Leakage protection device, electrical connection device and electrical appliance

Abstract

The application provides a leakage protection device, comprising: a switch module coupled between an input end and an output end of a power line and configured to control a power connection between the input end and the output end; a leakage detection module configured to detect a leakage current signal on the power line and drive the switch module to disconnect the power connection when the leakage current signal is detected; a monitoring module configured to generate an analog leakage current signal to detect whether the leakage detection module is working properly; and a fault detection module configured to detect a wiring fault of the power line and send a fault indication signal to indicate a fault state when the wiring fault of the power line is detected. The device can prompt a user to stop using an electrical appliance in time through the fault indication signal when the wiring fault is detected, and potential safety hazards are eliminated. In addition, the leakage protection device has simple circuit structure, low cost and high safety.

Description

Technical Field

[0001] This invention relates to the electrical field, and more particularly to a leakage current protection device, an electrical connection device, and an electrical appliance. Background Technology

[0002] With societal development, various household appliances are being used more and more widely, making electrical safety paramount. However, household appliance switches typically only disconnect the live wire. If the live and neutral wires on the plug are connected incorrectly (e.g., reversed), the switch will disconnect the neutral wire. This means that even when the appliance is not working, there will still be voltage inside, posing a safety hazard. Similarly, when the neutral wire is missing, there will still be voltage inside the appliance, also posing a safety hazard. Furthermore, when the ground wire is left unconnected, the appliance's casing may become electrified.

[0003] Existing residual current devices (RCDs) cannot detect or alert to the various wiring faults in the power lines mentioned above. Therefore, there is an urgent need for an RCD capable of detecting power line faults. Summary of the Invention

[0004] To address the aforementioned problems, a first aspect of the present invention provides a leakage current protection device. This leakage current protection device includes a switching module coupled between an input and an output terminal of a power supply line and configured to control the power connection between the input and output terminals; a leakage current detection module configured to detect a leakage current signal on the power supply line and, upon detecting the leakage current signal, drive the switching module to disconnect the power connection; a monitoring module configured to generate a simulated leakage current signal to detect whether the leakage current detection module is functioning correctly; and a fault detection module configured to detect wiring faults in the power supply line and, upon detecting the wiring fault, issue a fault indication signal to indicate a fault state.

[0005] In some embodiments, the power line includes a first current-carrying wire for connecting to the live wire of the power grid, a second current-carrying wire for connecting to the neutral wire of the power grid, and a ground wire for connecting to the ground wire of the power grid. A wiring fault in the power line includes the second current-carrying wire being missing or floating. The fault detection module includes: a load module coupled between the first and second current-carrying wires and configured to provide a current loop between the first and second current-carrying wires; a first current-limiting module coupled between the second current-carrying wire and the ground wire and configured to limit the current in its loop; and an indicator module connected in series with the first current-limiting module and coupled between the second current-carrying wire and the ground wire, configured to issue a fault indication signal when the second current-carrying wire is missing or floating.

[0006] In some embodiments, the load module includes at least one of a resistor, a capacitor, and an inductor, the first current limiting module includes at least one of a capacitor and a resistor, and the indicating module includes at least one of an indicator light, a buzzer, and a speaker.

[0007] In some embodiments, the power line includes a first current-carrying wire for connecting to the live wire of the power grid, a second current-carrying wire for connecting to the neutral wire of the power grid, and a ground wire for connecting to the ground wire of the power grid. Wiring faults in the power line include the absence or floating of the ground wire. The fault detection module includes: a first current-limiting module coupled between the second current-carrying wire and the ground wire, configured to limit the current in its circuit; a second current-limiting module coupled between the first current-carrying wire and the ground wire, configured to limit the current in its circuit; and an indication module connected in series with the first current-limiting module and coupled between the second current-carrying wire and the ground wire, configured to issue a fault indication signal when the ground wire is missing or floating.

[0008] In some embodiments, the first current limiting module and the second current limiting module each include at least one of a capacitor and a resistor, and the indicating module includes at least one of an indicator light, a buzzer, and a speaker.

[0009] In some embodiments, the power line includes a first current-carrying wire for connecting to the live wire of the power grid, a second current-carrying wire for connecting to the neutral wire of the power grid, and a ground wire for connecting to the ground wire of the power grid. Wiring faults in the power line include at least one of the following: the second current-carrying wire is missing or floating; the ground wire is missing or floating; the first and second current-carrying wires are reversed; the second current-carrying wire and the ground wire are reversed; and the ground wire is abnormally energized. The fault detection module includes: a load module coupled between the first and second current-carrying wires and configured to provide a current loop between them; a first current-limiting module coupled between the second current-carrying wire and the ground wire and configured to limit the current in its loop; a second current-limiting module coupled between the first current-carrying wire and the ground wire and configured to limit the current in its loop; and an indicator module connected in series with the first current-limiting module and coupled between the second current-carrying wire and the ground wire, configured to issue a fault indication signal when the power line experiences the fault.

[0010] In some embodiments, the load module includes at least one of a resistor, a capacitor, and an inductor; the first current limiting module and the second current limiting module each include at least one of a capacitor and a resistor; and the indicator module includes at least one of an indicator light, a buzzer, and a speaker.

[0011] A second aspect of the invention provides an electrical connection device comprising: a housing; and a leakage current protection device according to any one of the embodiments of the first aspect, the leakage current protection device being housed in the housing.

[0012] A third aspect of the invention provides an electrical appliance comprising: a load device; and an electrical connection device coupled between a power line and the load device for supplying power to the load device, wherein the electrical connection device includes a leakage current protection device according to any one of the embodiments of the first aspect.

[0013] In this invention, the leakage current protection device can detect power line faults and, upon detection, prompt the user to immediately stop using the electrical appliance via a fault indication signal, thus eliminating potential safety hazards. Furthermore, the leakage current protection device provided by this invention has a simple circuit structure, low cost, and high safety. Attached Figure Description

[0014] Embodiments are illustrated and explained with reference to the accompanying drawings. These drawings are used to illustrate the basic principles and thus only show aspects necessary for understanding the basic principles. These drawings are not to scale. In the drawings, the same reference numerals denote similar features. Furthermore, lines connecting each block in the architectural diagram indicate electrical coupling between the two blocks; the absence of a line between two blocks does not indicate that the two blocks are not coupled.

[0015] Figure 1 A schematic diagram of a leakage current protection device according to an embodiment of the present invention is shown;

[0016] Figure 2 A schematic diagram of a first embodiment of the leakage current protection device according to the present invention is shown;

[0017] Figure 3 A schematic diagram of a second embodiment of the leakage current protection device according to the present invention is shown;

[0018] Figure 4 A schematic diagram of a third embodiment of the leakage current protection device according to the present invention is shown; and

[0019] Figure 5 A schematic diagram of a fourth embodiment of the leakage current protection device according to the present invention is shown. Detailed Implementation

[0020] In the following detailed description of preferred embodiments, reference will be made to the accompanying drawings, which form part of this invention. The accompanying drawings illustrate specific embodiments by way of example that enable the implementation of the invention. The exemplary embodiments are not intended to be exhaustive of all embodiments according to the invention. It will be understood that other embodiments may be utilized, and structural or logical modifications may be made, without departing from the scope of the invention. Therefore, the following detailed description is not restrictive, and the scope of the invention is defined by the appended claims.

[0021] Before introducing the embodiments of the present invention, some of the terms involved in the present invention will be explained in order to better understand the present invention.

[0022] The terms “connection,” “coupling,” or “linkage” and similar terms used in this invention are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. Words such as “a,” “a group,” or “one” do not indicate a quantity limitation, but rather indicate the presence of at least one.

[0023] The terms "comprising," "including," and similar terms used in this invention should be understood as open-ended terms, meaning "including / including but not limited to," indicating that other contents may also be included. The term "based on" means "at least partially based on." The term "one embodiment" means "at least one embodiment"; the term "another embodiment" means "at least one additional embodiment," and so on. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Furthermore, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0024] This invention aims to provide a leakage current protection device. The device includes a fault detection module for detecting wiring faults in the power cord. Upon detecting a wiring fault, the module alerts the user to immediately stop using the appliance via a fault indication signal, thus eliminating potential safety hazards. This leakage current protection device features a simple circuit structure, low cost, and high safety.

[0025] Figure 1 A schematic diagram of a leakage current protection device according to an embodiment of the present invention is shown. Figure 1As shown, the leakage current protection device 100 includes a switch module 103, a leakage current detection module 104, a monitoring module 105, and a fault detection module 106. The switch module 103 is coupled between the input terminal 101 and the output terminal 102 of the power line and controls the power connection between them. The leakage current detection module 104 detects leakage current signals on the power line and drives the switch module 103 to disconnect the power connection when a leakage current signal is detected. The monitoring module 105 generates a simulated leakage current signal to detect whether the leakage current detection module 104 is working properly. That is, if the leakage current detection module 104 can detect the simulated leakage current signal and drive the switch module 103 to disconnect the power connection, it indicates that it is working properly; otherwise, it indicates that it is not working properly. The fault detection module 106 detects wiring faults in the power line and issues a fault indication signal to indicate the fault status when a wiring fault is detected. The power line may include a first current-carrying wire for connecting to the live wire of the power grid, a second current-carrying wire for connecting to the neutral wire of the power grid, and a ground wire for connecting to the ground wire of the power grid. Power line wiring faults can include one or more of the following: missing or floating second current-carrying wire, missing or floating ground wire, reversed first and second current-carrying wires, reversed second current-carrying wire and ground wire, and abnormally energized ground wire. Ground wire fault indication signals can be, for example, audible or indicator light signals, or both.

[0026] The leakage current protection device 100 of the present invention can detect wiring faults in the power cord and prompt the user to stop using the electrical appliance in time by means of a fault indication signal when a wiring fault is detected, thereby eliminating potential safety hazards. In addition, the leakage current protection device 100 provided by the present invention has a simple circuit structure, low cost and high safety.

[0027] In some embodiments, the leakage current protection device 100 can detect faults such as the second current-carrying line being missing or floating. The fault detection module 106 includes a load module, a first current-limiting module, and an indicator module. The load module is coupled between the first and second current-carrying lines; the first current-limiting module is coupled between the second current-carrying line and ground and also coupled to the load module; the indicator module is connected in series with the first current-limiting module and coupled between the second current-carrying line and ground, and issues a fault indication signal when the second current-carrying line is missing or floating. The load module provides a current loop between the first and second current-carrying lines. It can be a single component or a circuit module formed by combining multiple components, as long as it can provide a current loop between the first and second current-carrying lines. In some embodiments, the load module may include at least one of a resistor, capacitor, and inductor. For example, the load module may include only a resistor, capacitor, or inductor, or it may include a combination of resistors and capacitors, a combination of resistors and inductors, a combination of capacitors and inductors, or a combination of all three, etc. The number of resistors, capacitors, and inductors can be set as needed. For example, the load module may include any combination of resistors, capacitors, and / or inductors with other components. In some embodiments, the load module may include components other than resistors, capacitors, and inductors, or combinations thereof. In some embodiments, the leakage detection module 104 may be used as the load module without providing additional components. The first current limiting module is used to limit the current in its circuit. It may be a single component or a circuit module formed by combining multiple components, as long as it has a current limiting function. In some embodiments, the first current limiting module may include at least one of a capacitor and a resistor. For example, the first current limiting module may include only a capacitor or a resistor, or a combination of capacitors and resistors. The number of capacitors and resistors can be set as needed. When the first current limiting module includes a capacitor, it also has a voltage isolation function. The indicator module is used to issue a fault indication signal. It may be an indicator light (such as an LED), a buzzer, a speaker, or other components capable of issuing indication signals, or a combination thereof.

[0028] In some embodiments, the leakage current protection device 100 can detect faults such as missing or floating ground wires. The fault detection module 106 includes a first current-limiting module, a second current-limiting module, and an indicator module. The first current-limiting module is coupled between the second current-carrying line and the ground wire. The second current-limiting module is coupled between the first current-carrying line and the ground wire and is also coupled to the first current-limiting module. The indicator module is connected in series with the first current-limiting module and coupled between the second current-carrying line and the ground wire, and issues a fault indication signal when the ground wire is missing or floating. Both the first and second current-limiting modules are used to limit the current in their respective circuits. They can be single components or circuit modules formed by combining multiple components, as long as they have a current-limiting function. In some embodiments, the first and second current-limiting modules may each include at least one of a capacitor and a resistor. For example, the first and second current-limiting modules may each include only a capacitor or a resistor, or a combination of capacitors and resistors. The number of capacitors and resistors can be set as needed. When the first or second current-limiting module includes a capacitor, it also has a voltage isolation function. The indicator module is used to issue fault indication signals. It can be an indicator light (such as an LED), a buzzer, a speaker, or other components that can issue indication signals, or a combination thereof.

[0029] In some embodiments, the leakage current protection device 100 can detect at least one fault among the following: missing or floating second current-carrying wire, missing or floating ground wire, reversed connection of first and second current-carrying wires, reversed connection of second current-carrying wire and ground wire, and abnormally energized ground wire. The fault detection module 106 includes a load module, a first current-limiting module, a second current-limiting module, and an indicator module. The load module is coupled between the first and second current-carrying wires; the first current-limiting module is coupled between the second current-carrying wire and the ground wire and is also coupled to the load module; the second current-limiting module is coupled between the first current-carrying wire and the ground wire and is also coupled to the first current-limiting module; the indicator module is connected in series with the first current-limiting module and coupled between the second current-carrying wire and the ground wire, and issues a fault indication signal when a power line fault occurs. The load module is used to provide a current loop between the first and second current-carrying wires; it can be a single component or a circuit module formed by combining multiple components, as long as it can provide a current loop between the first and second current-carrying wires. In some embodiments, the load module may include at least one of a resistor, a capacitor, and an inductor. For example, a load module may include only resistors, capacitors, or inductors, or it may include combinations of resistors and capacitors, combinations of resistors and inductors, combinations of capacitors and inductors, or combinations of all three. The number of resistors, capacitors, and inductors can be set as needed. For another example, a load module may include any combination of resistors, capacitors, and / or inductors with other components. In some embodiments, a load module may include components other than resistors, capacitors, and inductors, or combinations thereof. In some embodiments, a leakage current detection module 104 can be used as a load module without providing additional components. Both the first and second current-limiting modules are used to limit the current in their respective circuits. They can be single components or circuit modules formed by combining multiple components, as long as they have a current-limiting function. In some embodiments, the first and second current-limiting modules may each include at least one of capacitors and resistors. For example, the first and second current-limiting modules may each include only capacitors or resistors, or combinations of capacitors and resistors. The number of capacitors and resistors can be set as needed. When the first or second current-limiting module includes a capacitor, it also has a voltage isolation function. The indicator module is used to issue fault indication signals. It can be an indicator light (such as an LED), a buzzer, a speaker, or other components that can issue indication signals, or a combination thereof.

[0030] Figure 2 A schematic diagram of a first embodiment of a leakage current protection device according to the present invention is shown. Figure 2 As shown, the leakage current protection device 200 includes a switch module 103, a leakage current detection module 104, a monitoring module 105, and a fault detection module 106. The power supply line includes a first current-carrying line 11, a second current-carrying line 12, and a ground wire 13. Figure 2 As shown, the switch module 103 includes a reset switch for controlling the power connection between the input and output terminals of the first current-carrying line 11 and the second current-carrying line 12. The leakage detection module 104 includes a leakage detection ring CT1 through which the first current-carrying line 11 and the second current-carrying line 12 pass, a shielding wire covering the outside of the first current-carrying line 11, the second current-carrying line 12 and the ground wire 13, a leakage detection chip IC1, a trip coil SOL1, a silicon controlled rectifier Q1 and peripheral circuitry of the leakage detection chip IC1. The monitoring module 105 includes a test switch and a resistor R1 connected in series, which are coupled between the first current-carrying line 11 and the second current-carrying line 12. The fault detection module 106 includes a resistor R2 (load module), a capacitor C1 (first current-limiting module) connected in series, a resistor R3 and a light-emitting diode LED1 (indicator module), a capacitor C3 (second current-limiting module) connected in series and a resistor R4. Resistor R2 is coupled between the first current-carrying line 11 and the second current-carrying line 12. Resistor R3, capacitor C1 and LED1 are coupled between the second current-carrying line 12 and ground line 13. Resistor R4 and capacitor C3 are coupled between the first current-carrying line 11 and ground line 13 and are also coupled to capacitor C1 and LED1.

[0031] Under normal operating conditions, the first current-carrying line 11 is connected to the live wire of the power grid, the second current-carrying line 12 is connected to the neutral wire, and the ground wire 13 is connected to the ground wire. The switch module 103 is in a reset state (i.e., closed state), and the input and output terminals of the first current-carrying line 11 and the second current-carrying line 12 are connected. In this state, there is no voltage between the second current-carrying line 12 and the ground wire 13, so no current flows through the loop from the second current-carrying line 12 to the ground wire 13, and the light-emitting diode LED1 will not light up. When leakage current occurs in the first current-carrying line 11 or the second current-carrying line 12, or when the insulation layer is damaged and detected by the shielding wire, i.e., when there is a leakage current signal in the power line, the leakage detection coil CT1 detects an unbalanced current in the first current-carrying line 11 and the second current-carrying line 12, generates a corresponding induced voltage, and transmits this induced voltage to the leakage detection chip IC1. When the voltage output by the leakage detection coil CT1 is greater than the threshold, pin 5 of the leakage detection chip IC1 outputs a high level; otherwise, it outputs a low level. A high level at pin 5 of the leakage current detection chip IC1 is provided to the control electrode of the thyristor Q1, triggering Q1 to conduct. This causes a current change in the solenoid SOL1, generating an electromagnetic force that drives the switch module 103 to disconnect the power connection between the input and output terminals of the first current-carrying line 11 and the second current-carrying line 12. When testing whether the leakage current protection device 200 is working properly, the test switch of the monitoring module 105 is closed, forming a current loop of the first current-carrying line 11-R1-the second current-carrying line 12, generating a simulated leakage current signal. If the switch module 103 disconnects the power connection between the input and output terminals of the first current-carrying line 11 and the second current-carrying line 12, it indicates that the leakage current detection module 104 is working properly; otherwise, it indicates that the leakage current detection module 104 has malfunctioned.

[0032] When the neutral and live wires at the input terminal (such as a socket) are reversed, the second current-carrying wire 12 of the leakage protection device 200 is actually connected to the live wire of the power grid. At this time, there is a voltage between the second current-carrying wire 12 and the ground wire 13. The second current-carrying wire 12-R3-C1-LED1-ground wire 13 form a current loop, and the light-emitting diode LED1 is lit, which means that a fault indication signal is issued, indicating that there is a wiring fault in the power cord, prompting the user to stop using the appliance and troubleshoot the fault.

[0033] When the live wire and ground wire at the input terminal (such as a socket) are reversed or the ground wire is abnormally energized, the ground wire 13 of the leakage protection device 200 is actually connected to the live wire of the power grid or is abnormally energized. At this time, there is a voltage between the second current-carrying wire 12 and the ground wire 13. The second current-carrying wire 12-R3-C1-LED1-ground wire 13 form a current loop, and the light-emitting diode LED1 is lit, which means that a fault indication signal is issued, indicating that there is a fault in the power line, prompting the user to stop using the appliance and troubleshoot the fault.

[0034] When the neutral wire at the input terminal (such as the socket) is missing or suspended, the second current-carrying wire 12 of the leakage protection device 200 is in a suspended state. At this time, the first current-carrying wire 11-R2-R3-C1-LED1-ground wire 13 forms a current loop, and the light-emitting diode LED1 is lit, which means that a fault indication signal is issued, indicating that there is a fault in the power line, prompting the user to stop using the appliance and troubleshoot the fault.

[0035] When the ground wire at the input terminal (such as the socket) is missing or floating, the ground wire 13 of the leakage protection device 200 is in a floating state. At this time, the second current-carrying line 12-R3-C1-LED1-C3-R4-first current-carrying line 11 forms a current loop, and the light-emitting diode LED1 is lit, which means that a fault indication signal is issued, indicating that there is a fault in the power line, prompting the user to stop using the appliance and troubleshoot the fault.

[0036] Figure 3 A schematic diagram of a second embodiment of the leakage current protection device according to the present invention is shown. Figure 2 Compared to the previous embodiment, the main difference lies in the fault detection module 106. Specifically, in Figure 3 In the leakage current protection device 300, the fault detection module 106 includes a capacitor C8 (load module), a capacitor C1 (first current limiting module) connected in series, a resistor R3 and an AC lamp LG1 (indicator module), a capacitor C3 (second current limiting module) connected in series, and a resistor R4. Capacitor C8 is coupled between the first current-carrying line 11 and the second current-carrying line 12; resistor R3, capacitor C1, and AC lamp LG1 are coupled between the second current-carrying line 12 and the ground line 13; resistor R4 and capacitor C3 are coupled between the first current-carrying line 11 and the ground line 13, and are also coupled to capacitor C1 and AC lamp LG1. Figure 1 Similar descriptions will not be repeated here.

[0037] When the neutral and live wires at the input terminal (such as a socket) are reversed, the second current-carrying wire 12 of the leakage protection device 300 is actually connected to the live wire of the power grid. At this time, there is a voltage between the second current-carrying wire 12 and the ground wire 13. The second current-carrying wire 12-R3-C1-LG1-ground wire 13 forms a current loop, and the AC lamp LG1 is lit, which means that a fault indication signal is issued, indicating that there is a wiring fault in the power cord, prompting the user to stop using the appliance and troubleshoot the fault.

[0038] When the live wire and ground wire at the input terminal (such as a socket) are reversed or the ground wire is abnormally energized, the ground wire 13 of the leakage protection device 300 is actually connected to the live wire of the power grid or is abnormally energized. At this time, there is a voltage between the second current-carrying wire 12 and the ground wire 13. The second current-carrying wire 12-R3-C1-LG1-ground wire 13 forms a current loop, and the AC lamp LG1 is lit, which means that a fault indication signal is issued, indicating that there is a fault in the power line, prompting the user to stop using the appliance and troubleshoot the fault.

[0039] When the neutral wire at the input terminal (such as the socket) is missing or suspended, the second current-carrying wire 12 of the leakage protection device 300 is in a suspended state. At this time, the first current-carrying wire 11-C8-R3-C1-LG1-ground wire 13 forms a current loop, and the AC lamp LG1 is lit, which means that a fault indication signal is issued, indicating that there is a fault in the power line, prompting the user to stop using the appliance and troubleshoot the fault.

[0040] When the ground wire at the input terminal (such as the socket) is missing or floating, the ground wire 13 of the leakage protection device 300 is in a floating state. At this time, the second current-carrying line 12-R3-C1-LG1-C3-R4-first current-carrying line 11 forms a current loop, and the AC lamp LG1 is lit, which means that a fault indication signal is issued, indicating that there is a fault in the power line, prompting the user to stop using the appliance and troubleshoot the fault.

[0041] Figure 4 A schematic diagram of a third embodiment of the leakage current protection device according to the present invention is shown. Figure 2 Compared to the previous embodiment, Figure 4 The main differences in the embodiments lie in the switch module 103, the leakage current detection module 104, and the fault detection module 106. Specifically, the switch module 103 adds a switch that can disconnect the ground wire 13; the leakage current detection module 104 does not include a shielding wire but adds a fault current detection function for the ground wire 13; the fault detection module 106 includes a resistor R2 (load module), a capacitor C1 (first current limiting module) connected in series, a resistor R3 and a buzzer B1 (indicator module), a capacitor C3 (second current limiting module) connected in series, and a resistor R4. Resistor R2 is coupled between the first current-carrying line 11 and the second current-carrying line 12; resistor R3, capacitor C1, and buzzer B1 are coupled between the second current-carrying line 12 and the ground wire 13; resistor R4 and capacitor C3 are coupled between the first current-carrying line 11 and the ground wire 13 and are also coupled to capacitor C1 and buzzer B1.

[0042] Under normal operating conditions, the first current-carrying line 11 is connected to the live wire of the power grid, the second current-carrying line 12 is connected to the neutral wire, and the ground wire 13 is connected to the ground wire. The switch module 103 is in the reset state (i.e., closed state), and the input and output terminals of the first current-carrying line 11, the second current-carrying line 12, and the ground wire 13 are connected. In this state, there is no voltage between the second current-carrying line 12 and the ground wire 13, so no current flows through the loop from the second current-carrying line 12 to the ground wire 13, and the buzzer B1 will not sound. When leakage current occurs in the first current-carrying line 11 or the second current-carrying line 12, or when a fault current is generated in the ground wire 13, i.e., when there is a leakage current signal in the power line, the leakage current detection coil CT1 generates a corresponding induced voltage and transmits this induced voltage to the leakage current detection chip IC1. When the voltage output by the leakage current detection coil CT1 is greater than the threshold, pin 5 of the leakage current detection chip IC1 outputs a high level; otherwise, it outputs a low level. A high level at pin 5 of the leakage current detection chip IC1 is provided to the control electrode of the thyristor Q1, triggering Q1 to conduct. This causes a current change in the solenoid SOL1, generating an electromagnetic force that drives the switch module 103 to disconnect the power connection between the input and output terminals of the first current-carrying line 11, the second current-carrying line 12, and the ground line 13. When testing whether the leakage current protection device 400 is working properly, the test switch of the monitoring module 105 is closed, forming a current loop of the first current-carrying line 11-R1-the second current-carrying line 12, generating a simulated leakage current signal. If the switch module 103 disconnects the power connection between the input and output terminals of the first current-carrying line 11, the second current-carrying line 12, and the ground line 13, it indicates that the leakage current detection module 104 is working properly; otherwise, it indicates that the leakage current detection module 104 has malfunctioned.

[0043] When the neutral and live wires at the input terminal (such as a socket) are reversed, the second current-carrying wire 12 of the leakage protection device 400 is actually connected to the live wire of the power grid. At this time, there is a voltage between the second current-carrying wire 12 and the ground wire 13. The second current-carrying wire 12-R3-C1-B1-ground wire 13 forms a current loop, and the buzzer B1 is sounded, which means that a fault indication signal is issued, indicating that there is a wiring fault in the power cord, prompting the user to stop using the appliance and troubleshoot the fault.

[0044] When the live wire and ground wire at the input terminal (such as a socket) are reversed or the ground wire is abnormally energized, the ground wire 13 of the leakage protection device 400 is actually connected to the live wire of the power grid or is abnormally energized. At this time, there is a voltage between the second current-carrying wire 12 and the ground wire 13. The second current-carrying wire 12-R3-C1-B1-ground wire 13 forms a current loop, and the buzzer B1 is sounded, which means that a fault indication signal is issued, indicating that there is a fault in the power line, prompting the user to stop using the appliance and troubleshoot the fault.

[0045] When the neutral wire at the input terminal (such as the socket) is missing or suspended, the second current-carrying wire 12 of the leakage protection device 400 is in a suspended state. At this time, the first current-carrying wire 11-R2-R3-C1-B1-ground wire 13 forms a current loop, and the buzzer B1 is sounded, which means that a fault indication signal is issued, indicating that there is a fault in the power line, prompting the user to stop using the appliance and troubleshoot the fault.

[0046] When the ground wire at the input terminal (such as the socket) is missing or suspended, the ground wire 13 of the leakage protection device 400 is in a suspended state. At this time, the second current-carrying line 12-R3-C1-B1-C3-R4-first current-carrying line 11 forms a current loop, and the buzzer B1 is sounded, which means that a fault indication signal is issued, indicating that there is a fault in the power line, prompting the user to stop using the appliance and troubleshoot the fault.

[0047] Figure 5 A schematic diagram of a fourth embodiment of the leakage current protection device according to the present invention is shown. Figure 2 Compared to the previous embodiment, Figure 5 The main difference between the embodiments lies in the switch module 103 and the leakage current detection module 104. Specifically, the switch module 103 adds a switch that can disconnect the ground wire 13, and the leakage current detection module 104 does not include a shielded wire, but adds a fault current detection function for the ground wire 13, and uses a different leakage current detection chip IC1 and its peripheral circuits.

[0048] Under normal operating conditions, the first current-carrying line 11 is connected to the live wire of the power grid, the second current-carrying line 12 is connected to the neutral wire, and the ground wire 13 is connected to the ground wire. The switch module 103 is in a reset state (i.e., closed state), and the input and output terminals of the first current-carrying line 11, the second current-carrying line 12, and the ground wire 13 are connected. In this state, there is no voltage between the second current-carrying line 12 and the ground wire 13, so no current flows through the loop from the second current-carrying line 12 to the ground wire 13, and the light-emitting diode LED1 will not be lit. When leakage current occurs in the first current-carrying line 11 or the second current-carrying line 12, or when a fault current is generated in the ground wire 13, i.e., when there is a leakage current signal in the power line, the leakage current detection coil CT1 generates a corresponding induced voltage and transmits this induced voltage to the leakage current detection chip IC1. When the voltage output by the leakage current detection coil CT1 is greater than the threshold, pin 5 of the leakage current detection chip IC1 outputs a high level; otherwise, it outputs a low level. A high level at pin 5 of the leakage current detection chip IC1 is provided to the control electrode of the thyristor Q1, triggering Q1 to conduct. This causes a current change in the solenoid SOL1, generating an electromagnetic force that drives the switch module 103 to disconnect the power connection between the input and output terminals of the first current-carrying line 11, the second current-carrying line 12, and the ground line 13. When testing whether the leakage current protection device 500 is working properly, the test switch of the monitoring module 105 is closed, forming a current loop of the first current-carrying line 11-R1-the second current-carrying line 12, generating a simulated leakage current signal. If the switch module 103 disconnects the power connection between the input and output terminals of the first current-carrying line 11, the second current-carrying line 12, and the ground line 13, it indicates that the leakage current detection module 104 is working properly; otherwise, it indicates that the leakage current detection module 104 has malfunctioned.

[0049] When the neutral and live wires at the input terminal (such as a socket) are reversed, the second current-carrying wire 12 of the leakage protection device 500 is actually connected to the live wire of the power grid. At this time, there is a voltage between the second current-carrying wire 12 and the ground wire 13. The second current-carrying wire 12-R3-C1-LED1-ground wire 13 form a current loop, and the light-emitting diode LED1 is lit, which means that a fault indication signal is issued, indicating that there is a wiring fault in the power cord, prompting the user to stop using the appliance and troubleshoot the fault.

[0050] When the live wire and ground wire at the input terminal (such as a socket) are reversed or the ground wire is abnormally energized, the ground wire 13 of the leakage protection device 500 is actually connected to the live wire of the power grid or is abnormally energized. At this time, there is a voltage between the second current-carrying wire 12 and the ground wire 13. The second current-carrying wire 12-R3-C1-LED1-ground wire 13 form a current loop, and the light-emitting diode LED1 is lit, which means that a fault indication signal is issued, indicating that there is a fault in the power line, prompting the user to stop using the appliance and troubleshoot the fault.

[0051] When the neutral wire at the input terminal (such as the socket) is missing or suspended, the second current-carrying wire 12 of the leakage protection device 500 is in a suspended state. At this time, the first current-carrying wire 11-R2-R3-C1-LED1-ground wire 13 forms a current loop, and the light-emitting diode LED1 is lit, which means that a fault indication signal is issued, indicating that there is a fault in the power line, prompting the user to stop using the appliance and troubleshoot the fault.

[0052] When the ground wire at the input terminal (such as the socket) is missing or floating, the ground wire 13 of the leakage protection device 500 is in a floating state. At this time, the second current-carrying line 12-R3-C1-LED1-C3-R4-first current-carrying line 11 forms a current loop, and the light-emitting diode LED1 is lit, which means that a fault indication signal is issued, indicating that there is a fault in the power line, prompting the user to stop using the appliance and troubleshoot the fault.

[0053] A second aspect of the invention provides an electrical connection device comprising: a housing; and a leakage current protection device according to any of the above embodiments, the leakage current protection device being housed in the housing.

[0054] A third aspect of the present invention provides an electrical appliance, comprising: a load device; and an electrical connection device coupled between a power line and the load device for supplying power to the load device, wherein the electrical connection device includes a leakage current protection device as described in any of the above embodiments.

[0055] Therefore, although the invention has been described with reference to specific examples, which are intended to be exemplary only and not to limit the invention, it will be apparent to those skilled in the art that changes, additions or deletions may be made to the disclosed embodiments without departing from the spirit and scope of the invention.

Claims

1. An electric leakage protection device, comprising: a switch module coupled between an input terminal and an output terminal of a power line and configured to control a power connection between the input terminal and the output terminal, wherein the power line comprises a first current-carrying line for connecting to a live line of a power grid, a second current-carrying line for connecting to a neutral line of the power grid, and a ground line for connecting to a ground line of the power grid; an electric leakage detection module configured to detect an electric leakage current signal on the power line and to drive the switch module to disconnect the power connection upon detecting the electric leakage current signal; a monitoring module configured to generate a simulated electric leakage current signal to detect whether the electric leakage detection module is working properly; and a fault detection module configured to detect a wiring fault of the power line, the wiring fault comprising a missing or floating of the second current-carrying line, a missing or floating of the ground line, a reversed connection of the first current-carrying line and the second current-carrying line, a reversed connection of the second current-carrying line and the ground line, and an abnormal electrification of the ground line, wherein the fault detection module comprises an indication module coupled between the second current-carrying line and the ground line and configured to emit a unified fault indication signal to indicate a fault state upon the fault detection module detecting any one or more of the wiring faults of the power line.

2. The ground fault protection device of claim 1, wherein, the fault detection module further comprises: a load module coupled between the first current-carrying line and the second current-carrying line and configured to provide a current loop between the first current-carrying line and the second current-carrying line; a first current-limiting module coupled between the second current-carrying line and the ground line in series connection with the indication module and configured to limit a current in a loop in which the first current-limiting module is located; a second current-limiting module coupled between the first current-carrying line and the ground line and configured to limit a current in a loop in which the second current-limiting module is located.

3. The ground fault protection device of claim 2, wherein, the load module comprises at least one of a resistor, a capacitor, and an inductor, the first current-limiting module and the second current-limiting module each comprise at least one of a capacitor and a resistor, and the indication module comprises at least one of an indicator light, a buzzer, and a speaker.

4. An electric leakage protection device, comprising: a switch module coupled between an input terminal and an output terminal of a power line and configured to control a power connection between the input terminal and the output terminal, wherein the power line comprises a first current-carrying line for connecting to a live line of a power grid, a second current-carrying line for connecting to a neutral line of the power grid, and a ground line for connecting to a ground line of the power grid; an electric leakage detection module configured to detect an electric leakage current signal on the power line and to drive the switch module to disconnect the power connection upon detecting the electric leakage current signal; a monitoring module configured to generate a simulated electric leakage current signal to detect whether the electric leakage detection module is working properly; and a fault detection module configured to detect a wiring fault of the power line, the wiring fault comprising a missing or floating of the second current-carrying line, and the fault detection module comprising: a load module coupled between the first current-carrying line and the second current-carrying line and configured to provide a current loop between the first current-carrying line and the second current-carrying line; a first current-limiting module coupled between the second current-carrying line and the ground line and configured to limit current in a loop in which it is located; and an indication module coupled in series with the first current-limiting module between the second current-carrying line and the ground line, wherein, when the second current-carrying line is missing or open, a current loop is formed between the first current-carrying line and the ground line, thereby causing the indication module to emit the fault indication signal.

5. The ground fault protection device of claim 4, wherein, The load module includes at least one of a resistor, a capacitor, and an inductor, the first current-limiting module includes at least one of a capacitor and a resistor, and the indication module includes at least one of an indicator light, a buzzer, and a speaker.

6. An electric leakage protection device, comprising: a switch module coupled between an input end and an output end of a power line and configured to control a power connection between the input end and the output end, wherein the power line includes a first current-carrying line for connecting to a live wire of a power grid, a second current-carrying line for connecting to a neutral wire of the power grid, and a ground line for connecting to a ground wire of the power grid; an electric leakage detection module configured to detect an electric leakage current signal on the power line and drive the switch module to disconnect the power connection when the electric leakage current signal is detected; a monitoring module configured to generate a simulated electric leakage current signal to detect whether the electric leakage detection module is working properly; and a fault detection module configured to detect a wiring fault of the power line, the wiring fault including that the ground line is missing or open, and the fault detection module includes: a first current-limiting module coupled between the second current-carrying line and the ground line and configured to limit current in a loop in which it is located; a second current-limiting module coupled between the first current-carrying line and the ground line and configured to limit current in a loop in which it is located; and an indication module coupled in series with the first current-limiting module between the second current-carrying line and the ground line, wherein, when the ground line is missing or open, a current loop is formed between the second current-carrying line and the first current-carrying line, thereby causing the indication module to emit the fault indication signal.

7. The ground fault protection device of claim 6, wherein, The first current-limiting module and the second current-limiting module each include at least one of a capacitor and a resistor, and the indication module includes at least one of an indicator light, a buzzer, and a speaker.

8. An electric connection apparatus, comprising: a housing; and the electric leakage protection device according to any one of claims 1-7, which is housed in the housing.

9. An electric appliance, comprising: a load apparatus; an electric connection apparatus coupled between a power line and the load apparatus for supplying power to the load apparatus, wherein the electric connection apparatus includes the electric leakage protection device according to any one of claims 1-7. ​

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