CN217590235U - Protection circuit, protection device, earth leakage protection control circuit and earth leakage protection switch - Google Patents

Abstract

The embodiment of the application provides a protection circuit, a protection device, a leakage protection control circuit and a leakage protection switch, which are applied to the technical field of leakage protection, and aims to solve the problem that the current leakage protection switch cannot be quickly powered off to cause damage to a circuit device after a load and a power supply are reversely connected. The protection circuit is provided with a switch control module between a tripping module and an electric leakage detection control module of the electric leakage protection switch; the first end of the tripping module is connected with the first connecting port, the second end of the tripping module is connected with the second connecting port, the second connecting port and the second end of the tripping module are both connected with the first end of the switch control module, and the switch control module controls the on-off state of the switch control module through the current between the positive electrode and the negative electrode of the first connecting port; the tripping module controls the on-off state of the tripping module through the current of the anode of the leakage detection control module. Even if the load is reversely connected with the power supply, the circuit can also power off the load and the electric leakage detection control module when the electric leakage problem occurs.

Description

Protection circuit, protection device, earth leakage protection control circuit and earth leakage protection switch

Technical Field

The application relates to the technical field of leakage protection, in particular to a protection circuit, a protection device, a leakage protection control circuit and a leakage protection switch.

Background

In the daily power utilization process, leakage current is possibly generated by electric equipment or human electric shock, and the leakage protection switch can control the corresponding tripping mechanism to act and cut off a circuit by detecting abnormal current or voltage signals when the leakage current is generated, so that the equipment damage or the long-time electric shock accident of a human is avoided. The current leakage protection switch is generally connected with a mains supply through an input connecting terminal and a load through an output connecting terminal; when leakage occurs, the trip module disconnects the contacts and simultaneously disconnects the load and the leakage protection circuit. However, if the input and the output are reversely connected (i.e. the input terminal is connected with the load, the output terminal is connected with the mains supply), when electric leakage occurs, the tripping module makes the contact disconnected, at this moment, the load is powered off, but the output terminal connected with the electric leakage protection circuit still has mains supply, so that the tripping coil of the tripping module continuously passes through working current, the silicon controlled rectifier cannot be turned off by zero crossing, the tripping coil passes through current which can be borne by the tripping coil for a long time, and finally, the tripping coil is burnt out by overheating, and even the electric leakage protection circuit is damaged.

SUMMERY OF THE UTILITY MODEL

An object of the embodiment of the application is to provide a protection circuit, a protection device, an earth leakage protection control circuit and an earth leakage protection switch, so as to solve the problem that the circuit device is damaged due to the fact that the power cannot be quickly cut off when the electric leakage problem occurs after the input and the output of the existing protection circuit are reversely connected.

In order to achieve the above purpose, the embodiment of the present application adopts the following technical solutions:

in a first aspect, an embodiment of the present application provides a protection circuit, where the protection circuit includes a first connection port, a second connection port, a switch control module, a trip module, and a power output port; the first end of the tripping module is connected with the first connection port; the second end of the tripping module is connected with the second connecting port, the positive pole of the second end of the tripping module and the positive pole of the second connecting port are both connected with the first end of the switch control module, and the negative pole of the second end of the tripping module is connected with the negative pole of the power output port; the second end of the switch control module is connected with the anode of the power output port; the switch control module is also connected with the first connection port; the tripping module is also connected with the anode of the power output port; the switch control module controls the on-off state of the switch control module through a first current between the positive electrode and the negative electrode of the first connection port; the tripping module controls the on-off state of the tripping module through the second current of the anode of the power output port.

Therefore, if the first connection port is connected with the mains supply, the second port is connected with the load, the power output port is connected with the leakage protection circuit, the tripping module is reset to be in a conduction state, the switch control module is in the conduction state, and the load and the leakage protection circuit can be normally powered on. If the load leaks electricity, the leakage protection circuit performs grounding control, the anode current of the power output port is instantly increased, and the tripping module is switched to a disconnection state under the driving of the current, so that the load and the leakage protection circuit are powered off simultaneously. If the first connection port is connected with the load, the second connection port is connected with the mains supply, the power output port is connected with the leakage protection circuit, the tripping module is reset to be in a conduction state, the switch control module is in the conduction state, and the load and the leakage protection circuit can be normally powered on. If the load leaks electricity, the earth leakage protection circuit performs earth control, the anode current of the power output port is instantly increased, and the tripping module is switched to the off state under the driving of the current, so that the switch control module is also switched to the off state, and the load and the earth leakage protection circuit are powered off simultaneously.

In a possible implementation manner, the switch control module includes a current-limiting protection unit, a unidirectional conduction unit, a relay, and an absorption unit; the first end of the current-limiting protection unit is connected with the anode of the first connection port; the second end of the current-limiting protection unit is connected with the anode of the one-way conduction unit; the absorption unit is connected with a coil of the relay in parallel, a first end of the absorption unit after the absorption unit is connected with the negative electrode of the one-way conduction unit, and a second end of the absorption unit after the absorption unit is connected with the negative electrode of the first connection port; the positive output end of the tripping module and the positive electrode of the second connecting port are both connected with the first end of the contact switch of the relay; and the second end of the contact switch of the relay is connected with the anode of the power output port. Based on this, under the circumstances that guarantees that on-off state can normally be switched to on-off control module, can avoid damaging each components and parts in the on-off control module.

In a possible implementation manner, the current limiting protection unit includes a first resistor and a first capacitor; the first end of the first resistor is connected with the anode of the first connection port; the second end of the first resistor is connected with the first end of the first capacitor; the second end of the first capacitor is connected with the anode of the unidirectional conducting unit. Therefore, the impedance of the line is improved, and the line can be subjected to current-limiting protection.

In one possible implementation, the unidirectional conducting unit includes a plurality of diodes connected in parallel. Through a plurality of diodes connected in parallel, unidirectional conduction can be realized, false triggering is avoided, and the switch control module can be ensured to normally operate when a certain diode breaks down.

In a possible implementation, the absorption unit comprises a second capacitor and a zener diode connected in parallel with the coil of the relay. Based on this, the absorption unit can be used for carrying out voltage stabilization and filtering processing on the input voltage of the coil, and can also be used for absorbing the electric energy released by the coil through the voltage stabilizing diode at the moment of power failure.

In a possible implementation manner, the protection circuit further includes a voltage dependent resistor; the piezoresistor is arranged between the negative electrode of the power output port and the second end of the switch control module. Based on this, can carry out overvoltage protection to the components and parts in the circuit.

In one possible implementation, the trip module includes a trip coil, a first contact switch, and a second contact switch; the trip coil is arranged on a circuit between the second end of the switch control module and the positive pole of the power output port; the first end of the first contact switch is connected with the anode of the first connecting port, and the first end of the second contact switch is connected with the cathode of the first connecting port; the second end of the first contact switch and the anode of the second connecting port are both connected with the first end of the switch control module, and the second end of the second contact switch is connected with the cathode of the second connecting port; the trip coil controls the on-off state of the first contact switch and the second contact switch through the generated magnetic field. Based on this, the tripping module can break the first contact switch and the second contact switch in time when the load has the electric leakage problem.

In a second aspect, an embodiment of the present application provides a protection device, which includes the protection circuit in any one of the possible implementation manners of the first aspect.

In a third aspect, an embodiment of the present application provides a leakage protection control circuit, including the protection circuit in any one of the possible implementation manners of the first aspect, and a leakage detection control module connected to a power output port of the protection circuit; and the electric leakage detection control module performs ground control through a third current on a line connected with the second connecting port of the protection circuit.

In a possible implementation manner, the leakage detection control module includes a rectifying unit, a filtering unit, a leakage detection unit, a control unit, and a ground connection on-off unit; the positive electrode of the rectifying unit is connected with the second end of the switch control module; the negative electrode of the rectifying unit is connected with the negative electrode of the second end of the tripping module; the current output end of the rectifying unit is respectively connected with the anode of the grounding on-off unit and the input end of the filtering unit; the negative electrode of the grounding on-off unit is grounded; the output end of the filtering unit is connected with the power port of the control unit; the electric leakage detection unit is connected with the control unit; the leakage detection unit is used for detecting a third current on a line connected with the second connection port and controlling the on-off state of the grounding on-off unit according to the third current. Based on this, the electric leakage detection control module can in time carry out ground control when the electric leakage problem appears in the load to increase the drive current of tripping module, make tripping module can move faster.

In a possible implementation manner, the leakage detecting unit includes a current transformer disposed on a line connected to the second connection port; and the sampling unit is connected with the current transformer and the control unit and is used for collecting a current signal of the current transformer and inputting the current signal into the control unit. Based on this, the control unit can detect the current on the line connected with the second connection port in time.

In a possible implementation manner, the leakage protection control circuit further includes a test circuit connected between the positive electrode and the negative electrode of the second connection port; the leakage detection control module is also used for detecting a fourth current when the test circuit is closed and carrying out grounding control according to the fourth current. Based on this, whether the producer or user can detect the circuit can normally operate before using, improve the security of using.

In a fourth aspect, an embodiment of the present application provides a leakage protection switch, where the leakage protection switch includes the leakage protection control circuit in any one of the possible implementation manners of the third aspect.

Drawings

Fig. 1 is a schematic diagram of a conventional leakage protection control circuit according to an embodiment of the present disclosure;

fig. 2 is a schematic diagram of a topology structure of a protection circuit according to an embodiment of the present disclosure;

fig. 3 is a schematic connection diagram of a switch control module according to an embodiment of the present disclosure;

fig. 4 is a schematic diagram of a protection circuit according to an embodiment of the present application;

fig. 5 is a schematic view of a topology structure of a protection device according to an embodiment of the present application;

fig. 6 is a schematic diagram of a topology structure of a leakage protection control circuit according to an embodiment of the present disclosure;

fig. 7 is a schematic diagram of a leakage protection control circuit according to an embodiment of the present disclosure;

fig. 8 is a schematic diagram of a topology structure of a leakage protection switch according to an embodiment of the present application.

Detailed Description

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, and it is obvious that the described embodiments are only a part of the embodiments of the present application, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

It should be noted that the terms "first" and "second" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or to indicate the number of technical features indicated. Thus, features defining "first", "second", may explicitly or implicitly include one or more of the features. In the description of the embodiments of the present application, unless otherwise specified, "a plurality" means two or more, and "several" means one or more.

In describing some embodiments, expressions of "coupled" and "connected," along with their derivatives, may be used. For example, the term "connected" may be used in describing some embodiments to indicate that two or more elements are in direct physical or point contact with each other. As another example, some embodiments may be described using the term "coupled" to indicate that two or more elements are in direct physical or electrical contact. However, the terms "coupled" or "communicatively coupled" may also mean that two or more elements are not in direct contact with each other, but yet still co-operate or interact with each other. The embodiments disclosed herein are not necessarily limited to the contents herein.

Referring to fig. 1, a conventional leakage protection switch control circuit includes an input terminal and an output terminal, where L1 is an anode of the input terminal, and N1 is a cathode of the input terminal; l2 is the output terminal positive pole and N2 is the output terminal negative pole. The first end of a contact switch K1 of the tripping module is connected with the N1, and the first end of a contact switch K2 of the tripping module is connected with the L1; the second end of the contact switch K1 of the tripping module is connected with the N2, and the second end of the contact switch K2 of the tripping module is connected with the L2; meanwhile, the first end of a tripping coil KJA of the tripping module is respectively connected with the second end of the K2 and the L2. The positive pole of the rectifier bridge B1 is connected with the second end of the trip coil, and the negative pole of the rectifier bridge B1 is connected with the second end of the K1. The output end of the rectifier bridge B1 is grounded through a Silicon Controlled Rectifier (SCR), and is connected to the leakage control chip U1 through a resistance-capacitance filter (RC filter for short) formed by a resistor R1 and a capacitor C1, and a leakage protection circuit formed by a zero-sequence current transformer ZCT, a capacitor C2, a capacitor C4, a capacitor C6, a capacitor C7, a capacitor C8, a resistor R2, a resistor R3, and the like is connected to the leakage detection chip U1. A test circuit consisting of a resistor R4 and a button T is arranged between the anode and the cathode of the output connecting terminal.

When the input wiring terminal is connected with a mains supply, the output wiring terminal is connected with a load, and the tripping module is reset to be in a conducting state (namely K1 and K2 are closed), the load and the leakage protection circuit can be normally powered on. If the load is in electric leakage or the button T is closed, the electric leakage control chip U1 controls the silicon controlled rectifier MCR to be conducted, the current flowing through the tripping coil is increased instantly, the tripping coil generates a magnetic field to drive the tripping mechanism connected with the contact switches K1 and K2 to move, so that the switches K1 and K2 are disconnected, and the load and the electric leakage protection circuit are powered off simultaneously. However, when the input terminal is connected to the load, the output terminal is connected to the mains supply, and the trip module is reset to the conducting state (i.e., K1 and K2 are closed), although the load and the leakage protection circuit can be normally powered on; however, if the load is electrically leaked or the button T is closed, the leakage control chip U1 controls the thyristor MCR to be turned on, the current flowing through the trip coil is instantly increased, the trip coil generates a magnetic field to drive the trip mechanism connected to the contact switches K1 and K2 to move, and only the power-off of the load can be realized. Based on this, the tripping coil can pass through the current which can be borne by the tripping coil for a long time and is finally burnt; even when the current is too large, the leakage control chip and other electronic components may be burned.

In order to solve the above problem, please refer to fig. 2, an embodiment of the present application provides a protection circuit 200, where the protection circuit 200 includes a first connection port 210, a second connection port 220, a switch control module 230, a trip module 240, and a power output port 250; wherein, the first end of the trip module 240 is connected to the first connection port 210; the second end of the trip module 240 is connected to the second connection port 220, the positive electrode of the second end of the trip module 240 and the positive electrode of the second connection port 220 are both connected to the first end of the switch control module 230, and the negative electrode of the second end of the trip module 240 is connected to the negative electrode of the power output port 250; a second terminal of the switch control module 230 is connected to the positive terminal of the power output port 250; the switch control module 230 is also connected to the first connection port 210; the trip module 240 is also connected to the positive pole of the power output port 250; the switch control module 230 controls the on-off state of itself through a first current between the positive electrode and the negative electrode of the first connection port 210; the trip module 240 controls the on-off state of itself through the second current of the positive electrode of the power output port 250.

For example, if the first connection port 210 is connected to a mains power supply, the second connection port 220 is connected to a load, the power output port 250 is connected to the leakage protection circuit, and the trip module 240 is reset to the on state, the switch control module 230 is in the on state, and the load and the leakage protection circuit can be powered on normally. If the load has electric leakage, the earth leakage protection circuit performs earth control, the positive current of the power output port 250 increases instantly, and the trip module 240 is switched to the off state under the driving of the current, so that the load and the earth leakage protection circuit are powered off simultaneously. If the first connection port 210 is connected to the load, the second connection port 220 is connected to the commercial power supply, the power output port 250 is connected to the leakage protection circuit, and the trip module 240 is reset to the on state, the switch control module 230 is in the on state, and the load and the leakage protection circuit can be normally powered on. If the load has electric leakage, the earth leakage protection circuit performs earth control, the positive current of the power output port 250 increases instantly, the trip module 240 is driven by the current to switch to the off state, and the switch control module 230 is powered off and switched to the off state, so that the load and the earth leakage protection circuit are powered off at the same time.

Through this kind of mode, even commercial power supply and load are reverse to be connect, when the electric leakage problem appears, protection circuit 200 also can cut off the power supply to load and earth leakage protection circuit fast, and the user need not worry and connects the contrary component, has improved the convenience of using.

As shown in fig. 3, in one possible embodiment, the switch control module 230 includes a current limiting protection unit 231, a unidirectional conducting unit 232, a relay 233, and a sink unit 234; the first end of the current limiting protection unit 231 is connected with the positive electrode of the first connection port 210; the second end of the current-limiting protection unit 231 is connected with the positive electrode of the unidirectional conduction unit 232; the absorption unit 234 is connected in parallel with the coil of the relay 233, and a first end after the parallel connection is connected with the negative electrode of the unidirectional conduction unit 232, and a second end after the parallel connection is connected with the negative electrode of the first connection port 210; the positive output end of the trip module 240 and the positive electrode of the second connection port 220 are both connected with the first end of the contact switch of the relay 233; the second terminal of the contact switch of the relay 233 is connected to the positive terminal of the power output port 250.

In a possible embodiment, as shown in fig. 4, fig. 4 is a schematic diagram of the protection circuit 200 corresponding to fig. 3, where the current-limiting protection unit includes a first resistor R5 and a first capacitor C10; a first end of the first resistor R5 is connected to the positive electrode of the first connection port 210; the second end of the first resistor R5 is connected with the first end of the first capacitor C10; the second terminal of the first capacitor C10 is connected to the positive electrode of the unidirectional conducting unit 232. The absorption unit 234 includes a second capacitor C9 and a zener diode Z1 connected in parallel with a coil of a relay 233 (RLY). The unidirectional conducting unit 232 may use a single diode D1, or may use a plurality of diodes connected in parallel.

The first resistor R5 may be a single resistor, or may be a plurality of resistors connected in series; the first capacitor C10 may be a single capacitor or a plurality of capacitors connected in series.

In a possible embodiment, as shown in fig. 4, the protection circuit further includes a voltage dependent resistor RV; the voltage dependent resistor RV is disposed between the negative electrode of the power output port 250 and the second end of the switch control module 230. Through the piezoresistor RV, can carry out overvoltage protection to the circuit, improve the security that the circuit used.

Further, in order to know whether the protection circuit is normal before use, a test circuit 260 consisting of a capacitor R4 and a button T may be further disposed between the positive electrode and the negative electrode of the second connection port, and after the protection circuit is connected to the load, the mains supply, the leakage protection circuit, and the like, the button T may be pressed to simulate the leakage condition and see whether the protection circuit can operate normally.

In one possible embodiment, as shown in fig. 4, the trip module 240 includes a trip coil KJA, a first contact switch K1, and a second contact switch K2; the trip coil is arranged on a line between the second end of the switch control module 230 and the positive electrode of the power output port 250; the first end of the first contact switch K1 is connected to the positive electrode of the first connection port 210, and the first end of the second contact switch is connected to the negative electrode of the first connection port 210; a second end of the first contact switch K1 and a positive electrode of the second connection port 220 are both connected with a first end of the switch control module 230, and a second end of the second contact switch K2 is connected with a negative electrode of the second connection port 220; the trip coil KJA controls the on-off state of the first contact switch K1 and the second contact switch K2 through the generated magnetic field. Through the trip module 240, a magnetic field may be generated when a large current occurs in the trip coil KJA, so as to drive the first contact switch K1 and the second contact switch K2, and switch the first contact switch K1 and the second contact switch K2 to an off state. The first contact switch KA and the second contact switch K2 may be provided with armatures, and when the trip coil KJA generates a magnetic field, the armatures drive the first contact switch K1 and the second contact switch K2 to move, so that the first contact switch K1 and the second contact switch K2 are switched to an off state. Of course, the first contact switch K1 and the second contact switch K2 may also use other trip structures in various electromagnetic trips commonly used at present, which is not described herein again in this embodiment of the application.

It should be noted that the tripping module 240 may also be directly selected from various electromagnetic trips commonly used at present.

Referring to fig. 5, in a possible implementation, the present application also provides a protection device 500, where the protection device 500 includes the protection circuit 200 in any of the above embodiments. The protection device 500 can be packaged and used in an earth leakage protection device, and specifically, the protection circuit can be packaged by using a PCB to form an earth leakage protection device with a first connection port and a second connection port. It should be noted that the protection device 500 may be packaged in other various manners commonly used at present, and the embodiment of the present application is not limited in this embodiment.

Referring to fig. 6, in a possible implementation, an embodiment of the present application further provides a leakage protection control circuit 600, where the leakage protection control circuit 600 includes the protection circuit 200 in the above embodiments, and a leakage detection control module 610 connected to a power output port of the protection circuit 200; the leakage detecting control module 610 performs ground control by a third current on a line connected to the second connection port 220 of the protection circuit 200. Specifically, when the leakage detection control module 610 is connected, the power output port 250 may be directly replaced with a wire.

For example, when the leakage protection control circuit 600 is used, if the first connection port 210 is connected to the mains power supply, the second connection port 220 is connected to the load, and the trip module 240 is reset to the on state, the switch control module 230 is in the on state, and the load and the leakage detection control module 610 may be powered on normally. If the load has leakage, the leakage detection control module 610 performs ground control, the positive current of the leakage detection control module 610 increases instantly, and the trip module 240 is switched to the off state under the driving of the current, so that the load and the leakage detection control module 610 are powered off simultaneously. If the first connection port 210 is connected to the load, the second connection port 220 is connected to the commercial power source, and the trip module 240 is reset to the on state, the switch control module 230 is in the on state, and the load and leakage detection control module 610 can be normally powered on. If the load has leakage and the leakage detection control module 610 performs ground control, the positive electrode current of the leakage detection control module 610 increases instantly, and the trip module 240 is switched to the off state under the driving of the current, so that the switch control module 230 is also switched to the off state, and the load and the leakage detection control module 610 are powered off at the same time.

In a possible embodiment, as shown in fig. 7, fig. 7 is a schematic diagram of the leakage protection control circuit 600 corresponding to fig. 6, where the leakage detection control module 610 includes a rectifying unit 611, a filtering unit 612, a leakage detecting unit 613, a control unit 614, and a ground connection switching unit 615; the positive electrode of the rectifying unit 611 is connected to the second end of the switch control module 230; the negative electrode of the rectifying unit 611 is connected with the negative electrode of the second end of the trip module 240; the current output end of the rectifying unit 611 is connected to the anode of the ground on-off unit 615 and the input end of the filtering unit 612, respectively; the negative electrode of the ground on/off unit 615 is grounded; the output end of the filtering unit 612 is connected with the power port of the control unit 614; the leakage detecting unit 613 is connected to the control unit 614; the leakage detecting unit 613 is configured to detect a third current on a line connected to the second connection port 220, and control a connection/disconnection state of the ground connection/disconnection unit 615 according to the third current. The leakage detecting unit 613 includes a current transformer ZCT provided on a line connected to the second connection port 220; and the sampling unit is connected with the current transformer ZCT and the control unit 614 and is used for collecting a current signal of the current transformer ZCT and inputting the current signal into the sampling unit of the control unit 614.

Specifically, as shown in fig. 7, the rectifying unit 611 may be a rectifying bridge B1; the filtering unit 612 may be an RC filter composed of a resistor R1 and a capacitor C1; the control unit 614 may select a leakage protection chip with a model number of M54123; the grounding on-off unit 615 can be a Silicon Controlled Rectifier (SCR); the sampling unit can be composed of resistors R2 and R3, capacitors C4, C6, C7, C8 and the like; wherein the resistor R2 and the capacitor C6 are connected in parallel between the anode and the cathode of the current transformer ZCT; the resistor R3 and the capacitor C7 form a resistance-capacitance filter circuit, a first end of the resistor R3 is connected to the anode of the current transformer ZCT, a second end of the resistor R3 and a first end of the capacitor C7 are both connected to an input pin (IN) of the control unit 614, and a second end of the capacitor C7 is grounded. The capacitor C8 is disposed between the input pin (IN) of the control unit 614 and the reference voltage pin (VR); a first terminal of the capacitor C4 is connected to a reference voltage pin (VR) of the control unit 614, and a second terminal of the capacitor C4 is grounded.

In a possible embodiment, as shown in fig. 7, the earth leakage protection control circuit 600 further includes a testing circuit 260 connected between the positive and negative electrodes of the second connection port 220; the leakage detection control module 610 is further configured to detect a fourth current when the test circuit is closed, and perform ground control according to the fourth current. Specifically, the test circuit 260 includes a resistor R4 and a button T connected in series between the positive electrode and the negative electrode of the second connection port 220, and after the load and the mains supply are connected, the button T can be pressed to detect whether the leakage protection control circuit 600 can normally operate, so as to improve the safety of use.

In a possible implementation, as shown in fig. 8, an example of the present application further provides a leakage protection switch 800, where the leakage protection switch 800 includes a leakage protection control circuit 600 according to any one of the embodiments in fig. 6 or fig. 7.

The above description is only for the specific embodiments of the present application, but the scope of the present application is not limited thereto, and any person skilled in the art can easily conceive of the changes or substitutions within the technical scope of the present application, and shall be covered by the scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

Claims (13)

1. A protection circuit is characterized by comprising a first connection port, a second connection port, a switch control module, a tripping module and a power output port; the first end of the tripping module is connected with the first connection port; the second end of the tripping module is connected with the second connecting port, the positive pole of the second end of the tripping module and the positive pole of the second connecting port are both connected with the first end of the switch control module, and the negative pole of the second end of the tripping module is connected with the negative pole of the power output port; the second end of the switch control module is connected with the anode of the power output port; the switch control module is also connected with the first connection port; the tripping module is also connected with the anode of the power output port; the switch control module controls the on-off state of the switch control module through a first current between the positive electrode and the negative electrode of the first connection port; the tripping module controls the on-off state of the tripping module through the second current of the anode of the power output port.

2. The protection circuit according to claim 1, wherein the switch control module includes a current limiting protection unit, a unidirectional conduction unit, a relay, and an absorption unit; the first end of the current-limiting protection unit is connected with the anode of the first connection port; the second end of the current-limiting protection unit is connected with the anode of the one-way conduction unit; the absorption unit is connected with a coil of the relay in parallel, a first end of the absorption unit after the absorption unit is connected with a negative electrode of the unidirectional conduction unit in parallel, and a second end of the absorption unit after the absorption unit is connected with a negative electrode of the first connection port in parallel; the positive output end of the tripping module and the positive electrode of the second connecting port are both connected with the first end of the contact switch of the relay; and the second end of the contact switch of the relay is connected with the anode of the power output port.

3. The protection circuit according to claim 2, wherein the current limiting protection unit includes a first resistor and a first capacitor; the first end of the first resistor is connected with the positive electrode of the first connecting port; the second end of the first resistor is connected with the first end of the first capacitor; and the second end of the first capacitor is connected with the anode of the unidirectional conducting unit.

4. The protection circuit according to claim 2, wherein the unidirectional conducting unit comprises a plurality of diodes connected in parallel.

5. The protection circuit of claim 2, wherein the absorption unit comprises a second capacitor and a zener diode connected in parallel with the coil of the relay.

6. The protection circuit of claim 1, further comprising a voltage dependent resistor; the voltage dependent resistor is arranged between the negative electrode of the power output port and the second end of the switch control module.

7. The protection circuit of claim 1, wherein the trip module comprises a trip coil, a first contact switch, and a second contact switch; the trip coil is arranged on a circuit between the second end of the switch control module and the positive electrode of the power output port; the first end of the first contact switch is connected with the anode of the first connecting port, and the first end of the second contact switch is connected with the cathode of the first connecting port; the second end of the first contact switch and the anode of the second connection port are both connected with the first end of the switch control module, and the second end of the second contact switch is connected with the cathode of the second connection port; the tripping coil controls the on-off state of the first contact switch and the second contact switch through a generated magnetic field.

8. A protection device comprising the protection circuit of any one of claims 1 to 7.

9. An earth leakage protection control circuit, comprising the protection circuit of any one of claims 1 to 7, and an earth leakage detection control module connected to a power output port of the protection circuit; and the electric leakage detection control module performs ground control through a third current on a line connected with the second connecting port of the protection circuit.

10. The earth leakage protection control circuit of claim 9, wherein the earth leakage detection control module comprises a rectifying unit, a filtering unit, an earth leakage detection unit, a control unit and an earth connection on-off unit; the positive electrode of the rectifying unit is connected with the second end of the switch control module; the negative electrode of the rectifying unit is connected with the negative electrode of the second end of the tripping module; the current output end of the rectifying unit is respectively connected with the anode of the grounding on-off unit and the input end of the filtering unit; the negative electrode of the grounding on-off unit is grounded; the output end of the filtering unit is connected with the power port of the control unit; the electric leakage detection unit is connected with the control unit; the electric leakage detection unit is used for detecting a third current on a circuit connected with the second connection port and controlling the on-off state of the grounding on-off unit according to the third current.

11. The earth leakage protection control circuit according to claim 10, wherein the earth leakage detecting unit comprises a current transformer provided on a line connected to the second connection port; and the sampling unit is connected with the current transformer and the control unit and used for acquiring a current signal of the current transformer and inputting the current signal into the control unit.

12. A leakage protection control circuit according to any of claims 9-11, further comprising a test circuit connected between the positive and negative poles of the second connection port; the electric leakage detection control module is also used for detecting a fourth current when the test circuit is closed and carrying out grounding control according to the fourth current.

13. A leakage protection switch comprising a leakage protection control circuit according to any one of claims 9 to 12.

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