Power line breakage protection device

Abstract

The utility model provides a power line damage protection device, which comprises a power supply connecting plug, a power line and a power line damage protection unit, and is characterized in that the power supply connecting plug comprises a shell, a tripping mechanism, a live wire insertion piece, a zero line insertion piece, a grounding insertion piece and a circuit board; the power line damage protection unit comprises a tripping mechanism driving circuit and an electric leakage detection circuit. The power line comprises a live wire core wire, a zero wire core wire, a ground wire core wire, an insulating layer, an insulating sheath and an electric leakage detection layer, and the insulating layer of the live wire core wire and the insulating layer of the zero wire core wire are coated with the electric leakage detection layer; when the electric leakage detection layer breaks down, current triggers a silicon controlled rectifier Q1 in the tripping mechanism driving circuit to be conducted through the electric leakage detection layer and drives a tripping mechanism in the power supply connecting plug to cut off electric connection between a power supply and a load in time, so that electricity utilization safety is ensured, and the fire risk is reduced.

Description

TECHNICAL FIELD

[0001] The utility model relates to the technical field of leakage current detection circuit breaker (LCDI) and concretely relates to a power line breakage protection device. BACKGROUND

[0002] With the social development and progress, people's living standards are continuously improved, and the use of various household electrical appliances is also more and more frequent. Due to space limitations, the power lines of most electrical appliances are hidden in hidden positions such as corners of the room, behind sofas, and under carpets, which makes the power lines vulnerable to animal bites, extrusion, bending and other adverse factors. These adverse factors may cause a short circuit of the power line and thus cause a fire. In addition, the load current of household appliances such as air conditioners, vacuum cleaners, dehumidifiers, and microwave ovens is generally large, and the power line generates a lot of heat, which accelerates the aging of the power line. The aging of the power line is one of the main causes of electrical fires.

[0003] Leakage current detection circuit breaker, abbreviated as LCDI, is an electrical fire safety protection device. Its main function is to detect whether the leakage current between the power line live wire, zero line, etc. and the power line protection layer (shield) between the power supply plug and the load electrical appliance (such as air conditioner, dehumidifier) exists. The existing power line leakage current detection technology of LCDI does not mutually insulate the leakage detection layer outside the live wire and the zero line. When the leakage detection layer in the middle section of the power line breaks, if the power line rear section occurs a leakage phenomenon at this time, it cannot be detected by the LCDI, and the LCDI is still in a normal working state. In this case, there may be a fire risk. Therefore, there is an urgent need in the art for an LCDI that can detect whether the power line protection layer and the leakage detection layer are damaged. SUMMARY

[0004] To solve the above problems, the utility model provides a power line breakage protection device, which can detect whether the leakage detection layer of the power line breaks in time, and reduce the risk of fire caused by misjudgment.

[0005] To achieve the above purpose, the utility model provides a power line breakage protection device, which comprises a power connection plug, a power line, and a power line breakage protection unit.

[0006] The power connection plug comprises:

[0007] An outer shell is formed by the outer shell upper cover and the outer shell lower cover being fastened together by screws. The power line is connected to the power connection plug through the circular groove on the outer shell.

[0008] A circuit board is provided with the power line breakage protection unit and fixed to the outer shell lower cover.

[0009] A trip mechanism, comprising two conductive contacts, a balance frame, a solenoid, a reset button, a reset spring and a coil cover, the two conductive contacts are supported by the balance frame, one end of each of the conductive contacts can move up and down, and the end is provided with a silver contact capable of conducting electricity, the other end of the two conductive contacts is a wiring end and is connected to the power cord; the balance frame is provided with a metal lock plate, the metal lock plate is linked with the armature in the solenoid, and the balance frame is placed in the coil cover; the reset button comprises a pull rod, the pull rod pulls the metal lock plate in the balance frame to drive the balance frame to move up and down, and the reset button is provided below the reset spring;

[0010] A live blade, a zero blade and a ground blade, the live blade and the zero blade are provided with silver contacts capable of conducting electricity, so that the silver contacts of the live blade and the silver contacts of the zero blade can respectively contact the silver contacts of the two movable ends of the conductive contacts.

[0011] The power cord comprises a live core wire, a zero core wire, a ground core wire, an insulation layer, an insulation sheath and a leakage detection layer; wherein the live core wire, the zero core wire and the ground core wire are each wrapped with an insulation layer, and the outermost layer is wrapped with an insulation sheath, and the insulation layer of the live core wire and the zero core wire is further wrapped with a leakage detection layer, which is composed of a copper shielding layer and an aluminum foil shielding layer;

[0012] In an embodiment of the utility model, wherein, the copper shielding layer is tightly attached to the insulation layer of the zero core wire and the insulation layer of the live core wire, and the copper shielding layer of the zero core wire and the copper shielding layer of the live core wire are connected to the circuit board;

[0013] In an embodiment of the utility model, wherein, the aluminum foil shielding layer comprises a conductive layer of aluminum foil and an insulation layer of aluminum foil, the conductive layer of aluminum foil is tightly attached to the copper shielding layer, and the insulation layer of aluminum foil separates the copper shielding layer of the zero core wire and the copper shielding layer of the live core wire to insulate each other.

[0014] The power cord damage protection unit comprises a trip mechanism driving circuit and a leakage detection circuit, so that the leakage current triggers the trip mechanism driving circuit to conduct through the leakage detection circuit, to drive the trip mechanism to disconnect the power connection between the power supply and the load, wherein:

[0015] In an embodiment of the utility model, wherein, the trip mechanism driving circuit comprises:

[0016] A thyristor Q1, the anode of the thyristor Q1 is connected to the live wire of the alternating current through a solenoid, the cathode of the thyristor Q1 is connected to the anode of a diode D2, the cathode of the diode D2 is connected to the zero line of the alternating current; the control electrode of the thyristor Q1 is connected to the anode of a voltage stabilizing diode D3, and the cathode of the voltage stabilizing diode D3 is connected to a resistor R2.

[0017] In an embodiment of the utility model, the control electrode of the thyristor Q1 can also be connected to one end of a bidirectional trigger diode Q2 and then connected to the resistor R2, and the other end of the bidirectional trigger diode Q2 is connected to the anode of the diode D2.

[0018] In an embodiment of the utility model, the control electrode of the thyristor Q1 can also be connected to one end of a bidirectional trigger diode Q2 and then connected to the resistor R2, and the other end of the bidirectional trigger diode Q2 is connected to the anode of the diode D2.

[0019] In an embodiment of the utility model, the leakage detection circuit comprises:

[0020] The resistor R4 and the resistor R6 are connected in series through a wire between the leakage detection layer of the live wire of the alternating current and the live wire core, the resistor R6 is connected to the leakage detection layer of the live wire core, and the connecting wire led out between the resistor R4 and the resistor R6 is connected to the resistor R2; the resistor R7 and a key switch Test are connected in series through a wire between the leakage detection layer of the zero line of the alternating current and the zero line core, and the resistor R7 is connected to the leakage detection layer of the zero line core.

[0021] In an embodiment of the utility model, the resistor R5 and a key switch can also be connected in series through a wire between the leakage detection layer of the zero line of the alternating current and the zero line core, and the resistor R5 is connected to the leakage detection layer of the zero line core.

[0022] In an embodiment of the utility model, the leakage detection layer of the live wire core and the leakage detection layer of the zero line core are electrically connected.

[0023] In an embodiment of the utility model, an LED lamp and a current limiting resistor R1 are connected in series between the live wire of the alternating current and the zero line of the alternating current, and whether the plug is connected can be judged according to the bright and dark state of the LED.

[0024] In an embodiment of the utility model, a pressure sensitive resistor MOV1 is arranged between the live wire of the alternating current and the zero line of the alternating current, and is used for absorbing the peak voltage interference from the external power grid.

[0025] The utility model provides a kind of power line breakage protection device, the device includes a power connection plug and a shielded cable, and the plug is provided with tripping mechanism and electronic circuit in it.The traditional protective plug does not cut off power when the leakage detection layer itself breaks in the middle section of cable, the power line breakage protection device proposed by the utility model designs a kind of protection circuit to detect the integrity of cable metal shielding layer, and power will be immediately cut off once cable metal shielding layer itself breaks, to ensure the power safety of load and livestock. BRIEF DESCRIPTION OF DRAWINGS

[0026] In order to more clearly illustrate the technical scheme in the embodiments of the utility model or prior art, the drawings needed to be used in the embodiment or prior art description will be simply introduced below, and obviously, the drawings in the following description are only some embodiments of the utility model, and for those skilled in the art, other drawings can also be obtained according to these drawings without creative labor.

[0027] Figure 1 It is the plug structure schematic diagram of an embodiment of the utility model.

[0028] Figure 2 It is the power line section view schematic diagram of an embodiment of the utility model.

[0029] Figure 3 It is the power line breakage protection unit circuit schematic of an embodiment of the utility model Figure 1 .

[0030] Figure 4 It is the power line breakage protection unit circuit schematic of embodiment 2 of the utility model Figure 2 .

[0031] Figure 5 It is the power line breakage protection unit circuit schematic of embodiment 3 of the utility model Figure 3 .

[0032] Explanation of reference signs: K1, K2 - power switch; J1 - solenoid; Q1 - thyristor; C1, C2 - capacitor; R1, R2, R3, R4, R5, R6, R7 - resistor; D1, D2 - diode; MOV1, MOV2 - varistor; Test - push button switch; LED - light emitting diode; D3 - voltage stabilizing diode; 1 - upper cover of housing; 2 - test key; 3 - reset key; 4 - reset spring; 5 - silicone waterproof cap of reset key and test key; 6 - live plug; 7 - zero plug; 8 - lower cover of housing; 9 - screw; 10 - ground plug; 11 - circuit board; 12 - test contact; 13 - fixing plate; 14 - balance frame; 15 - conductive contact; 16 - coil cover; 01 - core wire; 202 - insulation layer; 203 - copper shielding layer; 204 - aluminum shielding layer; 205 - aluminum foil insulation layer; 206 - sheath; 207 - filler; L - live wire; N - zero wire; G - ground wire. DETAILED DESCRIPTION

[0033] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0034] Figure 1 FIG. 1 is a schematic view of a plug structure according to an embodiment of the present application, Figure 2 FIG. 2 is a schematic view of a power cord cross section according to an embodiment of the present application, Figure 3 FIG. 3 is a schematic view of a power cord damage protection unit circuit according to an embodiment of the present application Figure 1 As shown in FIGS. 1, 2 and 3, the present embodiment provides a power cord damage protection device, which comprises a power connection plug, a power cord and a power cord damage protection unit. Figure 2 Figure 3 Figure 1 The power connection plug, as shown in FIG. 1, comprises:

[0035] a housing, which is fastened and combined by the upper cover of housing 1 and the lower cover of housing 8 through the screw 9, and the power cord is connected to the power connection plug through the circular groove on the housing; Figure 2

[0036] a circuit board 11, on which the power cord damage protection unit is arranged and fixed to the lower cover of housing 8;

[0037]

[0038] ​​​​A tripping mechanism includes two conductive contacts 15, a balance frame 14, a solenoid J1, a reset button 3, a reset spring 4, and a coil cover 16. The tripping mechanism is fixed to the circuit board by the snap-fit ​​of the coil cover.

[0039] The two conductive contacts 16 are supported by the balance frame 14. One end of each conductive contact can move up and down, and the end is provided with a silver contact that can conduct electricity. The other end of the two conductive contacts is a terminal and is connected to the power line.

[0040] The balance frame 14 is provided with a metal locking plate, which is linked to the armature in the solenoid J1. The balance frame is placed inside the coil cover 16.

[0041] The reset button 3 includes a pull rod, which pulls the metal locking piece inside the balance frame to drive the balance frame to move up and down. The reset spring 4 is installed below the reset button 3.

[0042] The plug includes a live wire connector 6, a neutral wire connector 7, and a ground connector 10. The live wire connector 6 and the neutral wire connector 7 are provided with conductive silver contacts, allowing the silver contacts of the live wire connector 6 and the neutral wire connector 7 to respectively contact the silver contacts at the movable ends of the two conductive contacts 16. The live wire connector 6 and the neutral wire connector 7 can connect to the external power supply and the internal conductive contacts of the plug. The ground connector 10 is connected to the ground wire of the power supply line.

[0043] A fixing plate 13 is welded to the upper cover 1, and the reset button 3 and the test button 2 are respectively fitted into the designated positions of the silicone waterproof cap.

[0044] When current flows through solenoid J1, it generates an electromagnetic force that drives the armature to move. This movement of the armature causes the metal locking plate inside the balance frame to move as well. The metal locking plate slides out from the lower end of the reset button 3, and simultaneously, the reset button 3 moves upward under the reaction force of the reset spring 4. The balance frame 14 also moves downward due to the loss of the pulling force from the lever. At this point, the silver contacts of the live wire plug 6 and the neutral wire plug 7 disconnect from the silver contacts at the movable ends of the two conductive contacts on the balance frame, thereby cutting off the electrical connection of the electrical equipment.

[0045] The power cord, such as Figure 3 As shown, it includes: a live wire, a neutral wire, a ground wire, an insulation layer, an insulation sheath, and a leakage current detection layer; wherein, the live wire, the neutral wire, and the ground wire are all covered with an insulation layer, and the outermost layer of each is covered with an insulation sheath; the insulation layers of the live wire and the neutral wire are also covered with a leakage current detection layer, which is composed of a copper shielding layer and an aluminum foil shielding layer;

[0046] The copper shielding layer is in close contact with the insulation layer of the neutral wire core and the live wire core. The copper shielding layer of the neutral wire core and the copper shielding layer of the live wire core are connected to the circuit board. The material of the copper shielding layer is not limited to copper, but can also be conductive materials such as iron and aluminum alloy.

[0047] The aluminum foil shielding layer includes a conductive layer and an insulating layer. The conductive layer of the aluminum foil is in close contact with the copper shielding layer, and the insulating layer of the aluminum foil separates the copper shielding layer of the neutral wire core from the copper shielding layer of the live wire core to insulate them from each other.

[0048] Example 1

[0049] The power cord damage protection unit, such as Figure 3 As shown, it includes: a tripping mechanism drive circuit and a leakage current detection circuit, so that leakage current triggers the tripping mechanism drive circuit to conduct via the leakage current detection circuit, thereby driving the tripping mechanism to disconnect the power connection between the power supply and the load, wherein:

[0050] The tripping mechanism drive circuit includes:

[0051] A thyristor Q1 is provided, with its anode connected to the AC live wire L via a solenoid J1, and its cathode connected to the anode of diode D2, the cathode of which is connected to the AC neutral wire N. The control electrode of the thyristor Q1 is connected to the anode of a Zener diode D3, and the cathode of the Zener diode D3 is connected to a resistor R2. The Zener diode D3 is used to prevent the leakage current detection circuit from triggering the tripping mechanism drive circuit to disconnect the power connection when the output voltage is lower than the threshold voltage.

[0052] In this embodiment, a varistor MOV2 and a reverse-connected diode D1 are connected in parallel between the anode and cathode of the thyristor Q1. The varistor MOV2 is used to absorb the surge voltage across the thyristor Q1 to prevent malfunction.

[0053] The leakage current detection circuit includes:

[0054] The AC live wire L and the leakage detection layer (i.e., AC live wire shielding layer) are connected in series by a wire with resistors R4 and R6, and resistor R6 is connected to the leakage detection layer of the live wire core. The connecting line led out between resistors R4 and R6 is connected to resistor R2.

[0055] In this embodiment, the leakage detection layer of the live wire core is referred to as the power input end (input end) as the AC live wire shielding layer power end, and the leakage detection layer of the live wire core is referred to as the power output end (output end) as the AC live wire shielding layer load end.

[0056] The leakage detection layer of the live wire is electrically connected with the leakage detection layer of the neutral wire.

[0057] In the embodiment, the leakage detection layer of the live wire is electrically connected with the leakage detection layer of the neutral wire.

[0058] In the embodiment, the leakage detection layer of the live wire is electrically connected with the leakage detection layer of the neutral wire.

[0059] In the embodiment, the leakage detection layer of the live wire is electrically connected with the leakage detection layer of the neutral wire.

[0060] In the embodiment, the leakage detection layer of the live wire is electrically connected with the leakage detection layer of the neutral wire.

[0061] In the embodiment, the leakage detection layer of the live wire is electrically connected with the leakage detection layer of the neutral wire.

[0062] In the embodiment, the leakage detection layer of the live wire is electrically connected with the leakage detection layer of the neutral wire.

[0063] The working principle of the power line breakage protection device is shown in Figure 4 and described as follows, but is not limited to:

[0064] Under normal circumstances, the current flows through the live wire L, the resistance R4, the resistance R6, the live wire shielding layer power end, the live wire shielding layer load end, the neutral wire shielding layer load end, the neutral wire shielding layer power end, the resistance R5, the diode D2, and then flows into the neutral wire N. At this time, the tripping mechanism is in a closed state, and the load device can be normally powered and used.

[0065] When the live core or the zero core of the power line touches the AC live wire shielding layer or the AC zero wire shielding layer, or the metal shielding layer in the power line is broken, the voltage N is negative and the voltage L is positive, the current flows through the AC live wire L, the AC live wire shielding layer, the AC zero wire shielding layer, the resistance R5, the resistance R3, the control electrode of the thyristor Q1, and the voltage of the control electrode of the thyristor Q1 is increased, so that the thyristor Q1 is turned on. The current flows through the solenoid J1, the thyristor Q1 and the diode D2 to the AC zero wire N. The current drives the iron core and the tripping mechanism to disconnect, thereby cutting off the power connection between the AC power supply end and the load end.

[0066] When the AC live wire shielding layer or the AC zero wire shielding layer is broken, the current flows through the AC live wire L, the resistance R4, the resistance R2, the zener diode D3 and the thyristor Q1, and the thyristor Q1 is turned on. The current flows through the solenoid J1, the thyristor Q1 and the diode D2 to the AC zero wire N. The electromagnetic force generated by the solenoid current drives the armature to move, drives the tripping mechanism to disconnect and cuts off the power supply in time, thereby reducing the risk of fire.

[0067] Embodiment 2

[0068] Figure 2 The power line breakage protection unit circuit of an embodiment of the utility model Figure 4 As shown in Figure 4 Compared with embodiment 1, the main difference lies in the power breakage protection unit; embodiment 2 provides a power line breakage protection device, the power connection plug and the power line of which are the same as those of embodiment 1, and will not be repeated here;

[0069] The power line breakage protection unit, as shown in Figure 4 It comprises a tripping mechanism driving circuit and a leakage detection circuit, so that the leakage current flows through the leakage detection circuit to trigger the tripping mechanism driving circuit to conduct, thereby driving the tripping mechanism to disconnect the power connection between the power supply and the load, wherein:

[0070] The tripping mechanism driving circuit comprises:

[0071] A thyristor Q1, the anode of the thyristor Q1 is connected to the AC live wire L through the solenoid J1, the cathode of the thyristor Q1 is connected with the anode of the diode D2, and the cathode of the diode D2 is connected with the AC zero wire N; the control electrode of the thyristor Q1 is connected with one end of the bidirectional trigger diode Q2 after being connected with the resistance R2, and the other end of the bidirectional trigger diode Q2 is connected with the anode of the diode D2, wherein the bidirectional trigger diode Q2 prevents the leakage detection circuit output voltage from being lower than the threshold voltage to trigger the tripping mechanism driving circuit to disconnect the power connection.

[0072] In the embodiment, the anode and the cathode of the thyristor Q1 are connected in parallel with a reverse-connection diode D1, which is used to absorb the surge voltage between the two ends of the thyristor Q1 and avoid misoperation.

[0073] In the embodiment, the control electrode and the cathode of the thyristor Q1 are connected in parallel with a capacitor C1 and a resistor R3 to form an RC filter circuit.

[0074] The leakage detection circuit comprises:

[0075] The resistance R4 and the resistance R6 are connected in series between the leakage detection layer (i.e. the AC live wire shielding layer) of the live wire core wire and the AC live wire L through a wire, and the resistance R6 is connected to the leakage detection layer of the live wire core wire; the connecting wire between the resistance R4 and the resistance R6 is connected to the resistance R2.

[0076] The resistance R5 and the key switch Test are connected in series between the leakage detection layer (i.e. the AC zero wire shielding layer) of the zero wire core wire and the AC zero wire N through a wire, and the resistance R5 is connected to the leakage detection layer of the zero wire core wire.

[0077] In the embodiment, the leakage detection layer of the live wire core wire and the leakage detection layer of the zero wire core wire are electrically connected.

[0078] The working principle of the power line breakage protection device is shown in Figure 5 and is described as follows, but is not limited to:

[0079] The working principle of the power line breakage protection device in the normal condition and when the AC live wire shielding layer or the AC zero wire shielding layer is broken in the embodiment 2 is the same as that in the embodiment 1 and will not be described here again.

[0080] When the AC live wire shielding layer or the AC zero wire shielding layer of the live wire core wire or the zero wire core wire in the power line is touched or the metal shielding layer in the power line is broken, at this time, the voltage N is negative and the voltage L is positive, the current flows through the AC live wire L, the AC live wire shielding layer, the AC zero wire shielding layer, the resistance R5, the bidirectional trigger diode Q2, the control electrode of the thyristor Q1, at this time, the voltage of the control electrode of the Q1 is raised and the Q1 is turned on. The current flows through the solenoid J1, the thyristor Q1 and the diode D2 to the AC zero wire N. The current drives the iron core and drives the tripping mechanism to disconnect, thereby cutting off the power connection between the AC power supply end and the load end.

[0081] Embodiment 3

[0082] Figure 3 The power line breakage protection unit circuit of the embodiment of the utility model is shown in Figure 5 as shown in Figure 5The main difference between the embodiment 1 and the embodiment 3 is the power line breakage protection unit. The power connection plug and the power line of the power line breakage protection unit of the embodiment 3 are the same as those of the embodiment 1, which will not be described here again.

[0083] The power line breakage protection unit, as shown in the embodiment 3, comprises a trip mechanism driving circuit and a leakage detection circuit. Figure 5

[0084] The trip mechanism driving circuit comprises:

[0085] A thyristor Q1, the anode of which is connected to the AC live wire L through a solenoid J1, the cathode of which is connected to the anode of a diode D2, and the cathode of the diode D2 is connected to the AC neutral wire N; the control electrode of the thyristor Q1 is connected to a resistor R2, and the other end of the resistor R2 is connected to one end of a bidirectional trigger diode Q2, and the other end of the bidirectional trigger diode Q2 is connected to the anode of the diode D2, wherein the bidirectional trigger diode Q2 prevents the leakage detection circuit from triggering the trip mechanism driving circuit to disconnect the power connection when the output voltage of the leakage detection circuit is lower than the threshold voltage.

[0086] The leakage detection circuit comprises:

[0087] The AC live wire L and the leakage detection layer of the live wire core wire (i.e. the AC live wire shielding layer) are connected through a resistor R4 and a resistor R6 connected in series by a wire, and the resistor R6 is connected to the leakage detection layer of the live wire core wire; the connection line led between the resistor R4 and the resistor R6 is connected to the connection line led between the resistor R2 and the bidirectional trigger diode.

[0088] The AC neutral wire N and the leakage detection layer of the neutral wire core wire (i.e. the AC neutral wire N shielding layer) are connected through a resistor R5 and a key switch Test, and the resistor R5 is connected to the leakage detection layer of the neutral wire core wire.

[0089] In this embodiment, the leakage detection layer of the live wire core wire and the leakage detection layer of the neutral wire core wire are electrically connected.

[0090] The working principle of the power line breakage protection device, as shown in the embodiment 3, is explained as follows, but is not limited to: ​

[0091] The working principle of the power line breakage protection device of the embodiment 3 under normal conditions and when the AC live wire shielding layer or the AC neutral wire shielding layer is broken and disconnected is the same as that of the embodiment 1, which will not be described here again.

[0092] ​​When the live core wire or the zero core wire in the power cord touches the alternating current live wire shielding layer or the alternating current zero wire shielding layer, or the metal shielding layer in the power cord is broken, the voltage N is negative and the voltage L is positive, the current passes through the alternating current live wire L, the alternating current live wire shielding layer, the alternating current zero wire shielding layer, the resistor R5, the bidirectional trigger diode Q2, the resistor R2 and reaches the thyristor Q1 control electrode, at this time the voltage of the Q1 control electrode is raised and the Q1 is turned on. The current passes through the solenoid J1, the thyristor Q1 and the diode D2 to the alternating current zero wire N. The current drives the iron core and the tripping mechanism to disconnect, cutting off the power connection between the alternating current power supply end and the load end.

[0093] Those skilled in the art can understand that the drawings are only schematic diagrams of an embodiment, and the modules or flows in the drawings are not necessarily necessary for implementing the utility model.

[0094] Those skilled in the art can understand that the modules in the device in the embodiment can be distributed in the device in the embodiment according to the embodiment description, or can be changed and located in one or more devices different from the embodiment. The modules in the above embodiment can be combined into one module, or can be further split into multiple sub-modules.

[0095] Finally, it should be noted that: the above examples are only used to illustrate the technical solutions of the utility model, and not to limit them; although the utility model has been described in detail with reference to the foregoing examples, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing examples, or make equivalent replacement for part of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiment of the utility model.

Claims

1. A power cord breakage protection device, characterized by, The power connection plug, the power cord and the power cord breakage protection unit are included, wherein: The power connection plug includes: A shell is closed together by a shell upper cover and a shell lower cover, and is fastened and combined by screws, the power cord connects the power connection plug through the circular groove on the shell; A circuit board is provided with the power cord breakage protection unit and is fixed to the shell lower cover; A tripping mechanism includes two conductive contacts, a balance frame, a solenoid, a reset button, a reset spring and a coil cover, the two conductive contacts are supported by the balance frame, one end of each of the conductive contacts can move up and down, and the end is provided with a silver contact capable of conducting electricity, the other end of the two conductive contacts is a wiring end and is connected to the power cord; the balance frame is provided with a metal lock plate inside, the metal lock plate is linked with an armature in the solenoid, and the balance frame is placed in the coil cover; the reset button includes a pull rod, the pull rod pulls the metal lock plate in the balance frame to drive the balance frame to move up and down, and the reset button is provided below the reset spring; A live plug, a zero plug and a ground plug, the live plug and the zero plug are provided with silver contacts capable of conducting electricity, so that the silver contacts of the live plug and the silver contacts of the zero plug can respectively contact the silver contacts of the two movable ends of the conductive contacts; The power cord includes a live core wire, a zero core wire, a ground core wire, an insulation layer, an insulation sheath and a leakage detection layer; wherein the live core wire, the zero core wire and the ground core wire are each coated with an insulation layer, and the outermost layer is coated with an insulation sheath, and the insulation layer of the live core wire and the zero core wire is further coated with a leakage detection layer, which is composed of a copper shielding layer and an aluminum foil shielding layer; The power cord breakage protection unit includes a tripping mechanism driving circuit and a leakage detection circuit, so that the leakage current passes through the leakage detection circuit to trigger the tripping mechanism driving circuit to conduct, so as to drive the tripping mechanism to disconnect the power connection between the power supply and the load.

2. The power cord breakage protection device of claim 1, wherein The copper shielding layer is tightly attached to the insulation layer of the zero core wire and the insulation layer of the live core wire, and the copper shielding layer of the zero core wire and the copper shielding layer of the live core wire are connected to the circuit board.

3. The power cord breakage protection device of claim 1, wherein The aluminum foil shielding layer includes a conductive layer of aluminum foil and an insulating layer of aluminum foil, the conductive layer of aluminum foil is tightly attached to the copper shielding layer, and the insulating layer of aluminum foil separates the copper shielding layer of the zero core wire and the copper shielding layer of the live core wire to insulate each other.

4. The power cord breakage protection device of claim 1, wherein The tripping mechanism driving circuit includes: A silicon controlled rectifier Q1, the anode of the silicon controlled rectifier Q1 is connected to the live core wire through the solenoid, the cathode of the silicon controlled rectifier Q1 is connected to the anode of the diode D2, the cathode of the diode D2 is connected to the zero core wire; the control electrode of the silicon controlled rectifier Q1 is connected to the anode of the voltage stabilizing diode D3, and the cathode of the voltage stabilizing diode D3 is connected to the resistor R2.

5. The power cord breakage protection device of claim 4, wherein, The control electrode of the silicon controlled rectifier Q1 can also be connected to one end of the bidirectional trigger diode Q2 after connecting the resistor R2, and the other end of the bidirectional trigger diode Q2 is connected to the anode of the diode D2.

6. The power cord breakage protection device of claim 4, wherein The control electrode of the thyristor Q1 is also connected to one end of a bidirectional trigger diode Q2 after connecting a resistor R2, and the other end of the bidirectional trigger diode Q2 is connected to the anode of a diode D2.

7. The power cord breakage protection device of claim 1, wherein The leakage detection circuit comprises a resistor R4 and a resistor R6 connected in series by a wire between the live core wire and the leakage detection layer of the live core wire, and the resistor R6 is connected to the leakage detection layer of the live core wire; and a resistor R7 and a button switch connected in series by a wire between the zero core wire and the leakage detection layer of the zero core wire, and the resistor R7 is connected to the leakage detection layer of the zero core wire.

8. The power cord breakage protection device of claim 7, wherein, The resistor R5 and a button switch connected in series by a wire between the zero core wire and the leakage detection layer of the zero core wire, and the resistor R5 is connected to the leakage detection layer of the zero core wire.

9. The power cord breakage protection device of claim 7, wherein, The leakage detection layer of the live core wire and the leakage detection layer of the zero core wire are electrically connected.

10. The power cord breakage protection device of claim 4, wherein, A pressure sensitive resistor MOV1 is further arranged between the live core wire and the zero core wire, and an LED lamp and a current limiting resistor R1 are further connected in series between the live core wire and the zero core wire.

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