CN204927704U - Convertible ground wire protected mode's leakage protection plug - Google Patents

Abstract

The utility model provides a convertible ground wire protected mode's leakage protection plug, the bolt, the phase line, the zero line, a ground wire, zero sequence current transformer, test circuit, the electromagnetism is threaded off and locking device, ground wire fault current detection circuitry, ground wire trouble voltage detection circuit, the 1st, 2 change over switch, the 1st, 2 amplifier circuit, the unidirectional flux circuit, the 2nd, 3 diode cluster becomes, zero sequence current transformer secondary output and 1 amplifier circuit input are connected, the electrified inductor secondary output that detects of ground wire is connected with the 2 amplifier circuit input through 2 change over switch, the 1st, 2 amplifier circuit triggers the output through the 2nd, 3 the diode and the thyristor control utmost point, unidirectional flux circuit output is connected. This leakage protection plug can change the selection to ground wire fault current protected mode and ground wire trouble voltage mode, has solved leakage protection plug mistrip problem, has ensured that people's power consumption is safer.

Description

A leakage protection plug with convertible ground wire protection mode

technical field

The utility model relates to the technical field of electricity safety protection, in particular to a leakage protection plug with a convertible ground wire protection mode.

Background technique

Existing leakage protection plugs can be divided into two types of products: ground fault current detection and protection and ground fault voltage detection and protection according to the detection and protection methods for live wires.

Chinese patent document CN1142618C discloses a leakage protection plug capable of detecting ground wire fault current. The leakage protection plug can detect whether there is a fault current in the ground wire when the ground wire is accidentally electrified due to an abnormal ground protection system, and the ground wire fault current reaches When the preset threshold value is reached, it will immediately cut off the phase wire, neutral wire and ground wire. It can be seen from this that, as long as the fault current of the ground wire of this kind of leakage protection plug reaches a predetermined threshold value, the leakage protection plug will trip regardless of the fault voltage carried by the ground wire. Low, but because the ground wire has a fault current greater than the predetermined threshold, it will cause the leakage protection plug to trip by mistake, causing people to be unable to use it normally.

Chinese patent document CN202142735U also discloses a leakage protection plug capable of detecting ground fault voltage. This leakage protection plug will automatically trip when the grounding system is abnormal and the ground fault voltage reaches a predetermined threshold, and it will be disconnected from the ground fault current. size is irrelevant. Therefore, when the fault voltage of the leakage protection plug in the ground wire is an induced voltage greater than a predetermined threshold but the fault current flowing through the ground wire is very weak, it will also cause the leakage protection plug to trip by mistake, causing people to be unable to use it normally.

For this reason, the electric water heater market urgently needs a kind of product that can adapt to the ground wire electrification protection technology of various electricity consumption environments, thereby can reach and reduce the probability of returning goods and repairing after sale.

Contents of the invention

The purpose of the utility model is to provide a leakage protection plug with a convertible ground wire protection mode. The leakage protection plug can not only detect the fault current and voltage of the ground wire, but also detect the fault current and voltage of the ground wire. The electrified protection function of the ground wire is selectively converted, which not only solves the problem that the leakage protection plug cannot be used normally due to false tripping, but also reduces the after-sales maintenance rate and maintenance cost of the product.

The technical solution proposed by the utility model is as follows:

A leakage protection plug with a convertible ground wire protection mode, including a shell, a pin, a first phase wire and a second phase wire, a first neutral wire and a second neutral wire, a first ground wire and a second ground wire, all Describe the zero-sequence current transformer, test circuit, electromagnetic tripping and locking device through which the second phase line and the second neutral line pass. The electromagnetic tripping and locking device consists of an electromagnetic coil and its driving circuit, a phase line head switch, zero line contact switch, and ground line contact switch. The drive circuit of the electromagnetic coil is mainly composed of the first rectifier circuit, thyristor, the first resistor, and the first amplifying circuit. The zero sequence current mutual inductance One output end and the other output end of the secondary winding of the device are respectively connected in parallel with the first input end and the second input end of the first amplifying circuit, and a ground wire fault current detection circuit and a ground wire fault voltage detection circuit are also provided , the first transfer switch, the second transfer switch, the one-way conduction circuit, and the second diode; the ground wire fault current detection circuit is provided with a ground wire electrification detection inductor, a second amplifying circuit, and a third diode. The line fault voltage detection circuit is equipped with a first capacitor, a second rectifier circuit, a third resistance-capacitance element, a photocoupler, a fourth resistor, a first triode, and a fifth resistor; one end of the first resistor is connected to the first rectifier circuit for DC output The positive pole of the terminal is connected to the anode of the thyristor, the other end of the first resistor is connected to the power supply terminal of the first amplifying circuit, the power supply terminal of the second amplifying circuit, and the third pin of the first transfer switch, the ground terminal of the first amplifying circuit, The ground terminal and the thyristor cathode of the second amplifying circuit are connected to the negative pole of the DC output terminal of the first rectifier circuit, and the trigger output terminal of the first amplifying circuit is connected to the positive pole of the second diode; the second ground wire passes through the ground wire for charged detection Inductor, the other output end of the secondary winding of the live wire detection sensor is connected to the second input end of the second amplifier circuit, and the first output end of the secondary winding of the live wire detection sensor is connected to the third pin end of the second changeover switch , the first pin end of the second transfer switch is connected to the first input end of the second amplifying circuit, and the trigger output end of the second amplifying circuit is connected to the anode of the third diode; the AC input end of the first capacitor and the second rectifying circuit , The loop formed by the third resistance-capacitance element in series is connected between the first ground line and the first neutral line, the DC output end of the second rectification circuit is connected in parallel with the input end of the photocoupler, and the photocoupler One output terminal, the collector of the first transistor is connected to the second pin of the first transfer switch, the other output terminal of the photocoupler is connected to the fourth resistor and the base of the first transistor, and the emitter of the first transistor is connected to the fifth resistor One end is connected to the input end of the one-way conduction circuit, the other end of the fifth resistor and the other end of the fourth resistor are connected to the negative pole of the DC output end of the first rectification circuit, and the output end of the one-way conduction circuit is connected to the cathode of the second diode and the cathode of the third diode . The control electrode of the silicon controlled rectifier is connected; the first transfer switch and the second transfer switch are linked on or off.

There is also a second resistor and a light-emitting diode; one end of the second resistor is connected to the second pin of the first transfer switch, the other end of the second resistor is connected to the positive pole of the light-emitting diode, and the negative pole of the light-emitting diode is connected to the negative pole of the DC output terminal of the first rectifier circuit .

The first transfer switch and the second transfer switch are integrally installed on the bottom case of the housing.

The light-emitting diodes are installed on the surface shell of the housing.

The unidirectional conduction circuit is composed of a first diode.

The one-way conduction circuit is formed by the second triode.

The third resistance-capacitance element is composed of a resistor.

The third resistance-capacitance element is composed of a capacitor.

The third resistance-capacitance element is composed of a resistor and a capacitor.

Compared with the prior art, the utility model has the following beneficial effects:

(1) A leakage protection plug of the utility model with a convertible ground wire protection mode can detect the fault current of the ground wire. The contact switches of the zero and ground wires are all disconnected, so the utility model provides a safer electricity use safety guarantee than the existing leakage protection plug.

(2) The leakage protection plug of the utility model can detect the fault voltage of the ground wire, once the fault voltage of the ground wire unexpectedly reaches a predetermined threshold, it directly triggers the conduction of the thyristor to drive the electromagnetic coil to work, which improves the reaction speed, The breaking time is shortened, and before people get an electric shock, it can immediately disconnect all the contact switches of the phase, zero, and ground wires, so the utility model provides a safer electricity use than the existing leakage protection plug. Assure.

(3) The leakage protection plug of the utility model can select different charging protection modes for the ground wire through two transfer switches, so that a suitable ground wire charging protection mode can be selected for a specific power consumption environment, which not only solves the current problem It is intentional that the accidental tripping of the leakage protection plug will cause the problem that it cannot be used normally, and it will also reduce the after-sales maintenance rate and maintenance cost of the product.

(4) The leakage protection plug of the present utility model skillfully utilizes the current-limiting resistor of the amplifying circuit and the built-in stabilizing power supply of the amplifying circuit, so there is no need to additionally set up a stabilizing power supply and a voltage-dropping resistor, which saves production costs.

(5) The leakage protection plug of the present utility model can separate the three-way signals and avoid mutual influence by triggering the same thyristor through the unidirectional conduction circuit, the second diode, and the third diode respectively, without additional controllable Silicon, thus saving production costs.

The utility model relates to a leakage protection plug with a convertible ground wire protection mode, which is mainly used in the leakage protection of various household appliances, and can be made into a power cord with a leakage protection plug.

Description of drawings

Fig. 1 is a schematic circuit diagram of a leakage protection plug with a convertible ground wire protection mode according to an embodiment of the present invention.

FIG. 2 is a schematic diagram of another alternative to the unidirectional conduction circuit 30 shown in FIG. 1 .

Detailed ways

The utility model is described in further detail by the following examples.

As shown in Figure 1, a leakage protection plug with a switchable ground wire protection mode includes a shell, a pin, a first phase wire 1 and a second phase wire 4, a first neutral wire 2 and a second neutral wire 5, a first neutral wire 2 and a second neutral wire 5. 1 ground wire 3 and the second ground wire 6, the zero-sequence current transformer 17 through which both the second phase wire 4 and the second neutral wire 5 pass, the test circuit 40, the electromagnetic tripping and locking device, the electromagnetic tripping The buckle and lock device is composed of an electromagnetic coil 13 and its drive circuit, a phase line contact switch 7, a neutral line contact switch 8, and a ground line contact switch 9. The drive circuit of the electromagnetic coil 13 is mainly composed of a first rectifier circuit 14. The thyristor 15, the first resistor 10, and the first amplifying circuit 16 are composed of one output end and the other output end of the secondary winding of the zero-sequence current transformer 17 and the first amplifying circuit 16 respectively. 1 The input terminal 16-1 is connected in parallel with the second input terminal 16-2, and a ground fault current detection circuit, a ground fault voltage detection circuit, a first transfer switch 26-1, a second transfer switch 26-2, One-way conduction circuit 30, the second diode 12; the ground wire fault current detection circuit is provided with a ground wire electrification detection inductor 18, the second amplifier circuit 11, the third diode 31, and the ground wire fault voltage detection circuit is There are a first capacitor 19, a second rectifier circuit 20, a third resistance-capacitance element 21, a photocoupler 22, a fourth resistor 23, a first triode 24, and a fifth resistor 25; one end of the first resistor 10 is connected to the first rectifier circuit 14 The positive pole of the DC output terminal is connected to the anode of the thyristor 15, and the other end of the first resistor 10 is connected to the power supply terminal Vs1 of the first amplifying circuit 16, the power supply terminal Vs2 of the second amplifying circuit 11, and the third terminal of the first transfer switch 26-1. The pins 26-1-3 are connected, the ground terminal GND1 of the first amplifying circuit 16, the ground terminal GND2 of the second amplifying circuit 11, the cathode of the thyristor 15 are connected to the negative pole of the DC output terminal of the first rectifying circuit 14, and the first amplifying circuit The trigger output terminal 16-3 of 16 is connected to the anode of the second diode 12; the second ground wire 6 passes through the ground wire electrification detection inductor 18, and the other output end of the ground wire electrification detection inductor 18 secondary winding and the second The second input end 11-2 of the amplification circuit 11 is connected, the ground wire electrification detection inductor 18 secondary winding one output end is connected with the third pin end 26-2-3 of the second changeover switch 26-2, the second changeover switch 26 The first pin end 26-2-1 of -2 is connected with the first input end 11-1 of the second amplifying circuit 11, and the trigger output end 11-3 of the second amplifying circuit 11 is connected with the anode of the third diode 31; 1. The loop formed by series connection of capacitor 19, the AC input terminal of the second rectifier circuit 20, and the third resistance-capacitance element 21 is connected between the first ground wire 3 and the first neutral wire 2. The second rectifier circuit 20 The DC output end of the photocoupler is connected in parallel with the input end of the optocoupler 22, the output end of the optocoupler 22, the collector of the first triode 24 are connected with the second pin end 26-1-2 of the first transfer switch 26-1, and the optoelectronic The other output end of the coupler 22 is connected to one end of the fourth resistor 23 and the base of the first triode 24, and the first The emitter of the triode 24 is connected to one end of the fifth resistor 25 and the input terminal Vi1 of the unidirectional conduction circuit 30, and the other end of the fifth resistor 25 and the other end of the fourth resistor 23 are connected to the negative pole of the DC output end of the first rectifier circuit 14 for unidirectional conduction. The output terminal Vo1 of the circuit 30 is connected to the negative pole of the second diode 12, the negative pole of the third diode 31, and the control pole of the thyristor 15; the first transfer switch 26-1 and the second transfer switch 26-2 are linked to open or close .

The utility model can also be provided with the 2nd resistance 29 and light-emitting diode 28, as shown in Figure 1, the 2nd resistance 29 one end is connected with the 2nd pin end 26-1-2 of the 1st transfer switch 26-1, the 2nd resistance The other end of the resistor 29 is connected to the anode of the LED 28 , and the cathode of the LED 28 is connected to the cathode of the DC output terminal of the first rectifier circuit 14 . The light-emitting diodes 28 are installed on the face shell of the housing.

In this embodiment, the first transfer switch 26-1 and the second transfer switch 26-2 are integrated and installed on the bottom shell of the housing

In this embodiment, the unidirectional conduction circuit 30 is composed of a first diode 30-1. As shown in Figure 2, the unidirectional conduction circuit 30 can also be composed of the second triode 30-2. At this time, the base of the second triode 30-2 is directly connected to the input terminal Vi1 of the unidirectional conduction circuit 30, and the second triode The emitter of 30-2 is connected to the output terminal Vo1 of the one-way conduction circuit 30, and the collector of the second triode 30-2 is connected to the second pin 26-1-2 of the first transfer switch 26-1.

In this embodiment, the third resistance-capacitance element 21 is composed of a resistor, and may also be composed of a capacitor or a combination of a resistor and a capacitor.

During use, the leakage protection plug reset button is pressed, and the phase line contact switch 7, the neutral line contact switch 8, and the ground line contact switch 9 are closed to connect the mains power supply to provide working power for the electrical appliances at the lower end.

In use, if the insulation of the electrical appliance is damaged to generate leakage, the zero-sequence current transformer 17 detects the leakage signal and inputs the signal to the first input terminal 16-1 and the second input terminal 16-1 of the first amplifying circuit 16. 2. When the leakage current reaches a predetermined threshold, the first amplifying circuit 16 triggers the output signal of the output terminal 16-3 to trigger the conduction of the thyristor 15 through the second diode 12, so that the electromagnetic coil 13 works to turn the phase line contact switch 7, The zero line contact switch 8 and the ground line contact switch 9 are all disconnected immediately, thereby ensuring the safety of people's electricity use.

If the leakage protection plug of the present utility model is selected in advance according to the use environment when the second transfer switch 26-2 and the first transfer switch 26-1 are connected to the ground fault current protection mode, the first pin of the second transfer switch 26-2 The terminal 26-2-1 is connected with the 3rd pin end 26-2-3 of the 2nd changeover switch 26-2, and the 2nd pin end 26-2-2 of the 2nd changeover switch 26-2 is connected with the 2nd changeover switch 26-2-2. 26-2 is disconnected between the 3rd pin end 26-2-3, at the same time, because the linkage action between the 1st transfer switch 26-1 and the 2nd transfer switch 26-2, so, the 1st transfer switch 26- Also connected between the 1st pin end 26-1-1 of 1 and the 3rd pin end 26-1-3 of the 1st transfer switch 26-1, the 2nd pin end 26-1 of the 1st transfer switch 26-1 -2 is also disconnected from the third pin end 26-1-3 of the first transfer switch 26-1, and the LED 28 is in a extinguished state to indicate that the leakage protection plug is in the ground fault current protection mode. When an abnormality in the grounding system causes the first ground wire 3 and the second ground wire 6 to be electrified accidentally, the ground wire electrification detection sensor 18 on the ground wire fault current detection circuit immediately detects the fault current flowing through the second ground wire 6 and Send the signal to the first input terminal 11-1 and the second input terminal 11-2 of the second amplifying circuit 11, when the detected ground fault current is greater than the predetermined current threshold, the second amplifying circuit 11 triggers the output terminal 11-3 The output signal triggers the silicon controlled rectifier 15 conduction through the third diode 31 to make the electromagnetic coil 13 work, and all the phase line contact switch 7, the neutral line contact switch 8, and the ground line contact switch 9 are all disconnected immediately, thereby further Good protection of people's electricity safety.

If the leakage protection plug of the present utility model is selected in advance according to the use environment when the first transfer switch 26-1 and the second transfer switch 26-2 are connected to the ground fault voltage protection mode, the first pin of the first transfer switch 26-1 Terminal 26-1-1 is disconnected from the 3rd pin end 26-1-3 of the 1st transfer switch 26-1, the 2nd pin end 26-1-2 of the 1st transfer switch 26-1 is connected to the 1st transfer switch Connect between the 3rd pin end 26-1-3 of 26-1, light-emitting diode 28 is illuminated, and the indication leakage protection plug is in ground wire fault voltage protection mode; Linkage action between the 2 transfer switches 26-2, the 1st pin end 26-2-1 of the 2nd transfer switch 26-2 and the 3rd pin end 26-2-3 of the 2nd transfer switch 26-2 are also disconnected. Open, also connected between the 2nd pin end 26-2-2 of the 2nd changeover switch 26-2 and the 3rd pin end 26-2-3 of the 2nd changeover switch 26-2. When an abnormality occurs in the grounding system and the first ground wire 3 and the second ground wire 6 are accidentally electrified, the photocoupler 22 on the ground fault voltage detection circuit outputs a signal to the first triode 24. When the detected ground fault voltage is greater than When the predetermined voltage threshold is reached, the first triode 24 outputs a high-level signal and triggers the conduction of the thyristor 15 through the first diode 30-1 in the one-way conduction circuit 30 to make the electromagnetic coil 13 work and turn the phase line contact switch 7 , zero line contact switch 8, and ground line contact switch 9 are all disconnected immediately, thereby better ensuring people's electricity safety.

Claims (9)

1. A leakage protection plug with a convertible ground wire protection mode, including a shell, a plug, a first phase wire and a second phase wire, a first neutral wire and a second neutral wire, a first ground wire and a second ground wire , the zero-sequence current transformer through which both the second phase line and the second neutral line pass, a test circuit, an electromagnetic tripping and locking device, the electromagnetic tripping and locking device consists of an electromagnetic coil and its driving circuit, a phase line contact switch, zero line contact switch, and ground line contact switch. The drive circuit of the electromagnetic coil is mainly composed of the first rectifier circuit, silicon controlled rectifier, first resistor, and first amplifying circuit. The zero sequence One output end and the other output end of the secondary winding of the current transformer are respectively connected in parallel with the first input end and the second input end of the first amplifying circuit, and it is characterized in that: a ground fault current detection circuit, Ground wire fault voltage detection circuit, first transfer switch, second transfer switch, one-way conduction circuit, second diode; the ground wire fault current detection circuit is provided with a ground wire live detection sensor, a second amplifying circuit, a second 3 diodes, the ground fault voltage detection circuit is provided with a first capacitor, a second rectifier circuit, a third resistance-capacitance element, a photocoupler, a fourth resistor, a first triode, and a fifth resistor; one end of the first resistor is connected to The positive pole of the DC output end of the first rectifier circuit is connected to the anode of the thyristor, and the other end of the first resistor is connected to the power end of the first amplifying circuit, the power end of the second amplifying circuit, and the third pin end of the first transfer switch. The ground terminal of the amplifying circuit, the ground terminal of the second amplifying circuit, and the cathode of the thyristor are connected to the negative pole of the DC output terminal of the first rectifier circuit, and the trigger output terminal of the first amplifying circuit is connected to the positive pole of the second diode; the second ground wire Through the live wire detection sensor, the other output terminal of the secondary winding of the live wire detection sensor is connected to the second input terminal of the second amplifier circuit, and the first output terminal of the secondary winding of the live wire detection sensor is connected to the second transfer switch The 3rd pin end is connected, the 1st pin end of the 2nd transfer switch is connected with the 1st input end of the 2nd amplifying circuit, the trigger output end of the 2nd amplifying circuit is connected with the anode of the 3rd diode; The AC input end of the rectifier circuit and the third resistance-capacitance element are connected in series between the first ground line and the first neutral line, and the DC output end of the second rectification circuit is connected to the input end of the photocoupler. Parallel connection, one output terminal of the photocoupler, the collector of the first transistor is connected to the second pin of the first transfer switch, the other output terminal of the photocoupler is connected to the fourth resistor and the base of the first transistor, and the first transistor The emitter is connected to one end of the fifth resistor and the input end of the unidirectional conduction circuit, the other end of the fifth resistor, the other end of the fourth resistor is connected to the negative pole of the DC output end of the first rectifier circuit, and the output end of the unidirectional conduction circuit is connected to the second diode The negative pole, the negative pole of the third diode, and the control pole of the silicon controlled rectifier are connected; the first transfer switch and the second transfer switch are linked on or off. 2. A leakage protection plug with a switchable ground wire protection mode according to claim 1, characterized in that: a second resistor and a light emitting diode are also provided; one end of the second resistor is connected to the second pin end of the first transfer switch connected, the other end of the second resistor is connected to the anode of the light-emitting diode, and the cathode of the light-emitting diode is connected to the cathode of the DC output terminal of the first rectifier circuit. 3 . The leakage protection plug with switchable ground wire protection mode according to claim 1 , wherein the first transfer switch and the second transfer switch are integrated and installed on the bottom shell of the housing. 4 . 4 . The leakage protection plug with switchable ground wire protection mode according to claim 2 , wherein the light-emitting diode is installed on the surface shell of the shell. 5 . 5 . The leakage protection plug with switchable ground wire protection mode according to claim 1 , wherein the unidirectional conduction circuit is composed of a first diode. 6 . 6 . The leakage protection plug with switchable ground wire protection mode according to claim 1 , wherein the unidirectional conduction circuit is composed of a second transistor. 6 . 7 . The earth leakage protection plug with switchable ground wire protection mode according to claim 1 , wherein the third resistance-capacitance element is composed of a resistor. 8 . 8 . The leakage protection plug with switchable ground wire protection mode according to claim 1 , wherein the third resistance-capacitance element is composed of a capacitor. 9 . The leakage protection plug with switchable ground wire protection mode according to claim 1 , wherein the third resistance-capacitance element is composed of a resistor and a capacitor. 10 .