WO2004102762A1

WO2004102762A1 - Safety device for electric equipments

Info

Publication number: WO2004102762A1
Application number: PCT/CN2004/000403
Authority: WO
Inventors: Li Hung Calog Ting Cheng; Kin Shin Karl Chung
Original assignee: Li Hung Calog Ting Cheng; Kin Shin Karl Chung
Priority date: 2003-04-29
Filing date: 2004-04-26
Publication date: 2004-11-25

Abstract

A safety device for electric equipments, which is aimed to get over the defects in the prior art, can monitor roundly the ground, the live line and the neutral line, and can prevent from reversing connection between the live line and the neutral line, and it is in favor of monitoring the circuit fault, also can reset automatically and can be embedded in all kinds of electric equipments. The safety device has simple configuration, small size and high safety protection performance. The safety device mainly comprises a switching circuit, a rectifier circuit and a relay, the live line and the neutral line which are connected to the power source pass though the rectifier circuit and the switching circuit, and then provide electricity to the relay. The switching circuit is used to controlling the connecting or disconnecting with the power source according to the connection state of the ground, the monitoring terminal of the switching circuit is connected to the ground. The rectifier circuit is used to provide electricity to the relay after the power source being rectified, the relay is used to controlling the power source connecting with the live line and the neutral line.

Description

Electrical equipment safety device

Technical field

The present invention relates to the field of electrical equipment safety protection devices, and more particularly to an electrical equipment safety device.

technical background

Existing general power supply systems generally use three-wire access, and live and neutral wires are used for power supply. The ground wire protects users from the danger of electric shock. With the widespread use of a variety of large-scale electrical equipment today, safe use of electricity has attracted more and more attention, and electrical equipment safety protection devices have also gradually developed. The more traditional methods in the prior art include fuses, safety switches, short-circuit switches, and safety protection devices in electrical equipment. Although the fuse is simple in structure and low in cost, it has gradually withdrawn from the market due to its relatively rough safety performance and slow response. It has little protection for users and electrical equipment; the safety protection devices in electrical equipment generally only protect the cost. The safety of the equipment or users using this equipment has little effect on the safety protection of the power grid; various safety switches and short-circuit switches are widely used in the prior art. Such safety devices are relatively responsive and can control their safety. The entire power grid under its jurisdiction, but has a complex structure, high cost, and large volume. Generally, only one or several such safety devices are set in a large network of power units, and it can only be controlled from a relatively large range. Safety of the power grid; safety devices such as safety switches and short-circuit switches are generally aimed at the danger of electric shock to users caused by the live and neutral wires in the power grid, but it is impossible to monitor the hidden danger to the user whether the ground wire is connected. , Even if the ground wire is not connected during wiring or installation It is often used, so there are some hidden dangers in this type of safety device. The above types of safety devices also have the following shortcomings. Since most of the current power grids are AC power grids, this type of safety device is used when the live and neutral wires are switched. However, safety devices can be used normally, causing great danger to users and electrical equipment. Generally, such safety devices are used to monitor a certain range of power grids or an electrical device.

ΗΊ

Confirm this RO / CN When the power is disconnected, it plays a role of safety protection, but it cannot help the user to confirm that there is a problem with the electricity network or the electrical equipment, which is not conducive to maintenance. The adjustable performance of such safety devices is poor. Users cannot control the sensitivity of their reactions, and can only choose safety devices with different sensitivities for different needs; and such safety devices generally need to be reset manually after the fault is removed in order to connect the power line.

Summary of the Invention

The present invention provides a safety device for electrical equipment, which aims to overcome various shortcomings in the prior art, and provides a comprehensive monitoring of ground, live and neutral wires, high safety protection performance, and the ability to prevent hot and neutral wires. Reverse connection is conducive to monitoring circuit failure, can be automatically reset, simple structure, small size, and can be embedded in various electrical equipment safety protection devices.

The present invention mainly achieves its object of invention by the following technical points.

The invention is a safety device for electrical equipment, which is characterized in that it includes a switch circuit, a rectifier circuit and a relay, which are connected to the live line of the power supply, and the neutral line supplies power to the relay after passing through the rectifier circuit and the switch-off circuit. And the ground wire are connected to the relay respectively before being connected to electrical equipment; the switch circuit is used to control the power on and off according to the path of the ground wire or the state of the open circuit; the monitoring end of the switch circuit is connected to the ground wire; The power is supplied to the relay after the power is rectified. The relay is used to control the on and off of the live, neutral and ground wires connected to the power. The present invention mainly controls the power supply to the relay by a switch circuit. When the ground wire is connected, the switch circuit is connected to the power supply. The relay is supported by the power source to maintain the circuit connection. When the ground wire is disconnected, the switch circuit is disconnected from the power supply. Power supply, relay loses support of power supply, disconnects circuit. The invention has a simple structure and a small volume. With the development of modern integrated circuit technology, various components and circuits can be integrated into a small integrated circuit and directly embedded in electrical equipment, such as directly embedded in switches, sockets, power strips or Inside the appliance, it protects it and its users.

^A RO / CN The switching circuit of the present invention is mainly composed of a logic chip and an amplification circuit, a ground wire is connected to an input end of the logic chip, and an output end of the logic chip is connected to a detection end of the amplification circuit. Testing the path and disconnection of the ground wire is mainly performed by the logic chip. The input end of the logic chip is connected to the ground wire. The level signal 0 generated by the path of the ground wire and the level signal 1 generated by the disconnection are input signals of the logic chip. The logic chip The on-off of the amplifier circuit is controlled according to the input signal and its own characteristic output level signal, so that the on-off state of the ground line can be used to control the on-off of the switching circuit.

The connection of the ground wire is the key to the safe use of electricity, especially the ground wire plays a critical protective role for the user or the equipment. The present invention can ensure that the ground wire is always connected, and overcomes the shortcomings that various safety devices in the prior art cannot find whether the ground wire is connected, and greatly improves the safety of power consumption.

In the process of using the present invention, the relay is mainly connected through the power supply of the live line and the neutral line, and no external power supply is required, and the relay will be lost when any one or more of the live line, the neutral line, or the ground line is disconnected. The power supply cannot maintain its closed state, cut off the power supply, and play a role of safety protection. In addition, when the live line and the neutral line are accidentally reversed, the relay will not work, completely eliminating the hidden dangers caused by wiring.

Because the present invention has a simple structure, low cost, small size, and is directly embedded in electrical equipment, when the electrical network is used for wiring, the present invention is embedded in each electrical equipment on the line, especially terminal equipment such as switches, Sockets, power strips, etc. Therefore, it is very useful for judging circuit faults. When a device in the circuit is not working due to safety problems, you can determine the line fault range by judging whether the upper and lower devices connected to it work, and the circuit fault can be quickly reduced to Very small range. After the fault in the line is eliminated, the relay of the present invention has power supply support, and the circuit is re-connected to automatically restore power to the line without manual intervention, making it more practical and more convenient to use.

The invention can also add a voltage divider circuit to the switching circuit. The voltage dividing circuit is used to adjust the detection sensitivity of the monitoring chip. The production personnel can adjust the safety sensitivity of the present invention according to the needs of specific situations, such as i RO / GN In the case of poor line quality, the sensitivity can be reduced and the probability of false alarms can be reduced. For a good line quality, increasing its sensitivity can improve the safety of power consumption.

In the present invention, a status indicator is provided between the relay and the electrical equipment, and the power terminal of the status indicator is connected to the live and neutral wires, respectively. The indicator light is used to indicate the working condition of the present invention, so that the user can simply and clearly judge whether the relay of the present invention is on or off in the power line, which is more conducive to determining the scope of the line fault.

Compared with the prior art, the present invention has the following significant advantages.

1. With the simultaneous monitoring of whether the live, neutral and ground wires are connected, the safety performance is high;

2. Effectively eliminate the safety hazards of reverse connection of live and neutral wires;

3. Conducive to quickly and accurately determine the scope of line failure;

4. With automatic reset function;

5. Wide application;

6. Simple structure, small size, can be used embeddedly;

7. Low cost, can be adopted in a wide range.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a control block diagram of the present invention;

FIG. 2 is a circuit diagram of FIG. 1;

detailed description

As shown in FIG. 1, the present invention is an electrical equipment safety device, which is characterized by including a switch circuit (1), a rectifier circuit 2, and a relay 3. The live line 4 and the neutral line 5 connected to a power source pass through the rectifier circuit 2 and the switch circuit. Power supply for relay 3 after 1. Connect live line 4, neutral line 5 and ground line 6 of the power supply to relay 3 respectively before connecting to electrical equipment 7. The switch circuit 1 is used to connect or disconnect the ground line 6. State to control the power on and off, the monitoring end of the switch circuit 1 is connected to the ground line 6; the rectifier circuit 2 is used for After rectifying the power supply, power is supplied to relay 3; relay 3 is used to control the on and off of live line 4, neutral line 5, and ground line 6 connected to the power supply. In this embodiment, the switching circuit 1 is composed of a logic chip 11, an amplification circuit 12, and a voltage dividing circuit 13. A ground line 4 is connected to an input terminal of the logic chip 11, and an output terminal of the logic chip 11 is connected to a detection terminal of the amplification circuit 12. A status indicator 8 is provided between the relay 3 and the electrical equipment 7, and the power terminals of the status indicator 8 are connected to the live wire 4 and the neutral wire 5, respectively.

The specific circuit diagram of this embodiment is shown in FIG. 2, where the switching circuit 1 includes an IC4011 logic chip 11; an amplifier circuit 12 composed of a transistor BG1 and a capacitor C1; and a voltage dividing circuit 13 composed of resistors R1, R2, R3, and R4. Set one input terminal of the IC4011 logic chip 11 to 0 and the other input terminal to the ground line 6, and the output terminal to the base of the transistor S1 of the amplifier circuit 12. When the ground line 6 is a path, the input of the other end of the logic chip 11 Is 0, according to the working principle of 1C4011, the signal output from the output terminal of the voltage divider circuit 13 is 1, and the transistor BG1 will ensure the circuit connection; when the ground line 6 is open, the input of the other end of the voltage divider circuit 13 is 1, According to the working principle of the iC4011, the signal output from the output terminal of the logic chip 11 is 0, and the transistor BG1 cannot connect to the circuit. The rectifier circuit 2 in this embodiment is composed of four diodes D1, D2, D3, and D4 connected to form a rectifier bridge, and the relay 3 is composed of a switch K1 and an inductor T1. The live wire 4, the neutral wire 5 supplies power to the relay 3 through the rectifier circuit 2 and the switch circuit 1. According to the above principle, the switch circuit 1 can control the on / off state of the ground wire 6 to control the power supply of the relay 3 on or off. When the inductor T1 of the relay 3 is supported by the power, the switch K1 is closed by magnetic force; since the hot wire 4, the neutral wire 5 and the ground wire 6 are respectively connected to the switch K1 of the relay 3 and then to the electrical equipment 7, respectively, when the inductor T1 has When the power supply supports, the electrical equipment 7 can be used normally. When the inductance coil T1 has no power support, the switch K1 is opened to cut off the power of the electrical equipment 7.

^Δ RO / CN

Claims

Claim

An electrical equipment safety device, comprising a switch circuit (1), a rectifier circuit (2) and a relay (3), a live wire (4) connected to a power source, and a neutral wire (5) passing through a rectifier circuit (2) And switching circuits

(1) power the relay (3), and connect the live wire (4), neutral wire (5) and ground wire (6) of the power supply to the relay (3) respectively before connecting to the electrical equipment (7); The switch circuit (1) is used to control the on / off of the power supply according to the path of the ground wire (6) or the state of the open circuit. The monitoring terminal of the switch-off circuit (1) is connected to the ground wire (6); the rectifier circuit (2) is used for The power is supplied to the relay (3) after the power is rectified; the relay (3) is used to control the on and off of the hot wire (4), the neutral wire (5) and the ground wire (6) connected to the power supply.

2. The electrical device safety device according to claim 1, characterized in that the switching circuit Π) is composed of a logic chip (11) and an amplifier circuit (12); the logic chip (11) is used for powering according to the ground wire (4) Level, output level signal to the amplifier circuit; the amplifier circuit (12) is used to turn on or off the circuit according to the level signal output from the logic chip (11), the ground wire (4) and the input of the logic chip (11) End connection,

I

The output terminal of the logic chip (11) is connected to the detection terminal of the amplifier circuit (12).

The electrical device safety device according to claim 1, characterized in that the switching circuit (1) is composed of a logic chip (11), an amplifier circuit (12), and a voltage dividing circuit (13), and the voltage dividing circuit ( 13) Used to adjust the voltage of the logic chip (11) and the amplifier circuit (12).

4. The electrical equipment safety device according to claim 1 or 2 or 3, characterized in that a status indicator (8), a status indicator (8) is provided between the relay (3) and the electrical equipment (7) It is used to indicate the status of the relay (3) is off and on. The power terminal of the status indicator (8) is connected to the live wire (4) and the neutral wire (5), respectively.

RO / CN