Ground wire miss connection protection circuit

Abstract

This invention discloses a ground wire leakage protection circuit, relating to the field of safety protection. The ground wire leakage protection circuit includes: a ground wire leakage detection module, used to detect whether a ground wire is connected. When a ground wire is connected, it outputs a first voltage signal to a drive control module; when a ground wire is not connected, it outputs a second voltage signal to the drive control module. Compared with the prior art, the beneficial effects of this invention are: by actively identifying the ground wire connection status, this invention connects the live wire and neutral wire power supply circuit only when the grounding is reliable, transforming passive protection into forced active protection, thus eliminating the risk of electric shock to users due to grounding failure from the source; at the same time, this solution uses conventional discrete components to implement logic control, resulting in a simple circuit structure, economical cost, no need for complex chips or expensive leakage protection modules, strong versatility, flexible adaptation to various household appliances, and good production consistency, facilitating large-scale industrial application.

Description

Technical Field

[0001] This invention relates to the field of safety protection, specifically a grounding leakage protection circuit. Background Technology

[0002] Currently, grounding protection is widely used as a basic electrical safety measure for various household appliances. In conventional designs, the metal casing or easily accessible conductive parts of the appliance are connected to the grounding terminal of the building's power supply system via the ground wire in the power cord, forming a protective grounding loop. When insulation fails or internal live parts accidentally come into contact with the casing, the fault current can be conducted to the earth through the grounding loop, thereby reducing the risk of electric shock.

[0003] However, the aforementioned existing technical solutions have significant limitations. Grounding protection methods relying on manual wiring do not actively identify or enforce the reliability of the ground wire connection. In actual use, the ground wire may be disconnected or not connected due to reasons such as a missing grounding terminal in the socket, a damaged power cord, or user modifications. The equipment can still operate normally under these circumstances, and the user may not notice the missing ground wire. In this case, if a leakage fault occurs inside the equipment, the protective grounding circuit fails due to the open circuit, the leakage current cannot be effectively discharged, and the equipment casing will carry a dangerous voltage for a long time, which can easily lead to electric shock or injury to the user. Improvements are needed. Summary of the Invention

[0004] The purpose of this invention is to provide a grounding leakage protection circuit to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, the present invention provides the following technical solution: A grounding leakage protection circuit includes: The ground wire missing detection module is used to detect whether a ground wire is connected. When the ground wire is connected, it outputs a first voltage signal (high level) to the drive control module; when the ground wire is not connected, it outputs a second voltage signal (low level) to the drive control module. The drive control module is used to drive the power supply circuit control module to build a circuit when it receives the first voltage signal, so that the power supply circuit control module can work; and to control the power supply circuit control module to disconnect the circuit when it receives the second voltage signal, so that the power supply circuit control module can stop working. The power supply circuit control module is used to control the switching between the live wire, neutral wire, and subsequent circuits during operation, thereby establishing a circuit between the live wire, neutral wire, and subsequent circuits to achieve power-on. The output of the grounding leakage detection module is connected to the input of the drive control module, and the output of the drive control module is connected to the input of the power supply circuit control module.

[0006] As a further embodiment of the present invention: the ground wire leakage detection module includes a resistor R6, a comparator IC1, a resistor R7, and a resistor R8. The inverting input of the comparator IC1 is connected to one end of the resistor R6 and the ground wire, and the other end of the resistor R6 is connected to a 12V power supply. The non-inverting input of the comparator IC1 is connected to one end of the resistor R7 and one end of the resistor R8. The other end of the resistor R8 is grounded, and the other end of the resistor R7 is connected to a 12V voltage. The output of the comparator IC1 is connected to the input of the drive control module.

[0007] As a further embodiment of the present invention: the drive control module includes resistors R3, R4, and R5. One end of resistor R3 is connected to a 12V voltage, and the other end of resistor R3 is connected to one end of resistor R4, one end of resistor R5, and the output terminal of the grounding leakage detection module. The other end of resistor R4 is connected to the input terminal of the power supply circuit control module, and the other end of resistor R5 is connected to the input terminal of the power supply circuit control module.

[0008] As a further embodiment of the present invention: the power supply circuit control module includes a relay RY1, a transistor Q1, and a transistor Q2. The base of transistor Q1 is connected to the output terminal of the drive control module, the base of transistor Q2 is connected to the output terminal of the drive control module, the emitter of transistor Q1 is connected to the collector of transistor Q2, the emitter of transistor Q2 is grounded, the collector of transistor Q1 is connected to the positive terminals of two diodes D1 connected in parallel and one end of relay RY1, and the negative terminals of the two diodes D1 connected in parallel are connected to the other end of relay RY1 and a 12V voltage.

[0009] As a further aspect of the present invention: transistors Q1 and Q2 are NPN transistors.

[0010] Compared with the prior art, the beneficial effects of the present invention are as follows: The present invention actively identifies the ground connection status and only connects the live wire and neutral wire power supply circuit when the grounding is reliable, turning passive protection into forced active protection, thus eliminating the risk of electric shock to users due to grounding failure from the source; at the same time, the present invention uses conventional discrete components to realize logic control, with a simple circuit structure, economical cost, no need for complex chips or expensive leakage protection modules, strong versatility, flexible adaptation to various home appliances, and good production consistency, which facilitates large-scale industrial application. Attached Figure Description

[0011] Figure 1 This is a circuit diagram of a grounding leakage protection circuit. Detailed Implementation

[0012] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0013] Please see Figure 1 A grounding leakage protection circuit includes: The ground wire missing detection module is used to detect whether a ground wire is connected. When the ground wire is connected, it outputs a first voltage signal (high level) to the drive control module; when the ground wire is not connected, it outputs a second voltage signal (low level) to the drive control module. The drive control module is used to drive the power supply circuit control module to build a circuit when it receives the first voltage signal, so that the power supply circuit control module can work; and to control the power supply circuit control module to disconnect the circuit when it receives the second voltage signal, so that the power supply circuit control module can stop working. The power supply circuit control module is used to control the switching between the live wire, neutral wire, and subsequent circuits during operation, thereby establishing a circuit between the live wire, neutral wire, and subsequent circuits to achieve power-on. The output of the grounding leakage detection module is connected to the input of the drive control module, and the output of the drive control module is connected to the input of the power supply circuit control module.

[0014] In this embodiment: Please refer to Figure 1 The grounding leakage detection module includes resistor R6, comparator IC1, resistor R7, and resistor R8. The inverting input of comparator IC1 is connected to one end of resistor R6 and ground, and the other end of resistor R6 is connected to a 12V power supply. The non-inverting input of comparator IC1 is connected to one end of resistor R7 and one end of resistor R8. The other end of resistor R8 is grounded, and the other end of resistor R7 is connected to a 12V voltage. The output of comparator IC1 is connected to the input of the drive control module.

[0015] When the ground wire is not connected to the grounding terminal of the building's power supply system, the 12V voltage provides a high level to the inverting input of comparator IC1 through resistor R6, making the voltage at the inverting input of comparator IC1 higher than the voltage at the non-inverting input, and comparator IC1 outputs a low level. When the ground wire is connected to the grounding terminal of the building's power supply system, the voltage at the inverting input of comparator IC1 is the ground voltage, which makes the voltage at the non-inverting input of comparator IC1 higher than the voltage at the inverting input, and comparator IC1 outputs a high level.

[0016] In this embodiment: Please refer to Figure 1The drive control module includes resistors R3, R4, and R5. One end of resistor R3 is connected to a 12V voltage, and the other end of resistor R3 is connected to one end of resistor R4, one end of resistor R5, and the output terminal of the grounding leakage detection module. The other end of resistor R4 is connected to the input terminal of the power supply circuit control module, and the other end of resistor R5 is connected to the input terminal of the power supply circuit control module.

[0017] When comparator IC1 outputs a high level, the high level drives the power supply circuit control module to conduct through resistors R4 and R5; when comparator IC1 outputs a low level, there is not enough voltage to drive the power supply circuit control module to conduct.

[0018] In this embodiment: Please refer to Figure 1 The power supply circuit control module includes a relay RY1, a transistor Q1, and a transistor Q2. The base of transistor Q1 is connected to the output terminal of the drive control module, the base of transistor Q2 is connected to the output terminal of the drive control module, the emitter of transistor Q1 is connected to the collector of transistor Q2, the emitter of transistor Q2 is grounded, the collector of transistor Q1 is connected to the positive terminal of two parallel diodes D1 and one end of relay RY1, and the negative terminal of the two parallel diodes D1 is connected to the other end of relay RY1 and 12V voltage.

[0019] In this embodiment: Please refer to Figure 1 Transistors Q1 and Q2 are NPN transistors.

[0020] When a high-level input is applied, transistors Q1 and Q2 are turned on, forming a circuit with the 12V voltage, relay RY1, transistors Q1 and Q2, and the negative terminal GND1. Relay RY1 is energized and controls the closing of the switch between the live wire ACL1, the neutral wire ACN1, and the subsequent circuit, thus forming a circuit. Conversely, relay RY1 is not energized and the controlled switch is opened.

[0021] The subsequent circuit includes fuse FUSE1, soft start NTC1, EMC filter circuit, live wire ACL1, neutral wire ACN1 output voltage to the electrical equipment through the subsequent circuit.

[0022] The working principle of this invention is as follows: The ground wire leakage detection module is used to detect whether a ground wire is connected. When a ground wire is connected, it outputs a first voltage signal (high level) to the drive control module; when a ground wire is not connected, it outputs a second voltage signal (low level) to the drive control module. When the drive control module receives the first voltage signal, it drives the power supply circuit control module to build a circuit, thereby enabling the power supply circuit control module to work. When the second voltage signal is received, it controls the power supply circuit control module to disconnect the circuit, thereby enabling the power supply circuit control module to stop working. When working, the power supply circuit control module controls the closing of the switch between the live wire, neutral wire, and subsequent circuits to build a circuit between the live wire, neutral wire, and subsequent circuits, thereby achieving power-on.

[0023] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and not restrictive.

[0024] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A grounding leakage protection circuit, characterized in that, The ground wire leakage protection circuit includes: The ground wire missing detection module is used to detect whether a ground wire is connected. When the ground wire is connected, it outputs a first voltage signal to the drive control module; when the ground wire is not connected, it outputs a second voltage signal to the drive control module. The drive control module is used to drive the power supply circuit control module to build a circuit when it receives the first voltage signal, so that the power supply circuit control module can work; and to control the power supply circuit control module to disconnect the circuit when it receives the second voltage signal, so that the power supply circuit control module can stop working. The power supply circuit control module is used to control the switching between the live wire, neutral wire, and subsequent circuits during operation, thereby establishing a circuit between the live wire, neutral wire, and subsequent circuits to achieve power-on. The output of the grounding leakage detection module is connected to the input of the drive control module, and the output of the drive control module is connected to the input of the power supply circuit control module.

2. The grounding leakage protection circuit according to claim 1, characterized in that, The grounding leakage detection module includes resistor R6, comparator IC1, resistor R7, and resistor R8. The inverting input of comparator IC1 is connected to one end of resistor R6 and the ground wire, and the other end of resistor R6 is connected to a 12V power supply. The non-inverting input of comparator IC1 is connected to one end of resistor R7 and one end of resistor R8. The other end of resistor R8 is grounded, and the other end of resistor R7 is connected to a 12V voltage. The output of comparator IC1 is connected to the input of the drive control module.

3. The grounding leakage protection circuit according to claim 1, characterized in that, The drive control module includes resistors R3, R4, and R5. One end of resistor R3 is connected to a 12V voltage, and the other end of resistor R3 is connected to one end of resistor R4, one end of resistor R5, and the output terminal of the grounding leakage detection module. The other end of resistor R4 is connected to the input terminal of the power supply circuit control module, and the other end of resistor R5 is connected to the input terminal of the power supply circuit control module.

4. The grounding leakage protection circuit according to claim 1, characterized in that, The power supply circuit control module includes a relay RY1, a transistor Q1, and a transistor Q2. The base of transistor Q1 is connected to the output terminal of the drive control module, the base of transistor Q2 is connected to the output terminal of the drive control module, the emitter of transistor Q1 is connected to the collector of transistor Q2, the emitter of transistor Q2 is grounded, the collector of transistor Q1 is connected to the positive terminals of two diodes D1 connected in parallel and one end of relay RY1, and the negative terminals of the two diodes D1 connected in parallel are connected to the other end of relay RY1 and a 12V voltage.

5. The grounding leakage protection circuit according to claim 4, characterized in that, Transistors Q1 and Q2 are NPN transistors.

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