An electric leakage control circuit, a substrate, and an electric leakage circuit breaker

Abstract

The application provides a leakage control circuit, a substrate and a leakage circuit breaker, and relates to the technical field of the leakage circuit breaker. The circuit comprises a rectifier circuit, a test button circuit, a leakage signal detection circuit, a power supply circuit, a leakage tripping circuit, a reset circuit and an execution circuit. The test button circuit comprises a relay and a test button. The leakage tripping circuit comprises a tripping device. The rectifier circuit outputs a rectified signal. The power supply circuit supplies power to the relay. The test button circuit is connected to the rectified signal, and outputs a leakage signal when the test button is pressed. The leakage signal detection circuit processes the leakage signal and outputs a leakage control signal. The leakage tripping circuit controls the tripping device to trip according to the leakage control signal. The execution circuit controls its own state according to the leakage control signal, so that the relay cuts off the path through which the test button circuit outputs the leakage signal, and no longer outputs the leakage control signal, thereby avoiding the problem of burning caused by heating due to the continuous power supply of the leakage tripping device.

Description

Technical Field

[0001] This application relates to the field of residual current circuit breaker technology, and in particular to a residual current control circuit, a substrate, and a residual current circuit breaker. Background Technology

[0002] A residual current circuit breaker, also known as a residual current switch or residual current device, is mainly used to protect equipment when a leakage current fault occurs. When a circuit or electrical appliance insulation is damaged, resulting in a short circuit to ground, a residual current circuit breaker can be used as a common protective device to prevent electric shock and electrical fires. It is typically installed on the socket circuit of each household's distribution box and on the power input line of the building's main distribution box.

[0003] A residual current circuit breaker (RCCB) includes an input terminal and an output terminal. Normally, the input terminal is used to connect an input voltage signal, and the output terminal is electrically connected to the load. However, sometimes users connect the input terminal of the RCCB to the load and the output terminal to the input voltage signal. In this case, due to the internal structure of the RCCB, when a leakage current occurs, the trip unit in the RCCB will trip, but the internal circuit board will remain energized, causing the trip unit to overheat and burn out. To solve this problem, a reverse-connection RCCB has been designed and developed.

[0004] For residual current circuit breakers that can be reverse-wired, if the user presses the test button for a long time, the trip unit will be continuously energized, causing the trip unit to overheat and eventually burn out. In order to solve this problem, this application is hereby submitted. Utility Model Content

[0005] This application provides a leakage current control circuit, a substrate, and a leakage current circuit breaker to solve the problem of the trip unit burning out when the user presses the test button for a long time.

[0006] In a first aspect, this application provides a leakage current control circuit, which is applied in a reversible leakage current circuit breaker. The leakage current control circuit includes: a rectifier circuit, a test button circuit, a leakage current signal detection circuit, a power supply circuit, a leakage current trip circuit, a reset circuit, and an execution circuit; the test button circuit includes a relay and a test button; the leakage current trip circuit includes a trip unit.

[0007] The rectifier circuit is electrically connected to the test button circuit, the power supply circuit, and the leakage current trip circuit, respectively; the test button circuit is electrically connected to the power supply circuit, the reset circuit, and the leakage current signal detection circuit, respectively; the leakage current signal detection circuit is electrically connected to the leakage current trip circuit and the execution circuit, respectively; the reset circuit is electrically connected to the execution circuit.

[0008] The rectifier circuit is configured to rectify the input AC voltage and output a rectified signal.

[0009] The power supply circuit is configured to process the incoming rectified signal and output a power supply voltage to power the relay.

[0010] The test button circuit is configured to receive a rectified signal and output a leakage signal when the test button is pressed.

[0011] The leakage signal detection circuit is configured to process the leakage signal and output a leakage control signal;

[0012] The leakage current trip circuit is configured to control the trip unit to trip according to the leakage current control signal, and is also configured to output working voltage to power the leakage current signal detection circuit.

[0013] The execution circuit is configured to control itself to be in a conducting state according to the leakage control signal, so that the relay cuts off the path of the leakage signal output by the test button circuit;

[0014] The reset circuit is configured to reset itself when the test button is pressed again, so that the relay connects the path of the test button circuit to output the leakage signal.

[0015] In one possible design, the rectifier circuit includes: a first diode, a second diode, a third diode, and a fourth diode; the AC voltage includes: phase A voltage, phase B voltage, and phase C voltage;

[0016] The anode of the first diode is connected to the phase A voltage, and the cathode of the first diode is electrically connected to the cathode of the second diode, serving as the output terminal of the rectifier circuit for outputting the rectified signal.

[0017] The anode of the second diode is electrically connected to the cathode of the third diode, for use in applying the B-phase voltage;

[0018] The anodes of the third diode and the fourth diode are both grounded;

[0019] The cathode of the fourth diode is connected to the C-phase voltage.

[0020] In one possible design, the test button circuit further includes: a first resistor, a fifth diode, and a current transformer;

[0021] The input terminal of the test button is connected to the rectified signal, the output terminal of the test button is electrically connected to the first terminal of the first resistor, and the second terminal of the first resistor is electrically connected to the normally open contact of the relay.

[0022] The common terminal of the relay is grounded after passing through the center through hole of the current transformer;

[0023] The cathode of the fifth diode is electrically connected to the power supply terminal of the relay for receiving the power supply voltage;

[0024] The anode of the fifth diode is electrically connected to the ground terminal of the relay and to the input terminal of the reset circuit.

[0025] In one possible design, the leakage signal detection circuit includes: a second resistor, a third resistor, a fourth resistor, a fifth resistor, a sixth resistor, a seventh resistor, a first capacitor, a second capacitor, a third capacitor, a fourth capacitor, a fifth capacitor, a sixth capacitor, a seventh capacitor, a bidirectional diode, and a leakage detection chip; the leakage signal includes: a first leakage signal and a second leakage signal;

[0026] The first end of the bidirectional diode is connected to the first leakage signal, the second end of the bidirectional diode is connected to the second leakage signal, and the first end of the seventh resistor is electrically connected to the first end of the bidirectional diode, the first end of the first capacitor, and the first end of the second resistor, respectively.

[0027] The second end of the seventh resistor is electrically connected to the second end of the bidirectional diode, the second end of the first capacitor, and the first end of the third resistor, respectively.

[0028] The second end of the second resistor is electrically connected to the first end of the second capacitor, the first end of the third capacitor, and the fourth end of the leakage current detection chip, respectively.

[0029] The second end of the third resistor is electrically connected to the second end of the second capacitor, the first end of the fourth capacitor, and the fifth end of the leakage current detection chip, respectively.

[0030] The first end of the fourth resistor is electrically connected to the second end of the leakage current detection chip, and the second end of the fourth resistor is connected to the operating voltage.

[0031] The first end of the fifth resistor is electrically connected to the ninth end of the leakage current detection chip;

[0032] The first terminal of the fifth capacitor is electrically connected to the eleventh terminal of the leakage current detection chip;

[0033] The first terminal of the sixth capacitor is electrically connected to the twelfth terminal of the leakage current detection chip.

[0034] The first end of the sixth resistor is electrically connected to the first end of the leakage detection chip, and the second end of the sixth resistor serves as the output end of the leakage signal detection circuit, and is configured to output the leakage control signal.

[0035] The first terminal of the seventh capacitor is electrically connected to the fourteenth terminal of the leakage current detection chip and is configured to be connected to the operating voltage;

[0036] The second terminal of the seventh capacitor is electrically connected to the seventh terminal of the leakage current detection chip and is set to ground;

[0037] The second terminals of the third capacitor, the fourth capacitor, the fifth resistor, the fifth capacitor, and the sixth capacitor are all grounded.

[0038] In one possible design, the power supply circuit includes: an eighth resistor, an eighth capacitor, a ninth capacitor, and a first Zener diode;

[0039] The first end of the eighth resistor is electrically connected to the output end of the rectifier circuit, and the second end of the eighth resistor is electrically connected to the cathode of the first Zener diode, the first end of the eighth capacitor, and the positive terminal of the ninth capacitor, respectively, and serves as the output end of the power supply circuit for outputting the power supply voltage.

[0040] The anode of the first Zener diode, the second terminal of the eighth capacitor, and the negative terminal of the ninth capacitor are grounded.

[0041] In one possible design, the leakage trip circuit further includes: a ninth resistor, a tenth resistor, a tenth capacitor, a second Zener diode, and a first thyristor;

[0042] The first end of the trip unit is electrically connected to the output end of the rectifier circuit, and the second end of the trip unit is electrically connected to the first end of the ninth resistor and the anode of the first thyristor, respectively.

[0043] The second terminal of the ninth resistor is electrically connected to the cathode of the second Zener diode and is configured to output the operating voltage.

[0044] The anode of the second Zener diode is grounded;

[0045] The control electrode of the first thyristor is electrically connected to the first terminal of the tenth resistor and the first terminal of the tenth capacitor, respectively.

[0046] The second terminal of the tenth resistor is configured to connect to the leakage control signal;

[0047] The second terminal of the tenth capacitor and the cathode of the first thyristor are grounded.

[0048] In one possible design, the reset circuit includes: a reset switch;

[0049] The first end of the reset switch is electrically connected to the input end of the reset circuit, and the second end of the reset switch is electrically connected to the output end of the reset circuit.

[0050] In one possible design, the execution circuit includes: a second thyristor and an eleventh capacitor;

[0051] The anode of the second thyristor is electrically connected to the output terminal of the reset circuit, and the cathode of the second thyristor is grounded.

[0052] The control electrode of the second thyristor is electrically connected to the first terminal of the eleventh capacitor and is configured to receive the leakage control signal;

[0053] The second terminal of the eleventh capacitor is grounded.

[0054] In a second aspect, this application provides a substrate comprising: a leakage current control circuit as described in the first aspect.

[0055] Thirdly, this application provides a residual current circuit breaker, comprising: a substrate as described in the second aspect.

[0056] The beneficial effects of the embodiments of this application are as follows:

[0057] In this embodiment, the leakage current control circuit includes: a rectifier circuit, a test button circuit, a leakage current signal detection circuit, a power supply circuit, a leakage current trip circuit, a reset circuit, and an execution circuit. The test button circuit includes a relay and a test button. The leakage current trip circuit includes a trip unit. The rectifier circuit rectifies the input AC voltage and outputs a rectified signal. The power supply circuit processes the input rectified signal and outputs a power supply voltage to power the relay. The test button circuit receives the rectified signal and outputs a leakage current signal when the test button is pressed. The leakage current signal detection circuit then processes the leakage current signal and outputs a leakage current control signal. The leakage current trip circuit controls the trip unit to trip according to the leakage current control signal. Simultaneously, the execution circuit controls itself to be in a conducting state according to the leakage current control signal, so that the relay cuts off the path for the leakage current signal output from the test button circuit, no longer outputting a leakage current signal or a leakage current control signal, and preventing the trip unit from being continuously energized, thus avoiding the problem of overheating and burnout caused by continuous energization of the leakage current trip unit. When the test button needs to be pressed again, the reset circuit controls itself to reset, so that the relay connects the path of the test button circuit to output the leakage signal, and generates the leakage signal again. Attached Figure Description

[0058] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other embodiments can be obtained based on these drawings.

[0059] Figure 1 A leakage current handling circuit is provided for use in a reversible residual current circuit breaker, in accordance with related technologies.

[0060] Figure 2 A schematic diagram of the circuit structure of a leakage current control circuit provided in this application;

[0061] Figure 3 A schematic diagram of the circuit structure corresponding to a rectifier circuit, a power supply circuit, and a leakage current trip circuit provided in an embodiment of this application;

[0062] Figure 4 A schematic diagram of the circuit structure corresponding to a test button circuit, a reset circuit, and an execution circuit provided in an embodiment of this application;

[0063] Figure 5 This is a schematic diagram of the circuit structure of a leakage current signal detection circuit provided in an embodiment of this application. Detailed Implementation

[0064] 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.

[0065] 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.

[0066] 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.

[0067] See Figure 1 , Figure 1 This provides a leakage current handling circuit for use in a reversible residual current circuit breaker, such as... Figure 1 As shown, when the user presses button PB, the rectified voltage COIL generates leakage output signals (i.e., ZCT-A1_0, ZCT-A2_0) through the current sensing coil Test. The leakage output signals (i.e., ZCT-A1_0, ZCT-A2_0) are converted into corresponding voltage signals through resistor RR1 and input to the fourth terminal IN1 and the fifth terminal IN2 of the leakage output chip UU1. After being amplified and processed by the leakage output chip UU1, the leakage detection signal TRIP_0 is output through the first terminal OS of the leakage output chip UU1. The leakage detection signal TRIP_0 is input to the control terminal of the SCR. When the SCR is turned on, the leakage trip unit L2 is energized, and the leakage trip unit L2 trips, causing the leakage circuit breaker to trip.

[0068] like Figure 1 As shown, the first rectifier diode DD1, the second rectifier diode DD2, the third rectifier diode DD3, and the fourth rectifier diode DD4 constitute a rectifier circuit to rectify the AC signal (i.e., A_0, B_0, C_0) to obtain the rectified voltage COIL. The resistor RR4 and the Zener diode ZD1 output power supply VDD_0, which powers the leakage current output chip UU1.

[0069] See Figure 1When the user presses button PB for a long time, the current sensing coil Test will continuously generate leakage output signals (i.e., ZCT-A1_0, ZCT-A2_0) and output them to the leakage output chip UU1. The first terminal OS of the leakage output chip UU1 will also continuously output the leakage detection signal TRIP_0. This leakage detection signal TRIP_0 will be continuously input to the control terminal of the SCR, causing the SCR to be continuously turned on. The SCR controls the leakage trip L2. When the SCR is continuously turned on, the leakage trip L2 will be continuously energized. Since the current of the rectified voltage COIL is very large, the leakage trip L2 will heat up and eventually burn out due to prolonged energization.

[0070] To address the problem raised in related technologies where prolonged button presses cause the residual current device (RCD) to remain energized, leading to overheating and eventual burnout, this application proposes a residual current control circuit, see [link to relevant documentation]. Figure 2 , Figure 2 A circuit structure diagram of a leakage current control circuit provided in this application is shown below. Figure 2 As shown, the leakage current control circuit 1000 is applied in a reversible leakage current circuit breaker. The leakage current control circuit 1000 may include: a rectifier circuit 100, a test button circuit 200, a leakage current signal detection circuit 300, a power supply circuit 400, a leakage current trip circuit 500, a reset circuit 600, and an execution circuit 700; the test button circuit 200 includes a relay and a test button; the leakage current trip circuit 500 includes a trip unit.

[0071] The rectifier circuit 100 is electrically connected to the test button circuit 200, the power supply circuit 400, and the leakage current trip circuit 500, respectively; the test button circuit 200 is electrically connected to the power supply circuit 400, the reset circuit 600, and the leakage current signal detection circuit 300, respectively; the leakage current signal detection circuit 300 is electrically connected to the leakage current trip circuit 500 and the execution circuit 700, respectively; and the reset circuit 600 is electrically connected to the execution circuit 700.

[0072] The rectifier circuit 100 is configured to rectify the input AC voltage and output the rectified signal COIL+.

[0073] The power supply circuit 400 is configured to process the input rectified signal COIL+ and output a power supply voltage VDD1 to power the relay.

[0074] The test button circuit 200 is configured to receive the rectified signal COIL+ and output leakage signals (i.e., ZCT-A1 and ZCT-A2) when the test button is pressed.

[0075] The leakage signal detection circuit 300 is configured to process the leakage signals (i.e., ZCT-A1 and ZCT-A2) and output the leakage control signal TRIP.

[0076] The leakage current trip circuit 500 is configured to control the trip unit to trip according to the leakage current control signal TRIP, and is also configured to output the working voltage VDD to power the leakage current signal detection circuit 300.

[0077] The execution circuit 700 is configured to control itself to be in a conducting state according to the leakage control signal TRIP, so that the relay cuts off the path of the leakage signal (i.e. ZCT-A1, ZCT-A2) output by the test button circuit 200.

[0078] The reset circuit 600 is configured to reset itself when the test button is pressed again, so that the relay connects the path of the leakage signal (i.e. ZCT-A1, ZCT-A2) output by the test button circuit 200.

[0079] The leakage current control circuit in this application is applied to a reversible leakage current circuit breaker. For a reversible leakage current circuit breaker, the input terminal can be used to connect an input voltage signal, and the output terminal can be electrically connected to the load; alternatively, the output terminal can be used to connect an input voltage signal, and the input terminal can be electrically connected to the load. In the case of the reverse wiring of the leakage current control circuit in this application, the output terminal of the reverse-wiring leakage current circuit breaker can be connected to an input voltage signal, and the input terminal can be electrically connected to the load.

[0080] The rectifier circuit rectifies the input AC voltage and outputs a rectified signal COIL+. In one example, the rectifier circuit rectifies the input AC voltage of 220VAC, outputting a rectified signal COIL+ of 380VDC. The rectified signal COIL+ serves as the input signal for the test button circuit, the power supply circuit, and the leakage current trip circuit. Specifically, the power supply circuit, after voltage conversion processing of the rectified signal COIL+, outputs a supply voltage VDD1 to power the relay; the leakage current trip circuit, after voltage conversion processing of the rectified signal COIL+, outputs an operating voltage VDD to power the leakage current signal detection circuit.

[0081] In a residual current circuit breaker (RCCB), a leakage current signal is generated by pressing a test button, which then controls the trip unit to trip or disconnect. In this application, the test button circuit first outputs leakage current signals (i.e., ZCT-A1 and ZCT-A2) when the test button is pressed. These leakage current signals (i.e., ZCT-A1 and ZCT-A2) are current signals. Then, the leakage current signal detection circuit converts the leakage current signals (i.e., ZCT-A1 and ZCT-A2) from current signals to voltage signals and amplifies them to output a leakage current control signal TRIP.

[0082] The leakage current trip circuit controls the trip unit to trip based on the leakage current control signal TRIP. Furthermore, based on the leakage current handling circuit provided in related technologies, this application adds a relay to the test button circuit, as well as an execution circuit and a reset circuit.

[0083] The execution circuit, based on the received leakage control signal TRIP, controls itself to be in a conducting state, causing the relay to cut off the leakage signal output path of the test button circuit. That is, when the user presses the test button for an extended period, generating a leakage signal, the leakage control signal TRIP, based on the leakage signal, controls the relay to cut off the leakage signal output path of the test button circuit, preventing further leakage signal generation and avoiding continuous energization of the leakage trip unit, thus preventing overheating and burnout due to continuous energization. Furthermore, when the test button is pressed again, the reset circuit needs to reset itself to allow the relay to reconnect the leakage signal output path (i.e., ZCT-A1, ZCT-A2) of the test button circuit 200, generating a leakage signal again.

[0084] In this embodiment, the leakage current control circuit includes: a rectifier circuit, a test button circuit, a leakage current signal detection circuit, a power supply circuit, a leakage current trip circuit, a reset circuit, and an execution circuit. The test button circuit includes a relay and a test button. The leakage current trip circuit includes a trip unit. The rectifier circuit rectifies the input AC voltage and outputs a rectified signal. The power supply circuit processes the input rectified signal and outputs a power supply voltage to power the relay. The test button circuit receives the rectified signal and outputs a leakage current signal when the test button is pressed. The leakage current signal detection circuit then processes the leakage current signal and outputs a leakage current control signal. The leakage current trip circuit controls the trip unit to trip according to the leakage current control signal. Simultaneously, the execution circuit controls itself to be in a conducting state according to the leakage current control signal, so that the relay cuts off the path for the leakage current signal output from the test button circuit, no longer outputting a leakage current signal or a leakage current control signal, and preventing the trip unit from being continuously energized, thus avoiding the problem of overheating and burnout caused by continuous energization of the leakage current trip unit. When the test button needs to be pressed again, the reset circuit controls itself to reset, so that the relay connects the path of the test button circuit to output the leakage signal, and generates the leakage signal again.

[0085] In one possible embodiment, see Figure 3 , Figure 3 This application provides a schematic diagram of the circuit structure corresponding to a rectifier circuit, a power supply circuit, and a leakage current tripping circuit, as shown in the embodiments. Figure 3 As shown, the rectifier circuit 100 may include: a first diode D1, a second diode D2, a third diode D3, and a fourth diode D4; the AC voltage includes: phase A voltage A, phase B voltage B, and phase C voltage C.

[0086] The anode of the first diode D1 is connected to the phase A voltage A, and the cathode of the first diode D1 is electrically connected to the cathode of the second diode D2. It serves as the output terminal of the rectifier circuit 100 and is used to output the rectified signal COIL+.

[0087] The anode of the second diode D2 is electrically connected to the cathode of the third diode D3, and is used to apply the phase B voltage B.

[0088] The anodes of the third diode D3 and the fourth diode D4 are both grounded.

[0089] The cathode of the fourth diode D4 is connected to the C-phase voltage C.

[0090] In this application, the AC voltage includes: phase A voltage A, phase B voltage B, and phase C voltage C. When inputting AC voltage, any two of phase A voltage A, phase B voltage B, and phase C voltage C are usually selected for connection. For example, 220VAC is connected between phase A voltage A and phase B voltage B; 220VAC is connected between phase A voltage A and phase C voltage C; and 220VAC is connected between phase B voltage B and phase C voltage C.

[0091] The first diode D1, the second diode D2, the third diode D3, and the fourth diode D4 constitute a rectifier circuit to rectify the input 220VAC AC voltage and output the rectified signal COIL+.

[0092] In one possible embodiment, see Figure 4 , Figure 4 A schematic diagram of the circuit structure corresponding to a test button circuit, a reset circuit, and an execution circuit provided in an embodiment of this application is shown below. Figure 4 As shown, the test button circuit 200 may also include: a first resistor R1, a fifth diode D5, and a current transformer CT.

[0093] The input terminal of the test button SW1 is connected to the rectified signal COIL+, the output terminal of the test button SW1 is electrically connected to the first terminal of the first resistor R1, and the second terminal of the first resistor R1 is electrically connected to the normally open contact NC of the relay KS.

[0094] The common terminal COM of relay KS is grounded after passing through the center through hole of current transformer CT.

[0095] The cathode of the fifth diode D5 is electrically connected to the power supply terminal S of the relay KS, and is used to connect the power supply voltage VDD1.

[0096] The anode of the fifth diode D5 is electrically connected to the ground terminal G of the relay KS, and is also electrically connected to the input terminal of the reset circuit 600.

[0097] The relay KS includes a power supply terminal S, a ground terminal G, a normally open contact NC, a normally closed contact NO, and a common terminal COM. When the relay is de-energized, the common terminal COM is electrically connected to the normally open contact NC; when the relay is energized, the common terminal COM is electrically connected to the normally closed contact NO. Therefore, by controlling whether the relay is energized, its common terminal COM switches between the normally open contact NC and the normally closed contact NO, thereby controlling the path of the leakage current signal output by the test button circuit. The normally closed contact NO in the test button circuit is left unused.

[0098] After the rectified signal COIL+ passes through its central through hole, the current transformer (CT) will induce leakage signals (i.e., ZCT-A1 and ZCT-A2), which are current signals.

[0099] In one possible embodiment, see Figure 5 , Figure 5 This is a schematic diagram of the circuit structure of a leakage current signal detection circuit provided in an embodiment of this application, as shown below. Figure 5 As shown, the leakage signal detection circuit 300 includes: a second resistor R2, a third resistor R3, a fourth resistor R4, a fifth resistor R5, a sixth resistor R6, a seventh resistor R7, a first capacitor C1, a second capacitor C2, a third capacitor C3, a fourth capacitor C4, a fifth capacitor C5, a sixth capacitor C6, a seventh capacitor C7, a bidirectional diode VT1, and a leakage detection chip U1; the leakage signals include: a first leakage signal ZCT-A1 and a second leakage signal ZCT-A2.

[0100] The first terminal of the bidirectional diode VT1 is connected to the first leakage signal ZCT-A1, and the second terminal of the bidirectional diode VT1 is connected to the second leakage signal ZCT-A2. The first terminal of the seventh resistor R7 is electrically connected to the first terminal of the bidirectional diode VT1, the first terminal of the first capacitor C1, and the first terminal of the second resistor R2, respectively.

[0101] The second end of the seventh resistor R7 is electrically connected to the second end of the bidirectional diode VT1, the second end of the first capacitor C1, and the first end of the third resistor R3.

[0102] The second end of the second resistor R2 is electrically connected to the first end of the second capacitor C2, the first end of the third capacitor C3, and the fourth end IN1 of the leakage current detection chip U1.

[0103] The second terminal of the third resistor R3 is electrically connected to the second terminal of the second capacitor C2, the first terminal of the fourth capacitor C4, and the fifth terminal IN2 of the leakage current detection chip U1.

[0104] The first end of the fourth resistor R4 is electrically connected to the second end MODE of the leakage current detection chip U1, and the second end of the fourth resistor R4 is connected to the working voltage VDD.

[0105] The first terminal of the fifth resistor R5 is electrically connected to the ninth terminal PR of the leakage current detection chip U1.

[0106] The first terminal of the fifth capacitor C5 is electrically connected to the eleventh terminal DLY of the leakage current detection chip U1.

[0107] The first terminal of the sixth capacitor C6 is electrically connected to the twelfth terminal OA of the leakage current detection chip U1.

[0108] The first end of the sixth resistor R6 is electrically connected to the first end OS of the leakage current detection chip U1, and the second end of the sixth resistor R6 serves as the output end of the leakage current signal detection circuit 300, which is set to output the leakage current control signal TRIP.

[0109] The first terminal of the seventh capacitor C7 is electrically connected to the fourteenth terminal Vdd of the leakage current detection chip U1 and is set to be connected to the working voltage VDD.

[0110] The second terminal of the seventh capacitor C7 is electrically connected to the seventh terminal VSS of the leakage current detection chip U1 and is set to ground.

[0111] The second terminals of the third capacitor C3, the fourth capacitor C4, the fifth resistor R5, the fifth capacitor C5, and the sixth capacitor C6 are all grounded.

[0112] The first leakage signal ZCT-A1 and the second leakage signal ZCT-A2 are converted into voltage signals through the seventh resistor R7 and input to the fourth terminal IN1 and the fifth terminal IN2 of the leakage detection chip U1. The leakage detection chip U1 amplifies and processes the input signals and outputs the leakage control signal TRIP.

[0113] In one possible embodiment, see Figure 3 The power supply circuit 400 may include: an eighth resistor R8, an eighth capacitor C8, a ninth capacitor C9, and a first Zener diode ZD1.

[0114] The first end of the eighth resistor R8 is electrically connected to the output end of the rectifier circuit. The second end of the eighth resistor R8 is electrically connected to the cathode of the first Zener diode ZD1, the first end of the eighth capacitor C8, and the positive terminal of the ninth capacitor C9, and serves as the output end of the power supply circuit 400 to output the power supply voltage VDD1.

[0115] The anode of the first Zener diode ZD1, the second terminal of the eighth capacitor C8, and the negative terminal of the ninth capacitor C9 are grounded.

[0116] The input terminal of the power supply circuit is electrically connected to the output terminal of the rectifier circuit. It performs voltage regulation on the input rectified signal COIL+ and outputs a power supply voltage VDD1 to provide power to the relay.

[0117] In one possible embodiment, see Figure 3 The leakage current trip circuit 500 also includes: a ninth resistor R9, a tenth resistor R10, a tenth capacitor C10, a second Zener diode ZD2, and a first thyristor SCR1.

[0118] The first terminal of the trip unit TQ is electrically connected to the output terminal of the rectifier circuit 100, and the second terminal of the trip unit TQ is electrically connected to the first terminal of the ninth resistor R9 and the anode of the first thyristor SCR1.

[0119] The second terminal of the ninth resistor R9 is electrically connected to the cathode of the second Zener diode ZD2 and is set as the output operating voltage VDD.

[0120] The anode of the second Zener diode ZD2 is grounded.

[0121] The control electrode of the first thyristor SCR1 is electrically connected to the first terminal of the tenth resistor R10 and the first terminal of the tenth capacitor C10, respectively.

[0122] The second terminal of the tenth resistor R10 is configured to connect to the leakage current control signal TRIP.

[0123] The second terminal of the tenth capacitor C10 and the cathode of the first thyristor SCR1 are grounded.

[0124] A thyristor, also known as a silicon controlled rectifier (SCR), is a high-power electrical component. It can be divided into unidirectional and bidirectional SCRs. Its on / off state is determined by the signal applied to its control electrode. Applying a positive (or negative) pulse to its control electrode will turn it on in either direction. In this application, the thyristor turns on after receiving the leakage control signal TRIP at its control electrode.

[0125] In one possible embodiment, see Figure 4 The reset circuit 600 may include a reset switch SW2.

[0126] The first end of the reset switch SW2 is electrically connected to the input end of the reset circuit 600, and the second end of the reset switch SW2 is electrically connected to the output end of the reset circuit 600.

[0127] The reset switch SW2 is normally kept closed, meaning the reset circuit 600 is in a conducting state. After a reset, it switches to a closed state, meaning that after the reset switch SW2 is pressed to reset, the reset circuit 600 changes from a conducting state to a closed state.

[0128] In one possible embodiment, see Figure 4 The execution circuit 700 may include: a second thyristor SCR2 and an eleventh capacitor C11.

[0129] The anode of the second thyristor SCR2 is electrically connected to the output terminal of the reset circuit 600, and the cathode of the second thyristor SCR2 is grounded.

[0130] The control electrode of the second thyristor SCR2 is electrically connected to the first terminal of the eleventh capacitor C11 and is configured to receive the leakage control signal TRIP.

[0131] The second terminal of the eleventh capacitor C11 is grounded.

[0132] See Figure 4 The grounding terminal G of relay KS is grounded through reset switch SW2 and second thyristor SCR2. By controlling reset switch SW2 and second thyristor SCR2 to be in the on or off state, the energization of relay KS can be controlled.

[0133] Based on all the above embodiments, see Figure 3 , Figure 4 and Figure 5 The working principle of the leakage current control circuit in this application is introduced as follows: For a leakage current circuit breaker that can be reverse-wired, since the common terminal COM of the relay KS is electrically connected to the normally open contact NC when it is not energized, after the reverse wiring is closed, when the test button SW1 is pressed, the circuit of the test button circuit 200 is in a conducting state and outputs leakage current signals (i.e., ZCT-A1, ZCT-A2). After the leakage current signals (i.e., ZCT-A1, ZCT-A2) are processed by the leakage current signal detection circuit 300, the leakage current control signal TRIP is output and transmitted to the first thyristor SCR1 of the leakage current trip circuit 500 and the second thyristor SCR2 of the execution circuit 700.

[0134] When the first thyristor SCR1 of the leakage current trip circuit 500 receives the leakage current control signal TRIP, it conducts, and the trip unit TQ of the leakage current trip circuit 500 operates, causing the leakage current circuit breaker to trip. At the same time, the second thyristor SCR2 of the execution circuit 700 also conducts. Since the reset switch SW2 is normally kept closed, the grounding terminal G of the relay is grounded, and the relay is energized. The common terminal COM is electrically connected to the normally closed contact NO. Since the normally closed contact NO is unused, the relay KS cuts off the path of the leakage current signal (i.e., ZCT-A1, ZCT-A2) output by the test button circuit 200. At this time, the test button SW1 will not generate a leakage current signal when pressed. Because the leakage current circuit breaker is reverse-wired, based on the internal structural characteristics of the leakage current circuit breaker itself, the relay is always energized, and the path of the leakage current signal output by the test button circuit 200 is always broken. This avoids the problem of overheating and burnout caused by the customer pressing the test button SW1 for a long time, keeping the trip unit energized.

[0135] When the trip unit needs to trip again and the test button needs to be pressed again, the reset switch SW2 in the reset circuit 600 needs to be reset. At this time, the reset circuit 600 changes from the on state to the off state, the second thyristor SCR2 in the execution circuit 700 is disconnected, the relay KS is de-energized, and the common terminal COM of the relay is reconnected to the normally open contact NC, so that the relay connects the path of the leakage current signal output by the test button circuit 200, ensuring that the test button SW1 can be used normally when the leakage current circuit breaker is reclosed. That is, when the test button SW1 is pressed again, the path of the test button circuit 200 is in the on state and can output leakage current signals (i.e., ZCT-A1, ZCT-A2).

[0136] This application also provides a substrate, including: the leakage control circuit as described above.

[0137] This application also provides a residual current circuit breaker, including: a substrate as described above.

[0138] In this embodiment, for ease of control, the residual current circuit breaker typically incorporates the test button SW1, reset switch SW2, current transformer CT, and trip unit TQ within its internal structure. Contact points are provided on the substrate, and the test button SW1, reset switch SW2, current transformer CT, and trip unit TQ are connected to these contact points via wires to achieve signal connectivity.

[0139] 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 control circuit, characterized in that, The leakage current control circuit is applied in a reversible leakage current circuit breaker. The leakage current control circuit includes: a rectifier circuit, a test button circuit, a leakage current signal detection circuit, a power supply circuit, a leakage current trip circuit, a reset circuit, and an execution circuit; the test button circuit includes a relay and a test button; the leakage current trip circuit includes a trip unit. The rectifier circuit is electrically connected to the test button circuit, the power supply circuit, and the leakage current trip circuit, respectively; the test button circuit is electrically connected to the power supply circuit, the reset circuit, and the leakage current signal detection circuit, respectively; the leakage current signal detection circuit is electrically connected to the leakage current trip circuit and the execution circuit, respectively; the reset circuit is electrically connected to the execution circuit. The rectifier circuit is configured to rectify the input AC voltage and output a rectified signal. The power supply circuit is configured to process the incoming rectified signal and output a power supply voltage to power the relay. The test button circuit is configured to receive a rectified signal and output a leakage signal when the test button is pressed. The leakage signal detection circuit is configured to process the leakage signal and output a leakage control signal; The leakage current trip circuit is configured to control the trip unit to trip according to the leakage current control signal, and is also configured to output working voltage to power the leakage current signal detection circuit. The execution circuit is configured to control itself to be in a conducting state according to the leakage control signal, so that the relay cuts off the path of the leakage signal output by the test button circuit; The reset circuit is configured to reset itself when the test button is pressed again, so that the relay connects the path of the test button circuit to output the leakage signal.

2. The leakage current control circuit according to claim 1, characterized in that, The rectifier circuit includes: a first diode, a second diode, a third diode, and a fourth diode; the AC voltage includes: phase A voltage, phase B voltage, and phase C voltage; The anode of the first diode is connected to the phase A voltage, and the cathode of the first diode is electrically connected to the cathode of the second diode, serving as the output terminal of the rectifier circuit for outputting the rectified signal. The anode of the second diode is electrically connected to the cathode of the third diode, for use in applying the B-phase voltage; The anodes of the third diode and the fourth diode are both grounded; The cathode of the fourth diode is connected to the C-phase voltage.

3. The leakage current control circuit according to claim 1, characterized in that, The test button circuit also includes: a first resistor, a fifth diode, and a current transformer; The input terminal of the test button is connected to the rectified signal, the output terminal of the test button is electrically connected to the first terminal of the first resistor, and the second terminal of the first resistor is electrically connected to the normally open contact of the relay. The common terminal of the relay is grounded after passing through the center through hole of the current transformer; The cathode of the fifth diode is electrically connected to the power supply terminal of the relay for receiving the power supply voltage; The anode of the fifth diode is electrically connected to the ground terminal of the relay and to the input terminal of the reset circuit.

4. The leakage current control circuit according to claim 1, characterized in that, The leakage signal detection circuit includes: a second resistor, a third resistor, a fourth resistor, a fifth resistor, a sixth resistor, a seventh resistor, a first capacitor, a second capacitor, a third capacitor, a fourth capacitor, a fifth capacitor, a sixth capacitor, a seventh capacitor, a bidirectional diode, and a leakage detection chip; the leakage signal includes: a first leakage signal and a second leakage signal; The first end of the bidirectional diode is connected to the first leakage signal, the second end of the bidirectional diode is connected to the second leakage signal, and the first end of the seventh resistor is electrically connected to the first end of the bidirectional diode, the first end of the first capacitor, and the first end of the second resistor, respectively. The second end of the seventh resistor is electrically connected to the second end of the bidirectional diode, the second end of the first capacitor, and the first end of the third resistor, respectively. The second end of the second resistor is electrically connected to the first end of the second capacitor, the first end of the third capacitor, and the fourth end of the leakage current detection chip, respectively. The second end of the third resistor is electrically connected to the second end of the second capacitor, the first end of the fourth capacitor, and the fifth end of the leakage current detection chip, respectively. The first end of the fourth resistor is electrically connected to the second end of the leakage current detection chip, and the second end of the fourth resistor is connected to the operating voltage. The first end of the fifth resistor is electrically connected to the ninth end of the leakage current detection chip; The first terminal of the fifth capacitor is electrically connected to the eleventh terminal of the leakage current detection chip; The first terminal of the sixth capacitor is electrically connected to the twelfth terminal of the leakage current detection chip. The first end of the sixth resistor is electrically connected to the first end of the leakage detection chip, and the second end of the sixth resistor serves as the output end of the leakage signal detection circuit, and is configured to output the leakage control signal. The first terminal of the seventh capacitor is electrically connected to the fourteenth terminal of the leakage current detection chip and is configured to be connected to the operating voltage; The second terminal of the seventh capacitor is electrically connected to the seventh terminal of the leakage current detection chip and is set to ground; The second terminal of the third capacitor, the second terminal of the fourth capacitor, the second terminal of the fifth resistor, the second terminal of the fifth capacitor, and the second terminal of the sixth capacitor are all grounded.

5. The leakage current control circuit according to claim 1, characterized in that, The power supply circuit includes: an eighth resistor, an eighth capacitor, a ninth capacitor, and a first Zener diode; The first end of the eighth resistor is electrically connected to the output end of the rectifier circuit, and the second end of the eighth resistor is electrically connected to the cathode of the first Zener diode, the first end of the eighth capacitor, and the positive terminal of the ninth capacitor, respectively, and serves as the output end of the power supply circuit for outputting the power supply voltage. The anode of the first Zener diode, the second terminal of the eighth capacitor, and the negative terminal of the ninth capacitor are grounded.

6. The leakage current control circuit according to claim 1, characterized in that, The leakage trip circuit also includes: a ninth resistor, a tenth resistor, a tenth capacitor, a second Zener diode, and a first thyristor; The first end of the trip unit is electrically connected to the output end of the rectifier circuit, and the second end of the trip unit is electrically connected to the first end of the ninth resistor and the anode of the first thyristor, respectively. The second terminal of the ninth resistor is electrically connected to the cathode of the second Zener diode and is configured to output the operating voltage. The anode of the second Zener diode is grounded; The control electrode of the first thyristor is electrically connected to the first terminal of the tenth resistor and the first terminal of the tenth capacitor, respectively. The second terminal of the tenth resistor is configured to connect to the leakage control signal; The second terminal of the tenth capacitor and the cathode of the first thyristor are grounded.

7. The leakage current control circuit according to claim 1, characterized in that, The reset circuit includes: a reset switch; The first end of the reset switch is electrically connected to the input end of the reset circuit, and the second end of the reset switch is electrically connected to the output end of the reset circuit.

8. The leakage current control circuit according to claim 1, characterized in that, The execution circuit includes: a second thyristor and an eleventh capacitor; The anode of the second thyristor is electrically connected to the output terminal of the reset circuit, and the cathode of the second thyristor is grounded. The control electrode of the second thyristor is electrically connected to the first terminal of the eleventh capacitor and is configured to receive the leakage control signal; The second terminal of the eleventh capacitor is grounded.

9. A substrate, characterized in that, include: The leakage current control circuit as described in any one of claims 1-8.

10. A residual current circuit breaker, characterized in that, include: The substrate as described in claim 9.

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