Leakage controller

Abstract

This application provides a leakage current controller. An AC voltage is obtained from the power line through a rectifier circuit, converted to DC voltage, and transmitted to a thyristor drive circuit. The control circuit can transmit a control signal to the thyristor drive circuit when the sampled signal is greater than a threshold signal. Thus, the reverse-current circuit can generate a drive signal based on the control signal after a preset time and transmit the drive signal to the thyristor drive circuit. In this way, when the DC voltage is at a first level, the thyristor drive circuit can drive the trip unit to operate according to the drive signal to achieve the reverse-current function. Furthermore, when implementing the reverse-current function, the first step-down circuit can use the voltage on the first capacitor in the first step-down circuit to supply power to the control circuit, which can prevent the large current on the trip unit from pulling down the power supply voltage of the control circuit. Therefore, damage to the trip unit can be avoided, and the service life of the trip unit can be improved.

Description

Technical Field

[0001] This application relates to the field of low-voltage electrical technology, and more particularly to a leakage current controller. Background Technology

[0002] A residual current device (RCD), also known as a leakage current controller, is an electrical safety device that detects and quickly cuts off power to a circuit by monitoring the leakage current, or residual current, in the circuit. Typically, when a leakage occurs in a circuit, such as in the event of electric shock or insulation failure in equipment, the RCD quickly cuts off the power supply to the circuit breaker, preventing electric shock injuries or fires caused by leakage. It is a core protective component in electrical safety systems for addressing leakage risks.

[0003] However, when implementing the reverse current function, the leakage current controller in the related technology makes the trip unit in the circuit breaker prone to damage. Utility Model Content

[0004] This application provides a leakage current controller that can prevent damage to the trip unit and improve the service life of the trip unit.

[0005] In a first aspect, this application provides a leakage current controller, which is applied in a circuit breaker. The circuit breaker includes a trip unit, and the leakage current controller includes a control circuit, a rectifier circuit, a reverse-current circuit, a thyristor drive circuit, and a first step-down circuit. The input terminal of the control circuit is electrically connected to a sampling signal, which is used to characterize the leakage current of the circuit breaker. The output terminal of the control circuit is electrically connected to the first terminal of the thyristor drive circuit. The second terminal of the thyristor drive circuit is electrically connected to the trip unit, the output terminal of the rectifier circuit, and the input terminal of the first step-down circuit. The output terminal of the first step-down circuit is electrically connected to the power supply terminal of the control circuit. The input terminal of the rectifier circuit is electrically connected to the power supply line. The rectifier circuit is used to obtain AC voltage from the power line, convert the AC voltage into DC voltage, and transmit the DC voltage to the thyristor drive circuit. The control circuit is used to transmit a control signal to the thyristor drive circuit when the sampled signal is greater than the threshold signal. The reverse input circuit is used to generate a drive signal according to the control signal after a preset time, and transmit the drive signal to the thyristor drive circuit. The thyristor drive circuit is used to drive the trip unit to operate according to the drive signal when the DC voltage is at the first level, so as to realize the reverse line function. The first step-down circuit is used to supply power to the control circuit using the voltage on the first capacitor in the first step-down circuit when implementing the reverse incoming line function.

[0006] The leakage current controller provided in the first aspect obtains AC voltage from the power line through a rectifier circuit, converts the AC voltage to DC voltage, and transmits the DC voltage to the thyristor drive circuit, enabling the thyristor drive circuit to acquire DC voltage. The control circuit can transmit a control signal to the thyristor drive circuit when the sampled signal is greater than a threshold signal, allowing the thyristor drive circuit to acquire the control signal. Thus, the reverse-current circuit can generate a drive signal based on the control signal after a preset time and transmit the drive signal to the thyristor drive circuit, enabling the thyristor drive circuit to acquire the drive signal. Therefore, when the DC voltage is at the first level, the thyristor drive circuit can drive the trip unit to operate according to the drive signal to achieve the reverse-current function. Furthermore, when implementing the reverse-current function, the first step-down circuit can use the voltage on the first capacitor in the first step-down circuit to supply power to the control circuit, preventing the large current on the trip unit from pulling down the power supply voltage of the control circuit. This avoids damage to the trip unit and extends its service life.

[0007] In one possible design, the leakage current controller further includes: a second step-down circuit; The input terminal of the second step-down circuit is electrically connected to the output terminal of the rectifier circuit, the output terminal of the second step-down circuit is electrically connected to the input terminal of the first step-down circuit, and the output terminal of the first step-down circuit is electrically connected to the power supply terminal of the control circuit. The second step-down circuit is used to obtain the DC voltage from the rectifier circuit after realizing the reverse input function, and to step down the DC voltage to obtain a first voltage, and to transmit the first voltage to the first step-down circuit. The first step-down circuit is used to step down the first voltage to obtain a second voltage, and to use the second voltage to supply power to the control circuit.

[0008] In one possible design, the second step-down circuit includes: a first transistor, a second transistor, a first Zener diode, a first resistor, a second resistor, and a first voltage divider circuit; The first end of the first resistor and the first end of the first voltage divider circuit are both electrically connected to the trip unit. The second end of the first resistor is electrically connected to the source end of the first transistor. The drain end of the first transistor is electrically connected to the first end of the second resistor. The second end of the second resistor is electrically connected to the source end of the second transistor. The drain end of the second transistor is electrically connected to the input end of the first buck circuit. The gate end of the first transistor is electrically connected to the second end of the first voltage divider circuit. The third end of the first voltage divider circuit is electrically connected to the gate end of the second transistor and the negative terminal of the first Zener diode. The positive terminal of the first Zener diode is grounded. The first voltage divider circuit includes: a third resistor, a fourth resistor, a fifth resistor, and a sixth resistor. The first end of the third resistor is electrically connected to the trip unit, the second end of the third resistor is electrically connected to the first end of the fourth resistor, the second end of the fourth resistor is electrically connected to the gate of the first transistor and the first end of the fifth resistor, the second end of the fifth resistor is electrically connected to the first end of the sixth resistor, and the second end of the sixth resistor is electrically connected to the gate of the second transistor.

[0009] In one possible design, the second buck circuit further includes: a second Zener diode; The negative terminal of the second Zener diode is electrically connected to the gate terminal of the second transistor, and the positive terminal of the second Zener diode is grounded.

[0010] In one possible design, the first step-down circuit includes: a first capacitor, a second capacitor, a seventh resistor, a first diode, and a third Zener diode; The positive terminal of the first diode is electrically connected to the output terminal of the rectifier circuit, the negative terminal of the first diode is electrically connected to the upper plate of the first capacitor and the first terminal of the seventh resistor, the second terminal of the seventh resistor is electrically connected to the negative terminal of the third Zener diode and the upper plate of the second capacitor, and the lower plate of the first capacitor, the positive terminal of the third Zener diode, and the lower plate of the second capacitor are all grounded.

[0011] In one possible design, the first step-down circuit further includes a third capacitor and a fourth capacitor; The upper plates of the third capacitor and the fourth capacitor are both electrically connected to the negative terminal of the first diode, and the lower plates of the third capacitor and the fourth capacitor are both grounded.

[0012] In one possible design, the leakage current controller further includes: a surge protection circuit; The surge protection circuit is electrically connected between the input terminal of the rectifier circuit and the power line; The surge protection circuit is used to provide surge protection for the power line.

[0013] In one possible design, the surge protection circuit includes: a first varistor, a second varistor, and a third varistor; The first end of the first varistor is electrically connected to the A-phase power line in the power line, the first end of the second varistor is electrically connected to the B-phase power line in the power line, the first end of the third varistor is electrically connected to the C-phase power line in the power line, and the second end of the first varistor is electrically connected to the second end of the second varistor and the second end of the third varistor, respectively.

[0014] In one possible design, the control circuit includes: a main chip, an eighth resistor, a ninth resistor, a tenth resistor, a fifth capacitor, and a sixth capacitor; The first pin of the main chip is electrically connected to the first end of the eighth resistor, the second end of the eighth resistor is electrically connected to the first end of the thyristor drive circuit, the second pin of the main chip is electrically connected to the first end of the ninth resistor, the second end of the ninth resistor and the fourteenth pin of the main chip are both electrically connected to the output end of the first step-down circuit, the fourth pin and the fifth pin of the main chip are electrically connected to the sampling signal, the twelfth pin of the main chip is electrically connected to the upper plate of the fifth capacitor, the eleventh pin of the main chip is electrically connected to the upper plate of the sixth capacitor, the ninth pin of the main chip is electrically connected to the first end of the tenth resistor, and the lower plates of the fifth capacitor, the sixth capacitor, and the second end of the tenth resistor are all grounded.

[0015] In one possible design, the thyristor drive circuit includes: a fourteenth resistor, a fifteenth resistor, a sixteenth resistor, a seventeenth resistor, an eighteenth resistor, a nineteenth resistor, a sixth diode, and a seventh diode; The first terminal of the fourteenth resistor and the anode of the sixth diode are both electrically connected to the trip unit. The second terminal of the fourteenth resistor is electrically connected to the first terminal of the fifteenth resistor. The second terminal of the fifteenth resistor is electrically connected to the first terminals of the sixteenth, eighteenth, and nineteenth resistors, respectively. The first terminal of the sixteenth resistor is electrically connected to the first terminal of the seventeenth resistor. The second terminal of the eighteenth resistor is electrically connected to the cathode of the sixth diode, the anode of the seventh diode, and the second terminal of the nineteenth resistor, respectively. The cathode of the seventh diode and the second terminal of the seventeenth resistor are both grounded. The cathode of the seventh diode is also electrically connected to the output terminal of the control circuit.

[0016] The above description is merely an overview of the technical solutions of the embodiments of this application. In order to better understand the technical means of the embodiments of this application and to implement them in accordance with the contents of the specification, and to make the above and other objects, features and advantages of the embodiments of this application more obvious and understandable, specific implementation methods of this application are described below. Attached Figure Description

[0017] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of the structure of a leakage current controller provided in an embodiment of this application; Figure 2 This is a schematic diagram of the sampling circuit in a leakage current controller provided in an embodiment of this application; Figure 3 This is a schematic diagram of the delay circuit in a leakage current controller provided in an embodiment of this application; Figure 4 This is a schematic diagram of the test circuit in a leakage current controller provided in an embodiment of this application; Figure 5 This is a schematic diagram of the structure of an alarm drive circuit in a leakage current controller provided in an embodiment of this application.

[0019] Explanation of reference numerals in the attached figures: 100. Leakage current controller; 110. Control circuit; 120. Rectifier circuit; 130. Reverse input circuit; 140. Thyristor drive circuit; 150. First step-down circuit; 160. Second step-down circuit; 161. First voltage divider circuit; 170. Surge protection circuit; 180. Sampling circuit; 190. Delay circuit; 200. Trial circuit; 210. Alarm drive circuit. Detailed Implementation

[0020] In this application, "at least one" means one or more, and "more than one" means two or more. "And / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can mean: A alone, A and B simultaneously, or B alone, where A and B can be singular or plural. The character " / " generally indicates that the preceding and following related objects are in an "or" relationship. "At least one of the following" or similar expressions refer to any combination of these items, including any combination of single or plural items. For example, at least one of a, b, or c alone can mean: a alone, b alone, c alone, a combination of a and b, a combination of a and c, a combination of b and c, or a, b, and c, where a, b, and c can be single or multiple. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0021] The terms “center,” “longitudinal,” “lateral,” “up,” “down,” “left,” “right,” “front,” and “rear,” etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0022] The terms "connected" and "connected" should be interpreted broadly. For example, in circuit structures, "connected" or "connected" can refer not only to physical connections but also to electrical or signal connections. This could be a direct connection (physical connection) or an indirect connection via at least one intermediate component, as long as the circuit is connected. It could also refer to the internal connection between two components. Similarly, a signal connection can refer to a connection via a circuit or a medium, such as radio waves. Those skilled in the art will understand the specific meaning of these terms in this application based on the specific circumstances.

[0023] Reference Figure 1 , Figure 1 This is a schematic diagram of a leakage current controller provided in an embodiment of this application. Figure 1 As shown, the leakage current controller 100 may include: a control circuit 110, a rectifier circuit 120, a reverse input circuit 130, a thyristor drive circuit 140, and a first step-down circuit 150.

[0024] The input terminal of the control circuit 110 is electrically connected to a sampling signal, which is used to characterize the leakage current of the circuit breaker. The output terminal of the control circuit 110 is electrically connected to the first terminal of the thyristor drive circuit 140. The second terminal of the thyristor drive circuit 140 is electrically connected to the trip unit COIL, the output terminal of the rectifier circuit 120, and the input terminal of the first step-down circuit 150, respectively. The output terminal of the first step-down circuit 150 is electrically connected to the power supply terminal of the control circuit 110, and the input terminal of the rectifier circuit 120 is electrically connected to the power supply line.

[0025] The control circuit 110, rectifier circuit 120, reverse input circuit 130, thyristor drive circuit 140 and first step-down circuit 150 can be integrated or set separately. This application embodiment does not specifically limit this.

[0026] in, Figure 1 The letters COIL+ in the circuit indicate one end of the trip unit, and COIL- indicate the other end.

[0027] The rectifier circuit 120 can obtain AC voltage from the power supply line. Furthermore, the rectifier circuit 120 can convert the AC voltage into DC voltage and transmit the DC voltage to the thyristor drive circuit 140, so that the thyristor drive circuit 140 can obtain DC voltage.

[0028] When the sampled signal is greater than the threshold signal, the control circuit 110 can transmit a control signal to the thyristor drive circuit 140, so that the thyristor drive circuit 140 can acquire the control signal.

[0029] In this way, the reverse-entry circuit 130 can generate a drive signal after a preset time according to the control signal. Furthermore, the reverse-entry circuit 130 can transmit the drive signal to the thyristor drive circuit 140, enabling the thyristor drive circuit 140 to acquire the drive signal.

[0030] Thus, when the DC voltage is at the first level, the thyristor drive circuit 140 can drive the trip unit COIL to operate according to the drive signal to achieve the reverse line function.

[0031] The first level state is, for example, a low level state.

[0032] Furthermore, when implementing the reverse input function, the first step-down circuit 150 can use the voltage on the first capacitor C1 in the first step-down circuit 150 to supply power to the control circuit 110. This prevents the large current on the trip unit COIL from pulling down the power supply voltage VDD of the control circuit 110 at the moment the trip unit COIL trips. Therefore, damage to the trip unit COIL can be avoided, and its service life can be extended.

[0033] The leakage current controller provided in this application obtains AC voltage from the power line through a rectifier circuit, converts the AC voltage into DC voltage, and transmits the DC voltage to the thyristor drive circuit, enabling the thyristor drive circuit to acquire DC voltage. The control circuit can transmit a control signal to the thyristor drive circuit when the sampled signal is greater than a threshold signal, allowing the thyristor drive circuit to acquire the control signal. Thus, the reverse-current circuit can generate a drive signal based on the control signal after a preset time and transmit the drive signal to the thyristor drive circuit, enabling the thyristor drive circuit to acquire the drive signal. In this way, when the DC voltage is at a first level, the thyristor drive circuit can drive the trip unit to operate according to the drive signal to achieve the reverse-current function. Furthermore, when implementing the reverse-current function, the first step-down circuit can use the voltage on the first capacitor in the first step-down circuit to supply power to the control circuit, preventing the large current on the trip unit from pulling down the power supply voltage of the control circuit. This avoids damage to the trip unit and extends its service life.

[0034] Based on the description of the above embodiments, an exemplary possible implementation of the leakage current controller 100 is provided. Figure 1 As shown, the leakage current controller 100 may further include a second step-down circuit 160.

[0035] The input terminal of the second step-down circuit 160 is electrically connected to the output terminal of the rectifier circuit 120, the output terminal of the second step-down circuit 160 is electrically connected to the input terminal of the first step-down circuit 150, and the output terminal of the first step-down circuit 150 is electrically connected to the power supply terminal of the control circuit 110.

[0036] After implementing the reverse input function, the second step-down circuit 160 can obtain DC voltage from the rectifier circuit 120, step down the DC voltage to obtain the first voltage, and transmit the first voltage to the first step-down circuit 150 so that the first step-down circuit 150 can obtain the first voltage.

[0037] Thus, the first step-down circuit 150 can step down the first voltage to obtain a second voltage, and use the second voltage to supply power to the control circuit 110.

[0038] Based on the description of the above embodiments, an exemplary possible implementation of the second buck circuit 160 is provided. Figure 1 As shown, the second step-down circuit 160 may include: a first transistor T1, a second transistor T2, a first Zener diode VD1, a first resistor R1, a second resistor R2, and a first voltage divider circuit 161.

[0039] The first terminal of the first resistor R1 and the first terminal of the first voltage divider circuit 161 are both electrically connected to the trip unit COIL. The second terminal of the first resistor R1 is electrically connected to the source terminal of the first transistor T1. The drain terminal of the first transistor T1 is electrically connected to the first terminal of the second resistor R2. The second terminal of the second resistor R2 is electrically connected to the source terminal of the second transistor T2. The drain terminal of the second transistor T2 is electrically connected to the input terminal of the first buck circuit 150. The gate terminal of the first transistor T1 is electrically connected to the second terminal of the first voltage divider circuit 161. The third terminal of the first voltage divider circuit 161 is electrically connected to the gate terminal of the second transistor T2 and the negative terminal of the first Zener diode VD1. The positive terminal of the first Zener diode VD1 is grounded.

[0040] The second step-down circuit 160 meets the wide voltage requirement of the circuit breaker 100, effectively optimizing the temperature rise of the circuit board of the leakage current controller 100. Simultaneously, the second step-down circuit 160 has the advantages of low cost, low power consumption, and low temperature rise.

[0041] In some examples, the first voltage divider circuit 161 may include: a third resistor R3, a fourth resistor R4, a fifth resistor R5, and a sixth resistor R6.

[0042] The first end of the third resistor R3 is electrically connected to the trip unit COIL. The second end of the third resistor R3 is electrically connected to the first end of the fourth resistor R4. The second end of the fourth resistor R4 is electrically connected to the gate of the first transistor T1 and the first end of the fifth resistor R5. The second end of the fifth resistor R5 is electrically connected to the first end of the sixth resistor R6. The second end of the sixth resistor R6 is electrically connected to the gate of the second transistor T2.

[0043] Based on the description of the above embodiments, an exemplary alternative implementation of the second buck circuit 160 is provided. Figure 1 As shown, the second step-down circuit 160 may further include a second Zener diode VD2.

[0044] The negative terminal of the second Zener diode VD2 is electrically connected to the gate terminal of the second transistor T2, and the positive terminal of the second Zener diode VD2 is grounded.

[0045] Based on the description of the above embodiments, an exemplary possible implementation of the first step-down circuit 150 is provided. Figure 1 As shown, the first step-down circuit 150 may include: a first capacitor C1, a second capacitor C2, a seventh resistor R7, a first diode D1, and a third Zener diode VD3.

[0046] The positive terminal of the first diode D1 is electrically connected to the output terminal of the rectifier circuit 120. The negative terminal of the first diode D1 is electrically connected to the upper plate of the first capacitor C1 and the first terminal of the seventh resistor R7. The second terminal of the seventh resistor R7 is electrically connected to the negative terminal of the third Zener diode VD3 and the upper plate of the second capacitor C2. The lower plate of the first capacitor C1, the positive terminal of the third Zener diode VD3, and the lower plate of the second capacitor C2 are all grounded.

[0047] Based on the description of the above embodiments, an exemplary alternative implementation of the first buck circuit 150 is provided. Figure 1 As shown, the first step-down circuit 150 may further include a third capacitor C3 and a fourth capacitor C4.

[0048] The upper plates of the third capacitor C3 and the fourth capacitor C4 are both electrically connected to the negative terminal of the first diode D1, and the lower plates of the third capacitor C3 and the fourth capacitor C4 are both grounded.

[0049] In some examples, the first step-down circuit 150 may also include a seventh capacitor C7.

[0050] The upper plate of the seventh capacitor C7 is electrically connected to the upper plate of the second capacitor C2, and the lower plate of the seventh capacitor C7 is grounded.

[0051] When the leakage current controller 100 is powered on, the first capacitor C1, the third capacitor C3, and the fourth capacitor C4 are charged first, and then the second capacitor C2 is charged. Therefore, the test time for the leakage current controller 100 to close is increased, and the tripping response time of the trip unit COIL is shortened. Simultaneously, the first diode D1 prevents the first capacitor C1, the second capacitor C2, the third capacitor C3, and the fourth capacitor C4 from transmitting energy to the second step-down circuit 160 in the reverse direction.

[0052] Based on the description of the above embodiments, another possible implementation of the leakage current controller 100 is exemplarily described. For example... Figure 1 As shown, the leakage current controller 100 may also include a surge protection circuit 170.

[0053] Surge protection circuit 170 is electrically connected between the input terminal of rectifier circuit 120 and the power supply line.

[0054] The surge protection circuit 170 can protect the power line from surges, preventing excessive AC voltage values.

[0055] Based on the description of the above embodiments, an exemplary possible implementation of the surge protection circuit 170 is provided. For example... Figure 1As shown, the surge protection circuit 170 may include: a first varistor RV1, a second varistor RV2 and a third varistor RV3.

[0056] The first end of the first varistor RV1 is electrically connected to the A-phase power line in the power supply line, the first end of the second varistor RV2 is electrically connected to the B-phase power line in the power supply line, the first end of the third varistor RV3 is electrically connected to the C-phase power line in the power supply line, and the second end of the first varistor RV1 is electrically connected to the second end of the second varistor RV2 and the second end of the third varistor RV3, respectively.

[0057] Compared to the surge protection circuit in the leakage current controller in related technologies, the surge protection circuit 170 in this application adopts a star connection, which has the advantages of high withstand voltage and low cost.

[0058] Based on the description of the above embodiments, an exemplary possible implementation of the control circuit 110 is provided. For example... Figure 1 As shown, the control circuit 110 may include: main chip IC1, eighth resistor R8, ninth resistor R9, tenth resistor R10, fifth capacitor C5 and sixth capacitor C6.

[0059] The first pin of the main chip IC1 is electrically connected to the first end of the eighth resistor R8. The second end of the eighth resistor R8 is electrically connected to the first end of the thyristor drive circuit 140. The second pin of the main chip IC1 is electrically connected to the first end of the ninth resistor R9. The second end of the ninth resistor R9 and the fourteenth pin of the main chip IC1 are both electrically connected to the output of the first step-down circuit 150. The fourth and fifth pins of the main chip IC1 are both electrically connected to the sampling signal. The twelfth pin of the main chip IC1 is electrically connected to the upper plate of the fifth capacitor C5. The eleventh pin of the main chip IC1 is electrically connected to the upper plate of the sixth capacitor C6. The ninth pin of the main chip IC1 is electrically connected to the first end of the tenth resistor R10. The lower plates of the fifth capacitor C5, the sixth capacitor C6, and the second end of the tenth resistor R10 are all grounded.

[0060] In some examples, the control circuit 110 may also include an eighth capacitor C8, a ninth capacitor C9, and a thirteenth resistor R13.

[0061] The upper plate of the eighth capacitor C8 is electrically connected to the eighth pin of the main chip IC1. The upper plate of the ninth capacitor C9 and the first end of the thirteenth resistor R13 are both electrically connected to the fourteenth pin of the main chip IC1. The lower plates of the eighth capacitor C8 and the ninth capacitor C9 are both grounded. The second end of the thirteenth resistor R13 is electrically connected to the first end of the third terminal J4 in the leakage current controller 100.

[0062] Based on the description of the above embodiments, an exemplary possible implementation of the rectifier circuit 120 is provided. Figure 1 As shown, the rectifier circuit 120 may include: a second diode D2, a third diode D3, a fourth diode D4, and a fifth diode D5.

[0063] The cathodes of the second diode D2 and the third diode D3 are both electrically connected to the trip unit COIL. The anode of the second diode D2 is electrically connected to the A-phase power line. The anode of the third diode D3 is electrically connected to the B-phase power line and the cathode of the fourth diode D4, respectively. The cathode of the fifth diode D5 is electrically connected to the C-phase power line. The anodes of the fourth diode D4 and the fifth diode D5 are both grounded.

[0064] Among them, the rectifier circuit 120 has the advantage of low cost.

[0065] Based on the description of the above embodiments, an exemplary possible implementation of the reverse-entry circuit 130 is provided. For example... Figure 1 As shown, the reverse input circuit 130 may include: an eighth diode D8, a twentieth resistor R20, a twenty-first resistor R21, a third transistor T3, an eleventh capacitor C11, and a twelfth capacitor C12.

[0066] The positive terminal of the eighth diode D8 is electrically connected to the first pin of the main chip IC1, and the negative terminal of the eighth diode D8 is electrically connected to the first end of the twentieth resistor R20. The second end of the twentieth resistor R20 is electrically connected to the first end of the twenty-first resistor R21, the upper plate of the eleventh capacitor C11, and the gate terminal of the third transistor T3. The drain terminal of the third transistor T3 is electrically connected to the second end of the eighth resistor R8 and the upper plate of the twelfth capacitor C12. The second end of the twenty-first resistor R21, the lower plate of the eleventh capacitor C11, the lower plate of the twelfth capacitor C12, and the source terminal of the third transistor T3 are all grounded.

[0067] Specifically, when the main chip IC1 outputs the TRIP signal, the eleventh capacitor C11 is charged, causing the third transistor T3 to conduct. Thus, the reverse-current circuit 130 can generate a drive signal after a preset time, causing the trip unit COIL to activate, preventing the leakage current controller from burning out or being damaged.

[0068] Based on the description of the above embodiments, an exemplary possible implementation of the thyristor drive circuit 140 is provided. Figure 1 As shown, the thyristor drive circuit 140 may include: a fourteenth resistor R14, a fifteenth resistor R15, a sixteenth resistor R16, a seventeenth resistor R17, an eighteenth resistor R18, a nineteenth resistor R19, a sixth diode D6, and a seventh diode D7.

[0069] The first terminal of the fourteenth resistor R14 and the positive terminal of the sixth diode D6 are both electrically connected to the trip unit COIL. The second terminal of the fourteenth resistor R14 is electrically connected to the first terminal of the fifteenth resistor R15. The second terminal of the fifteenth resistor R15 is electrically connected to the first terminals of the sixteenth resistor R16, the eighteenth resistor R18, and the nineteenth resistor R19, respectively. The first terminal of the sixteenth resistor R16 is electrically connected to the first terminal of the seventeenth resistor R17. The second terminal of the eighteenth resistor R18 is electrically connected to the negative terminal of the sixth diode D6, the positive terminal of the seventh diode D7, and the second terminal of the nineteenth resistor R19, respectively. The negative terminal of the seventh diode D7 and the second terminal of the seventeenth resistor R17 are both grounded. The negative terminal of the seventh diode D7 is also electrically connected to the output terminal of the control circuit 110.

[0070] When the DC voltage is at the first level, under the action of the drive signal, the seventh diode D7 conducts, causing the sixth diode D6 to conduct as well. This results in a large current flowing through the trip unit COIL, causing it to activate and trip.

[0071] Specifically, the voltage is divided by resistors R14, R15, R16, and R17, and after passing through resistors R18 and R19, the potential at the second terminal of resistor R18 and the second terminal of resistor R19 are made equal. In other words, the thyristor drive circuit 140 uses an equipotential approach, making the tripping of the COIL more reliable and improving its withstand voltage.

[0072] Based on the description of the above embodiments, an exemplary possible implementation of the thyristor drive circuit 140 is provided. Figure 1 As shown, the thyristor drive circuit 140 may further include: a tenth capacitor C10.

[0073] The upper plate of the tenth capacitor C10 is electrically connected to the negative terminal of the seventh diode D7, and the lower plate of the tenth capacitor C10 is grounded.

[0074] Based on the description of the above embodiments, another possible implementation of the leakage current controller 100 is exemplarily described. For example... Figure 1 As shown, the leakage current controller 100 may further include: a fourth varistor RV4 and a fifth varistor RV5.

[0075] The first terminal of the fourth varistor RV4 is electrically connected to the trip unit COIL, the second terminal of the fourth varistor RV4 is electrically connected to the first terminal of the fifth varistor RV5, and the second terminal of the fifth varistor RV5 is grounded.

[0076] Based on the description of the above embodiments, another possible implementation of the leakage current controller 100 is provided, by way of example. (Refer to...) Figure 2 , Figure 2 This is a schematic diagram of the sampling circuit in a leakage current controller provided in an embodiment of this application. Figure 2 As shown, the leakage current controller 100 may further include a sampling circuit 180.

[0077] The sampling circuit 180 is electrically connected to the main winding of the transformer via the first terminal JP2.

[0078] The sampling circuit 180 can collect the current on the main winding of the current transformer and obtain the sampling signal.

[0079] In some examples, the sampling circuit 180 may include: a first switch S1, a twenty-second resistor R22, a twenty-third resistor R23, a twenty-fourth resistor R24, a twenty-fifth resistor R25, a twenty-sixth resistor R26, a twenty-seventh resistor R27, a thirteenth capacitor C13, a fourteenth capacitor C14, a fifteenth capacitor C15, a sixteenth capacitor C16, and a first variable capacitor diode VT1.

[0080] The first terminal of the first switch S1 is electrically connected to the first terminal of the twenty-seventh resistor R27. The second terminal of the first switch S1 is electrically connected to the first terminal of the twenty-sixth resistor R26. The fourth terminal of the first switch S1 is electrically connected to the first terminal of the twenty-fifth resistor R25. The second terminals of the twenty-seventh resistor R27, the twenty-sixth resistor R26, and the twenty-fifth resistor R25 are all electrically connected to the first terminal of the twenty-second resistor R22. The first terminal of the twenty-second resistor R22 is also electrically connected to the upper plate of the thirteenth capacitor C13, the first terminal of the first variable capacitor diode VT1, and the first terminal of the twenty-third resistor R23. The fourth terminal of the twenty-third resistor R23 is electrically connected to the first terminal of the thirteenth capacitor C13. The two ends are electrically connected to the upper plate of the fourteenth capacitor C14 and the fourth pin of the main chip IC1, respectively. The lower plate of the fourteenth capacitor C14 is electrically connected to the fifth pin of the main chip IC1, the first end of the twenty-fourth resistor R24, the upper plate of the fifteenth capacitor C15, and the upper plate of the sixteenth capacitor C16, respectively. The second end of the twenty-fourth resistor R24 ​​is electrically connected to the second end of the first variable capacitor diode VT1, the third end of the first variable capacitor diode VT1, the lower plate of the thirteenth capacitor C13, the second end of the twenty-second resistor R22, and the third end of the first switching transistor S1, respectively. The lower plates of the fifteenth capacitor C15 and the sixteenth capacitor C16 are both grounded.

[0081] Among them, the sampling circuit 180 has the advantages of simple circuit and high stability.

[0082] Based on the description of the above embodiments, another possible implementation of the leakage current controller 100 is provided, by way of example. (Refer to...) Figure 3 , Figure 3 This is a schematic diagram of the delay circuit in a leakage current controller provided in an embodiment of this application. Figure 3 As shown, the leakage current controller 100 may further include a delay circuit 190.

[0083] The delay circuit 190 is electrically connected to the eighth pin of the main chip IC1.

[0084] The delay circuit 190 can provide a delay duration to the main chip IC1 when the main chip IC1 detects that the sampled signal is greater than the threshold signal, that is, when leakage current is detected.

[0085] In some examples, the delay circuit 190 may include: a second switch S2, a seventeenth capacitor C17, an eighteenth capacitor C18, a nineteenth capacitor C19, a twentieth capacitor C20, a twenty-first capacitor C21, and a twenty-second capacitor C22.

[0086] The upper plates of the seventeenth capacitor C17 and the eighteenth capacitor C18 are both electrically connected to the first terminal of the second switch S2. The upper plates of the nineteenth capacitor C19 and the twentieth capacitor C20 are both electrically connected to the second terminal of the second switch S2. The upper plates of the twenty-first capacitor C21 and the twenty-second capacitor C22 are both electrically connected to the fourth terminal of the second switch S2. The third terminal of the second switch S2 is electrically connected to the eighth pin of the main chip IC1.

[0087] Based on the description of the above embodiments, another possible implementation of the leakage current controller 100 is provided, by way of example. (Refer to...) Figure 4 , Figure 4 This is a schematic diagram of the test circuit in a leakage current controller provided in an embodiment of this application. Figure 4 As shown, the leakage current controller 100 may further include a test circuit 200.

[0088] The first end of the test circuit 200 is electrically connected to the input end of the first step-down circuit 150, and the second end of the test circuit 200 is electrically connected to the test winding of the transformer through the second terminal JP3.

[0089] The test circuit 200 can detect whether the leakage current controller 100 is working properly.

[0090] In some examples, the test circuit 200 may include: a test button S4, a twenty-eighth resistor R28, a twenty-ninth resistor R29, and a thirtieth resistor R30.

[0091] The first end of the test jump button S4 is electrically connected to the first end of the thirtieth resistor R30, the second end of the thirtieth resistor R30 is electrically connected to the first end of the twenty-ninth resistor R29, the second end of the twenty-ninth resistor R29 is electrically connected to the first end of the twenty-eighth resistor R28, the second end of the twenty-eighth resistor R28 is electrically connected to the input end of the first step-down circuit 150, and the second end of the test jump button S4 is electrically connected to the second terminal JP3.

[0092] Based on the description of the above embodiments, another possible implementation of the leakage current controller 100 is provided, by way of example. (Refer to...) Figure 5 , Figure 5 This is a schematic diagram of the alarm drive circuit in a leakage current controller provided in an embodiment of this application. Figure 5 As shown, the leakage current controller 100 may also include an alarm drive circuit 210.

[0093] The first end of the alarm drive circuit 210 is electrically connected to the first pin of the main chip IC1, and the second end of the alarm drive circuit 210 is electrically connected to the second end of the third terminal J4.

[0094] The alarm drive circuit 210 can obtain control signals from the control circuit 110 and drive the corresponding alarm circuit according to the control signals, so that the leakage current controller 100 can realize extended functions for warning or alarm.

[0095] In some examples, the alarm drive circuit 210 may include: a fourth transistor T4 and a twenty-third capacitor C23.

[0096] The source terminal of the fourth transistor T4 is electrically connected to the second terminal of the third terminal J4. The gate terminal of the fourth transistor T4 and the upper plate of the second thirteenth capacitor C23 are both electrically connected to the first pin of the main chip IC1. The drain terminal of the fourth transistor T4 and the lower plate of the second thirteenth capacitor C23 are both grounded.

[0097] The working principle of the leakage current controller 100 is explained in detail below: After power is applied, the AC voltage output from the power line is rectified by the rectifier circuit 120, the second step-down circuit 160, and the first step-down circuit 150 before supplying power to the control circuit 110. In this way, the control circuit 110 can detect the relationship between the sampled signal obtained from the sampling circuit and the threshold signal through the main chip IC1 to determine whether there is residual current and output the corresponding control signal.

[0098] When a circuit fault occurs, that is, when the sampled signal exceeds the threshold signal, the leakage current signal is amplified through the current transformer and the sampling circuit. The main chip IC1 in the control circuit 110 will output a response signal, enabling the control circuit 110 to generate a drive signal and transmit the drive signal to the thyristor drive circuit 140. Subsequently, the thyristor drive circuit 140 drives the trip unit COIL to operate according to the drive signal, causing the circuit breaker to trip.

[0099] Finally, it should be noted that the above embodiments are merely specific implementations of this application, but the scope of protection of this application is not limited thereto. Any changes or substitutions within the technical scope disclosed in this application should be covered within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A leakage current controller, characterized in that, The leakage current controller is used in a circuit breaker, the circuit breaker includes a trip unit, and the leakage current controller includes a control circuit, a rectifier circuit, a reverse input circuit, a thyristor drive circuit, and a first step-down circuit. The input terminal of the control circuit is electrically connected to a sampling signal, which is used to characterize the leakage current of the circuit breaker. The output terminal of the control circuit is electrically connected to the first terminal of the thyristor drive circuit. The second terminal of the thyristor drive circuit is electrically connected to the trip unit, the output terminal of the rectifier circuit, and the input terminal of the first step-down circuit. The output terminal of the first step-down circuit is electrically connected to the power supply terminal of the control circuit. The input terminal of the rectifier circuit is electrically connected to the power supply line. The rectifier circuit is used to obtain AC voltage from the power line, convert the AC voltage into DC voltage, and transmit the DC voltage to the thyristor drive circuit. The control circuit is used to transmit a control signal to the thyristor drive circuit when the sampled signal is greater than the threshold signal. The reverse input circuit is used to generate a drive signal according to the control signal after a preset time, and transmit the drive signal to the thyristor drive circuit. The thyristor drive circuit is used to drive the trip unit to operate according to the drive signal when the DC voltage is at the first level, so as to realize the reverse line function. The first step-down circuit is used to supply power to the control circuit using the voltage on the first capacitor in the first step-down circuit when implementing the reverse incoming line function.

2. The leakage current controller according to claim 1, characterized in that, The leakage current controller further includes: a second step-down circuit; The input terminal of the second step-down circuit is electrically connected to the output terminal of the rectifier circuit, the output terminal of the second step-down circuit is electrically connected to the input terminal of the first step-down circuit, and the output terminal of the first step-down circuit is electrically connected to the power supply terminal of the control circuit. The second step-down circuit is used to obtain the DC voltage from the rectifier circuit after realizing the reverse input function, and to step down the DC voltage to obtain a first voltage, and to transmit the first voltage to the first step-down circuit. The first step-down circuit is used to step down the first voltage to obtain a second voltage, and to use the second voltage to supply power to the control circuit.

3. The leakage current controller according to claim 2, characterized in that, The second step-down circuit includes: a first transistor, a second transistor, a first Zener diode, a first resistor, a second resistor, and a first voltage divider circuit; The first end of the first resistor and the first end of the first voltage divider circuit are both electrically connected to the trip unit. The second end of the first resistor is electrically connected to the source end of the first transistor. The drain end of the first transistor is electrically connected to the first end of the second resistor. The second end of the second resistor is electrically connected to the source end of the second transistor. The drain end of the second transistor is electrically connected to the input end of the first buck circuit. The gate end of the first transistor is electrically connected to the second end of the first voltage divider circuit. The third end of the first voltage divider circuit is electrically connected to the gate end of the second transistor and the negative terminal of the first Zener diode. The positive terminal of the first Zener diode is grounded. The first voltage divider circuit includes: a third resistor, a fourth resistor, a fifth resistor, and a sixth resistor. The first end of the third resistor is electrically connected to the trip unit, the second end of the third resistor is electrically connected to the first end of the fourth resistor, the second end of the fourth resistor is electrically connected to the gate of the first transistor and the first end of the fifth resistor, the second end of the fifth resistor is electrically connected to the first end of the sixth resistor, and the second end of the sixth resistor is electrically connected to the gate of the second transistor.

4. The leakage current controller according to claim 3, characterized in that, The second step-down circuit also includes: a second Zener diode; The negative terminal of the second Zener diode is electrically connected to the gate terminal of the second transistor, and the positive terminal of the second Zener diode is grounded.

5. The leakage current controller according to claim 1, characterized in that, The first step-down circuit includes: a first capacitor, a second capacitor, a seventh resistor, a first diode, and a third Zener diode; The positive terminal of the first diode is electrically connected to the output terminal of the rectifier circuit, the negative terminal of the first diode is electrically connected to the upper plate of the first capacitor and the first terminal of the seventh resistor, the second terminal of the seventh resistor is electrically connected to the negative terminal of the third Zener diode and the upper plate of the second capacitor, and the lower plate of the first capacitor, the positive terminal of the third Zener diode, and the lower plate of the second capacitor are all grounded.

6. The leakage current controller according to claim 5, characterized in that, The first step-down circuit further includes: a third capacitor and a fourth capacitor; The upper plates of the third capacitor and the fourth capacitor are both electrically connected to the negative terminal of the first diode, and the lower plates of the third capacitor and the fourth capacitor are both grounded.

7. The leakage current controller according to any one of claims 1-6, characterized in that, The leakage current controller also includes: a surge protection circuit; The surge protection circuit is electrically connected between the input terminal of the rectifier circuit and the power line; The surge protection circuit is used to provide surge protection for the power line.

8. The leakage current controller according to claim 7, characterized in that, The surge protection circuit includes: a first varistor, a second varistor, and a third varistor; The first end of the first varistor is electrically connected to the A-phase power line in the power line, the first end of the second varistor is electrically connected to the B-phase power line in the power line, the first end of the third varistor is electrically connected to the C-phase power line in the power line, and the second end of the first varistor is electrically connected to the second end of the second varistor and the second end of the third varistor, respectively.

9. The leakage current controller according to any one of claims 1-6, characterized in that, The control circuit includes: a main chip, an eighth resistor, a ninth resistor, a tenth resistor, a fifth capacitor, and a sixth capacitor; The first pin of the main chip is electrically connected to the first end of the eighth resistor, the second end of the eighth resistor is electrically connected to the first end of the thyristor drive circuit, the second pin of the main chip is electrically connected to the first end of the ninth resistor, the second end of the ninth resistor and the fourteenth pin of the main chip are both electrically connected to the output end of the first step-down circuit, the fourth pin and the fifth pin of the main chip are electrically connected to the sampling signal, the twelfth pin of the main chip is electrically connected to the upper plate of the fifth capacitor, the eleventh pin of the main chip is electrically connected to the upper plate of the sixth capacitor, the ninth pin of the main chip is electrically connected to the first end of the tenth resistor, and the lower plates of the fifth capacitor, the sixth capacitor, and the second end of the tenth resistor are all grounded.

10. The leakage current controller according to any one of claims 1-6, characterized in that, The thyristor drive circuit includes: a fourteenth resistor, a fifteenth resistor, a sixteenth resistor, a seventeenth resistor, an eighteenth resistor, a nineteenth resistor, a sixth diode, and a seventh diode; The first terminal of the fourteenth resistor and the anode of the sixth diode are both electrically connected to the trip unit. The second terminal of the fourteenth resistor is electrically connected to the first terminal of the fifteenth resistor. The second terminal of the fifteenth resistor is electrically connected to the first terminals of the sixteenth, eighteenth, and nineteenth resistors, respectively. The first terminal of the sixteenth resistor is electrically connected to the first terminal of the seventeenth resistor. The second terminal of the eighteenth resistor is electrically connected to the cathode of the sixth diode, the anode of the seventh diode, and the second terminal of the nineteenth resistor, respectively. The cathode of the seventh diode and the second terminal of the seventeenth resistor are both grounded. The cathode of the seventh diode is also electrically connected to the output terminal of the control circuit.

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