Voltage limiting type shunt trip circuit

Abstract

The utility model discloses a voltage limiting type shunt trip circuit, which comprises a power supply circuit and a shunt trip coil TK used for controlling the on-off of the power supply circuit, and the power supply circuit is provided with an acquisition circuit used for detecting the voltage information of the power supply circuit. A control circuit used in cooperation with the acquisition circuit to control the shunt trip coils TK is arranged between the shunt trip coils TK, and the power supply end of the acquisition circuit, the power supply end of the shunt trip coils TK and the power supply end of the control circuit are electrically connected with the power supply circuit. The signal transmission end of the acquisition circuit is electrically connected with the signal receiving end of the control circuit, and the signal output end of the control circuit is electrically connected with the signal receiving end of the shunt trip coil TK. According to the utility model, the problem of low working stability of a traditional shunt release in the prior art is solved. The device has the advantages of simple structure, high stability and the like.

Description

Technical Field

[0001] The utility model relates to the technical field of low-voltage electrical appliances, and more specifically to a voltage-limiting shunt tripping circuit. Background Art

[0002] With the rapid development of the national economy, the continuous improvement of people's living standards and the diversification of electrical appliances, the demand for electricity consumption is also increasing day by day. At the same time, the country's active construction of power projects has enabled people to gradually popularize electricity supply. Therefore, the demand for electricity continues to grow, and it also brings a huge market for low-voltage electrical products. In low-voltage electrical appliances, circuit breakers are important components in the safety control of electrical equipment. Among them, the shunt release is an important accessory for remotely controlling the circuit breaker. The action requirement for executing the shunt release is that when the power supply voltage provided to the shunt release is equal to any voltage between 70% and 110% of the rated control power supply voltage, the circuit breaker can be reliably disconnected. Generally, the shunt tripping process is to directly apply voltage to the release coil to activate the electromagnetic release.

[0003] At present, a shunt release is disclosed on the Chinese Patent Network, with the publication number CN201868357U, and in particular refers to a shunt release in which a group of auxiliary contacts are arranged in the shell of the shunt release, and the power supply of the auxiliary contacts is different from the power supply of the shunt release coil of the shunt release. The utility model adopts the following technical scheme: a shunt release with auxiliary contacts, including a shell, a shunt release unit and an auxiliary contact unit arranged in the shell, the shunt release unit including a handle, a tripping mechanism and a contact mechanism, characterized in that: the power supply of the auxiliary contact unit is independent of the power supply used by the coil of the shunt release unit. By adopting the above scheme, the utility model overcomes the shortcomings of the prior art and provides a new type of shunt release in which a group of auxiliary contacts are arranged in the shell of the shunt release, and the power supply of the auxiliary contacts is different from the power supply used by the coil of the shunt release unit.

[0004] During the shunt tripping process of a shunt release in the above patent, the shunt action voltage value can only be changed or confirmed by controlling the internal release parameters. However, the change of the release parameters is affected by the coil skeleton or the space allowed for the shunt release by the circuit breaker, and the ideal shunt action voltage value cannot be accurately achieved. At the same time, there may be a phenomenon of false operation of the circuit breaker due to low voltage or coupling voltage, affecting the reliable operation of the circuit breaker. Utility Model Content

[0005] In order to overcome the problem of low working stability of the traditional shunt release in the prior art, the utility model provides a voltage-limiting shunt release circuit with high working stability.

[0006] The utility model discloses a voltage-limiting shunt tripping circuit, comprising a power supply line and a shunt tripping coil TK for controlling the on-off circuit of the power supply line. The power supply line is provided with a collection circuit for detecting voltage information of the power supply line. A control circuit for controlling the shunt tripping coil TK in cooperation with the collection circuit is provided between the shunt tripping coil TK and the shunt tripping coil TK. The power supply end of the collection circuit, the power supply end of the shunt tripping coil TK and the power supply end of the control circuit are electrically connected to the power supply line respectively. The signal transmission end of the collection circuit is electrically connected to the signal receiving end of the control circuit. The signal output end of the control circuit is electrically connected to the signal receiving end of the shunt tripping coil TK.

[0007] Preferably, the power supply circuit includes a live wire L and a neutral wire N, the acquisition circuit includes a power supply circuit and a voltage detection circuit, the output end of the live wire L and the output end of the neutral wire N are electrically connected to the input end of the acquisition circuit respectively, the output end of the acquisition circuit is electrically connected to the signal receiving end of the voltage detection circuit, and the signal output end of the voltage detection circuit is electrically connected to the signal receiving end of the control circuit.

[0008] Preferably, the power supply circuit includes a rectifier bridge D1 and a polarity capacitor C1, pin 1 of the rectifier bridge D1 is electrically connected to the live wire L, pin 2 of the rectifier bridge D1 is electrically connected to the neutral wire N, pin 3 of the rectifier bridge D1 is electrically connected to the negative pole of the polarity capacitor C1, and pin 4 of the rectifier bridge D1 is electrically connected to the positive pole of the polarity capacitor C1.

[0009] Preferably, the voltage detection circuit includes resistor R1, resistor R2, resistor R3, resistor R4 and voltage monitoring chip U1, one end of the resistor R1 is electrically connected to the positive electrode of the polarity capacitor C1 and one end of the resistor R3, respectively, the other end of the resistor R1 is electrically connected to pin 1 of the voltage monitoring chip U1 and one end of the resistor R2, the other end of the resistor R2 is electrically connected to the negative electrode of the polarity capacitor C1, pin 2 of the voltage monitoring chip U1 and one end of the resistor R4, the other end of the resistor R4 is electrically connected to the other end of the resistor R3 and pin 3 of the voltage monitoring chip U1, and pin 3 of the voltage monitoring chip U1 is electrically connected to the signal receiving end of the control circuit.

[0010] Preferably, the control circuit includes an on-off circuit and a power conversion circuit, the input end of the on-off circuit is electrically connected to pin 3 of the voltage monitoring chip U1, the output end of the on-off circuit is electrically connected to the input end of the power conversion circuit, and the output end of the power conversion circuit is electrically connected to the signal receiving end of the shunt trip coil TK.

[0011] Preferably, the on-off circuit includes resistor R5, resistor R6, resistor R7, resistor R8, MOS tube U2, transistor Q1 and transistor Q2, pin 3 of the voltage monitoring chip U1 is electrically connected to the base of the transistor Q1, the collector of the transistor Q1 is electrically connected to one end of the resistor R5, one end of the resistor R6 and the base of the transistor Q2 respectively, the other end of the resistor R5 is electrically connected to one end of the resistor R3, one end of the resistor R7 and pin 1 of the MOS tube U2 respectively, the other end of the resistor R7 is electrically connected to one end of the resistor R8, the other end of the resistor R8 is electrically connected to pin 2 of the MOS tube U2 and the collector of the transistor Q2 respectively, pin 3 of the MOS tube U2 is electrically connected to the input end of the power conversion circuit, the emitter of the transistor Q1 is electrically connected to one end of the resistor R4, the other end of the resistor R6 and the emitter of the transistor Q2 respectively, and the emitter of the transistor Q2 is grounded.

[0012] Preferably, the power conversion circuit includes a resistor R9, a resistor R10, a resistor R11, a resistor R12, a resistor R13, a resistor R14, a capacitor C2, a polar capacitor C3, a capacitor C4, a capacitor C5, a capacitor C6, a polar capacitor C7, a high-frequency transformer T1, a diode D2, a diode D3, a diode D4, a diode D5, a power chip U3, an optocoupler U4 and a voltage stabilizing chip U5, one end of the resistor R9 is electrically connected to pin 3 of the MOS tube U2, one end of the resistor R10, one end of the capacitor C4 and pin 1 of the high-frequency transformer T1, and the other end of the resistor R9 is electrically connected to one end of the capacitor C2 and the power chip U3. 1 pin is electrically connected, the other end of the capacitor C2 is electrically connected to the negative electrode of the polarity capacitor C3, the negative electrode of the polarity capacitor C3 is grounded, the positive electrode of the polarity capacitor C3 is electrically connected to the negative electrode of the diode D2 and the 3 pin of the power chip U3 respectively, the positive electrode of the diode D2 is electrically connected to the 4 pin of the high-frequency transformer T1, the other end of the resistor R10 is electrically connected to the negative electrode of the diode D3 and the other end of the capacitor C4 respectively, the positive electrode of the diode D3 is electrically connected to the 6 pin of the power chip U3 and the 2 pin of the high-frequency transformer T1 respectively, the 3 pin of the high-frequency transformer T1 is grounded, and the 6 pin of the high-frequency transformer T1 is electrically connected to the ground. The pin is electrically connected to the positive electrode of the diode D4, the negative electrode of the diode D4 is electrically connected to one end of the resistor R12, one end of the resistor R13 and the positive electrode of the polarity capacitor C7, the 5th pin of the power chip U3 is grounded, the 4th pin of the power chip U3 is electrically connected to one end of the capacitor C5, one end of the resistor R11 and the 1st pin of the optocoupler U4, the other end of the capacitor C5 is electrically connected to the other end of the resistor R11 and the 2nd pin of the power chip U3, the other end of the capacitor C5 is grounded, the 4th pin of the optocoupler U4 is electrically connected to the other end of the resistor R12, the 3rd pin of the optocoupler U4 is electrically connected to the voltage stabilizing chip U5 Pin 1 of the voltage stabilizing chip U5 is electrically connected to one end of the capacitor C6, pin 3 of the voltage stabilizing chip U5 is electrically connected to the other end of the capacitor C6, the other end of the resistor R13 and one end of the resistor R14, pin 2 of the voltage stabilizing chip U5 is electrically connected to the other end of the resistor R14 and the negative pole of the polarity capacitor C7, pin 2 of the voltage stabilizing chip U5 outputs VCC, pin 5 of the high-frequency transformer T1 is connected to VCC, one end of the shunt tripping coil TK is electrically connected to the negative pole of the diode D5 and the negative pole of the diode D4, and the other end of the shunt tripping coil TK is electrically connected to the positive pole of the diode D5 and the negative pole of the polarity capacitor C7.

[0013] The operating principle of the utility model is as follows: when the shunt power supply is supplied, it is rectified and filtered by the power supply circuit; to the voltage detection circuit, the voltage value of the applied voltage is judged by the voltage detection circuit. If it reaches the preset voltage value, the voltage detection circuit issues an opening command, otherwise, the voltage detection circuit issues a disconnection command; the on-off circuit receives the corresponding command and executes the corresponding operation. Only when the on-off circuit is in the on-operation state, the power conversion circuit will convert the low voltage power required by the shunt release for the release to operate. Thus, the shunt release function is realized.

[0014] The power supply circuit plays the role of rectification and filtering for the entire circuit. The voltage detection circuit monitors the voltage signal and issues corresponding commands according to the preset value. The on-off circuit performs corresponding on-off operations according to the command of the voltage detection circuit. The power conversion circuit converts high voltage into low voltage to provide the voltage for the release coil.

[0015] The utility model has the following beneficial effects:

[0016] It can accurately change and confirm the shunt tripping action value, is easy to operate, and does not require changing the shunt tripping structure. At the same time, it can effectively avoid some false operation phenomena, improve the operating reliability of the circuit breaker, and effectively protect the safety of low-voltage distribution lines, electrical equipment, and people. The circuit is low-cost, simple in structure, high in stability, and easy to implement. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Attached Figure 1 This is a principle block diagram of the utility model.

[0018] Attached Figure 2 This is a circuit schematic diagram of the utility model.

[0019] Attached Figure 3 It is a schematic diagram of the power supply circuit of the utility model.

[0020] Attached Figure 4 It is a schematic diagram of the voltage detection circuit of the utility model.

[0021] Attached Figure 5 It is the principle diagram of the on-off circuit of the utility model.

[0022] Attached Figure 6 It is a schematic diagram of the power conversion circuit of the utility model.

[0023] Power supply circuit 1, voltage detection circuit 2, on-off circuit 3, power conversion circuit 4. DETAILED DESCRIPTION

[0024] The technical solution of the utility model is further specifically described below through embodiments and in conjunction with the accompanying drawings.

[0025] Embodiment: According to the attached Figure 1 and attached Figure 2 The utility model is further explained. In this example, a voltage-limiting shunt tripping circuit includes a power supply line and a shunt tripping coil TK for controlling the on / off circuit of the power supply line. The power supply line is provided with an acquisition circuit for detecting voltage information of the power supply line. A control circuit for controlling the shunt tripping coil TK is provided between the shunt tripping coil TK and the shunt tripping coil TK, and the power supply end of the acquisition circuit, the power supply end of the shunt tripping coil TK and the power supply end of the control circuit are electrically connected to the power supply line respectively, the signal transmission end of the acquisition circuit is electrically connected to the signal receiving end of the control circuit, and the signal output end of the control circuit is electrically connected to the signal receiving end of the shunt tripping coil TK.

[0026] The power supply circuit includes a live wire L and a neutral wire N, the acquisition circuit includes a power supply circuit 1 and a voltage detection circuit 2, the output end of the live wire L and the output end of the neutral wire N are electrically connected to the input end of the acquisition circuit respectively, the output end of the acquisition circuit is electrically connected to the signal receiving end of the voltage detection circuit 2, and the signal output end of the voltage detection circuit 2 is electrically connected to the signal receiving end of the control circuit.

[0027] The power supply circuit 1 includes a rectifier bridge D1 and a polarity capacitor C1, wherein pin 1 of the rectifier bridge D1 is electrically connected to the live wire L, pin 2 of the rectifier bridge D1 is electrically connected to the neutral wire N, pin 3 of the rectifier bridge D1 is electrically connected to the negative pole of the polarity capacitor C1, and pin 4 of the rectifier bridge D1 is electrically connected to the positive pole of the polarity capacitor C1.

[0028] The voltage detection circuit 2 includes a resistor R1, a resistor R2, a resistor R3, a resistor R4 and a voltage monitoring chip U1. One end of the resistor R1 is electrically connected to the positive electrode of the polarity capacitor C1 and one end of the resistor R3, respectively. The other end of the resistor R1 is electrically connected to pin 1 of the voltage monitoring chip U1 and one end of the resistor R2, respectively. The other end of the resistor R2 is electrically connected to the negative electrode of the polarity capacitor C1, pin 2 of the voltage monitoring chip U1 and one end of the resistor R4, respectively. The other end of the resistor R4 is electrically connected to the other end of the resistor R3 and pin 3 of the voltage monitoring chip U1, respectively. Pin 3 of the voltage monitoring chip U1 is electrically connected to the signal receiving end of the control circuit.

[0029] The control circuit includes an on-off circuit 3 and a power conversion circuit 4, the input end of the on-off circuit 3 is electrically connected to pin 3 of the voltage monitoring chip U1, the output end of the on-off circuit 3 is electrically connected to the input end of the power conversion circuit 4, and the output end of the power conversion circuit 4 is electrically connected to the signal receiving end of the shunt trip coil TK.

[0030] The on-off circuit 3 includes a resistor R5, a resistor R6, a resistor R7, a resistor R8, a MOS tube U2, a transistor Q1 and a transistor Q2. Pin 3 of the voltage monitoring chip U1 is electrically connected to the base of the transistor Q1. The collector of the transistor Q1 is electrically connected to one end of the resistor R5, one end of the resistor R6 and the base of the transistor Q2 respectively. The other end of the resistor R5 is electrically connected to one end of the resistor R3, one end of the resistor R7 and pin 1 of the MOS tube U2 respectively. The other end of the resistor R7 is electrically connected to one end of the resistor R8. The other end of the resistor R8 is electrically connected to pin 2 of the MOS tube U2 and the collector of the transistor Q2 respectively. Pin 3 of the MOS tube U2 is electrically connected to the input end of the power conversion circuit 4. The emitter of the transistor Q1 is electrically connected to one end of the resistor R4, the other end of the resistor R6 and the emitter of the transistor Q2 respectively. The emitter of the transistor Q2 is grounded.

[0031] The power conversion circuit 4 includes a resistor R9, a resistor R10, a resistor R11, a resistor R12, a resistor R13, a resistor R14, a capacitor C2, a polar capacitor C3, a capacitor C4, a capacitor C5, a capacitor C6, a polar capacitor C7, a high-frequency transformer T1, a diode D2, a diode D3, a diode D4, a diode D5, a power chip U3, an optocoupler U4 and a voltage stabilizing chip U5. One end of the resistor R9 is electrically connected to the 3rd pin of the MOS tube U2, one end of the resistor R10, one end of the capacitor C4 and the 1st pin of the high-frequency transformer T1, and the other end of the resistor R9 is electrically connected to one end of the capacitor C2 and the 1st pin of the power chip U3. The other end of the capacitor C2 is electrically connected to the negative electrode of the polarity capacitor C3, the negative electrode of the polarity capacitor C3 is grounded, the positive electrode of the polarity capacitor C3 is electrically connected to the negative electrode of the diode D2 and the 3rd pin of the power chip U3, the positive electrode of the diode D2 is electrically connected to the 4th pin of the high-frequency transformer T1, the other end of the resistor R10 is electrically connected to the negative electrode of the diode D3 and the other end of the capacitor C4, the positive electrode of the diode D3 is electrically connected to the 6th pin of the power chip U3 and the 2nd pin of the high-frequency transformer T1, the 3rd pin of the high-frequency transformer T1 is grounded, and the 6th pin of the high-frequency transformer T1 is electrically connected to the ground. The positive electrode of the diode D4 is electrically connected, the negative electrode of the diode D4 is electrically connected to one end of the resistor R12, one end of the resistor R13 and the positive electrode of the polarity capacitor C7, the 5th pin of the power chip U3 is grounded, the 4th pin of the power chip U3 is electrically connected to one end of the capacitor C5, one end of the resistor R11 and the 1st pin of the optocoupler U4, the other end of the capacitor C5 is electrically connected to the other end of the resistor R11 and the 2nd pin of the power chip U3, the other end of the capacitor C5 is grounded, the 4th pin of the optocoupler U4 is electrically connected to the other end of the resistor R12, the 3rd pin of the optocoupler U4 is electrically connected to the Pin 1 is electrically connected to one end of the capacitor C6, pin 3 of the voltage stabilizing chip U5 is electrically connected to the other end of the capacitor C6, the other end of the resistor R13 and one end of the resistor R14, pin 2 of the voltage stabilizing chip U5 is electrically connected to the other end of the resistor R14 and the negative pole of the polarity capacitor C7, pin 2 of the voltage stabilizing chip U5 outputs VCC, pin 5 of the high-frequency transformer T1 is connected to VCC, one end of the shunt tripping coil TK is electrically connected to the negative pole of the diode D5 and the negative pole of the diode D4, and the other end of the shunt tripping coil TK is electrically connected to the positive pole of the diode D5 and the negative pole of the polarity capacitor C7.

[0032] The above description is only a specific embodiment of the present invention, but the structural features of the present invention are not limited thereto. Any changes or modifications made by any technician in the field of the present invention are included in the patent scope of the present invention.

Claims

1. A voltage-limiting shunt tripping circuit, comprising a power supply circuit and a shunt tripping coil TK for controlling the on / off circuit of the power supply circuit, characterized in that: The power supply line is provided with an acquisition circuit for detecting the voltage information of the power supply line, and a control circuit used in conjunction with the acquisition circuit to control the shunt tripping coil TK is provided between the shunt tripping coil TK and the shunt tripping coil TK. The power supply end of the acquisition circuit, the power supply end of the shunt tripping coil TK and the power supply end of the control circuit are electrically connected to the power supply line respectively, the signal transmission end of the acquisition circuit is electrically connected to the signal receiving end of the control circuit, and the signal output end of the control circuit is electrically connected to the signal receiving end of the shunt tripping coil TK.

2. A voltage-limiting shunt tripping circuit according to claim 1, characterized in that: The power supply circuit comprises a live wire L and a neutral wire N, the acquisition circuit comprises a power supply circuit (1) and a voltage detection circuit (2), the output end of the live wire L and the output end of the neutral wire N are respectively electrically connected to the input end of the acquisition circuit, the output end of the acquisition circuit is electrically connected to the signal receiving end of the voltage detection circuit (2), and the signal output end of the voltage detection circuit (2) is electrically connected to the signal receiving end of the control circuit.

3. A voltage-limiting shunt tripping circuit according to claim 2, characterized in that: The power supply circuit (1) comprises a rectifier bridge D1 and a polar capacitor C1, wherein pin 1 of the rectifier bridge D1 is electrically connected to a live wire L, pin 2 of the rectifier bridge D1 is electrically connected to a neutral wire N, pin 3 of the rectifier bridge D1 is electrically connected to a negative electrode of the polar capacitor C1, and pin 4 of the rectifier bridge D1 is electrically connected to a positive electrode of the polar capacitor C1.

4. A voltage-limiting shunt tripping circuit according to claim 3, characterized in that: The voltage detection circuit (2) comprises a resistor R1, a resistor R2, a resistor R3, a resistor R4 and a voltage monitoring chip U1, one end of the resistor R1 is electrically connected to the positive electrode of the polarity capacitor C1 and one end of the resistor R3 respectively, the other end of the resistor R1 is electrically connected to the 1 pin of the voltage monitoring chip U1 and one end of the resistor R2 respectively, the other end of the resistor R2 is electrically connected to the negative electrode of the polarity capacitor C1, the 2 pin of the voltage monitoring chip U1 and one end of the resistor R4 respectively, the other end of the resistor R4 is electrically connected to the other end of the resistor R3 and the 3 pin of the voltage monitoring chip U1 respectively, and the 3 pin of the voltage monitoring chip U1 is electrically connected to the signal receiving end of the control circuit.

5. A voltage-limiting shunt tripping circuit according to claim 4, characterized in that: The control circuit comprises an on-off circuit (3) and a power conversion circuit (4), the input end of the on-off circuit (3) being electrically connected to pin 3 of the voltage monitoring chip U1, the output end of the on-off circuit (3) being electrically connected to the input end of the power conversion circuit (4), and the output end of the power conversion circuit (4) being electrically connected to the signal receiving end of the shunt tripping coil TK.

6. A voltage-limiting shunt tripping circuit according to claim 5, characterized in that: The on-off circuit (3) comprises a resistor R5, a resistor R6, a resistor R7, a resistor R8, a MOS tube U2, a transistor Q1 and a transistor Q2, the 3rd pin of the voltage monitoring chip U1 is electrically connected to the base of the transistor Q1, the collector of the transistor Q1 is electrically connected to one end of the resistor R5, one end of the resistor R6 and the base of the transistor Q2 respectively, the other end of the resistor R5 is electrically connected to one end of the resistor R3, one end of the resistor R7 and the 1st pin of the MOS tube U2 respectively, the other end of the resistor R7 is electrically connected to one end of the resistor R8, the other end of the resistor R8 is electrically connected to the 2nd pin of the MOS tube U2 and the collector of the transistor Q2 respectively, the 3rd pin of the MOS tube U2 is electrically connected to the input end of the power conversion circuit (4), the emitter of the transistor Q1 is electrically connected to one end of the resistor R4, the other end of the resistor R6 and the emitter of the transistor Q2 respectively, and the emitter of the transistor Q2 is grounded.

7. A voltage-limiting shunt tripping circuit according to claim 6, characterized in that: The power conversion circuit (4) comprises a resistor R9, a resistor R10, a resistor R11, a resistor R12, a resistor R13, a resistor R14, a capacitor C2, a polar capacitor C3, a capacitor C4, a capacitor C5, a capacitor C6, a polar capacitor C7, a high-frequency transformer T1, a diode D2, a diode D3, a diode D4, a diode D5, a power chip U3, an optocoupler U4 and a voltage stabilizing chip U5, one end of the resistor R9 is respectively electrically connected to the 3rd pin of the MOS tube U2, one end of the resistor R10, one end of the capacitor C4 and the 1st pin of the high-frequency transformer T1, and the other end of the resistor R9 is respectively electrically connected to the one end of the capacitor C2 and the 1st pin of the power chip U3. The other end of the capacitor C2 is electrically connected to the negative electrode of the polarity capacitor C3, the negative electrode of the polarity capacitor C3 is grounded, the positive electrode of the polarity capacitor C3 is electrically connected to the negative electrode of the diode D2 and the 3rd pin of the power chip U3 respectively, the positive electrode of the diode D2 is electrically connected to the 4th pin of the high-frequency transformer T1, the other end of the resistor R10 is electrically connected to the negative electrode of the diode D3 and the other end of the capacitor C4 respectively, the positive electrode of the diode D3 is electrically connected to the 6th pin of the power chip U3 and the 2nd pin of the high-frequency transformer T1 respectively, the 3rd pin of the high-frequency transformer T1 is grounded, the 6th pin of the high-frequency transformer T1 is electrically connected to the ground, and the 6th pin of the high-frequency transformer T1 is electrically connected to the ground. The pin is electrically connected to the positive electrode of the diode D4, the negative electrode of the diode D4 is electrically connected to one end of the resistor R12, one end of the resistor R13 and the positive electrode of the polarity capacitor C7, the 5th pin of the power chip U3 is grounded, the 4th pin of the power chip U3 is electrically connected to one end of the capacitor C5, one end of the resistor R11 and the 1st pin of the optocoupler U4, the other end of the capacitor C5 is electrically connected to the other end of the resistor R11 and the 2nd pin of the power chip U3, the other end of the capacitor C5 is grounded, the 4th pin of the optocoupler U4 is electrically connected to the other end of the resistor R12, the 3rd pin of the optocoupler U4 is electrically connected to the voltage stabilizing chip U5, and the 4th pin of the optocoupler U4 is electrically connected to the other end of the resistor R12. Pin 1 of the voltage stabilizing chip U5 is electrically connected to one end of the capacitor C6, pin 3 of the voltage stabilizing chip U5 is electrically connected to the other end of the capacitor C6, the other end of the resistor R13 and one end of the resistor R14, pin 2 of the voltage stabilizing chip U5 is electrically connected to the other end of the resistor R14 and the negative pole of the polarity capacitor C7, pin 2 of the voltage stabilizing chip U5 outputs VCC, pin 5 of the high-frequency transformer T1 is connected to VCC, one end of the shunt tripping coil TK is electrically connected to the negative pole of the diode D5 and the negative pole of the diode D4, and the other end of the shunt tripping coil TK is electrically connected to the positive pole of the diode D5 and the negative pole of the polarity capacitor C7.

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