An abnormality detection alarm circuit for household electrical equipment

Abstract

This utility model discloses an abnormality detection and alarm circuit for household electrical equipment, including an AC input circuit, a power supply module, an MCU control module, a signal detection module, an AC detection module, and an alarm module. The AC input circuit supplies power to the equipment and circuits and provides front-end protection. The power supply module rectifies and regulates the AC power to DC +5V to power each module. The signal detection module collects AC current signals, and the AC detection module collects AC voltage signals; both output the detection signals to the MCU control module. The MCU control module processes and analyzes the signals. When an abnormality in current / voltage is detected, it controls the alarm module to activate the alarm and simultaneously indicates the status via an indicator light. This utility model provides comprehensive detection, timely response, stable circuitry, low cost, and strong adaptability. It can be integrated into most household electrical equipment, effectively improving electrical safety. Furthermore, it can be upgraded via a programmer interface, offering strong expandability.

Description

Technical Field

[0001] This utility model relates to the field of electrical equipment testing technology, specifically to an abnormality detection alarm circuit for household electrical equipment. Background Technology

[0002] With the improvement of residents' living standards, the types and number of household electrical appliances have increased significantly, and their operational safety has become a core concern for household electricity use. At present, most household electrical appliances rely only on their own built-in simple overcurrent protection (such as fuses), lacking the ability to continuously monitor real-time current fluctuations and voltage anomalies (overvoltage / undervoltage) during operation. When equipment experiences sudden current increases or voltage over-limits due to factors such as aging wiring, abnormal loads, or grid voltage fluctuations, traditional protection mechanisms often can only cut off the circuit after the fault occurs, failing to provide early warning. Moreover, some equipment faults have no obvious symptoms in the early stages, which can easily lead to short circuits, fires, equipment burnout, and other safety accidents due to failure to detect them in time, seriously threatening the safety of users' lives and property.

[0003] In the existing technology, a few commercial electrical devices are equipped with dedicated testing devices, but such devices are usually complex in structure, expensive, and mostly designed for industrial scenarios. They are large in size and inconvenient to install, making it difficult to adapt to the miniaturization and low-cost requirements of household electrical devices.

[0004] Therefore, there is an urgent need for a simple, low-cost, accurate, and real-time alarm circuit for detecting abnormalities in household electrical equipment to fill the gap in existing technology. Summary of the Invention

[0005] To address the issues of existing household electrical appliances lacking real-time anomaly detection and early warning functions, and the poor compatibility of existing detection devices, this utility model provides an anomaly detection and alarm circuit for household electrical appliances. It enables synchronous monitoring of AC current and voltage of household electrical appliances, analyzes data in real time through an MCU, and quickly triggers an alarm when an anomaly is detected, thereby improving electrical safety.

[0006] To solve the above-mentioned technical problems, this utility model provides the following solution: An abnormality detection alarm circuit for household electrical equipment, comprising: The power module has an input terminal connected to an AC input circuit and outputs DC. An MCU control module, the power input terminal of which is electrically connected to the output terminal of the power module, is used for data acquisition, data processing, and control output; The signal detection module has its electrical input terminal connected to the AC input circuit for detecting AC current signals, and its signal output terminal connected to the signal receiving pin of the MCU control module. An AC detection module is provided, whose electrical input terminal is connected to the AC input circuit and is used to detect AC voltage signals. Its signal output terminal is connected to the signal receiving pin of the MCU control module. The alarm module is electrically connected to the MCU control module. The MCU control module processes and analyzes the received signals, and when it detects abnormal data, it controls the alarm module to start.

[0007] Furthermore, the MCU control module includes an MCU processor U1; The MCU processor U1 has a capacitor C1 connected in series with its 6th pin VDD and is connected to a +5V voltage. The other end of the capacitor C1 is grounded. Pin 13 PA9 of the MCU processor U1 is electrically connected to the negative terminal of LED D1. The positive terminal of LED D1 is connected to the first end of resistor R4, and the second end of resistor R4 is connected to +5V voltage. The MCU processor U1 outputs the AD1 circuit at pin 11, PA7; The MCU processor U1 outputs the AD8 circuit from pin 16 PA15; The PWM circuit is output at pin 10 PA6 of the MCU processor U1.

[0008] Furthermore, the AC input circuit includes a connector CN1, one end of which is connected to one end of a varistor VR1 and the 4th interface of an inductor L2, the other end of which is connected to one end of a fuse F1, and the other end of which is connected to one end of a current sensor NT15D-9. The other end of the current sensor NT15D-9 is connected to one end of capacitor CX1, one end of connector CN2, the other end of varistor VR1, and the 3rd interface of inductor L2. The other end of capacitor CX1 is connected to one end of connector CN2. The 1st interface of inductor L2 is connected to the 2nd interface of bridge rectifier diode. The 2nd interface of inductor L2 is connected to the 1st interface of bridge rectifier diode. The bridge rectifier diode converts AC to DC output. The power module includes a power management chip U3; The power management chip U3 has one port connected to one end of capacitor C6, one end of capacitor C7, the negative terminal of diode D4, and one end of resistor R13. The 2nd port of the power management chip U3 is connected to one end of resistor R18 and one end of resistor R16. The 4th port of the power management chip U3 is connected to one end of resistor RS1. The 5th port and its 6th port of the power management chip U3 are interconnected and then connected to the 4th port of the primary coil of transformer T1 and the positive terminal of diode D3. The other ends of capacitor C6, capacitor C7, resistor R18 and resistor RS1 are all connected to the 3rd port of the bridge rectifier diode. The positive terminal of diode D4 is connected to one end of resistor R15, the other ends of resistors R15 and R16 are connected to the grounding coil 7 port of transformer T1, and the other end of resistor R13 is connected to one end of resistor R10. The negative terminal of diode D3 is connected to one end of capacitor C3 and one end of resistor R11. The primary coil 1 port of transformer T1, the other end of resistor R11, the other end of capacitor C3, and the other end of resistor R10 are all connected to the 4th port of bridge rectifier diode. The secondary coil 6 port of transformer T1 is connected to the positive terminal of diode D2. An electrolytic capacitor EC1, a resistor R12, and an electrolytic capacitor C4 are connected in parallel between the negative terminal of diode D2 and the secondary coil 5 port of transformer T1. The negative terminal of diode D2 outputs a +5V voltage. The signal detection module includes an operational amplifier comparator U2A; The operational amplifier comparator U2A has its output terminal at port 1, which is connected to one end of resistor R3 and one end of resistor R7 respectively. The 2-port of the operational amplifier comparator U2A is the inverting input terminal. Its inverting input terminal is connected to one end of resistor R8 and the other end of resistor R3 respectively. The other end of resistor R8 is connected to one end of resistor R9 and one end of inductor L1. The other end of resistor R9 is connected to the other end of inductor L1. The other end of resistor R7 is connected to the AD8 circuit and is connected to one end of capacitor C2. The 3rd port of the operational amplifier comparator U2A is the non-inverting input, and its non-inverting input and its 4th port are grounded; The other end of capacitor C2 is grounded; The AC detection module includes a series circuit consisting of resistors R14, R17, and R19 connected in sequence. The first end of the series circuit is connected to the L-line circuit output by the connector CN1, and the second end is grounded. Resistor R19 is connected in parallel with capacitor C5. The circuit node between resistors R17 and R19 is electrically connected to the AD1 circuit. The alarm module includes a buzzer, transistor Q1, resistors R1, R2, R5, and R6; The buzzer has two pins. The first pin is connected to a +5V voltage. A resistor R1 is connected between the first pin and the second pin. The first end of the resistor R1 is connected to a +5V voltage, and the second end is connected to a resistor R2. The other end of the resistor R2 is connected to the collector of the transistor Q1. The emitter of the transistor Q1 is grounded, and a resistor R6 is connected between its base and its emitter. The base of the transistor Q1 is connected to a resistor R5, and the other end of the resistor R5 is connected to the PWM circuit.

[0009] Furthermore, the anomaly detection alarm circuit also includes a programmer interface J1, which is connected to the MCU processor U1.

[0010] Compared with the prior art, the beneficial effects of this utility model are: 1. Comprehensive detection of abnormality alarm circuit of this utility model: It can simultaneously monitor the AC current and voltage signals of household electrical equipment, covering common abnormal scenarios such as overcurrent, overvoltage, and undervoltage, avoiding the limitations of single detection.

[0011] The anomaly detection alarm circuit of this utility model has a timely response: it adopts an MCU as the core control unit to collect and process detection signals in real time, and immediately triggers a buzzer alarm when an anomaly occurs. Compared with the traditional "fault-based disconnection" protection method, it can provide early warning and reduce the risk of accidents.

[0012] The abnormal detection alarm circuit of this utility model is stable: the AC input circuit has built-in fuses for overcurrent protection and varistors for overvoltage protection, the power supply module adopts multi-stage filtering and voltage regulation design, and the signal detection module optimizes signal quality through operational amplifiers and RC filtering to ensure stable operation of the circuit in complex power grid environments.

[0013] This utility model's abnormal detection alarm circuit is low in cost: it uses discrete components and general-purpose chips to build the circuit, resulting in low cost, small size, and compatibility with the installation needs of most household electrical appliances.

[0014] This utility model's anomaly detection alarm circuit has strong scalability: the MCU program can be flexibly upgraded through the programmer interface J1, and a Bluetooth / WiFi module can be added in the future to realize remote alarm via mobile APP, improving the user experience. Attached Figure Description

[0015] Figure 1 This is a block diagram of the abnormal detection alarm circuit of this utility model.

[0016] Figure 2 This is the AC input circuit diagram of this utility model.

[0017] Figure 3 This is the circuit diagram of the power supply module of this utility model.

[0018] Figure 4 This is a circuit diagram of the signal detection module of this utility model.

[0019] Figure 5 This is the circuit diagram of the AC detection module of this utility model.

[0020] Figure 6 This is the circuit diagram of the MCU control module of this utility model.

[0021] Figure 7 This is the circuit diagram of the alarm module of this utility model. Detailed Implementation

[0022] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments, so that the advantages and features of the present utility model can be more easily understood by those skilled in the art, thereby making a clearer and more definite definition of the protection scope of the present utility model. Obviously, the embodiments described in this utility model are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of the present utility model.

[0023] Furthermore, the technical features involved in the different embodiments of this utility model described below can be combined with each other as long as they do not conflict with each other.

[0024] Example 1: The specific structure of this utility model is as follows: Please refer to the appendix. Figure 1 An abnormality detection alarm circuit for household electrical equipment includes: The power module has an input terminal connected to the AC input circuit, and its output is DC. The AC input circuit serves as the AC power input for the entire circuit and also provides operating power for household electrical appliances. It has built-in overcurrent and overvoltage protection components to ensure the safety of the front-end circuit. The power module rectifies and regulates the AC power output from the AC input circuit to a DC +5V voltage, providing a stable operating power for the MCU control module, signal detection module, and alarm module. The MCU control module has its power input terminal electrically connected to the output terminal of the power supply module. It is used for data acquisition, data processing, and control output. The MCU control module is the core control unit. Its power input terminal is electrically connected to the +5V output terminal of the power supply module. It is connected to the output terminals of the signal detection module and the AC detection module through the signal receiving pin. It is used to acquire current and voltage detection signals, perform AD conversion and data processing on the signals, and connect to the alarm module through the control output pin to realize alarm control in case of abnormality. The signal detection module has its electrical input terminal connected to the AC input circuit for detecting the AC current signal, and its signal output terminal connected to the signal receiving pin of the MCU control module. It is used to acquire the current signal in the AC input circuit, amplify and filter it, and then output it to the signal receiving pin of the MCU control module. An AC detection module is included. Its electrical input terminal is connected to the AC input circuit to detect AC voltage signals. Its signal output terminal is connected to the signal receiving pin of the MCU control module. The voltage signal in the AC input circuit is acquired through a resistor voltage divider method, filtered, and then output to the signal receiving pin of the MCU control module. The alarm module is electrically connected to the MCU control module. The MCU control module processes and analyzes the received signals. When it detects abnormal data, it controls the alarm module to start. When the MCU control module detects abnormal current or voltage data, the alarm module receives the control signal from the MCU and starts the alarm.

[0025] The MCU control module includes an MCU processor U1, which is a microcontroller, and the microcontroller model can be an STM32 series microcontroller; the MCU is connected to the load device, such as a brushless motor or lighting equipment.

[0026] The MCU processor U1 has a capacitor C1 connected in series with its 6th pin VDD and connected to a +5V voltage. The other end of the capacitor C1 is grounded; this achieves power filtering and ensures stable power supply to the MCU.

[0027] Pin 13 PA9 of the MCU processor U1 is electrically connected to the negative terminal of LED D1. The positive terminal of LED D1 is connected to the first end of resistor R4, and the second end of resistor R4 is connected to +5V voltage; thus forming a working status indicator light. D1 lights up when the device is running normally, and flashes in conjunction with the alarm module when there is an abnormality.

[0028] The MCU processor U1 outputs an AD1 circuit at pin 11 (PA7) to receive the voltage detection signal from the AC detection module.

[0029] The MCU processor U1 outputs an AD8 circuit at pin 16 PA15; this circuit is used to receive the current detection signal from the signal detection module.

[0030] The PWM circuit output at pin 10 PA6 of the MCU processor U1 is used to output control signals to the alarm module.

[0031] The AC input circuit includes connector CN1, which is used to connect to a household 220V AC power grid. Terminal 1 of connector CN1 is connected to one end of varistor VR1 and pin 4 of inductor L2. Terminal 2 of connector CN1 is connected to one end of fuse F1, and the other end of fuse F1 is connected to one end of current sensor NT15D-9. Fuse F1 provides overcurrent protection, and current sensor NT15D-9 is used to collect circuit current.

[0032] The other end of the current sensor NT15D-9 is connected to one end of capacitor CX1, one end of connector CN2, the other end of varistor VR1, and interface 3 of inductor L2. Capacitor CX1 suppresses common-mode interference. Connector CN2 is used to connect household electrical appliances. The other end of capacitor CX1 is connected to one end of connector CN2. Interface 1 of inductor L2 is connected to interface 2 of bridge rectifier diode, and interface 2 of inductor L2 is connected to interface 1 of bridge rectifier diode. Inductor L2 filters out high-frequency interference from the power grid. The bridge rectifier diode converts AC to DC output, which is then sent to the power module.

[0033] The power module includes a power management chip U3; the power management chip U3 can be a UC3842 series chip.

[0034] The power management chip U3 has one port connected to one end of capacitor C6, one end of capacitor C7, the negative terminal of diode D4, and one end of resistor R13. The 2nd port of the power management chip U3 is connected to one end of resistor R18 and one end of resistor R16. The 4th port of the power management chip U3 is connected to one end of resistor RS1. The 5th port and its 6th port of the power management chip U3 are interconnected and then connected to the 4th port of the primary coil of transformer T1 and the positive terminal of diode D3. The other ends of capacitor C6, capacitor C7, resistor R18 and resistor RS1 are all connected to the 3rd port of the bridge rectifier diode. The positive terminal of diode D4 is connected to one end of resistor R15, the other ends of resistors R15 and R16 are connected to the grounding coil 7 port of transformer T1, and the other end of resistor R13 is connected to one end of resistor R10. The negative terminal of diode D3 is connected to one end of capacitor C3 and one end of resistor R11. The primary coil port 1 of transformer T1, the other end of resistor R11, the other end of capacitor C3, and the other end of resistor R10 are all connected to port 4 of the bridge rectifier diode. The secondary coil port 6 of transformer T1 is connected to the positive terminal of diode D2. An electrolytic capacitor EC1, resistor R12, and electrolytic capacitor C4 are connected in parallel between the negative terminal of diode D2 and port 5 of the secondary coil of transformer T1. The negative terminal of diode D2 outputs a +5V voltage. Electrolytic capacitor EC1 and capacitor C4 are used for filtering to ensure stable output voltage.

[0035] The signal detection module includes an operational amplifier comparator U2A; the operational amplifier comparator U2A can be an LM324 series operational comparator.

[0036] The operational amplifier comparator U2A has its output terminal at port 1, which is connected to one end of resistor R3 and one end of resistor R7.

[0037] The 2-port of the operational amplifier comparator U2A is the inverting input. Its inverting input is connected to one end of resistor R8 and the other end of resistor R3. The other end of resistor R8 is connected to one end of resistor R9 and one end of inductor L1. The other end of resistor R9 is connected to the other end of inductor L1. The other end of resistor R7 is connected to the AD8 circuit and to one end of capacitor C2. Inductor L1 and resistor R9 form a filter circuit to suppress noise in the current signal.

[0038] The 3rd port of the operational amplifier comparator U2A is the non-inverting input, and its non-inverting input and its 4th port are grounded; The other end of capacitor C2 is grounded; capacitor C2 further filters the signal to ensure the stability of the current detection signal.

[0039] The AC detection module includes a series circuit consisting of resistors R14, R17, and R19 connected in sequence. The first end of the series circuit is connected to the L-line circuit output by the connector CN1, and the second end is grounded. The L-line circuit is connected here to collect the grid voltage.

[0040] A capacitor C5 is connected in parallel with resistor R19, and the circuit node between resistors R17 and R19 is electrically connected to the AD1 circuit. Capacitor C5 serves to filter and reduce voltage signal fluctuations. The AD1 circuit outputs the divided voltage signal to the MCU processor U1.

[0041] The alarm module includes a buzzer, transistor Q1, resistors R1, R2, R5, and R6; The buzzer has two pins. The first pin is connected to a +5V voltage, and a resistor R1 is connected between the first pin and the second pin for current limiting protection. The first end of the resistor R1 is connected to a +5V voltage, the second end is connected to a resistor R2, and the other end of the resistor R2 is connected to the collector of the transistor Q1. The emitter of the transistor Q1 is grounded, and a resistor R6 is connected between its base and its emitter. Resistor R6 is a pull-down resistor to prevent the transistor from being accidentally triggered.

[0042] The base of transistor Q1 is connected to resistor R5, and the other end of resistor R5 is connected to the PWM circuit. When the MCU detects an abnormality, it outputs a high-level PWM signal through pin PA6 to drive transistor Q1 to conduct, and the buzzer is powered on to emit an alarm sound.

[0043] The anomaly detection alarm circuit also includes a programmer interface J1, which is connected to the MCU processor U1. This interface is used for programming the MCU and subsequent upgrades, improving the circuit's flexibility and maintainability.

[0044] Example 2: The working principle of the anomaly detection alarm circuit of this utility model is as follows (hereinafter, the MCU processor U1 is referred to as MCU): Power connection and supply: The household 220V AC power grid is connected to the AC input circuit through connector CN1. After passing through fuse F1 (rated current 10A) and current sensor NT15D-9, one path supplies power to household electrical equipment through connector CN2, and the other path outputs DC power to the power module after filtering by inductor L2 and rectification by bridge rectifier diode.

[0045] In the power module, the power management chip U3 (model UC3842) drives the transformer T1 to convert the rectified DC power into low-voltage AC power. After being rectified by diode D2 and filtered by electrolytic capacitors EC1 / C4, a stable +5V DC power is output to power the MCU processor U1 (model STM32F103C8T6), the op-amp comparator U2A (model LM324), and the alarm module.

[0046] Signal Acquisition and Processing: Current Signal Acquisition: The current in the AC input circuit is converted into a voltage signal by the current sensor NT15D-9. The filter circuit composed of inductor L1 and resistor R9 in the input signal detection module filters out high-frequency noise and sends it to the inverting input terminal (port 2) of the op-amp comparator U2A. The op-amp comparator U2A compares and amplifies this signal with the reference voltage at the non-inverting input terminal (port 3, ground), and then filters it twice through resistor R7 and capacitor C2 before inputting it to the MCU through the AD8 circuit (PA15 pin of the MCU).

[0047] Voltage signal acquisition: The L-line voltage of the AC input circuit is divided by resistors R14, R17, and R19 (voltage division ratio 1000:1, reducing the 220V voltage to 0.22V to match the MCU's AD sampling range), filtered by capacitor C5, and then input to the MCU through the AD1 circuit (MCU's PA7 pin). The MCU performs AD conversion on the acquired current and voltage signals, converting the analog signals into digital signals, and compares them with preset normal thresholds (such as current threshold 0.5-10A, voltage threshold 180-240V).

[0048] Anomaly detection and alarm: When the MCU detects a current > 10A (overcurrent), voltage > 240V (overvoltage), or voltage < 180V (undervoltage), it determines an abnormal state: Control pin 13 (PA9 pin) outputs a high / low level signal to make LED D1 flash (frequency 1Hz) to indicate a device malfunction; Control pin 10 (PA6 pin) outputs a high-level PWM signal, which is fed to the base of transistor Q1 after current limiting by resistor R5, making transistor Q1 conduct; The buzzer obtains current through resistors R1 and R2 and emits a continuous alarm sound (volume ≥ 80dB) to remind the user to disconnect the power and check in time.

[0049] In summary, the anomaly detection alarm circuit of this utility model has comprehensive detection capabilities: it can simultaneously monitor the AC current and voltage signals of household electrical equipment, covering common anomaly scenarios such as overcurrent, overvoltage, and undervoltage, thus avoiding the limitations of single detection.

[0050] The anomaly detection alarm circuit of this utility model has a timely response: it adopts an MCU as the core control unit to collect and process detection signals in real time, and immediately triggers a buzzer alarm when an anomaly occurs. Compared with the traditional "fault-based disconnection" protection method, it can provide early warning and reduce the risk of accidents.

[0051] The abnormal detection alarm circuit of this utility model is stable: the AC input circuit has built-in fuses for overcurrent protection and varistors for overvoltage protection, the power supply module adopts multi-stage filtering and voltage regulation design, and the signal detection module optimizes signal quality through operational amplifiers and RC filtering to ensure stable operation of the circuit in complex power grid environments.

[0052] This utility model's abnormal detection alarm circuit is low in cost: it uses discrete components and general-purpose chips to build the circuit, resulting in low cost, small size, and compatibility with the installation needs of most household electrical appliances.

[0053] This utility model's anomaly detection alarm circuit has strong scalability: the MCU program can be flexibly upgraded through the programmer interface J1, and a Bluetooth / WiFi module can be added in the future to realize remote alarm via mobile APP, improving the user experience.

[0054] The above description is only a preferred embodiment of the present utility model and does not limit the patent scope of the present utility model. Any equivalent structural or procedural transformations made based on the contents of the present utility model specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of the present utility model.

Claims

1. An abnormality detection alarm circuit for household electrical equipment, characterized in that, include: The power module has an input terminal connected to an AC input circuit and outputs DC. The MCU control module has its power input terminal electrically connected to the output terminal of the power module, and is used for data acquisition, data processing, and control output. The signal detection module has its electrical input terminal connected to the AC input circuit for detecting AC current signals, and its signal output terminal connected to the signal receiving pin of the MCU control module. An AC detection module is provided, whose electrical input terminal is connected to the AC input circuit and is used to detect AC voltage signals. Its signal output terminal is connected to the signal receiving pin of the MCU control module. The alarm module is electrically connected to the MCU control module. The MCU control module processes and analyzes the received signals, and when it detects abnormal data, it controls the alarm module to start.

2. The fault detection alarm circuit for household electrical equipment according to claim 1, characterized in that: The MCU control module includes an MCU processor U1; The MCU processor U1 has a capacitor C1 connected in series with its 6th pin VDD and is connected to a +5V voltage. The other end of the capacitor C1 is grounded. The MCU processor U1 has its 13th pin PA9 electrically connected to the negative terminal of LED D1. The positive terminal of LED D1 is connected to the first end of resistor R4, and the second end of resistor R4 is connected to a +5V voltage. The MCU processor U1 outputs the AD1 circuit at pin 11, PA7; The MCU processor U1 outputs the AD8 circuit from pin 16 PA15; The PWM circuit is output at pin 10 PA6 of the MCU processor U1.

3. The abnormal detection alarm circuit for household electrical equipment according to claim 2, characterized in that: The AC input circuit includes a connector CN1. One end of the connector CN1 is connected to one end of the varistor VR1 and the 4th interface of the inductor L2. The other end of the connector CN1 is connected to one end of the fuse F1. The other end of the fuse F1 is connected to one end of the current sensor NT15D-9. The other end of the current sensor NT15D-9 is connected to one end of capacitor CX1, one end of connector CN2, the other end of varistor VR1, and the 3rd interface of inductor L2. The other end of capacitor CX1 is connected to one end of connector CN2. The 1st interface of inductor L2 is connected to the 2nd interface of bridge rectifier diode. The 2nd interface of inductor L2 is connected to the 1st interface of bridge rectifier diode. The bridge rectifier diode converts AC to DC output. The power module includes a power management chip U3; The power management chip U3 has one port connected to one end of capacitor C6, one end of capacitor C7, the negative terminal of diode D4, and one end of resistor R13. The 2nd port of the power management chip U3 is connected to one end of resistor R18 and one end of resistor R16. The 4th port of the power management chip U3 is connected to one end of resistor RS1. The 5th port and its 6th port of the power management chip U3 are interconnected and then connected to the 4th port of the primary coil of transformer T1 and the positive terminal of diode D3. The other ends of capacitor C6, capacitor C7, resistor R18 and resistor RS1 are all connected to the 3rd port of the bridge rectifier diode. The positive terminal of diode D4 is connected to one end of resistor R15, the other ends of resistors R15 and R16 are connected to the grounding coil 7 port of transformer T1, and the other end of resistor R13 is connected to one end of resistor R10. The negative terminal of diode D3 is connected to one end of capacitor C3 and one end of resistor R11. The primary coil 1 port of transformer T1, the other end of resistor R11, the other end of capacitor C3, and the other end of resistor R10 are all connected to the 4th port of bridge rectifier diode. The secondary coil 6 port of transformer T1 is connected to the positive terminal of diode D2. An electrolytic capacitor EC1, a resistor R12, and an electrolytic capacitor C4 are connected in parallel between the negative terminal of diode D2 and the secondary coil 5 port of transformer T1. The negative terminal of diode D2 outputs a +5V voltage. The signal detection module includes an operational amplifier comparator U2A; The operational amplifier comparator U2A has its output terminal at port 1, which is connected to one end of resistor R3 and one end of resistor R7 respectively. The 2-port of the operational amplifier comparator U2A is the inverting input terminal. Its inverting input terminal is connected to one end of resistor R8 and the other end of resistor R3 respectively. The other end of resistor R8 is connected to one end of resistor R9 and one end of inductor L1. The other end of resistor R9 is connected to the other end of inductor L1. The other end of resistor R7 is connected to the AD8 circuit and is connected to one end of capacitor C2. The 3rd port of the operational amplifier comparator U2A is the non-inverting input, and its non-inverting input and its 4th port are grounded; The other end of capacitor C2 is grounded; The AC detection module includes a series circuit consisting of resistors R14, R17, and R19 connected in sequence. The first end of the series circuit is connected to the L-line circuit output by the connector CN1, and the second end is grounded. Resistor R19 is connected in parallel with capacitor C5. The circuit node between resistors R17 and R19 is electrically connected to the AD1 circuit. The alarm module includes a buzzer, transistor Q1, resistors R1, R2, R5, and R6; The buzzer has two pins. The first pin is connected to a +5V voltage. A resistor R1 is connected between the first pin and the second pin. The first end of the resistor R1 is connected to a +5V voltage, and the second end is connected to a resistor R2. The other end of the resistor R2 is connected to the collector of the transistor Q1. The emitter of the transistor Q1 is grounded, and a resistor R6 is connected between its base and its emitter. The base of the transistor Q1 is connected to a resistor R5, and the other end of the resistor R5 is connected to the PWM circuit.

4. The abnormal detection alarm circuit for household electrical equipment according to claim 2, characterized in that: The anomaly detection alarm circuit also includes a programmer interface J1, which is connected to the MCU processor U1.

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