Anti-misconnection protection circuit and protection indication panel for household electrical appliance

Abstract

The utility model discloses a household electrical appliance anti-misconnection protection circuit and a protection indication panel, which are characterized in that a first detection circuit, a second detection circuit and a third detection circuit are arranged to respectively detect the wiring between every two of a live wire, a zero wire and a ground wire, and a processing unit carries out comprehensive analysis according to feedback signals of the first detection circuit, the second detection circuit and the third detection circuit; the circuit can accurately judge the fault types of null line open circuit, null line and live line reverse connection and ground wire failure of a current electric appliance, can detect abnormal signals at the end of the electric appliance at the first time when the fault occurs, and can immediately reflect fault information to a user through the alarm circuit, so as to solve the blind area of the existing home-entry protection switch. Active and real-time detection and local early warning of dangerous wiring faults are achieved at an electric appliance end, meanwhile, the power supply electricity taking circuit can still obtain a stable low-voltage direct-current power supply when wiring abnormity occurs, a reliable and stable working power supply is provided for a processing unit and other circuits, and it is ensured that the detection and early warning functions do not fail.

Description

Technical Field

[0001] The utility model relates to the technical field of protection switches, in particular to a household appliance anti-misconnection protection circuit and a protection indicator panel. Background Art

[0002] Common circuit failure types of household appliances include missing neutral, reverse connection of neutral and hot wire, grounding failure, etc. Among them, the broken neutral wire causes abnormal voltage increase and burns the electrical winding; the reverse connection of neutral and hot wire makes the outer casing of the appliance accidentally charged (such as the metal casing of a water heater), which causes electric shock when touched, and even the leakage protection may fail; the ground wire is disconnected or poorly connected, and when leakage occurs, the current cannot be conducted into the ground, and the human body can easily become a conductive path, causing the risk of electric shock.

[0003] Currently, the fault protection of household appliances during use relies on the house switch, such as air switches, over-voltage and under-voltage switches, and leakage protection switches. For some household appliances, this protection mechanism has some blind spots, resulting in the inability to provide wiring fault indication and warning in the first time. Often, power failures are discovered only after the house switch is disconnected, and the fault point needs to be investigated. Timely warnings and protection cannot be provided at the source of the fault (i.e., the appliance end), posing a hidden danger to household electricity safety. In addition, when setting up a protection circuit at the appliance end, it is also necessary to consider whether the protection circuit can provide stable power supply support for the circuit under voltage fluctuations and misconnection, as well as the size and component cost of the overall circuit.

[0004] In view of this, there is an urgent need to design a household appliance anti-misconnection protection circuit and a protection indicator panel to provide reliable and timely misconnection warning from the appliance end. Utility Model Content

[0005] In order to solve the above problems, the utility model provides a household appliance anti-misconnection protection circuit and a protection indicator panel.

[0006] In a first aspect of the present utility model, a household appliance anti-misconnection protection circuit is provided, comprising a power supply terminal, wherein the power supply terminal comprises a live wire terminal, a neutral wire terminal and a ground wire terminal, and further comprising a processing unit, a power supply circuit, a transient protection circuit, a first detection circuit, a second detection circuit, a third detection circuit and an alarm circuit; the transient protection circuit is connected to the power supply terminal, the input end of the power supply circuit is respectively connected to the live wire terminal, the neutral wire terminal and the ground wire terminal, the output end of the power supply circuit is connected to the power supply terminal of the processing unit, the input end of the first detection circuit is respectively connected to the live wire terminal and the neutral wire terminal, the input end of the second detection circuit is respectively connected to the live wire terminal and the ground wire terminal, the input end of the third detection circuit is respectively connected to the neutral wire terminal and the ground wire terminal, the output ends of the first detection circuit, the second detection circuit and the third detection circuit are respectively connected to the input end of the processing unit, and the output end of the processing unit is connected to the input end of the alarm circuit.

[0007] Based on the first aspect, in a possible implementation, the transient protection circuit includes a first varistor RV1 and a second varistor RV2, wherein the two ends of the first varistor RV1 are respectively connected to the neutral wire terminal and the ground wire terminal, and the two ends of the second varistor RV2 are respectively connected to the neutral wire terminal and the live wire terminal.

[0008] Based on the first aspect, in a possible implementation, the power supply circuit includes a first diode, a second diode, a first resistor, a second resistor, a third resistor, a fourth resistor, a first capacitor, a second capacitor, a third capacitor and a TVS diode, the positive electrode of the first diode is connected to the live wire terminal, the positive electrode of the second diode is connected to the ground wire terminal, the negative electrode of the first diode and the negative electrode of the second diode are both connected to the first end of the first resistor, the second end of the first resistor is connected to the negative electrode of the TVS diode, the positive electrode of the TVS diode is connected to the neutral wire terminal, the second resistor, the third resistor and the fourth resistor are respectively connected in parallel at both ends of the first resistor, the first capacitor, the second capacitor and the third capacitor are respectively connected in parallel at both ends of the TVS diode, and the working voltage is output at both ends of the third capacitor.

[0009] Based on the first aspect, in a possible implementation manner, the third capacitor is an electrolytic capacitor, and the first capacitor and the second capacitor are thin film capacitors.

[0010] Based on the first aspect, in a possible implementation, the first detection circuit includes a first unidirectional current limiting circuit and a first isolation circuit, the first end of the first unidirectional current limiting circuit is connected to the live wire terminal, and the second end of the first unidirectional current limiting circuit and the neutral wire terminal are respectively connected to the first isolation circuit; the second detection circuit includes a second unidirectional current limiting circuit and a second isolation circuit, the first end of the second unidirectional current limiting circuit is connected to the live wire terminal, and the second end of the second unidirectional current limiting circuit and the ground wire terminal are respectively connected to the second isolation circuit; the third detection circuit includes a third unidirectional current limiting circuit and a third isolation circuit, the first end of the third unidirectional current limiting circuit is connected to the neutral wire terminal, and the second end of the third unidirectional current limiting circuit and the ground wire terminal are respectively connected to the third isolation circuit.

[0011] Based on the first aspect, in a possible implementation, the first isolation circuit, the second isolation circuit and the third isolation circuit are all optocouplers; the second end of the first unidirectional current limiting circuit is connected to the positive pole of the first isolation circuit, the neutral line terminal is connected to the negative pole of the first isolation circuit, the collector of the first isolation circuit is connected to the input end of the processing unit, and the emitter of the first isolation circuit is grounded; the second end of the second unidirectional current limiting circuit is connected to the positive pole of the second isolation circuit, the ground line terminal is connected to the negative pole of the second isolation circuit, the collector of the second isolation circuit is connected to the input end of the processing unit, and the emitter of the second isolation circuit is grounded; the second end of the third unidirectional current limiting circuit is connected to the positive pole of the third isolation circuit, the ground line terminal is connected to the negative pole of the third isolation circuit, the collector of the third isolation circuit is connected to the input end of the processing unit, and the emitter of the third isolation circuit is grounded.

[0012] Based on the first aspect, in a possible implementation, the first unidirectional current limiting circuit, the second unidirectional current limiting circuit, and the third unidirectional current limiting circuit all include a diode and a current limiting resistor connected in series.

[0013] Based on the first aspect, in a possible implementation, the alarm circuit includes a first alarm circuit and a second alarm circuit, the input ends of the first alarm circuit and the second alarm circuit are respectively connected to the output end of the processing unit, the first alarm circuit is used to indicate that the electrical wiring is normal, and the second alarm circuit is used to indicate that the electrical wiring is abnormal.

[0014] Based on the first aspect, in a possible implementation, the first alarm circuit and the second alarm circuit both include a light emitting diode (LED) and a current limiting resistor connected in series.

[0015] In a second aspect of the present invention, a protection indicator panel is provided, comprising the above-mentioned household appliance anti-misconnection protection circuit.

[0016] Compared with the prior art, the technical solution provided by this utility model has the following beneficial effects:

[0017] In the technical solution, the household appliance anti-misconnection protection circuit is provided with a first detection circuit, a second detection circuit, and a third detection circuit to respectively detect the connection between the live wire, the neutral wire, and the ground wire. The processing unit performs a comprehensive analysis based on the feedback signals of the first detection circuit, the second detection circuit, and the third detection circuit to accurately determine the current fault type of the appliance, such as the neutral wire circuit break, the neutral-live wire reverse connection, and the ground wire failure. The circuit can detect the abnormal signal at the appliance end as soon as the fault (such as the neutral wire circuit break, the neutral-live wire reverse connection, and the ground wire failure) occurs, and immediately reflect the fault information to the user through the alarm circuit. In view of the blind spots of the existing household protection switches, active and real-time detection and local early warning of dangerous wiring faults are realized at the appliance end.

[0018] The power supply circuit in the household appliance anti-misconnection protection circuit of this technical solution can still obtain a stable low-voltage DC power supply when the above-mentioned wiring abnormality occurs, providing a reliable and stable working power supply for circuits such as the processing unit, ensuring that the detection and early warning functions do not fail.

[0019] The household appliance anti-misconnection protection circuit of this technical solution adds an independent transient protection circuit at the power supply terminal to absorb surge voltage from the power grid and protect the subsequent power supply circuit, detection circuit and processing unit from damage, thereby improving the reliability and service life of the entire protection circuit. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is a block diagram of a household appliance anti-misconnection protection circuit according to an embodiment of the present utility model.

[0021] Figure 2 This is a schematic diagram of a household appliance anti-misconnection protection circuit according to an embodiment of the present utility model.

[0022] Figure 3 This is a schematic diagram of the transient protection circuit and power supply circuit of an embodiment of the utility model.

[0023] Figure 4 This is a schematic diagram of the connection between each detection circuit, power supply terminal and processing unit in an embodiment of the present utility model.

[0024] Figure 5 This is a schematic diagram of the alarm circuit according to an embodiment of the present utility model.

[0025] Figure 6 This is a three-dimensional diagram of the protection indicator panel according to an embodiment of the present invention. DETAILED DESCRIPTION

[0026] To make the purpose, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the embodiments described are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0027] Example 1

[0028] Combined with attachment Figure 1 To the attached Figure 5 The technical solution of the present utility model is a household appliance anti-misconnection protection circuit, comprising a power supply terminal 1, wherein the power supply terminal 1 comprises a live wire terminal 11, a neutral wire terminal 12 and a ground wire terminal 13, and further comprising a processing unit 2, a power supply circuit 3, a transient protection circuit 4, a first detection circuit 5, a second detection circuit 6, a third detection circuit 7 and an alarm circuit 8; the transient protection circuit 4 is connected to the power supply terminal 1, the input end of the power supply circuit 3 is respectively connected to the live wire terminal 11, the neutral wire terminal 12 and the ground wire terminal 13, and the power supply circuit 3 is connected to the power supply terminal 1. The output end is connected to the power supply end of the processing unit 2, the input end of the first detection circuit 5 is respectively connected to the live wire terminal 11 and the neutral wire terminal 12, the input end of the second detection circuit 6 is respectively connected to the live wire terminal 11 and the ground wire terminal 13, the input end of the third detection circuit 7 is respectively connected to the neutral wire terminal 12 and the ground wire terminal 13, the output ends of the first detection circuit 5, the second detection circuit 6 and the third detection circuit 7 are respectively connected to the input end of the processing unit 2, and the output end of the processing unit 2 is connected to the input end of the alarm circuit 8.

[0029] In this embodiment, as shown in the attached Figure 3 As shown, the transient protection circuit 4 includes a first varistor RV1 and a second varistor RV2, wherein the two ends of the first varistor RV1 are respectively connected to the neutral terminal 12 and the ground terminal 13, and the two ends of the second varistor RV2 are respectively connected to the neutral terminal 12 and the live terminal 11.

[0030] In this embodiment, an independent transient protection circuit is added to the power supply terminal to absorb surge voltage from the power grid and protect the subsequent power supply circuit 3, detection circuit and processing unit 2 from damage, thereby improving the reliability and service life of the entire protection circuit.

[0031] In this embodiment, varistors are provided between the live wire and the ground wire, and between the neutral wire and the ground wire, to provide an effective low-impedance discharge path for the common-mode surge voltage, clamping the dangerous high voltage to a safe level, protecting the subsequent circuits from surge damage, and improving the surge protection capability and electromagnetic compatibility of the entire system.

[0032] In this embodiment, as shown in the attached Figure 3 As shown, the power supply circuit 3 includes a first diode D1, a second diode D2, a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4, a first capacitor C1, a second capacitor C2, a third capacitor C3 and a TVS diode D3, the positive electrode of the first diode D1 is connected to the live wire terminal, the positive electrode of the second diode D2 is connected to the ground wire terminal, the negative electrode of the first diode D1 and the negative electrode of the second diode D2 are both connected to the first end of the first resistor R1, the second end of the first resistor R1 is connected to the negative electrode of the TVS diode D3, the positive electrode of the TVS diode D3 is connected to the neutral wire terminal, the second resistor R2, the third resistor R3 and the fourth resistor R4 are respectively connected in parallel at both ends of the first resistor R1, the first capacitor C1, the second capacitor C2 and the third capacitor C3 are respectively connected in parallel at both ends of the TVS diode D3, and the working voltage is output at both ends of the third capacitor C3.

[0033] In this embodiment, the power supply circuit in the household appliance anti-misconnection protection circuit can still obtain a stable low-voltage DC power supply when the above-mentioned wiring abnormality occurs, providing a reliable and stable working power supply for circuits such as the processing unit, ensuring that the detection and warning functions do not fail.

[0034] In this embodiment, the power supply circuit 3 adopts a half-wave rectification design with dual diodes (D1 and D2). The core purpose is to ensure that the protection circuit can continue to obtain working power in the event of reverse connection of the neutral and the live (L / N interchange) and the zero failure.

[0035] In this embodiment, when the neutral terminal 12 and the live terminal 11 are correctly connected, the first diode D1 is forward-conducted, and a DC power supply is generated through the step-down, voltage-stabilizing and filtering circuit to supply power to the processing unit 2; when the neutral terminal 12 and the live terminal 11 are reversely connected, or the neutral line is disconnected or has unstable contact, the first diode D1 is reverse-cut off and the second diode D2 is forward-conducted, and the circuit is powered by the ground line instead, and a DC power supply is generated through the step-down, voltage-stabilizing and filtering circuit to supply power to the processing unit 2. This design cleverly utilizes the "unconventional" path of the ground line, and ensures that the ground line is only slightly energized in the event of a fault through the unidirectional conductivity of the second diode D2.

[0036] In this embodiment, the third capacitor C3 is an electrolytic capacitor, and the first capacitor C1 and the second capacitor C2 are film capacitors; the third capacitor C3 performs low-frequency filtering and energy storage, and the first capacitor C1 and the second capacitor C2 perform high-frequency filtering and decoupling.

[0037] In this embodiment, the first detection circuit 5 includes a first unidirectional current limiting circuit 51 and a first isolation circuit 52, the first end of the first unidirectional current limiting circuit 51 is connected to the live wire terminal 11, and the second end of the first unidirectional current limiting circuit 51 and the neutral wire terminal 12 are respectively connected to the first isolation circuit 52; the second detection circuit 6 includes a second unidirectional current limiting circuit 61 and a second isolation circuit 2, the first end of the second unidirectional current limiting circuit 61 is connected to the live wire terminal 11, and the second end of the second unidirectional current limiting circuit 61 and the ground wire terminal 13 are respectively connected to the second isolation circuit 62; the third detection circuit 7 includes a third unidirectional current limiting circuit 71 and a third isolation circuit 72, the first end of the third unidirectional current limiting circuit 71 is connected to the neutral wire terminal 12, and the second end of the third unidirectional current limiting circuit 71 and the ground wire terminal 13 are respectively connected to the third isolation circuit 72.

[0038] In this embodiment, the unidirectional current limiting circuit converts the sinusoidal signal into a positive signal, and the isolation circuit is used for signal isolation.

[0039] In this embodiment, the type of the processing unit 2 is not limited, as long as the ADC channels are ≥ 3 and there is at least one I / O interface for driving indication.

[0040] In this embodiment, as shown in the attached Figure 4 As shown, the first isolation circuit 52, the second isolation circuit 62 and the third isolation circuit 72 are all optocouplers; the second end of the first unidirectional current limiting circuit 51 is connected to the positive electrode of the first isolation circuit 52, the neutral line terminal 12 is connected to the negative electrode of the first isolation circuit 52, the collector of the first isolation circuit 52 is connected to the input end of the processing unit 2, and the emitter of the first isolation circuit 52 is grounded; the second end of the second unidirectional current limiting circuit 61 is connected to the positive electrode of the second isolation circuit 62, the ground line terminal 13 is connected to the negative electrode of the second isolation circuit 62, the collector of the second isolation circuit 62 is connected to the input end of the processing unit 2, and the emitter of the second isolation circuit 62 is grounded; the second end of the third unidirectional current limiting circuit 71 is connected to the positive electrode of the third isolation circuit 72, the ground line terminal 13 is connected to the negative electrode of the third isolation circuit 72, the collector of the third isolation circuit 72 is connected to the input end of the processing unit 2, and the emitter of the third isolation circuit 72 is grounded.

[0041] In this embodiment, the first unidirectional current limiting circuit 51, the second unidirectional current limiting circuit 61 and the third unidirectional current limiting circuit 71 all include a diode and a current limiting resistor connected in series; Figure 4 As shown, the first unidirectional current limiting circuit 51 includes a fifth resistor R5 and a fourth diode D4 connected in series, the second unidirectional current limiting circuit 61 includes a sixth resistor R6 and a fifth diode D5 connected in series, and the third unidirectional current limiting circuit 71 includes a seventh resistor R7 and a sixth diode D6 connected in series.

[0042] In this embodiment, as shown in the attached Figure 5 As shown, the alarm circuit 8 includes a first alarm circuit 81 and a second alarm circuit 82. The input ends of the first alarm circuit 81 and the second alarm circuit 82 are respectively connected to the output end of the processing unit 2. The first alarm circuit 81 is used to indicate that the electrical wiring is normal, and the second alarm circuit 82 is used to indicate that the electrical wiring is abnormal.

[0043] In this embodiment, the first alarm circuit 81 and the second alarm circuit 82 both include a light emitting diode LED and a current limiting resistor connected in series. Figure 5 As shown, the first alarm circuit 81 is a first light emitting diode LED1 and an eighth resistor R8 connected in series, and the second alarm circuit 82 is a second light emitting diode LED2 and a ninth resistor R9 connected in series.

[0044] In another embodiment, the alarm circuit 8 may also be a buzzer alarm.

[0045] In order to more clearly explain the working conditions of the protection circuit against misconnection of household appliances, the following are specific descriptions of various wiring methods and instructions:

[0046] When the live wire, neutral wire, and ground wire are correctly connected to the live wire terminal 11, the neutral wire terminal 12, and the ground wire terminal 13, the signal output by the first detection circuit 5 is a periodic variation signal, the signal output by the second detection circuit 6 is a periodic variation signal, and the signal output by the third detection circuit 7 is a static high level. At this time, the first light-emitting diode LED1 emits light and displays a green light that is always on.

[0047] When the live wire and the neutral wire are correctly connected to the live wire terminal 11 and the neutral wire terminal 12, and the ground wire is not connected to the ground wire terminal 13, the signal output by the first detection circuit 5 is a periodic changing signal, the signal output by the second detection circuit 6 is a static high level, and the signal output by the third detection circuit 7 is a static high level. At this time, the second light-emitting diode LED2 is lit, and the second light-emitting diode LED2 is lit, showing a red light flashing once per second;

[0048] When the local wire is correctly connected to the ground terminal 13, and the live and neutral wires are reversely connected to the neutral terminal 12 and the live terminal 11, the signal output by the first detection circuit 5 is a periodic variation signal, the signal output by the second detection circuit 6 is a static high level, and the signal output by the third detection circuit 7 is a periodic variation signal. At this time, the second light-emitting diode LED2 is lit, and the second light-emitting diode LED2 is lit, showing a red light flashing twice per second;

[0049] When the live wire and the ground wire are correctly connected to the live wire terminal 11 and the ground wire terminal 13, and the neutral wire is not connected to the neutral wire terminal 12, the signal output by the first detection circuit 5 is a static high level, the signal output by the second detection circuit 6 is a static high level, and the signal output by the third detection circuit 7 is a periodically changing signal. At this time, the second light-emitting diode LED2 lights up, and the second light-emitting diode LED2 lights up, showing a red light flashing 3 times per second.

[0050] In this embodiment, the household appliance anti-misconnection protection circuit is provided with a first detection circuit 5, a second detection circuit 6, and a third detection circuit 7, which respectively detect the connection between the live wire, the neutral wire, and the ground wire. The processing unit performs a comprehensive analysis based on the feedback signals of the first detection circuit 5, the second detection circuit 6, and the third detection circuit 7 to accurately determine the current appliance fault type of neutral wire disconnection, neutral-live reverse connection, and ground wire failure. This circuit can detect abnormal signals at the appliance end as soon as a fault (such as neutral wire disconnection, neutral-live reverse connection, and ground wire failure) occurs, and immediately reflect the fault information to the user through the alarm circuit. In view of the blind spots of existing household protection switches, active, real-time detection and local early warning of dangerous wiring faults are achieved at the appliance end.

[0051] Example 2

[0052] Combined with attachment Figure 1 To the attached Figure 6 The technical solution of the present utility model is a protection indicator panel, including a panel body 10 and the household appliance anti-misconnection protection circuit described in Example 1, the household appliance anti-misconnection protection circuit is integrated inside the panel body 10, and the surface of the panel body 10 is provided with an indicator area 20.

[0053] It should also be noted that, in this specification, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus comprising a series of elements includes not only those elements, but also other elements not explicitly listed, or elements inherent to such process, method, article, or apparatus. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of additional identical elements in the process, method, article, or apparatus comprising the element.

[0054] The above description of the disclosed embodiments will enable one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be readily apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not limited to the embodiments shown herein but is intended to conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A household appliance anti-misconnection protection circuit, comprising a power supply terminal, wherein the power supply terminal comprises a live wire terminal, a neutral wire terminal and a ground wire terminal, characterized in that: It also includes a processing unit, a power supply circuit, a transient protection circuit, a first detection circuit, a second detection circuit, a third detection circuit and an alarm circuit; the transient protection circuit is connected to the power supply terminal, the input end of the power supply circuit is respectively connected to the live wire terminal, the neutral wire terminal and the ground wire terminal, the output end of the power supply circuit is connected to the power supply end of the processing unit, the input end of the first detection circuit is respectively connected to the live wire terminal and the neutral wire terminal, the input end of the second detection circuit is respectively connected to the live wire terminal and the ground wire terminal, the input end of the third detection circuit is respectively connected to the neutral wire terminal and the ground wire terminal, the output ends of the first detection circuit, the second detection circuit and the third detection circuit are respectively connected to the input end of the processing unit, and the output end of the processing unit is connected to the input end of the alarm circuit.

2. A household appliance anti-misconnection protection circuit according to claim 1, characterized in that: The transient protection circuit includes a first varistor RV1 and a second varistor RV2, wherein two ends of the first varistor RV1 are respectively connected to the neutral terminal and the ground terminal, and two ends of the second varistor RV2 are respectively connected to the neutral terminal and the live terminal.

3. A household appliance anti-misconnection protection circuit according to claim 1, characterized in that: The power supply circuit includes a first diode, a second diode, a first resistor, a second resistor, a third resistor, a fourth resistor, a first capacitor, a second capacitor, a third capacitor and a TVS diode. The positive electrode of the first diode is connected to the live wire terminal, the positive electrode of the second diode is connected to the ground wire terminal, the negative electrode of the first diode and the negative electrode of the second diode are both connected to the first end of the first resistor, the second end of the first resistor is connected to the negative electrode of the TVS diode, the positive electrode of the TVS diode is connected to the neutral wire terminal, the second resistor, the third resistor and the fourth resistor are respectively connected in parallel at both ends of the first resistor, the first capacitor, the second capacitor and the third capacitor are respectively connected in parallel at both ends of the TVS diode, and the two ends of the third capacitor output the working voltage.

4. A household appliance anti-misconnection protection circuit according to claim 3, characterized in that: The third capacitor is an electrolytic capacitor, and the first capacitor and the second capacitor are film capacitors.

5. A household appliance anti-misconnection protection circuit according to claim 1, characterized in that: The first detection circuit includes a first unidirectional current limiting circuit and a first isolation circuit, the first end of the first unidirectional current limiting circuit is connected to the live wire terminal, and the second end of the first unidirectional current limiting circuit and the neutral wire terminal are respectively connected to the first isolation circuit; the second detection circuit includes a second unidirectional current limiting circuit and a second isolation circuit, the first end of the second unidirectional current limiting circuit is connected to the live wire terminal, and the second end of the second unidirectional current limiting circuit and the ground wire terminal are respectively connected to the second isolation circuit; the third detection circuit includes a third unidirectional current limiting circuit and a third isolation circuit, the first end of the third unidirectional current limiting circuit is connected to the neutral wire terminal, and the second end of the third unidirectional current limiting circuit and the ground wire terminal are respectively connected to the third isolation circuit.

6. A household appliance anti-misconnection protection circuit according to claim 5, characterized in that: The first isolation circuit, the second isolation circuit and the third isolation circuit are all optocouplers; the second end of the first unidirectional current limiting circuit is connected to the positive electrode of the first isolation circuit, the neutral line terminal is connected to the negative electrode of the first isolation circuit, the collector of the first isolation circuit is connected to the input end of the processing unit, and the emitter of the first isolation circuit is grounded; the second end of the second unidirectional current limiting circuit is connected to the positive electrode of the second isolation circuit, the ground line terminal is connected to the negative electrode of the second isolation circuit, the collector of the second isolation circuit is connected to the input end of the processing unit, and the emitter of the second isolation circuit is grounded; the second end of the third unidirectional current limiting circuit is connected to the positive electrode of the third isolation circuit, the ground line terminal is connected to the negative electrode of the third isolation circuit, the collector of the third isolation circuit is connected to the input end of the processing unit, and the emitter of the third isolation circuit is grounded.

7. A household appliance anti-misconnection protection circuit according to claim 6, characterized in that: The first unidirectional current limiting circuit, the second unidirectional current limiting circuit, and the third unidirectional current limiting circuit each include a diode and a current limiting resistor connected in series.

8. A household appliance anti-misconnection protection circuit according to any one of claims 1 to 7, characterized in that: The alarm circuit includes a first alarm circuit and a second alarm circuit. The input ends of the first alarm circuit and the second alarm circuit are respectively connected to the output end of the processing unit. The first alarm circuit is used to indicate that the wiring of the electrical appliance is normal, and the second alarm circuit is used to indicate that the wiring of the electrical appliance is abnormal.

9. A household appliance anti-misconnection protection circuit according to claim 8, characterized in that: The first alarm circuit and the second alarm circuit both include a light emitting diode (LED) and a current limiting resistor connected in series.

10. A protective indicator panel, characterized in that: The invention comprises a household appliance anti-misconnection protection circuit according to any one of claims 1 to 9.

Images