of the twenty-fourth capacitor C21, and one end of the reset switch SW2. The other end of the fourteenth resistor R20 is connected to the +3.3V terminal. The other end of the twenty-fourth capacitor C21 and the other end of the reset switch SW2 are grounded. Pin 44 of the control chip U7 is connected to one end of the twenty-fifth resistor R22. The other end of the twenty-fifth resistor R22 is connected to pin 3 of terminal J2. Pins 1 and 2 of terminal J2 are connected to the +3.3V terminal. Pin 4 of terminal J2 is connected to one end of the twenty-sixth resistor R23. The other end of the twenty-sixth resistor R23 is connected to pin 20 of the control chip U7. Pins 5 and 6 of terminal J2 are grounded.

[0067] Specifically, such as Figure 4 As shown, the dual leakage detection circuit module includes a first MQ-5 sensor interface circuit and a second MQ-5 sensor interface circuit; and the first MQ-5 sensor interface circuit includes a 27th resistor R46, a 28th resistor R47 and a 25th capacitor C29; one end of the 27th resistor R46, one end of the 28th resistor R47 and one end of the 25th capacitor C29 are connected to pin 42 of the control chip U7, the other end of the 28th resistor R47 and the other end of the 25th capacitor C29 are grounded, the other end of the 27th resistor R46 is connected to pin 3 of the terminal U12, pin 1 of the terminal U12 is connected to the +5V terminal, and pin 2 of the terminal U12 is grounded;

[0068] The second MQ-5 sensor interface circuit includes a twenty-ninth resistor R48, a thirtieth resistor R49, and a twenty-sixth capacitor C30. One end of the twenty-ninth resistor R48, one end of the thirtieth resistor R49, and one end of the twenty-sixth capacitor C30 are connected to pin 41 of the control chip U7. The other end of the thirtieth resistor R49 and the other end of the twenty-sixth capacitor C30 are grounded. The other end of the twenty-ninth resistor R48 is connected to pin 3 of the terminal U13. Pin 1 of the terminal U13 is connected to the +5V terminal, and pin 2 of the terminal U13 is grounded.

[0069] Specifically, such as Figure 5As shown, the dual water leakage detection circuit module includes a first water immersion sensor interface circuit and a second water immersion sensor interface circuit. The first water immersion sensor interface circuit includes a terminal U8 and a thirty-first resistor R24. One end of the terminal U8 and the thirty-first resistor R24 ​​is connected to the pin 40 of the control chip U7, and the other end of the thirty-first resistor R24 ​​is grounded to the pin 2 of the terminal U8. The pin 1 of the terminal U8 is connected to the +12V terminal, and the pin 3 of the terminal U8 is connected to the +3.3V terminal. The second water immersion sensor interface circuit includes a terminal U9 and a thirty-second resistor R31. One end of the terminal U9 and the thirty-second resistor R31 is connected to the pin 39 of the control chip U7, and the other end of the thirty-second resistor R31 is grounded to the pin 2 of the terminal U9. The pin 1 of the terminal U9 is connected to the +12V terminal, and the pin 3 of the terminal U9 is connected to the +3.3V terminal.

[0070] Specifically, such as Figures 7 to 8 As shown, the terminal lighting circuit module includes a water leakage lighting circuit and a natural gas indicator circuit. The water leakage lighting circuit includes a first transistor Q5, with the collector of the first transistor Q5 connected to one end of the thirty-fourth resistor R33 and one end of the thirty-third resistor R32. The other end of the thirty-fourth resistor R33 is connected to pin 11 of the control chip U7, and the other end of the thirty-third resistor R32 is grounded to the emitter of the first transistor Q5. The source of the first transistor Q5 is connected to one end of the first light-emitting diode LED3, and the other end of the first light-emitting diode LED3 is connected to one end of the second light-emitting diode LED6. The other end of the second light-emitting diode LED6 is connected to one end of the thirty-fifth resistor R50, and the other end of the thirty-fifth resistor R50 is connected to the +12V terminal. The natural gas indicator circuit includes a thirty-sixth resistor R36, with one end of the thirty-sixth resistor R36 connected to the +3.3V terminal. The other end of the thirty-sixth resistor R36 is connected to one end of the third light-emitting diode LED5, and the other end of the third light-emitting diode LED5 is connected to pin 12 of the control chip U7.

[0071] Specifically, such as Figure 9 As shown, the terminal alarm circuit module includes a second transistor Q4, a thirty-seventh resistor R27, and a thirty-eighth resistor R29. The collector of the second transistor Q4 is connected to one end of the thirty-seventh resistor R27 and one end of the thirty-eighth resistor R29. The other end of the thirty-seventh resistor R27 is connected to pin 25 of the control chip U7. The emitter of the second transistor Q4 is grounded to the other end of the thirty-eighth resistor R29. The source of the second transistor Q4 is connected to one end of the buzzer BUZZER1. The other end of the buzzer BUZZER1 is connected to the +5V terminal.

[0072] In this embodiment, the STM32 system (control unit circuit module) mainly performs the functions of water immersion sensor, natural gas detection sensor, driving water leakage detection LED, natural gas leak indicator light, buzzer alarm drive, self-test reset button, and GSM module UART communication of the GSM module remote communication circuit module. For example, when the water immersion sensor detects a water leak, it will light up the water leakage LED through the dual water leakage detection circuit module and drive the buzzer in the terminal alarm circuit module to sound an alarm, and notify the GSM module to send a notification SMS to indicate the water leak and simultaneously dial a designated phone number; when the natural gas detection sensor detects a natural gas leak, it will light up the natural gas leak indicator light through the natural gas indicator circuit, drive the buzzer to sound an alarm through the terminal alarm circuit module, and notify the GSM module to send a notification SMS to indicate the natural gas leak and simultaneously dial a designated phone number. The water immersion sensor model is KW2 (Chengdu Kejiexun Electronics). When the sensor detects water immersion, the normally open contact of the internal relay closes. The STM32 microcontroller detects the closure of the sensor contact and determines that water immersion has occurred. Two water immersion sensors can be used to detect leaks at two different preset installation locations. That is, when both water immersion sensors detect leaks at the same time, it is confirmed that there is a leak in the household natural gas. If only one water immersion sensor detects a leak, it is confirmed as a false alarm of natural gas leak. In terms of circuit design, the wiring terminals (U8 and U9) of the water immersion sensor have 4 pins. Pin 1 is connected to the +12V terminal and pin 2 GND to power the sensor. Pins 3 and 4 form the normally open contact of the sensor. When the sensor detects water, pins 3 and 4 are in a closed (short circuit) state, so the WATER_DET signal changes from low voltage to high voltage.

[0073] The natural gas detection sensor model is MQ-5 (Shenzhen RISYM Electronics). When butane, propane, methane, and other gases are present in the environment, the MQ-5 has high detection sensitivity. When the natural gas sensors (U12 and U13) detect a natural gas leak, they will change the voltage of the DO signal on sensor pin 3 from high to low. The high voltage of the DO output is 5V. A 20K ohm and a 10K ohm resistor are used to divide the voltage at the end of the DO signal to 3.3V, which can be recognized by the STM32 (control chip U7). Sensor pins 1 and 2 are power supply pins. The natural gas detection also uses two natural gas detection sensors to detect natural gas leaks at two different preset installation locations. That is, when both natural gas detection sensors detect a leak at the same time, it is confirmed that there is a natural gas leak in the household. If only one natural gas detection sensor detects a leak, it is confirmed as a false alarm.

[0074] The STM32 microcontroller drives a water leak lighting LED circuit. When the microcontroller detects a water leak, it activates the LED circuit. This circuit uses dual high-power LEDs, driven by a transistor Q5. When the microcontroller's WATER_LED1 signal outputs a high voltage, transistor Q5 conducts, lighting LED3 and LED6. When the WATER_LED1 signal outputs a low voltage, transistor Q5 is turned off, extinguishing LED3 and LED6. Similarly, a natural gas leak indicator light illuminates LED5 when a natural gas leak is detected. LED5 is activated when the STM32's MQ5_LED2 signal outputs a low voltage.

[0075] The buzzer alarm drive circuit (terminal alarm circuit module) uses a common 5V active buzzer, BUZZER1, which will sound an alarm when a natural gas leak or water leak is detected. The STM32's WATER_ALARM outputs a 2.4kHz periodic square wave signal to drive the second transistor Q4, which in turn drives the buzzer. The first transistor Q5 and the second transistor Q4 are S8050s, the first LED3 and the second LED6 are SSL-LX5093UWC / H, and the third LED5 is a 204-10SDRD / S530-A3 / F182-6B.

[0076] The self-test reset button circuit, when the button (reset switch SW2) is pressed, the RESET pin of the STM32 microcontroller is at a low voltage, the microcontroller enters the reset state, the program will return to the initialization state and then perform the circuit self-test again. The self-test functions include: lighting LED test, lighting natural gas leak indicator test, buzzer alarm test, and GSM module call test. After the self-test, it enters the normal working mode. The computer program and control method of the STM32 microcontroller involved are all existing technologies and will not be described in detail here.

[0077] The STM32 microcontroller (control unit circuit module) and the GSM module remote communication circuit module exchange data via UART communication. The control information for making calls and sending text messages in the GSM module remote communication circuit module comes from the STM32. The STM32 microcontroller used is the low-cost STM32F103C8T6, which has abundant pins, powerful functions, 20kb of SRAM, and 64kb of Flash. The minimum system circuit of the STM32 microcontroller consists of a crystal oscillator circuit (with X1 and X2 peripheral circuits) and a programming circuit (such as...). Figure 10 The circuit consists of the H1 peripheral circuit, the startup configuration circuit (J2 peripheral circuit), and the reset circuit (SW2 peripheral circuit), which meets the basic operating requirements of the STM32 microcontroller.

[0078] like Figures 11 to 13 As shown, the GSM module remote communication circuit module in this embodiment mainly consists of two parts: the SIM800C chip and the SIM card slot. The SIM800C chip is a GSM module chip launched by SIMCom Wireless Technology Co., Ltd., supporting GSM phone calls and GSM SMS functions. It is powerful, secure, and reliable, making it very suitable for applications such as smart meters and security monitoring. Since the SIM800C uses GSM communication, a SIM card needs to be inserted into the card slot; the SIM card can be a standard mobile phone SIM card. Communication between the STM32 microcontroller and the GSM module remote communication circuit module uses UART. However, the operating voltages of the two chips are not the same. In the circuit design, MOSFETs (Q2 and Q3) are used to perform voltage conversion for UART communication. When pin 1 of the GSM module outputs a low voltage, MOSFET Q2 is turned on, and the STM32's USART1_RX pin is also low. When pin 2 of the GSM module outputs a high voltage, MOSFET Q2 is turned off, and the USART1_RX pin of the STM32 is at a high voltage (provided by a 3.3V pull-up resistor R9). J1 is a debugging interface. When the GSM module needs to be tested separately, it can be disconnected from the UART of the STM32 microcontroller. The UART of the GSM module's remote communication circuit can be connected to a computer for debugging. When debugging is complete, short-circuiting J1 with a jumper cap will allow the STM32 microcontroller and the GSM module's remote communication circuit to work normally.

[0079] Specifically, in this embodiment, CARD1 is a SIM card socket, D4 is the electrostatic discharge circuit of the SIM card socket, which can prevent the damage of the GSM module remote communication circuit module caused by inserting or removing the SIM card during the operation of the terminal. Pins 15 to 18 of the GSM module remote communication circuit module are SIM card interfaces, and pin 20 is the reserved interface for the Bluetooth antenna. The signals on connector U6 are all reserved signals and are not used in this embodiment. Pin 32 is the GSM antenna pin, and the GSM antenna interface uses an SMA elbow interface to be able to externally connect a Xiaomi antenna. Pins 34 and 35 are the power supply pins of the GSM module, and the first decoupling capacitor C8 and the second decoupling capacitor C9 are arranged around the pins. Pin 38 is the GSM operation enable signal PWRKEY. When it is necessary to enable the GSM module remote communication circuit module, the STM32 single-chip microcomputer gives a high voltage to the SIM800_PWRKEY signal, and the triode S8050 (Q1) conducts. When the PWRKEY signal is at a low voltage and lasts for more than 1 second, the GSM module remote communication circuit module can be enabled. When it is in the enabled state and the PWRKEY signal is at a low voltage again and lasts for more than 1 second, the GSM module (GSM module remote communication circuit module) can be turned off. There is also a button SW1 in the peripheral circuit of the GSM module to manually power on and power off the GSM module. Pin 41, that is, the NETLIGHT pin, externally connects an LED to indicate the working state of the GSM module remote communication circuit module. When the LED is off, the SIM800 chip is not working; when the LED flashes quickly, the SIM800 chip cannot find the service (no service for the SIM card); when the LED flashes slowly, the SIM800 chip is normally connected to the service signal;

[0080] When making a call, the STM32 single-chip microcomputer sends: ATD + phone number to the GSM module. After 3 minutes of calling, the STM32 single-chip microcomputer sends: ATH to hang up the phone. When sending a text message, the STM32 single-chip microcomputer first sends: AT+CMGF=1 to the GSM module, then sends: AT+CSCS="GSM", then sends: AT+CMGS="phone number", and then receives: > sent by the GSM module, and then the specific text message content can be sent. For example, in this embodiment, for natural gas leakage, it sends: natural gas alarm, and for water leakage, it sends: water leak alarm. If it is necessary to send a text message with Chinese characters, UNICODE code conversion is required. For example, in this embodiment, when sending a Chinese text message: YYROBOT_SIM800 Chinese and English text message sending test, after UNICODE conversion, it is:

[0081] 005900590052004F0042004F0054005F00530049004D0038003000304E2D82F1658777ED4FE153D190016D4B8BD5, and then receive the remote prompt signal through the GSM module remote communication circuit module, and send it to the mobile client for remote early warning. In this embodiment, only the structure of the hardware circuit is designed. The computer control program and control method involved in this embodiment are all existing known technologies and will not be described in detail here.

[0082] The beneficial effects of this utility model are as follows:

[0083] (1) By using a dual water leakage detection circuit module and a dual leak detection circuit module, dual MQ-5 sensors and water immersion sensors are used to monitor natural gas leaks or water leaks at multiple points. This overcomes the problem that the detection and positioning range of local natural gas leaks / water leaks is small, which affects the accurate location of natural gas leaks / water leaks, thereby improving the accuracy of leak detection.

[0084] (2) By using the GSM module remote communication circuit module, the problem of natural gas leak detection not being able to be remotely alerted was solved by utilizing the communication technology of the GSM module.

[0085] (3) The terminal lighting circuit module provides an interface circuit for LED lighting equipment that corresponds to water leakage lighting or natural gas indication, which facilitates the investigation or repair of water leaks in dark environments.

[0086] (4) The design circuit of the household natural gas leak and water leak detection alarm terminal provided by this utility model integrates the terminal circuit structure for natural gas leak and water leak detection, which solves the problem that the existing detection terminals only have either a natural gas detection terminal or a water leak detection terminal, and the detection equipment is too simple. It is more suitable for places such as family kitchens or company canteens, so as to avoid some water or natural gas leaks from occurring, which may endanger personal safety or cause property damage.

[0087] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model, and are not intended to limit it. Although this utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or make equivalent substitutions for some or all of the technical features therein; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this utility model.

Claims

1. A design circuit for a household natural gas leak and water leakage detection alarm terminal, characterized in that, This includes a multi-level power supply circuit module, a control unit circuit module, a GSM module remote communication circuit module, a dual water leakage detection circuit module, a dual leak detection circuit module, a terminal lighting circuit module, and a terminal alarm circuit module. The multi-stage power supply circuit module includes a primary power supply circuit, a secondary power supply circuit, and a tertiary power supply circuit; the output terminal of the primary power supply circuit is electrically connected to the input terminal of the GSM module remote communication circuit module; the output terminal of the secondary power supply circuit is electrically connected to the input terminal of the dual leakage detection circuit module; and the output terminal of the tertiary power supply circuit is electrically connected to the input terminal of the control unit circuit module. The control unit circuit module is electrically connected to the dual water leakage detection circuit module, the dual leak detection circuit module, the terminal lighting circuit module, and the terminal alarm circuit module through the I / O interface, respectively. The control unit circuit module is used to generate alarm signals and remote prompt signals based on the water or natural gas leak detection results of the dual water leak detection circuit module or the dual leak detection circuit module, and send them to the terminal alarm circuit module and the GSM module remote communication circuit module respectively; the terminal alarm circuit module is used to sound a buzzer warning based on the received alarm signal; the terminal lighting circuit module is used to provide a light source through the control signals issued by the control unit circuit module when detecting / maintaining natural gas and water leaks. One end of the GSM module remote communication circuit module is electrically connected to the control unit circuit module via a UART interface, and the GSM module remote communication circuit module is equipped with a GSM antenna inside. The other end of the GSM module remote communication circuit module is connected to the mobile client via the GSM antenna. The GSM module remote communication circuit module receives remote prompt signals and sends them to the mobile client for remote early warning prompts.

2. The design circuit of a household natural gas leak and water leakage detection alarm terminal according to claim 1, characterized in that, The primary power supply circuit includes a first power supply chip U2; Pin 1 of the first power supply chip U2 is connected to one end of the first capacitor C1. Pin 2 of the first power supply chip U2 is connected to one end of the first resistor R2, one end of the second capacitor C2, one end of the third capacitor C3, and one end of the first diode D1, which are all connected to the output pin of the +12V power supply. The other end of the first diode D1 is connected to pin 1 of the first terminal U1, and pin 2 of the first terminal U1 is grounded. Pin 3 of the first power supply chip U2 is connected to the other end of the first resistor R2 and one end of the second resistor R4. Pin 4 of the first power supply chip U2 is connected to one end of the third resistor R5. The other end of the third resistor R5 is grounded along with the other ends of the second resistor R4, the second capacitor C2, and the third capacitor C3. Pin 5 of the first power supply chip U2 is connected to one end of the fourth capacitor C4, pin 7 of the first power supply chip U2, one end of the second diode D2, one end of the fourth resistor R6, one end of the fifth capacitor C5, one end of the sixth capacitor C6, one end of the seventh capacitor C7, and one end of the fifth resistor R8, with the other end of the fifth resistor R8 grounded; pin 6 of the first power supply chip U2 is connected to the other end of the fourth capacitor C4, pin 8 of the first power supply chip U2 is connected to the other end of the first capacitor C1, one end of the first inductor L1, and the other end of the second diode D2, the other end of the first inductor L1 is connected to the other end of the fourth resistor R6, the other end of the fifth capacitor C5, the other end of the sixth capacitor C6, and the other end of the seventh capacitor C7, and pin 9 of the first power supply chip U2 is grounded.

3. The design circuit of a household natural gas leak and water leakage detection alarm terminal according to claim 2, characterized in that, The secondary power supply circuit includes a second power supply chip U4; Pin 1 of the second power supply chip U4 is connected to one end of the eighth capacitor C10. Pin 2 of the second power supply chip U4 is connected to one end of the sixth resistor R13 and one end of the ninth capacitor C13, which are connected to the output pin of the +12V power supply. Pin 3 of the second power supply chip U4 is connected to the other end of the sixth resistor R13 and one end of the seventh resistor R15. Pin 4 of the second power supply chip U4 is connected to one end of the eighth resistor R16. The other end of the eighth resistor R16, the other end of the seventh resistor R15, and the other end of the ninth capacitor C13 are grounded. Pin 5 of the second power supply chip U4 is connected to one end of the ninth resistor R19, one end of the tenth capacitor C14, pin 7 of the second power supply chip U4, one end of the third diode D3, one end of the tenth resistor R52, and the... One end of capacitor C15 (eleventh), one end of capacitor C16 (twelfth), one end of capacitor C17 (thirteenth), and one end of LED2 (first light-emitting diode) are connected. The other end of resistor R19 (ninth) is grounded. Pin 6 of the second power supply chip U4 is connected to the other end of capacitor C14 (tenth). Pin 8 of the second power supply chip U4 is connected to the other end of capacitor C10 (eighth), one end of inductor L2 (second), and the other end of diode D3 (third). The other end of inductor L2 is connected to one end of resistor R51 (eleventh), capacitor C15 (eleventh), capacitor C16 (twelfth), capacitor C17 (thirteenth), and LED2 (first light-emitting diode). The other end of resistor R51 (eleventh) is connected to the other end of resistor R52 (tenth).

4. The design circuit of a household natural gas leak and water leakage detection alarm terminal according to claim 3, characterized in that, The three-level power supply circuit includes a third power supply chip U14; Pin 1 of the third power supply chip U14 is grounded to one end of the fourteenth capacitor C27 and one end of the fifteenth capacitor C31. Pin 2 of the third power supply chip U14 is connected to pin 4 of the third power supply chip U14 and the other end of the fifteenth capacitor C31 and outputs a +3.3V voltage. Pin 3 of the third power supply chip U14 is connected to the other end of the fourteenth capacitor C27, the other end of the twelfth capacitor C18 and the other end of the thirteenth capacitor C17.

5. The design circuit of a household natural gas leak and water leakage detection alarm terminal according to claim 4, characterized in that, The control unit circuit module includes a control chip U7 and a self-test reset button circuit. Pin 1 of the control chip U7 is connected to the +3.3V terminal; pin 3 of the control chip U7 is connected to one end of the sixteenth capacitor C18 and one end of the first resonator X1; pin 4 of the control chip U7 is connected to one end of the seventeenth capacitor C19 and the other end of the first resonator X1; the other ends of the sixteenth capacitor C18 and the seventeenth capacitor C19 are grounded; pin 5 of the control chip U7 is connected to one end of the thirteenth resistor R21, pin 1 of the second resonator X2, and one end of the eighteenth capacitor C20; pin 6 of the control chip U7 is connected to the other end of the thirteenth resistor R21. Pin 3 of the second resonator X2 and one end of the nineteenth capacitor C22 are connected; the other end of the eighteenth capacitor C20 is grounded to pin 4 of the second resonator X2, the other end of the nineteenth capacitor C22, and pin 2 of the second resonator X2; one end of the twentieth capacitor C23 is connected to one end of the twenty-first capacitor C24, one end of the twenty-second capacitor C25, and one end of the twenty-third capacitor C26 to the +3.3V terminal; the other end of the twentieth capacitor C23 is grounded to the other end of the twenty-first capacitor C24, the other end of the twenty-second capacitor C25, and the other end of the twenty-third capacitor C26. The self-test reset button circuit is connected to pin 7 of the control chip U7; The self-test reset button circuit includes a fourteenth resistor R20, a twenty-fourth capacitor C21, and a reset switch SW2. Pin 7 of the control chip U7 is connected to one end of the fourteenth resistor R20, one end of the twenty-fourth capacitor C21, and one end of the reset switch SW2. The other end of the fourteenth resistor R20 is connected to the +3.3V terminal. The other end of the twenty-fourth capacitor C21 and the other end of the reset switch SW2 are grounded. Pin 44 of the control chip U7 is connected to one end of the twenty-fifth resistor R22. The other end of the twenty-fifth resistor R22 is connected to pin 3 of terminal J2. Pins 1 and 2 of terminal J2 are connected to the +3.3V terminal. Pin 4 of terminal J2 is connected to one end of the twenty-sixth resistor R23. The other end of the twenty-sixth resistor R23 is connected to pin 20 of the control chip U7. Pins 5 and 6 of terminal J2 are grounded.

6. The design circuit of a household natural gas leak and water leakage detection alarm terminal according to claim 5, characterized in that, The dual leakage detection circuit module includes a first MQ-5 sensor interface circuit and a second MQ-5 sensor interface circuit; The first MQ-5 sensor interface circuit includes a 27th resistor R46, a 28th resistor R47, and a 25th capacitor C29. One end of the 27th resistor R46, one end of the 28th resistor R47, and one end of the 25th capacitor C29 are connected to pin 42 of the control chip U7. The other end of the 28th resistor R47 and the other end of the 25th capacitor C29 are grounded. The other end of the 27th resistor R46 is connected to pin 3 of the terminal U12. Pin 1 of the terminal U12 is connected to the +5V terminal, and pin 2 of the terminal U12 is grounded. The second MQ-5 sensor interface circuit includes a twenty-ninth resistor R48, a thirtieth resistor R49, and a twenty-sixth capacitor C30. One end of the twenty-ninth resistor R48, one end of the thirtieth resistor R49, and one end of the twenty-sixth capacitor C30 are connected to pin 41 of the control chip U7. The other end of the thirtieth resistor R49 and the other end of the twenty-sixth capacitor C30 are grounded. The other end of the twenty-ninth resistor R48 is connected to pin 3 of the terminal U13. Pin 1 of the terminal U13 is connected to the +5V terminal, and pin 2 of the terminal U13 is grounded.

7. The design circuit of a household natural gas leak and water leakage detection alarm terminal according to claim 6, characterized in that, The dual leakage detection circuit module includes a first water immersion sensor interface circuit and a second water immersion sensor interface circuit. The first water immersion sensor interface circuit includes a terminal U8 and a 31st resistor R24; pin 4 of terminal U8 and one end of the 31st resistor R24 ​​are connected to pin 40 of the control chip U7, and the other end of the 31st resistor R24 ​​is grounded to pin 2 of terminal U8; pin 1 of terminal U8 is connected to the +12V terminal, and pin 3 of terminal U8 is connected to the +3.3V terminal. The second water immersion sensor interface circuit includes a terminal U9 and a 32nd resistor R31; pin 4 of terminal U9 and one end of the 32nd resistor R31 are connected to pin 39 of the control chip U7, and the other end of the 32nd resistor R31 is grounded to pin 2 of terminal U9; pin 1 of terminal U9 is connected to the +12V terminal, and pin 3 of terminal U9 is connected to the +3.3V terminal.

8. The design circuit of a household natural gas leak and water leakage detection alarm terminal according to claim 7, characterized in that, The terminal lighting circuit module includes a water leakage lighting circuit and a natural gas indicator circuit. The water leakage lighting circuit includes a first transistor Q5, with the collector of the first transistor Q5 connected to one end of the thirty-fourth resistor R33 and one end of the thirty-third resistor R32. The other end of the thirty-fourth resistor R33 is connected to pin 11 of the control chip U7, and the other end of the thirty-third resistor R32 is grounded to the emitter of the first transistor Q5. The source of the first transistor Q5 is connected to one end of the first light-emitting diode LED3, and the other end of the first light-emitting diode LED3 is connected to one end of the second light-emitting diode LED6. The other end of the second light-emitting diode LED6 is connected to one end of the thirty-fifth resistor R50, and the other end of the thirty-fifth resistor R50 is connected to the +12V terminal. The natural gas indicator circuit includes a thirty-sixth resistor R36, with one end of the thirty-sixth resistor R36 connected to the +3.3V terminal. The other end of the thirty-sixth resistor R36 is connected to one end of the third light-emitting diode LED5, and the other end of the third light-emitting diode LED5 is connected to pin 12 of the control chip U7.

9. The design circuit of a household natural gas leak and water leakage detection alarm terminal according to claim 8, characterized in that, The terminal alarm circuit module includes a second transistor Q4, a thirty-seventh resistor R27, and a thirty-eighth resistor R29. The collector of the second transistor Q4 is connected to one end of the thirty-seventh resistor R27 and one end of the thirty-eighth resistor R29. The other end of the thirty-seventh resistor R27 is connected to pin 25 of the control chip U7. The emitter of the second transistor Q4 is grounded to the other end of the thirty-eighth resistor R29. The source of the second transistor Q4 is connected to one end of the buzzer BUZZER1. The other end of the buzzer BUZZER1 is connected to the +5V terminal.

10. The design circuit of a household natural gas leak and water leakage detection alarm terminal according to claim 9, characterized in that, The first power supply chip U2 and the second power supply chip U4 adopt GBI1450SMAR; The third power supply chip U14 is an AMS1117-3.3; The control chip U7 is an STM32F103C8T6, and the water immersion sensor is a KW2. The first tertiary tube Q5 and the second tertiary tube Q4 are both S8050. The first light-emitting diode LED3 and the second light-emitting diode LED6 are SSL-LX5093UWC / H; The third light-emitting diode LED5 is 204-10SDRD / S530-A3 / F182-6B; The GSM module's remote communication circuit module uses the SIM800C chip.

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