WO2010108360A1 - Leakage protective plug - Google Patents

Abstract

A leakage protective plug includes an electromagnetic tripping device (4) and a leakage protective circuit (A). The leakage protective circuit includes a ground wire leakage detection chip (IC2). A power phase line is electrically connected to a positive pole pin of the ground wire leakage detection chip after divided by a resistor (R9,R10). A negative pole pin is electrically connected to a power ground wire. A collector electrode is connected to an input terminal of the electromagnetic tripping device. The ground wire leakage detection chip starts the electromagnetic tripping device to cut off the power when the ground wire is not well grounded or disconnected.

Description

 Instruction manual

Title of Invention: Leakage protection plug

 Technical field

 [1] The present invention relates to a power plug, and more particularly to a leakage protection plug, which is mainly used in electric water heaters, air conditioners or mobile power tools, such as hand drills, bathroom hair dryers, etc., to provide leakage protection for the above devices.

 Background technique

 Background technique

 [2] With the increasing popularity of industrial production facilities and household appliances, people have more opportunities to get in touch with electricity.

The occurrence of electric shock and injury caused by the failure of the electrical equipment has occurred. According to relevant information, electrical accidents in industrial accidents in the country are as high as 37%. For personal safety and equipment safety, the leakage protector has been widely used as an effective electrical safety technology device and has played a pivotal role.

 [3] Based on the leakage protector principle, in order to better protect the user, many products are now equipped with a leakage protection plug. When the electrical equipment connected to the leakage protection plug is leaking, the leakage protection plug can be in the tens of milliseconds. The power is automatically cut off to protect the user from the danger of electric shock and protect the safety of the user. In particular, it is applied to electrical equipment in some special occasions below. (1) In particularly humid places (such as swimming pools, shower rooms, kitchens, bathrooms, etc.), the risk of electrocution is greatly increased due to the reduction in the skin resistance of the human body. (2) When some electronic equipment is damaged by insulation, its exposed metal accessories (such as TV sets, drawbar antennas of tape recorders, etc.) may carry dangerous voltage.

 [4] However, a large number of facts prove that even if the load is not faulty, due to power failure, such as neutral line, ground line misconnection, grounding grounding poor or disconnected, excessive voltage caused by electrical appliances burning, etc., will also make electrical equipment The electric shock of the outer casing causes an electric shock accident. The existing leakage protection plug can only generate residual current between the phase line and the neutral line and will cut off the power supply to protect the rear load when the residual current reaches the set value (for example, 10MA). Moreover, although the product with ground fault indication on the market has a ground fault indicator alarm, it cannot be cut off. Because the leakage protection plug is generally installed in a concealed place, even if the ground line is faulty, the user cannot see it. This will lead to an electric shock accident.

Summary of the invention [5] The technical problem to be solved by the present invention is to solve the problem that the leakage protection plug can only cut off the power supply after there is residual current between the phase and neutral lines, and cannot give power failure protection when the ground line fails.

 [6] In order to solve the above technical problem, the technical solution adopted by the present invention is to provide a leakage protection plug, which is connected to the end of the power cable of the electrical device to provide input power to the electrical device, and the leakage protection plug includes:

 [7] The outer casing is fastened by the upper and lower casings;

 [8] phase, neutral and ground copper plugs, the plugs are respectively inserted and fixed on the lower casing;

 [9] an electromagnetic trip device for cutting off the phase line, the neutral line and the ground copper plug and the power line, the electromagnetic trip device comprising a trip wire and a unidirectional thyristor, the trip wire The crucible has first and second terminals, the anode of the unidirectional thyristor is electrically connected to the neutral copper plug, and the cathode is connected to the first terminal of the trip bobbin;

 [10] The reset device is disposed in the outer casing and the reset button passes through the upper surface of the upper casing, and the reset device is configured to reconnect the phase line, the neutral wire and the ground copper plug and the power line;

[11] a rectifier circuit for providing a DC operating voltage;

 [12] The leakage protection circuit includes a zero sequence current protection circuit, and the zero sequence current protection circuit includes a zero sequence current transformer and an amplification circuit, and the zero sequence current transformer is sleeved on the phase line, the neutral line and the ground line The output end is electrically connected to the input end of the amplifying circuit, and the output end of the amplifying circuit is electrically connected to the control pole of the unidirectional thyristor;

 [13] The leakage protection circuit also includes an overvoltage protection circuit and a ground leakage protection circuit:

 [14] The overvoltage protection circuit includes two first and second voltage dividing resistors connected in series and a first diode connected between the two voltage dividing resistors, and the other end of the first diode is connected to the single To the control electrode of the thyristor, the other end of the first voltage dividing resistor is connected to the positive output terminal of the rectifier circuit, and the other end of the second voltage dividing resistor is connected to the negative output terminal of the rectifier circuit;

[15] The ground leakage protection circuit includes a third and fourth voltage dividing resistor and a ground leakage detecting chip connected in series, and the other ends of the third and fourth voltage dividing resistors are electrically connected to the power phase line and the middle, respectively a neutral line, the anode lead of the ground leakage detecting chip is electrically connected between the third and fourth voltage dividing resistors, the cathode lead is electrically connected to the power ground, and the first emitter and the first collector are respectively connected Both ends of the fourth voltage dividing resistor in the overvoltage protection circuit, the first collector is also connected to the positive output terminal of the rectifier circuit via an LED The first emission set is also connected to the second terminal of the trip wire ;;

 [16] If the local line is poorly grounded or disconnected, the first emitter and the first collector of the ground leakage detection chip are turned off to trigger the one-way thyristor to start the electromagnetic trip device to cut off the power.

 [17] Based on the above scheme, the ground leakage detecting chip is a photocoupler.

 [18] Further, the present invention further includes a leakage alarm circuit, the leakage alarm circuit includes a speaker, and the two input ends of the speaker are respectively connected to the input power source and are respectively electrically connected to the second ground leakage detecting chip. An emitter and a second collector.

[19] further comprising a neutral grounding protection circuit, the neutral grounding protection circuit comprising a neutral detecting magnetic ring disposed on the power phase line and the neutral line, the neutral line detecting the current output terminal of the magnetic ring To the input of the amplifier circuit.

 [20] According to the invention, a grounding electrification detecting device is connected to the power line ground, and a zero-sequence current protection circuit and a neutral line grounding protection circuit are also provided, and the electromagnetic tripping device realizes breaking, regardless of phase or neutral line. If there is residual current between the ground or the grounding is poor or disconnected, the three plugs in the plug are disconnected from the power supply. It not only prevents electric shock accidents caused by electrical failures, but also prevents electric shock accidents caused by power failures other than electrical appliances, thus meeting the requirements for safe use of electricity.

 DRAWINGS

 Figure 1 is a schematic view showing the structure of the present invention;

 [22] FIG. 2 is a schematic view showing the internal structure of the present invention after removing the outer casing;

 [23] FIG. 3 is a circuit schematic diagram of the present invention.

 detailed description

 [24] The present invention will be described in detail below with reference to the accompanying drawings.

 [25] As shown in FIG. 1 and FIG. 2, the present invention provides a leakage protection plug, which is connected to an end of a power cable of an electrical device to provide input power to the electrical device. The leakage protection plug includes a casing, a phase line, and a middle Thread and ground copper plugs 11, 12, 13, leakage protection circuit board 15, electromagnetic trip device and reset device.

 [26] The outer casing is fastened by the upper and lower casings 20, 21;

 [27] The phase, neutral and ground copper plugs 11, 12, 13 are respectively inserted and fixed on the lower casing 21 for inserting corresponding sockets to provide input power;

[28] The leakage protection circuit board 15 is respectively provided with three phase, neutral and ground three-pole copper plugs 11, 12, 13 opposite contacts, the leakage protection circuit board 15 is fixed on the inner surface of the lower casing 21 and the contacts on the leakage protection circuit board 15 are respectively electrically connected to the top ends of the copper plugs 11, 12, 13. The leakage protection circuit board 15 is provided with three terminals 5, which are respectively connected to the phase line, the neutral line and the ground line of the power line 30, and the three elastic movable contacts 6 are respectively fixed and electrically connected to the terminal 5. The other end is provided with a movable contact opposite to the contact on the leakage protection circuit board 15, and the movable contact is elastically connected to the contact on the leakage protection circuit board 15 for normal connection during normal operation.

[29] The reset device is for reconnecting the phase, neutral and ground three-pole copper plugs 11, 12, 13 and the power line 30, the reset device comprising a reset button 1, a reset moving block 2 and an opening The upward U-shaped bracket 8, the reset button 1 passes through the upper surface of the upper casing 20; the bracket 8 is fixed on the upper surface of the leakage protection circuit board 15, and the reset moving block 2 is disposed in the U-shaped opening of the bracket 8 and along The U-shaped opening moves up and down. The upper surface of the reset moving block 2 is provided with a C-shaped opening groove with an opening upward and the bottom surface of the groove is horizontal. The bottom surface of the groove is provided with a longitudinal through hole, and the reset button 1 is stepped. The lower portion is inserted into the through hole of the resetting moving block 2 and is provided with a horizontal groove facing the electromagnetic trip device _4. The central portion of the reset button 1 is provided with an annular convex edge, and the upper surface of the annular convex edge and the C-shaped opening are concave. The lower surface of the opening of the slot is offset, the reset button 1 is provided with a return spring 3, and two springs are disposed between the lower surface of the flange on the reset button 1 and the bottom surface of the C-shaped opening groove, respectively symmetrically disposed at Resetting the sides of the spring 3; resetting the moving block 2 The lower surface respectively abuts the movable contact on the elastic movable contact piece 6. When the reset button 1 is pressed, the reset moving block 2 moves downward in the U-shaped opening of the bracket 8, and the elastic movable contact piece 6 is pressed down and The movable contact is in contact with the contact on the leakage protection circuit board 15 to achieve electrical connection.

[30] The electromagnetic trip device 4 is fixed on the leakage protection circuit board 15 for cutting the phase, neutral and ground three-pole copper plugs 11, 12, 13 and the power line 30, the electromagnetic off The buckle device 4 includes a movable iron core 41, a trip thread L1 and a lock plate 7. The movable iron core 41 elastically projects outwardly under the action of a trip spring in the electromagnetic trip device, and a protruding end is provided with a ring shape. Groove. The locking plate 7 has a right-angled plate shape, and the vertical plate portion has a U-shaped groove communicating with the top surface, and the two side walls of the U-shaped groove are fitted in the annular groove of the protruding end of the movable iron core 41, The front end of the horizontal plate portion of the lock plate 7 elastically abuts against the lower portion of the reset button 1. When the reset button 1 is pressed to a certain depth, the front end of the horizontal plate portion of the lock plate 7 extends into the reset button. 1 is caught in the lower horizontal groove, and the movable contact on the elastic movable contact piece 6 is in contact with the contact on the leakage protection circuit board 15 to achieve electrical connection. When the electromagnetic trip device 4 is operated, that is, the tripping line of the electromagnetic trip device 4 1 When the power is turned on, the movable iron core 41 is retracted, and then the front end of the horizontal plate portion of the lock plate 7 is disengaged from the horizontal groove at the lower portion of the reset button 1, and the reset button 1 is bounced upward by the return spring, and thus three The elastic movable contacts 6 are all bounced upward, and the movable contacts on the elastic movable contact piece 6 are separated from the contacts on the leakage protection circuit board 15, thereby disconnecting the three copper plugs 11, 12 and 13 from the power supply line 30. .

[31] The circuit portion on the leakage protection circuit board 15 of the present invention includes a rectifier circuit E, a trip circuit 0, a zero sequence current detection circuit A, a ground leakage protection circuit C, an overvoltage protection circuit B, and an alarm circuit D, such as Figure 3 shows.

 [32] The rectifier circuit E consists of four diodes D2, D3, D5 and D6 to form a rectifier bridge to provide DC operating voltage for other circuits:

 [33] The trip circuit G includes a trip wire 圏L1 and a unidirectional thyristor SCR, and the control pole of the unidirectional thyristor SCR is connected to the zero sequence current detecting circuit A, the ground leakage protection circuit C and the overvoltage protection circuit The current output end of B, the anode is connected to the neutral line of the power supply, and the cathode is connected to the first terminal of the trip line 圏L1. When the above three circuits detect a power failure or a simulated fault, the output trigger current is single. To the thyristor SCR, the unidirectional thyristor SCR is turned from the off state to the on state, and the trip line 1L1 is energized to drive the electromagnetic trip device to cut off the power.

 [34] The zero-sequence current detection circuit A includes a zero-sequence current transformer CT1 and a neutral line transformer CT2, a zero-sequence current transformer CT1 and a neutral line transformer arranged on the phase line, the neutral line and the ground line. The output end of CT2 is respectively connected to the input end of the amplifying circuit, and the output end of the amplifying circuit is electrically connected to the control pole of the unidirectional thyristor SCR; the zero sequence current transformer CT1 is made of permalloy, the neutral line transformer The neutral detection magnetic ring in CT2 is made of ferrite. The power ground wire passes through the zero-sequence current transformer CT1 around two turns to measure whether there is a fault current to the ground. When the phase line fault occurs, there is a current output in the zero-sequence current transformer CT1, and the output current is amplified by the amplification circuit to trigger When the one-way thyristor is turned on, the trip wire 圏L1 acts, and the trip mechanism K2 is pushed to trip, thereby cutting off the power. In this embodiment, the RV4145 amplification chip is used for implementation. Of course, those skilled in the art can also implement other amplification circuits or amplification chips. When the neutral line transformer CT2 detects a zero line fault, the same output current is amplified by the amplifier circuit, and the control pole of the one-way thyristor is activated to activate the electromagnetic trip device to cut off the power.

[35] The overvoltage protection circuit B includes two first and second voltage dividing resistors R6 and R7 connected in series and a first diode D4 connected between the two voltage dividing resistors R6 and R7, the first two The other end of the pole tube D4 is connected to the one-way controllable On the control pole of the silicon SCR. The other end of the first voltage dividing resistor R6 is connected to the positive output terminal of the rectifier circuit E, and the other end of the second voltage dividing resistor R7 is connected to the negative output terminal of the rectifier circuit E. The voltage value across the second voltage dividing resistor R7 varies with the fluctuation of the power supply voltage. When the power supply voltage is too large, the voltage value across the second voltage dividing resistor R7 exceeds the conduction voltage of the first diode D4, the second point The output voltage of the voltage resistor R7 to the control pole of the unidirectional thyristor S CR triggers the unidirectional thyristor SCR to be turned on, and the trip line 1L1 works to cut off the power.

[36] The ground leakage protection circuit of the present invention comprises third and fourth voltage dividing resistors R9 and R10 and a ground leakage detecting chip IC2 connected in series, and the third and fourth voltage dividing resistors R9 and R10 The other end is connected to the power phase line and the neutral line respectively. The anode pin 1 of the ground leakage detecting chip IC2 is connected between the third and fourth voltage dividing resistors R9 and R10, and the cathode pin 4 is connected to the power ground. The first emitter (pin 7) and the first collector (pin 8) are respectively connected to the two ends of the second voltage dividing resistor R7 in the overvoltage protection circuit B, and the first collector is also passed through an LED LED 2 is connected to the positive output of rectifier circuit E. The ground leakage detecting chip IC2 is a photocoupler, and the TLP621-2 is selected in the embodiment. However, other types of photocouplers can be selected by those skilled in the art. If the local line is poorly grounded or disconnected, the ground leakage detection IC2 pins 7 and 8 are turned off, and the current on the first voltage dividing resistor R9 is applied to the first diode D4 via the LED 2 to be turned on. Thereby triggering the one-way thyristor SCR to activate the electromagnetic trip device to cut off the power.

 [37] The alarm circuit includes a speaker, the two input ends of the speaker are respectively connected to the input power, and the two input terminals of the speaker are also electrically connected to the second emitter (pin 5) of the ground leakage detecting IC2, respectively. And the second collector (pin 6), under normal conditions, the second emitter and the second collector of the ground leakage detecting chip IC2 are turned on, the speaker is shorted, and the local line leakage detecting chip IC2 detects the ground line After the disconnection or contact failure, the second emitter and the second collector pins are turned off, and the speaker power is turned on to alarm.

 [38] The present invention has the following advantages:

 [39] 1. The electrical equipment protected by the ground fault leakage protection plug can cut off the power regardless of whether there is residual current between the phase and neutral lines or if the grounding wire is poorly grounded or disconnected during use.

[40] 2. If the neutral wire is grounded or the case is disconnected from the power supply.

[41] 3. If the voltage is too high, the power can be cut off to meet the safety requirements.

[42] 4. Buzzer alarm, avoiding electric shock caused by failure to see the fault indication.

[43] The present invention is not limited to the above-described preferred embodiments, and anyone should be aware of what has been made under the inspiration of the present invention. Structural changes, which are the same or similar to the present invention, fall within the scope of the present invention.

Claims

Claim  1. Leakage protection plug, which is connected to the end of the power cord of the electrical equipment to provide input power to the electrical equipment. The leakage protection plug includes: The outer casing is fastened by the upper and lower casings; Phase, neutral and ground copper plugs, the plugs are respectively inserted and fixed on the lower casing, and are used for cutting off the phase, neutral and ground copper plugs and the power cord, the electromagnetic stripping The buckle device comprises a trip wire and a unidirectional thyristor, the trip wire has a first and a second terminal, the anode of the unidirectional thyristor is electrically connected to the neutral copper plug, and the cathode connection On the first terminal of the trip wire ;; a resetting device disposed in the outer casing and a reset button extending out of an upper surface of the upper casing, wherein the resetting device is configured to reconnect the phase line, the neutral wire and the ground copper plug and the power line a rectifier circuit for providing a DC operating voltage; The leakage protection circuit includes a zero sequence current protection circuit, and the zero sequence current protection circuit includes a zero sequence current transformer and an amplification circuit, and the zero sequence current transformer is sleeved on the phase line, the neutral line and the ground line, The output end is electrically connected to the input end of the amplifying circuit, and the output end of the amplifying circuit is electrically connected to the control pole of the unidirectional thyristor; The leakage protection circuit further comprises an overvoltage protection circuit and a ground leakage protection circuit: The overvoltage protection circuit includes two first and second voltage dividing resistors connected in series and a first diode connected between the two voltage dividing resistors, and the other end of the first diode is connected to the one-way controllable On the control pole of silicon, the other end of the first voltage dividing resistor is connected to the positive output terminal of the rectifier circuit, and the other end of the second voltage dividing resistor is connected to the negative output terminal of the rectifier circuit; The ground leakage protection circuit includes a third and fourth voltage dividing resistor and a ground leakage detecting chip connected in series, and the other ends of the third and fourth voltage dividing resistors are electrically connected to the power phase line and the neutral line, respectively. The anode of the ground leakage detecting chip is electrically connected to the first pole 3. The fourth voltage dividing resistor is electrically connected to the power ground line, and the first emitter and the first collector are respectively connected to the two ends of the fourth voltage dividing resistor in the overvoltage protection circuit, the first set The electrode is also connected to the positive output end of the rectifier circuit via a light-emitting diode, and the first emission set is also connected to the second terminal of the trip wire; the local line is poorly grounded or disconnected, and the ground leakage detecting chip The first emitter and the first collector are turned off to trigger the one-way thyristor to activate the electromagnetic trip device to cut off the power. A leakage protection plug according to claim 1, wherein the ground leakage detecting chip is a photocoupler.  3. The leakage protection plug according to claim 1 or 2, further comprising a leakage alarm circuit, wherein the leakage alarm circuit comprises a speaker, wherein the two input ends of the speaker are respectively connected to the input power source and are respectively powered Connected to the second emitter and the second collector of the ground leakage detecting chip.  4. The earth leakage protection plug according to claim 3, further comprising a neutral grounding protection circuit, wherein the neutral grounding protection circuit comprises a neutral detecting magnetic ring disposed on the power phase line and the neutral line The current output terminal of the neutral detecting magnetic ring is connected to the input end of the amplifying circuit.