A non-contact leakage detection device

Abstract

The present invention relates to a non-contact leakage detection device, which includes a single-chip microcomputer module, an RC filtering detection circuit, an amplifying circuit, a signal processing module, an alarm circuit module, and a power supply module. The RC filtering detection circuit includes an operational amplifier U2, pins 1 to 8 provided on the operational amplifier U2, a second-path signal detection circuit, and a first-path signal detection circuit. During use, the first and second-path signal detection circuits are used to detect whether there is leakage in the live wire electric field voltage or the floating ground voltage. During this detection process, the first-path signal detection circuit and the second-path signal detection circuit are isolated and set, and the electric fields generated by the floating ground voltage and the live wire are respectively detected in a dynamic non-contact manner to determine whether there is leakage in the electric water heater or the water heater, thereby being able to avoid potential safety hazards to consumers caused by the failure of the leakage switch.

Description

[Technical field]

[0001] The invention relates to a non-contact leakage detection device used in the technical field of electric water heaters. [Background technology]

[0002] Electric water heaters have become an indispensable part of the daily life of some consumers. The function of the electric water heaters in the prior art is to convert electrical energy into thermal energy, that is, to convert cold water into hot water for consumers to use. In the process of energy conversion, since the electric water heater uses electrical energy as the energy source, leakage is inevitable. In order to eliminate or prevent the electric water heater from causing harm to consumers due to leakage during use, generally, the electric water heater adopts a leakage alarm device to achieve this purpose. Although the leakage alarm device can prevent or eliminate the leakage from causing harm to consumers, since the device is protected by a contact leakage switch, if the leakage switch fails or the neutral wire and ground wire in the leakage switch are connected reversely, the leakage protection function is lost, thereby bringing safety hazards to consumers. [Summary of the invention]

[0003] In view of this, the technical problem to be solved by the present invention is to provide a non-contact leakage detection device which can avoid the potential safety hazard to consumers caused by the failure of the leakage switch.

[0004] To solve the above technical problems, the technical solution of the present invention provides a non-contact leakage detection device, which is applied to an electric water heater or a water heater, and includes a single-chip microcomputer module, an RC filter detection circuit, an amplifier circuit, a signal processing module, an alarm circuit module, and a power supply module; the output end of the RC filter detection circuit is connected to the input end of the amplifier circuit, the output end of the amplifier circuit is connected to the input end of the signal processing module, the output end of the signal processing module is connected to the input end of the single-chip microcomputer module, and the output end of the single-chip microcomputer module is connected to the input end of the alarm circuit module; the output end of the power supply module is respectively connected to the signal processing module, the single-chip microcomputer module, and the alarm circuit module; The RC filter detection circuit includes an operational amplifier U2, which is arranged on pins 1 to 8 of the operational amplifier U2, a first signal detection circuit for detecting the live wire electric field voltage and a second signal detection circuit for detecting the floating ground voltage connected to pins 1 to 8 of the operational amplifier U2; the first signal detection circuit is isolated from the second signal detection circuit; when the RC filter detection circuit collects AC voltage signals and amplifies the collected signals through the amplifier circuit and transmits them to the signal processing module, if the voltage is abnormal after analysis and processing by the single-chip microcomputer module, pin 1 on the single-chip microcomputer module sends a high level, driving the LED1 in the alarm circuit module to light up and alarm.

[0005] Further defined, the single-chip microcomputer module includes an operational amplifier U1, pins 1 to 64 provided on the operational amplifier U1, a resistor R2 and a resistor R3 connected in series between pin 1 and pin 2, and the common end of the resistor R2 and the resistor R3 is grounded; a resistor R1 and a capacitor C1 connected to pin 3, the resistor R1 and the capacitor C1 are connected in series, one end of the resistor R1 is connected to the power supply terminal, and the other end of the capacitor C1 is grounded; push-button switches CAL and power push-button switch POWER connected to pins 5 and 6 respectively, a capacitor C2 connected to pin 13, capacitors C3, C4, and C5 respectively connected to pins 22, 25, and 26; a capacitor C6 connected to pin 63; wherein, the input VDDA voltage of the single-chip microcomputer module is filtered by the capacitor C3 to provide a stable voltage for the RC filtering detection circuit.

[0006] Further defined, the first signal detection circuit includes a resistor R14 and a capacitor C9 connected to pin 6, the resistor R14 and the capacitor C9 are connected in series; resistors R11, R12, and R13 connected to the other end of the capacitor C9, the resistor R12 and the resistor R13 are connected in series, and the resistor R11 is connected in parallel across the two ends of the resistor R12 and the resistor R13; a capacitor C10 and a resistor R16 connected to pin 7, the capacitor C10 and the resistor R16 are connected in series, and the other end of the resistor R16 is connected to a first power supply terminal SGND, a reference resistor R15 connected between pin 6 and pin 7; when the resistor R11 at the first power supply terminal SGND receives a signal, and then passes through a filter formed by the resistor R12, the resistor R13, and the capacitor C9, after being processed by the filter, it enters the operational amplifier U2 for amplification processing, taking the parameter value obtained by the resistor R15 as the amplification parameter value, and after the operational amplifier U2 finishes the amplification processing, it enters the capacitor C10 and the resistor R16 for filtering and then enters the operational amplifier U2 for signal processing.

[0007] Further defined, the second signal detection circuit includes a resistor R7 and a capacitor C7 connected to pin 2, the resistor R7 and the capacitor C7 are connected in series; resistors R4, R5, and R6 connected to the other end of the capacitor C7, the resistor R5 and the resistor R6 are connected in series, and the resistor R4 is connected in parallel across the two ends of the resistor R5 and the resistor R6, and the other end of the resistor R6 is grounded; a capacitor C8 and a resistor R10 connected to pin 1, the capacitor C8 and the resistor R10 are connected in series, the other end of the capacitor C8 is connected to a second power supply terminal SGND, a reference resistor R8 connected between pin 1 and pin 2; when the resistor R4 at the second power supply terminal SGND receives a signal, and then passes through a filter formed by the resistor R5, the resistor R6, and the capacitor C7, after being processed by the filter, it enters the operational amplifier U2 for amplification processing, taking the parameter value obtained by the resistor R8 as the amplification parameter value, and after the operational amplifier U2 finishes the amplification processing, it enters the capacitor C8 and the resistor R10 for filtering and then enters the operational amplifier U2 for signal processing.

[0008] Further defined, the power supply module includes chip U7, pins 1 to 3 provided on chip U7; capacitors C12, C13, C14, C15, C16 respectively connected in parallel between pin 3 and pin 1, one end of capacitor C12 is connected to the VCC1 terminal, capacitor C11 connected in series between pin 2 and pin 1, one end of capacitor C11 is connected to the BATT terminal, and the other end of capacitor C11 is grounded; the power supply module consists of chip U7, capacitors C11 to C16 to form a voltage stabilizing and filtering circuit; when the power is connected to both ends of capacitor C11 for filtering, and then regulated to 3.3V by chip U7, and then filtered by capacitors C12, C13, C14, C15, C16, a clean and stable 3.3V voltage is obtained to supply power to the operational amplifier U1, enabling the operational amplifier U1 to work properly.

[0009] Further defined, the alarm module includes LED1 indicator light, resistor R17 connected to one end of LED1 indicator light, and the other end of LED1 indicator light is grounded.

[0010] The beneficial technical effects of the present invention: Since the output end of the RC filtering detection circuit of this technical solution is connected to the input end of the amplification circuit, the output end of the amplification circuit is connected to the input end of the signal processing module, the output end of the signal processing module is connected to the input end of the single-chip microcomputer module, and the output end of the single-chip microcomputer module is connected to the input end of the alarm circuit module; the output end of the power supply module is respectively connected to the signal processing module, the single-chip microcomputer module, and the alarm circuit module to form the leakage detection device. The RC filtering detection circuit in this leakage detection device includes operational amplifier U2, pins 1 to 8 provided on operational amplifier U2, and a second signal detection circuit and a first signal detection circuit connected to pins 1 to 8 of operational amplifier U2. When in use, the first signal detection circuit is used to detect whether there is leakage in the live wire electric field voltage, and the second signal detection circuit is used to detect whether there is leakage in the floating ground voltage. When the RC filtering detection circuit collects an AC voltage signal and amplifies the collected signal through the amplification circuit and transmits it to the signal processing module, if the voltage is abnormal after analysis and processing by the single-chip microcomputer module, then a high level is emitted from pin 1 on the single-chip microcomputer module, driving the LED1 light in the alarm circuit module to light up and alarm. During this detection process, the first signal detection circuit and the second signal detection circuit are isolated, and the electric fields generated by the floating ground voltage and the live wire are respectively detected in a dynamic non-contact manner to determine whether the electric water heater or the water heater is leaking, thereby being able to avoid potential safety hazards to consumers caused by the failure of the leakage switch.

[0011] Next, in combination with the drawings and embodiments, the technical solution of the present invention will be further described in detail.

Description of the Drawings

[0012] Figure 1 It is a schematic structural diagram of the electric water heater in the present invention;

[0013] Figure 2 It is a block schematic diagram of the non-contact leakage detection device in the present invention;

[0014] Figure 3 It is a circuit diagram of the single-chip microcomputer module in the present invention;

[0015] Figure 4 It is a circuit diagram of the RC filter detection circuit in the present invention;

[0016] Figure 5 It is a circuit diagram of the power supply module in the present invention;

[0017] Figure 6 It is a circuit diagram of the alarm circuit module in the present invention.

Specific Embodiment

[0018] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention clearer and more understandable, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0019] Please refer to Figures 1 to 6 As shown, a non-contact leakage detection device will be described below in conjunction with an embodiment. The non-contact leakage detection device is applied to an electric water heater. The electric water heater includes an electric water heater shell 1, an inner tank 2 installed inside the electric water heater shell 1, an inlet and outlet water pipe 3 installed at the bottom of the inner tank 2, a metal magnesium rod 4 installed at the bottom of the inner tank 2, a heating pipe 5 provided at the bottom of the inner tank 2, a temperature control module provided inside the electric water heater, and a non-contact leakage detection device provided inside the electric water heater shell 1 and connected to the temperature control module. The non-contact leakage detection device described in this embodiment includes a single-chip microcomputer module, an RC filter detection circuit, an amplification circuit, a signal processing module, an alarm circuit module, and a power supply module.

[0020] The single-chip microcomputer module includes an operational amplifier U1, pins 1 to 64 provided on the operational amplifier U1, a resistor R2 and a resistor R3 connected in series between pin 1 and pin 2, and the common end of the resistor R2 and the resistor R3 is grounded; a resistor R1 and a capacitor C1 connected to pin 3, the resistor R1 and the capacitor C1 are connected in series, one end of the resistor R1 is connected to the power supply terminal, and the other end of the capacitor C1 is grounded; a key switch CAL and a power key switch POWER respectively connected to pin 5 and pin 6, a capacitor C2 connected to pin 13, and capacitors C3, C4, and C5 respectively connected to pin 22, pin 25, and pin 26; a capacitor C6 connected to pin 63; wherein, the input VDDA voltage of the single-chip microcomputer module is filtered by the capacitor C3 to provide a stable voltage for the RC filtering detection circuit.

[0021] The RC filtering detection circuit includes an operational amplifier U2, pins 1 to 8 provided on the operational amplifier U2, a first signal detection circuit for detecting the live wire electric field voltage and a second signal detection circuit for detecting the floating ground voltage connected to pins 1 to 8 of the operational amplifier U2; the first signal detection circuit and the second signal detection circuit are isolated.

[0022] The first signal detection circuit includes a resistor R14 and a capacitor C9 connected to pin 6, the resistor R14 and the capacitor C9 are connected in series; a resistor R11, a resistor R12, and a resistor R13 connected to the other end of the capacitor C9, the resistor R12 and the resistor R13 are connected in series, and the resistor R11 is connected in parallel across the resistor R12 and the resistor R13; a capacitor C10 and a resistor R16 connected to pin 7, the capacitor C10 and the resistor R16 are connected in series, the other end of the resistor R16 is connected to a first power supply terminal SGND, and a reference resistor R15 connected between pin 6 and pin 7; when the resistor R11 at the first power supply terminal SGND receives a signal, it passes through a filter formed by the resistor R12, the resistor R13, and the capacitor C9, and after being processed by the filter, it enters the operational amplifier U2 for amplification processing, obtains a parameter value as the amplification parameter value with the resistor R15, and after being amplified by the operational amplifier U2, it enters the capacitor C10 and the resistor R16 for filtering and then enters the signal processing of the operational amplifier U2.

[0023] The second path signal detection circuit includes a resistor R7 and a capacitor C7 connected to pin 2, with the resistor R7 and the capacitor C7 connected in series; resistors R4, R5, and R6 connected to the other end of the capacitor C7, with the resistor R5 and the resistor R6 connected in series, the resistor R4 connected in parallel across the two ends of the resistor R5 and the resistor R6, and the other end of the resistor R6 grounded; a capacitor C8 and a resistor R10 connected to pin 1, with the capacitor C8 and the resistor R10 connected in series, the other end of the capacitor C8 connected to a second power supply terminal SGND, and a reference resistor R8 connected between pin 1 and pin 2; when the resistor R4 at the second power supply terminal SGND receives a signal, it passes through a filter formed by the resistor R5, the resistor R6, and the capacitor C7. After being processed by this filter, it enters the operational amplifier U2 for amplification processing, and the parameter value obtained by the resistor R8 is the amplification parameter value. After being amplified by the operational amplifier U2, it then enters the capacitor C8 and the resistor R10 for filtering and then enters the signal processing of the operational amplifier U2.

[0024] The power supply module includes a chip U7, pins 1 to 3 provided on the chip U7; capacitors C12, C13, C14, C15, and C16 respectively connected in parallel between pin 3 and pin 1, with one end of the capacitor C12 connected to the VCC1 terminal, a capacitor C11 connected in series between pin 2 and pin 1, one end of the capacitor C11 connected to the BATT terminal, and the other end of the capacitor C11 grounded; the power supply module consists of the chip U7 and the capacitors C11 to C16 to form a voltage stabilization and filtering circuit; when the power supply is connected to both ends of the capacitor C11 for filtering, and then regulated to 3.3V by the chip U7, and then filtered by the capacitors C12, C13, C14, C15, and C16, a clean and stable 3.3V voltage is obtained to supply power to the operational amplifier U1, enabling the operational amplifier U1 to work properly.

[0025] The alarm module includes an LED1 indicator light and a resistor R17 connected to one end of the LED1 indicator light, with the other end of the LED1 indicator light grounded.

[0026] During installation, the output end of the RC filtering detection circuit is connected to the input end of the amplification circuit, the output end of the amplification circuit is connected to the input end of the signal processing module, the output end of the signal processing module is connected to the input end of the single-chip microcomputer module, and the output end of the single-chip microcomputer module is connected to the input end of the alarm circuit module; the output end of the power supply module is respectively connected to the signal processing module, the single-chip microcomputer module, and the alarm circuit module. When the RC filtering detection circuit collects an AC voltage signal and amplifies the collected signal through the amplification circuit and transmits it to the signal processing module, if the voltage is abnormal after being analyzed and processed by the single-chip microcomputer module, then a high level is emitted from pin 1 on the single-chip microcomputer module, driving the LED1 light in the alarm circuit module to light up and give an alarm.

[0027] In this embodiment, the power supply part inside the electric water heater includes the power supply for the electric water heater and the power supply for the detection device. That is, the power supply for the detection device is isolated from the power supply for the water heater. The isolation methods include transformer isolation and isolation by using dry batteries or lithium batteries for power supply, which means that the power supply for the detection device uses dry batteries, lithium batteries or the power after mains voltage transformation, and the power supply for the water heater uses the power after mains voltage transformation. The voltage of the isolated power supply relative to the power supply is not fixed, that is, the power supply for the detection device is not fixed relative to the power supply for the electric water heater, which is the floating ground voltage. During detection, the electric field voltage generated by the live wire is detected through the first detection circuit, and the electric field generated by the floating ground voltage is detected through the second signal detection circuit, so as to judge whether there is a leakage phenomenon in the electric water heater. The first signal detection circuit can also detect the electric field generated by the floating ground voltage, and the second signal detection circuit can also detect the electric field generated by the live wire.

[0028] During the detection by the first signal detection circuit, after the external signal is received on the resistor R11, the external signal is filtered through the resistors R12, R13 and the capacitor C9, and then enters the inside of the operational amplifier U2 through the resistor R14. The parameter value obtained by the resistor R15 is used as the amplification reference value for amplification processing. After the amplification processing, it enters the capacitor C10 and the resistor R16 for filtering processing, and then enters the operational amplifier U2 for signal processing.

[0029] During the detection by the second signal detection circuit, after the external signal is received on the resistor R4, the external signal is filtered through the resistors R5, R6 and the capacitor C7, and then enters the inside of the operational amplifier U2 through the resistor R7. The parameter value obtained by the resistor R8 is used as the amplification reference value for amplification processing. After the amplification processing, it enters the capacitor C8 and the resistor R10 for filtering processing, and then enters the operational amplifier U2 for signal processing. After the signals detected by the first signal detection circuit and the second signal detection circuit both enter the operational amplifier, the single-chip microcomputer module will compare and analyze the two signals inside, and then judge whether the measured voltage is normal according to the analysis result. If it is abnormal, an alarm will be issued. When the operational amplifier U1 analyzes that the voltage is in an abnormal state, the pin 7 of the operational amplifier U1 emits a high level, driving the LED1 in the alarm module to be lit, and at the same time releasing an alarm sound. During this detection process, the first signal detection circuit and the second signal detection circuit are isolated. The electric fields generated by the floating ground voltage and the live wire are respectively detected in a dynamic non-contact manner, so as to judge whether the electric water heater or the water heater leaks, avoiding the phenomenon in the prior art that it is impossible to effectively distinguish whether the power supplies of the electric water heater or the water heater itself and the power supply of the detection device are both leaking, thus being able to avoid potential safety hazards to consumers caused by the failure of the leakage switch.

[0030] In summary, in this technical solution, the output end of the RC filtering detection circuit is connected to the input end of the amplification circuit, the output end of the amplification circuit is connected to the input end of the signal processing module, the output end of the signal processing module is connected to the input end of the single-chip microcomputer module, and the output end of the single-chip microcomputer module is connected to the input end of the alarm circuit module; the output end of the power supply module is respectively connected to the signal processing module, the single-chip microcomputer module, and the alarm circuit module to form the leakage detection device. The RC filtering detection circuit in the leakage detection device includes an operational amplifier U2, pins 1 to 8 provided on the operational amplifier U2, a second signal detection circuit and a first signal detection circuit connected to pins 1 to 8 of the operational amplifier U2. During use, the first signal detection circuit is used to detect whether there is leakage in the live wire electric field voltage, and the second signal detection circuit is used to detect whether there is leakage in the floating ground voltage. When the RC filtering detection circuit collects an AC voltage signal and amplifies the collected signal through the amplification circuit and transmits it to the signal processing module, if the voltage is abnormal after analysis and processing by the single-chip microcomputer module, then pin 1 on the single-chip microcomputer module emits a high level, driving the LED1 light in the alarm circuit module to light up and give an alarm. During this detection process, the first signal detection circuit and the second signal detection circuit are isolated, and the electric fields generated by the floating ground voltage and the live wire are respectively detected in a dynamic non-contact manner to determine whether there is leakage in the electric water heater or the water heater, avoiding the phenomenon in the prior art that it is impossible to effectively distinguish whether there is leakage in both the power supply of the electric water heater or the water heater itself and the power supply of the detection device, thereby being able to avoid potential safety hazards to consumers caused by the failure of the leakage switch.

[0031] The preferred embodiments of the present invention have been described above with reference to the accompanying drawings, and the scope of the rights of the present invention is not limited thereby. Any modifications, equivalent replacements, and improvements made by those skilled in the art without departing from the scope and essence of the present invention shall fall within the scope of the rights of the present invention.

Claims

1. A non-contact leakage detection device is applied to an electric water heater or a water heater. It is characterized in that: It includes a single-chip microcomputer module, an RC filter detection circuit, an amplifier circuit, a signal processing module, an alarm circuit module, and a power supply module; the output end of the RC filter detection circuit is connected to the input end of the amplifier circuit, the output end of the amplifier circuit is connected to the input end of the signal processing module, the output end of the signal processing module is connected to the input end of the single-chip microcomputer module, and the output end of the single-chip microcomputer module is connected to the input end of the alarm circuit module; the output end of the power supply module is respectively connected to the signal processing module, the single-chip microcomputer module, and the alarm circuit module. The RC filter detection circuit includes an operational amplifier U2, a first signal detection circuit for detecting the live wire electric field voltage and a second signal detection circuit for detecting the floating ground voltage which are arranged on pins 1 to 8 of the operational amplifier U2 and connected to pins 1 to 8 of the operational amplifier U2; the first signal detection circuit and the second signal detection circuit are isolated; when the RC filter detection circuit collects an AC voltage signal and amplifies the collected signal through the amplifier circuit and transmits it to the signal processing module, if the voltage is abnormal after the analysis and processing by the single-chip microcomputer module, then a high level is sent out from pin 1 of the single-chip microcomputer module, driving the LED1 lamp in the alarm circuit module to light up and alarm. The first signal detection circuit includes a resistor R14 and a capacitor C9 connected to pin 6, the resistor R14 and the capacitor C9 are connected in series; resistors R11, R12, and R13 connected to the other end of the capacitor C9, the resistor R12 and the resistor R13 are connected in series, and the resistor R11 is connected in parallel at both ends of the resistor R12 and the resistor R13; a capacitor C10 and a resistor R16 connected to pin 7, the capacitor C10 and the resistor R16 are connected in series, the other end of the resistor R16 is connected to a first power supply terminal SGND, and a reference resistor R15 connected between pin 6 and pin 7; when the resistor R11 at the first power supply terminal SGND receives a signal, and then passes through a filter formed by the resistors R12, R13, and the capacitor C9, after being processed by this filter, it enters the operational amplifier U2 for amplification processing, takes the resistor R15 to obtain a parameter value as the amplification parameter value, and after the amplification processing by the operational amplifier U2, it enters the capacitor C10 and the resistor R16 for filtering and then enters the signal processing of the operational amplifier U2. The second path signal detection circuit includes a resistor R7 and a capacitor C7 connected to pin 2, with the resistor R7 and the capacitor C7 connected in series; resistors R4, R5, and R6 connected to the other end of the capacitor C7, with the resistor R5 and the resistor R6 connected in series, the resistor R4 connected in parallel across the two ends of the resistor R5 and the resistor R6, and the other end of the resistor R6 grounded; a capacitor C8 and a resistor R10 connected to pin 1, with the capacitor C8 and the resistor R10 connected in series, the other end of the capacitor C8 connected to a second power supply terminal SGND, and a reference resistor R8 connected between pin 1 and pin 2; when the resistor R4 at the second power supply terminal SGND receives a signal, it passes through a filter formed by the resistor R5, the resistor R6, and the capacitor C7. After being processed by this filter, it enters the operational amplifier U2 for amplification processing, obtaining a parameter value as the amplification parameter value with the resistor R8. After the amplification processing by the operational amplifier U2, it then enters the capacitor C8 and the resistor R10 for filtering and then enters the operational amplifier U2 for signal processing; The single-chip microcomputer module includes an operational amplifier U1, pins 1 to 64 provided on the operational amplifier U1, a resistor R2 and a resistor R3 connected in series between pin 1 and pin 2, with the common end of the resistor R2 and the resistor R3 grounded; a resistor R1 and a capacitor C1 connected to pin 3, with the resistor R1 and the capacitor C1 connected in series, one end of the resistor R1 connected to the power supply terminal and the other end of the capacitor C1 grounded; push-button switches CAL and POWER switch connected to pins 5 and 6 respectively, a capacitor C2 connected to pin 13, and capacitors C3, C4, and C5 connected to pins 22, 25, and 26 respectively; a capacitor C6 connected to pin 63; among them, the input VDDA voltage of the single-chip microcomputer module is filtered by the capacitor C3 to provide a stable voltage for the RC filtering detection circuit; The power supply module includes a chip U7, pins 1 to 3 provided on the chip U7; capacitors C12, C13, C14, C15, and C16 connected in parallel between pins 3 and 1 respectively, one end of the capacitor C12 connected to the VCC1 terminal, a capacitor C11 connected in series between pins 2 and 1, one end of the capacitor C11 connected to the BATT terminal and the other end of the capacitor C11 grounded; the power supply module is composed of the chip U7, the capacitor C11 to the capacitor C16 to form a voltage stabilization and filtering circuit; when the power supply is connected to both ends of the capacitor C11 for filtering, and then regulated to 3.3V by the chip U7, and then filtered by the capacitors C12, C13, C14, C15, and C16, a clean and stable 3.3V voltage is obtained to supply power to the operational amplifier U1 so that the operational amplifier U1 can work normally; The alarm circuit module includes an LED1 indicator light and a resistor R17 connected to one end of the LED1 indicator light, with the other end of the LED1 indicator light grounded.

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