CN221227120U - Residual current protector, electronic equipment and power supply system - Google Patents

Abstract

The application provides a residual current protector, an electronic device and a power supply system, wherein the residual current protector comprises: the device comprises a zero sequence current transformer, a power supply circuit, a resistor step-down voltage stabilizing circuit, a tripping mechanism, a current sampling circuit, a main chip, a transistor driving circuit and a double-thyristor driving circuit. The power supply circuit is electrically connected with the tripping mechanism, the tripping mechanism is also electrically connected with the double-silicon-controlled drive circuit, the zero sequence current transformer is electrically connected with the current sampling circuit, the current sampling circuit is also electrically connected with the main chip, the main chip is also electrically connected with the transistor drive circuit, and the transistor drive circuit is also electrically connected with the double-silicon-controlled drive circuit. When the residual current protector detects leakage current, the voltage signal can be output through the main chip with smaller working voltage, and the transistor driving circuit amplifies the voltage signal, so that the residual current protector can interrupt the connection between a load and a power supply and ensure the safety of the load.

Description

Residual current protector, electronic equipment and power supply system

Technical Field

The present application relates to the field of residual current protection, and in particular, to a residual current protector, an electronic device, and a power supply system.

Background

The residual current protector is an electrical protection device for protecting loads and persons. The protection function is realized mainly by detecting the residual current in the current loop. When a load leaks, current flows into the ground through the leakage path, which causes the total current in the current loop to change. The residual current protection circuit monitors the difference between the total current in the current loop and the current through the neutral line, and once the difference exceeds a set value, the residual current protection circuit rapidly cuts off the circuit to prevent personal injury and equipment damage caused by electric leakage.

The residual current protector is used for preventing dangers caused by electric leakage, such as electric shock, fire and the like. The device is widely applied to electrical systems such as families, industrial and commercial buildings, public places and the like, and is very important electrical safety equipment. In particular, the residual current protector can protect a load in the field of the piezoelectric device.

The load may be a lighting device, such as an LED lamp, an electronic ballast, a photosensitive controller, etc., or a power transmission and distribution device, such as a switch cabinet, a distribution box, a cable, etc., and various power electronic devices, such as a frequency converter, a UPS, etc.

Therefore, there is a need for a residual current protection circuit that can be applied to the field of piezoelectric devices.

Disclosure of utility model

The application provides a residual current protector, electronic equipment and a power supply system, wherein a transistor driving circuit is used for amplifying a voltage signal of a main chip, and the amplified voltage signal can enable the residual current protector to interrupt the connection of a load and a power supply, so that the safety of the load is ensured.

In a first aspect, the present application provides a residual current protector comprising: the device comprises a zero sequence current transformer, a power supply circuit, a resistor step-down voltage stabilizing circuit, a tripping mechanism, a current sampling circuit, a main chip, a transistor driving circuit and a double-thyristor driving circuit.

The power supply circuit is electrically connected with the tripping mechanism, the tripping mechanism is also electrically connected with the double-silicon-controlled drive circuit, the double-silicon-controlled drive circuit is also electrically connected with the resistor step-down voltage stabilizing circuit, the resistor step-down voltage stabilizing circuit is also respectively electrically connected with the main chip, the current sampling circuit and the transistor drive circuit, and the resistor step-down voltage stabilizing circuit respectively provides working voltage for the main chip, the current sampling circuit and the transistor drive circuit, and the numerical value of the working voltage is smaller than or equal to a preset threshold value. The zero sequence current transformer is electrically connected with the current sampling circuit, the current sampling circuit is also electrically connected with the main chip, the main chip is also electrically connected with the transistor driving circuit, and the transistor driving circuit is also electrically connected with the double-silicon-controlled driving circuit.

According to the residual current protector provided by the application, the transistor driving circuit is electrically connected to the control end of the main chip, and when the voltage signal output by the control end of the main chip is smaller, the transistor driving circuit can amplify the voltage signal output by the control end of the main chip. The transistor driving circuit outputs the amplified voltage signal as driving voltage to the double-silicon-controlled driving circuit, the double-silicon-controlled driving circuit is conducted, and the tripping mechanism interrupts the connection between the load and the power supply. Therefore, when the residual current protector detects leakage current, the voltage signal can be output through the main chip with smaller working voltage, and the transistor driving circuit amplifies the voltage signal, so that the residual current protector can interrupt the connection between a load and a power supply, and the safety of the load is ensured.

The transistor driving circuit includes: the first triode, the second triode, the first resistor, the second resistor and the third resistor.

The second resistor is electrically connected between the control end of the main chip and the control end of the second triode, the first end of the first resistor and the first end of the third resistor are connected with working voltage, the second end of the first resistor and the first end of the second triode are electrically connected, the second end of the third resistor and the first end of the first triode are electrically connected, the control end of the first triode is electrically connected with the first connecting point, the first connecting point is arranged between the second end of the first resistor and the first end of the second triode, and the second end of the first triode and the second end of the second triode are grounded.

The second connection point provides driving voltage for the double-silicon controlled driving circuit and is arranged between the second end of the third resistor and the first end of the first triode.

In one possible design, the residual current protector further comprises: and a reverse incoming line circuit.

The reverse incoming line circuit is respectively and electrically connected with the transistor driving circuit and the double-thyristor driving circuit and is used for preventing the tripping mechanism from being damaged when the input end of the residual current protector is electrically connected with a load.

Based on this, the reverse incoming line circuit can prevent damage to the tripping mechanism when the input end of the residual current protector is electrically connected with a load.

In one possible design, the residual current protector further comprises: and an alarm output circuit.

The alarm output circuit is electrically connected with the transistor driving circuit. The alarm output circuit is used for early warning that the input end of the residual current protector has leakage current. In one possible design, the residual current protector further comprises: and a test trip circuit.

The test trip circuit is electrically connected with the trip mechanism. The test trip circuit is used for determining whether the tripping mechanism can work normally. In one possible design, the power supply circuit includes: a surge protection circuit and a rectifying circuit.

The surge protection circuit comprises an ABC three-phase power input end, a first piezoresistor, a second piezoresistor and a third piezoresistor. The rectifying circuit comprises a first diode, a second diode, a third diode and a fourth diode.

The first piezoresistor is electrically connected between the A-phase power input end and the B-phase power input end in parallel, the third piezoresistor is electrically connected between the B-phase power input end and the C-phase power input end in parallel, the second piezoresistor is electrically connected between a third connecting point and a fourth connecting point in parallel, the third connecting point is arranged between the A-phase power input end and the first piezoresistor, and the fourth connecting point is arranged between the C-phase power input end and the third piezoresistor. The anode of the first diode is electrically connected with a fifth connecting point, the fifth connecting point is arranged between the third connecting point and the first piezoresistor, the anode of the second diode and the cathode of the third diode are electrically connected with a seventh connecting point, the seventh connecting point is arranged between the first piezoresistor and the third piezoresistor, the cathode of the fourth diode is electrically connected with a sixth connecting point, the sixth connecting point is arranged between the fourth connecting point and the third piezoresistor, the cathode of the first diode and the cathode of the second diode are electrically connected with the input end of the tripping mechanism, and the anode of the third diode and the anode of the fourth diode are grounded.

Based on this, the power supply circuit can protect the residual current protector from the impact of the high voltage input by the input end of the ABC three-phase power supply, and can also convert the alternating current input by the input end of the ABC three-phase power supply into direct current.

In one possible design, the residual current protector further comprises: a current threshold adjustment circuit.

The current threshold adjusting circuit is electrically connected with the current sampling circuit. The current threshold adjustment circuit is used for providing different current comparison thresholds to the current sampling circuit.

In a second aspect, the present application provides an electronic device comprising: a residual current protector according to any one of the preceding claims.

In one possible design, the types of electronic devices include low voltage appliances and molded case circuit breakers.

In a third aspect, the present application provides a power supply system comprising: a power supply, a load and a residual current protector of any of the above.

The power supply is electrically connected with a power circuit in the residual current protector, and a zero sequence current transformer in the residual current protector is electrically connected with the load. The advantages provided by the second aspect, the third aspect and the possible designs of the second aspect and the third aspect may be referred to the advantages brought by the possible embodiments of the first aspect and the first aspect, and are not described herein.

Drawings

Fig. 1 is a schematic structural diagram of a power supply system according to an embodiment of the present application;

fig. 2 is a schematic structural diagram of a residual current protector according to an embodiment of the present application;

fig. 3 is a schematic circuit diagram of a residual current protector according to an embodiment of the present application;

FIG. 4 is a schematic diagram of another residual current protector according to an embodiment of the present application;

fig. 5 is a schematic structural diagram of a power circuit according to an embodiment of the application.

Reference numerals illustrate:

10—residual current protector; 20-a power supply; 30—load; 101-a power supply circuit; 102-zero sequence current transformer; 103—a trip mechanism; 104-a dual thyristor drive circuit; 105-resistance step-down voltage stabilizing circuit; 106-a current sampling circuit; 107-master chip; 108—transistor drive circuit; 109-reverse incoming line circuit; 110-an alarm output circuit; 111—a test trip circuit; 112—a current threshold adjustment circuit; vdd—operating voltage.

Detailed Description

In the present application, "at least one" means one or more, and "a plurality" means two or more. "and/or", describes an association relationship of an association object, and indicates that there may be three relationships, for example, a and/or B, and may indicate: a alone, a and B together, and B alone, wherein a, B may be singular or plural. The character "/" generally indicates that the context-dependent object is an "or" relationship. "at least one of" or the like means any combination of these items, including any combination of single item(s) or plural items(s). For example, at least one (one) of a, b, or c alone may represent: a alone, b alone, c alone, a combination of a and b, a combination of a and c, b and c, or a combination of a, b and c, wherein a, b, c may be single or plural. Furthermore, the terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

The terms "center," "longitudinal," "transverse," "upper," "lower," "left," "right," "front," "rear," and the like refer to an orientation or positional relationship based on that shown in the drawings, merely for convenience of description and to simplify the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore should not be construed as limiting the application.

The terms "connected," "connected," and "connected" are to be construed broadly, and may refer to, for example, electrical or signal connections in addition to physical connections, e.g., direct connections, i.e., physical connections, or indirect connections via at least one element therebetween, such as long as electrical circuit communication is achieved, and communications within two elements; signal connection may refer to signal connection through a medium such as radio waves, in addition to signal connection through a circuit. The specific meaning of the above terms in the present application will be understood in specific cases by those of ordinary skill in the art.

The application provides a residual current protector, an electronic device and a power supply system. Referring to fig. 1, fig. 1 is a schematic structural diagram of a power supply system according to an embodiment of the application.

As shown in fig. 1, the power supply system of the present application may include: a power supply 20, a load 30 and a residual current protector 10.

The power supply 20 is electrically connected with a power supply circuit 101 in the residual current protector 10, and a zero sequence current transformer 102 in the residual current protector 10 is electrically connected with the load 30.

The power supply 20 may be a single-phase two-wire power supply, a two-phase three-wire power supply, a three-phase three-wire power supply, or a three-phase four-wire power supply. Taking the power supply 20 as an example of a three-phase four-wire power supply, the three-phase four-wire power supply includes three phase conductors of an a-phase power supply line, a B-phase power supply line, and a C-phase power supply line, and an N-phase power supply line as a neutral conductor, and four conductors in total. The power supply 20 may provide an ac voltage to the load 30 and the residual current protector 10.

When the load 30 receives an earth leakage, the residual current protector 10 disconnects the load 30 from the power supply 20, and the load 30 stops operating. When no ground leakage occurs to the load 30, the load 30 operates by the input ac voltage. The load 30 may be a smaller rated household consumer such as an incandescent lamp, an electric fan, an electronic scale, or the like.

The residual current protector 10 may be an electronic device. Types of electronic devices may include low voltage appliances and molded case circuit breakers. The residual current protector 10 may also be a chip.

The residual current protector 10 can be applied to a load with a small rated power. When the load 30 with a small rated power leaks to the ground, the residual current protector 10 can detect the leakage current of the load 30 to the ground and interrupt the connection of the load 30 to the power supply 20.

Therefore, in the power supply system of the present application, when the load 30 with a small rated power is subjected to the earth leakage, the residual current protector 10 can interrupt the connection between the load 30 and the power supply 20, thereby protecting the load 30 from the damage of personal safety in case of fire.

Next, a residual current protector 10 according to an embodiment of the present application will be described in detail with reference to fig. 2 and 3.

Referring to fig. 2 and 3, fig. 2 is a schematic structural diagram of a residual current protector according to an embodiment of the application, and fig. 3 is a schematic circuit structural diagram of a residual current protector according to an embodiment of the application. As shown in fig. 2, the residual current protector 10 of the present application may include: the zero sequence current transformer 102, the power supply circuit 101, the resistor-step-down voltage stabilizing circuit 105, the tripping mechanism 103, the current sampling circuit 106, the main chip 107, the transistor driving circuit 108 and the double-thyristor driving circuit 104.

The power supply circuit 101 is electrically connected with the trip mechanism 103, the trip mechanism 103 is also electrically connected with the double-silicon-controlled drive circuit 104, the double-silicon-controlled drive circuit 104 is also electrically connected with the resistor-step-down voltage stabilizing circuit 105, and the resistor-step-down voltage stabilizing circuit 105 is also electrically connected with the main chip 107, the current sampling circuit 106 and the transistor drive circuit 108, respectively. The zero sequence current transformer 102 is electrically connected with a current sampling circuit 106, the current sampling circuit 106 is also electrically connected with a main chip 107, the main chip 107 is also electrically connected with a transistor driving circuit 108, and the transistor driving circuit 108 is also electrically connected with a double-thyristor driving circuit 104.

In fig. 3, the first thyristor is VT1, the second thyristor is VT2, the first triode is Q1, the second triode is Q2, the third triode is Q3, the first varistor is RV1, the second varistor is RV2, the third varistor is RV3, the fourth varistor is RV4, the first diode is VD1, the second diode is VD2, the third diode is VD3, the fourth diode is VD4, the fifth zener diode is VD5, the bidirectional clamping diode is VD6, the seventh diode is D1, the eighth diode is D2, the first switching transistor is VT3, the second capacitance is C2, the third capacitance is C3, the fourth capacitance is C4, the fifth capacitance is C5, the sixth capacitance is C6, the seventh capacitance is C7, the eighth capacitance is C8, the ninth capacitance is C9, the tenth capacitance is C10, the eleventh capacitance is C11, the first resistance is denoted as R1, the second resistance is denoted as R2, the third resistance is denoted as R3, the fourth resistance is denoted as R4, the fifth resistance is denoted as R5, the sixth resistance is denoted as R6, the seventh resistance is denoted as R7, the eighth resistance is denoted as R8, the ninth resistance is denoted as R9, the tenth resistance is denoted as R10, the eleventh resistance is denoted as R11, the twelfth resistance is denoted as R12, the thirteenth resistance is denoted as R13, the fourteenth resistance is denoted as R14, the fifteenth resistance is denoted as R15, the sixteenth resistance is denoted as R16, the seventeenth resistance is denoted as R17, the eighteenth resistance is denoted as R18, the nineteenth resistance is denoted as R19, the twentieth resistance is denoted as R20, the twenty-first resistance is denoted as R21, the twenty-second resistance is denoted as R22, the twenty-third resistance is denoted as R23, the twenty-fourth resistance is denoted as R24, the twenty-fifth resistance is denoted as R25, the twenty-sixth resistance is denoted as R26, the twenty-seventh resistance is denoted as R27, the twenty-eighth resistance is denoted as R28, the thirty-first resistor is recorded as R30, the thirty-first resistor is recorded as R31, the leakage current simulation module is recorded as JP1, the chip is recorded as U1, the alarm module is recorded as JP2, the tripping device is recorded as JP3, the dial switch is recorded as S1, and the trial jump switch is recorded as S2.

The zero sequence current transformer 102 can be wound in a ring shape from an iron core. The zero sequence current transformer 102 can detect whether leakage current is generated in the load 30. Four wires in the three-phase four-wire system power supply pass through the annular zero-sequence current transformer 102, and three phase wires and one N-phase power supply wire perform electromagnetic induction in the zero-sequence current transformer 102. When the load 30 generates leakage current, electromagnetic induction generates zero sequence current, that is, the zero sequence current transformer 102 induces leakage current. The zero sequence current transformer 102 may input the induced leakage current into the current sampling circuit 106.

The power circuit 101 may convert the ac voltage input from the ABC three-phase power line into the dc voltage required for the residual current protector 10.

The resistance step-down voltage stabilizing circuit 105 includes a fourth resistor R4, a fifth resistor R5, a sixth resistor R6, a seventh resistor R7, an eighth resistor R8, a ninth resistor R9, a tenth resistor R10, an eleventh resistor R11, a twelfth resistor R12, a thirteenth resistor R13, a fourteenth resistor R14, a fifteenth resistor R15, a sixteenth resistor R16, a seventeenth resistor R17, an eighth diode D2, a fifth voltage stabilizing tube VD5, and a third capacitor C3.

The resistor-step-down voltage stabilizing circuit 105 may step down, and the step-down voltage may provide the main chip 107, the current sampling circuit 106, and the transistor driving circuit 108 with an operating voltage VDD, where the value of the operating voltage VDD is less than or equal to a preset threshold. The preset threshold may be set to a maximum operating voltage VDD that can be sustained when the main chip 107, the current sampling circuit 106, and the transistor driving circuit 108 are operated. In order to prevent the main chip 107 from being overheated due to the high voltage impact of the main chip 107, the preset threshold may be set to a small value, for example, the preset threshold may be 5V. Setting the smaller operating voltage VDD protects the main chip 107 and improves the stability of the residual current protector 10.

The current sampling circuit 106 includes: the capacitor comprises a twenty-first resistor R20, a twenty-first resistor R21, a twenty-second resistor R22, a sixth capacitor C6, a seventh capacitor C7, an eighth capacitor C8, a tenth capacitor C10, an eleventh capacitor C11, a twelfth capacitor C12 and a bidirectional clamp diode VD6.

The current sampling circuit 106 can convert the leakage current induced by the zero sequence current transformer 102 into a voltage signal, and the voltage signal is input into the main chip 107.

The main chip 107 includes a fourth capacitor C4 and a chip U1. The fourth capacitor C4 is electrically connected in parallel between the VDD interface and the VSS interface of the chip U1.

The main chip 107 may receive the voltage signal of the current sampling circuit 106 and make a logic judgment on the voltage signal. The main chip 107 outputs a voltage signal to the transistor driving circuit 108 within a preset control time in which the main chip 107 receives the voltage signal. The output voltage signal may be a voltage of 4V to 5V. The preset control time may be set to a small value, for example, the preset control time may be 10ms, and the preset control time may be other time less than 10 ms. In the presence of leakage current in the load 30, the residual current protector 10 may interrupt the connection of the load 30 to the power supply 20 for a short preset control time.

When the rated power of the load 30 is small, the rated power of the main chip 107 is also small. Therefore, the voltage signal output from the main chip 107 to the transistor driving circuit 108 is small.

The transistors in the transistor driver circuit 108 may be transistors. The transistor driving circuit 108 may amplify the smaller voltage signal output from the main chip 107 through a transistor and output the amplified voltage signal to the dual thyristor driving circuit 104.

The dual-thyristor driving circuit 104 includes a first thyristor VT1, a second thyristor VT2, a fourth varistor RV4, and a second capacitor C2.

Two thyristors are provided in the dual thyristor drive circuit 104. The provision of two thyristors can improve the voltage resistance, stability, and surge impact resistance of the dual thyristor drive circuit 104 compared to a single thyristor. The dual-thyristor drive circuit 104 receives the voltage signal amplified by the transistor drive circuit 108, and the dual-thyristor drive circuit 104 is turned on. When the dual thyristor drive circuit 104 is turned on, the dual thyristor drive circuit 104 can supply voltage to the trip mechanism 103.

The trip mechanism 103 includes a seventh diode D1 and a trip device JP3. The trip mechanism 103 may be an electromagnetic device. The trip device JP3 may include an action coil, a main contact and a spring. The main contacts may be made of a metallic material, and the main contacts may be opened when the circuit of the trip mechanism 103 is turned on, and the disconnection of the main electric shock may interrupt the connection of the load 30 to the power supply 20.

In addition, the residual current protector 10 may further include: a current threshold adjustment circuit 112. The current threshold adjustment circuit 112 is electrically connected to the current sampling circuit 106. The current threshold adjustment circuit 112 includes a twenty-third resistor R23, a twenty-fourth resistor R24, a twenty-fifth resistor R25, and a dial switch S1.

The current threshold adjustment circuit 112 may provide different current comparison thresholds to the current sampling circuit 106. The current threshold adjustment circuit 112 may adjust the current comparison threshold by adjusting the resistance of the different resistances connected to the dial switch S1. The current threshold adjustment circuit 112 may also adjust the current comparison threshold via a knob switch. The number of resistors to which the dial switch S1 is connected with the knob switch may be different. For example, the number of resistors connected to the dial switch S1 may be three, and the number of resistors connected to the knob switch may be five. The current comparison threshold set in the current threshold adjustment circuit 112 should be greater than the rated current of the load 30. For example, the current comparison threshold may be set to 30mA.

The twenty-third resistor R23, the twenty-fourth resistor R24 and the twenty-fifth resistor R25 have different resistance values, and the dial switch S1 can adjust the current comparison threshold value by connecting the resistors with different resistance values. The resistance of the resistor is inversely proportional to the magnitude of the current comparison threshold. When the current comparison threshold value is larger, the resistance value of the resistor is smaller. When the current comparison threshold is smaller, the resistance value of the resistor is larger.

When an ac voltage is input to the power supply circuit 101, the power supply circuit 101 converts the ac voltage into a dc voltage. The dc voltage is input to the resistor-step-down voltage-stabilizing circuit 105 through the trip mechanism 103, and the resistor-step-down voltage-stabilizing circuit 105 receives the dc voltage. The resistor step-down voltage stabilizing circuit 105 steps down the direct current voltage through a series resistor, thereby reducing the device cost. For example, the resistance step-down voltage stabilizing circuit 105 steps down a direct-current voltage of 500V to 5V. The stepped-down voltage is input as an operating voltage VDD to the main chip 107, the current sampling circuit 106, and the transistor driving circuit 108 through the fifth voltage stabilizing tube VD5 and the third capacitor C3. The voltage after the step-down also turns on the first thyristor VT1 through the eighth diode D2 and the sixteenth resistor R16.

When the load 30 is grounded, the zero sequence current transformer 102 can sense leakage current, the zero sequence current transformer 102 inputs the leakage current into the current sampling circuit 106, and the current sampling circuit 106 converts the leakage current into a voltage signal to be input into the main chip 107. The main chip 107 determines the magnitude of the current comparison threshold in the leakage current and current threshold adjustment circuit 112 from the input voltage signal. When the leakage current is greater than or equal to the current comparison threshold, the main chip 107 outputs a voltage signal to the transistor driving circuit 108. The transistor driving circuit 108 amplifies and outputs the voltage signal to the dual-thyristor driving circuit 104, and provides the driving voltage for the thyristor driving circuit 104. The driving voltage passes through the control end of the silicon controlled rectifier, the first silicon controlled rectifier VT1 and the second silicon controlled rectifier VT2 form a loop, the double silicon controlled rectifier driving circuit 104 is conducted, the tripping mechanism 103 is conducted, and the main contact of the tripping mechanism 103 is disconnected. Thus, the residual current protector 10 interrupts the connection of the load 30 to the power supply 20.

When the circuit of the trip mechanism 103 is turned on, the seventh diode D1 can supply a voltage to the operating coil, and the operating coil generates a large magnetic field. The magnetic field breaks contacts on the main contacts by attractive force or moment action, thereby interrupting the connection of the load 30 to the power supply 20. The spring can provide a restoring force of the trip mechanism 103, and when the leakage current of the load 30 disappears, the spring controls the main contact to restore to the closed state.

Next, with reference to fig. 3, a transistor driving circuit 108 according to an embodiment of the present application will be described in detail.

As shown in fig. 3, the transistor driving circuit 108 may include: the first triode Q1, the second triode Q2, the first resistor R1, the second resistor R2 and the third resistor R3.

The second resistor R2 is electrically connected between the control end OS of the main chip and the control end of the second triode Q2, the first end of the first resistor R1 and the first end of the third resistor R3 are connected with the working voltage VDD, the second end of the first resistor R1 is electrically connected with the first end of the second triode Q2, the second end of the third resistor R3 is electrically connected with the first end of the first triode Q1, the control end of the first triode Q1 is electrically connected with a first connection point, the first connection point is arranged between the second end of the first resistor R1 and the first end of the second triode Q2, and the second end of the first triode Q1 and the second end of the second triode Q2 are grounded. The second connection point is provided to the dual-thyristor driving circuit 104 and is disposed between the second end of the third resistor R3 and the first end of the first transistor Q1.

In fig. 3, the control terminal of the main chip is denoted as OS, the first terminal of the first transistor is denoted as 1, the second terminal of the first transistor is denoted as 2, the control terminal of the first transistor is denoted as 3, the first terminal of the second transistor is denoted as 1, the second terminal of the second transistor is denoted as 2, the control terminal of the second transistor is denoted as 3, the driving voltage is denoted as TRIP, the first connection point is denoted as E, and the second connection point is denoted as F.

The first transistor Q1 and the second transistor Q2 may be NPN transistors.

When the control terminal OS of the main chip does not output a voltage signal, the second transistor Q2 is not turned on, the first transistor Q1 is turned on by the operating voltage VDD, and the driving voltage TRIP is low.

When the control terminal OS of the main chip outputs a voltage signal, the second transistor Q2 is turned on, the first transistor Q1 is turned off, and the operating voltage VDD makes the driving voltage TRIP be a high voltage.

Since the voltage signal output by the control terminal OS of the main chip is smaller, the transistor driving circuit 108 controls the second transistor Q2 to be conductive, and the first transistor Q1 to be non-conductive. Thus, the transistor driving circuit 108 amplifies the smaller voltage signal output from the control terminal OS of the main chip, and the amplified voltage signal is output as the driving voltage TRIP to the dual-thyristor driving circuit 104. By amplifying the voltage signal by the transistor driving circuit 108, the anti-interference capability and reliability of the residual current protector 10 can be improved.

According to the residual current protector provided by the application, the transistor driving circuit is electrically connected to the control end of the main chip, and when the voltage signal output by the control end of the main chip is smaller, the transistor driving circuit can amplify the voltage signal output by the control end of the main chip. The transistor driving circuit outputs the amplified voltage signal as driving voltage to the double-silicon-controlled driving circuit, the double-silicon-controlled driving circuit is conducted, and the tripping mechanism interrupts the connection between the load and the power supply. Therefore, when the residual current protector detects leakage current, the voltage signal can be output through the main chip with smaller working voltage, and the transistor driving circuit amplifies the voltage signal, so that the residual current protector can interrupt the connection between a load and a power supply, and the safety of the load is ensured.

Next, a specific implementation of the residual current protector 10 according to the present application will be described in detail with reference to fig. 3 and 4. Fig. 4 is a schematic structural diagram of another residual current protector according to an embodiment of the present application. As shown in fig. 4, the residual current protector 10 of the present application further includes: an anti-wire-in circuit 109, an alarm output circuit 110 and a test trip circuit 111.

The inverse wire-in circuit 109 is electrically connected to the transistor driving circuit 108 and the double-thyristor driving circuit 104, respectively. The alarm output circuit 110 is electrically connected to the transistor driving circuit 108. The trip circuit 111 is electrically connected to the trip mechanism 103.

The reverse incoming circuit 109 includes: eighteenth resistance R18, nineteenth resistance R19, ninth capacitance C9 and first switching tube VT3.

The reverse incoming circuit 109 can prevent the tripping mechanism 103 from being damaged when the input end of the residual current protector 10 is electrically connected with the load 30, and improve the anti-interference capability and reliability of the residual current protector 10.

When the residual current protector 10 is normally in wire, the input end of the residual current protector 10 is electrically connected with the power supply 20, and the output end of the residual current protector 10 is electrically connected with the load 30. When the input end and the output end of the residual current protector 10 are connected reversely, the output end of the residual current protector 10 is electrically connected with the power supply 20, and the input end of the residual current protector 10 is electrically connected with the load 30.

When the input terminal and the output terminal of the residual current protector 10 are opposite, the disconnection of the trip mechanism 103 cannot interrupt the connection of the power supply 20 and the load 30. In order to ensure the safety of the TRIP mechanism 103 of the residual current protector 10, when detecting the leakage current, the reverse incoming circuit 109 lowers the driving voltage TRIP, the lowered driving voltage TRIP makes the double-thyristor driving circuit 104 non-conductive, and the double-thyristor driving circuit 104 non-conductive makes the TRIP mechanism 103 non-disconnected. Thus, the reverse incoming circuit 109 can prevent the trip mechanism 103 from being continuously turned off, and protect the trip mechanism 103 from damage.

The input and output terminals of the residual current protector 10 are connected in forward direction, and when a leakage current is detected, the main chip 107 controls the tripping mechanism 103 to interrupt the connection of the load 30 and the power supply 20 in a short preset time. For example, the preset time may be 10ms. After a preset delay time, the inverse wire circuit 109 decreases the driving voltage TRIP. The preset delay time is greater than the preset time, for example, the preset delay time may be 30ms, or may be other values greater than the preset time. After a preset delay time, the reverse incoming circuit 109 does not affect the trip mechanism 103 to interrupt the connection of the load 30 to the power supply 20.

The alarm output circuit 110 includes: thirty-first resistor R31, fifth capacitor C5, third triode Q3 and alarm module JP2.

The alarm output circuit 110 may alarm when the residual current protector 10 detects a leakage current, reminding the user of the leakage of the load 30. The alarm output circuit 110 may alarm by sounding an alarm or generating a flashing light. The alarm module JP2 may include an optocoupler diode and a buzzer. The alarm output circuit 110 can generate light flash through the electrically connected optocoupler diode, and the alarm output circuit 110 can also generate alarm sound through the electrically connected buzzer. The alarm and trip mechanism 103 may be operated simultaneously.

Taking the light emitting alarm of the optocoupler diode as an example, when the residual current protector 10 detects the electric leakage, the driving voltage TRIP output by the main chip 107 passes through the thirty-first resistor R31 and the third triode Q3, and the driving voltage TRIP triggers the optocoupler diode to generate light flash to alarm to the user.

The trial jump circuit 111 includes: twenty-sixth resistor R26, twenty-seventh resistor R27, twenty-eighth resistor R28, twenty-ninth resistor R29, thirty-sixth resistor R30, trial jump switch S2 and leakage current simulation module JP1.

The test trip circuit 111 can simulate the situation that the load 30 has leakage current, so as to detect whether the trip mechanism 103 can work normally. The leakage current simulation module JP1 can simulate and generate leakage current.

The trip switch S2 may be manually or automatically closed and the simulated leakage current may be input into the trip mechanism 103 through the closed trip switch S2. When the trip mechanism 103 interrupts the connection of the load 30 to the power supply 20, it indicates that the trip mechanism 103 can operate normally. When the trip mechanism 103 does not interrupt the connection of the load 30 to the power supply 20, it indicates that the trip mechanism 103 cannot operate normally.

Next, a power supply circuit 101 according to an embodiment of the present application is described in detail with reference to fig. 5. Fig. 5 is a schematic structural diagram of a power circuit according to an embodiment of the application.

As shown in fig. 5, the power supply circuit 101 may include: a surge protection circuit 1011 and a rectifying circuit 1012.

The surge protection circuit 1011 includes an ABC three-phase power input terminal, a first varistor RV1, a second varistor RV2, and a third varistor RV3. The rectifying circuit 1012 includes a first diode VD1, a second diode VD2, a third diode VD3, and a fourth diode VD4.

The first piezoresistor RV1 is electrically connected between the A-phase power input end and the B-phase power input end in parallel, the third piezoresistor RV3 is electrically connected between the B-phase power input end and the C-phase power input end in parallel, the second piezoresistor RV2 is electrically connected between a third connecting point and a fourth connecting point in parallel, the third connecting point is arranged between the A-phase power input end and the first piezoresistor RV1, and the fourth connecting point is arranged between the C-phase power input end and the third piezoresistor RV 3.

The anode of the first diode VD1 is electrically connected with a fifth connection point, the fifth connection point is arranged between the third connection point and the first piezoresistor RV1, the anode of the second diode VD2 and the cathode of the third diode VD3 are electrically connected with a seventh connection point, the seventh connection point is arranged between the first piezoresistor RV1 and the third piezoresistor RV3, the cathode of the fourth diode VD4 is electrically connected with a sixth connection point, the sixth connection point is arranged between the fourth connection point and the third piezoresistor RV3, the cathode of the first diode VD1 and the cathode of the second diode VD2 are electrically connected with the input end coil+ of the tripping mechanism, and the anode of the third diode VD3 and the anode of the fourth diode VD4 are grounded.

In fig. 5, the surge protection circuit is 1011, the rectifying circuit is 1012, the a-phase power input terminal is a, the B-phase power input terminal is B, the C-phase power input terminal is C, the third connection point is G, the fourth connection point is H, the fifth connection point is I, the sixth connection point is J, the seventh connection point is K, and the input terminal of the trip mechanism is coil+.

The surge protection circuit 1011 may protect the residual current protector 10 from the high voltage input from the ABC three-phase power input terminal.

The first, second and third varistors RV1, RV2 and RV3 may be zinc oxide varistors.

When the voltage input by the ABC three-phase power input end is too high, the conductivities of the first piezoresistor RV1, the second piezoresistor RV2 and the third piezoresistor RV3 are increased sharply, and the first piezoresistor RV1, the second piezoresistor RV2 and the third piezoresistor RV3 absorb the high voltage input by the ABC three-phase power input end.

The rectifying circuit 1012 may convert alternating current input from the ABC three-phase power input terminal into direct current. The first diode VD1, the second diode VD2, the third diode VD3, and the fourth diode VD4 may also be referred to as a full-wave bridge rectifier.

In the positive half cycle of the rectifier circuit 1012 converting the alternating current into the direct current, the first diode VD1 and the third diode VD3 are turned on, and the second diode VD2 and the fourth diode VD4 are turned off. The input voltage of the a-phase power supply input end enters the residual current protector 10 through the first diode VD1, and returns to the B-phase power supply input end through the third diode VD 3. Thus, the alternating current of the positive half cycle is converted to direct current.

In the negative half cycle of the rectification circuit 1012 converting the alternating current into the direct current, the second diode VD2 and the fourth diode VD4 are turned on, and the first diode VD1 and the third diode VD3 are turned off. The input voltage of the B-phase power supply input terminal enters the residual current protector 10 through the second diode VD2, and returns to the C-phase power supply input terminal through the fourth diode VD 4. Thus, the alternating current of the negative half cycle is converted to direct current.

Finally, it should be noted that: the above embodiments are merely specific embodiments of the present application, but the scope of the present application is not limited thereto, and any changes or substitutions within the technical scope of the present application should be covered by the scope of the present application. Therefore, the protection scope of the application is subject to the protection scope of the claims.

Claims (10)

1. A residual current protector, characterized in that the residual current protector comprises:

The device comprises a zero sequence current transformer, a power supply circuit, a resistor step-down voltage stabilizing circuit, a tripping mechanism, a current sampling circuit, a main chip, a transistor driving circuit and a double-thyristor driving circuit;

The power supply circuit is electrically connected with the tripping mechanism, the tripping mechanism is also electrically connected with the double-silicon-controlled drive circuit, the double-silicon-controlled drive circuit is also electrically connected with the resistor step-down voltage stabilizing circuit, the resistor step-down voltage stabilizing circuit is also electrically connected with the main chip, the current sampling circuit and the transistor drive circuit respectively, the resistor step-down voltage stabilizing circuit provides working voltages for the main chip, the current sampling circuit and the transistor drive circuit respectively, and the numerical value of the working voltages is smaller than or equal to a preset threshold value;

The zero sequence current transformer is electrically connected with the current sampling circuit, the current sampling circuit is also electrically connected with the main chip, the main chip is also electrically connected with the transistor driving circuit, and the transistor driving circuit is also electrically connected with the double-silicon-controlled driving circuit.

2. The residual current protector according to claim 1, wherein the transistor driving circuit includes: the first triode, the second triode, the first resistor, the second resistor and the third resistor;

The second resistor is electrically connected between the control end of the main chip and the control end of the second triode, the first end of the first resistor and the first end of the third resistor are connected with the working voltage, the second end of the first resistor is electrically connected with the first end of the second triode, the second end of the third resistor is electrically connected with the first end of the first triode, the control end of the first triode is electrically connected with a first connection point, the first connection point is arranged between the second end of the first resistor and the first end of the second triode, and the second end of the first triode and the second end of the second triode are grounded;

The second connection point provides driving voltage for the double-silicon controlled driving circuit, and the second connection point is arranged between the second end of the third resistor and the first end of the first triode.

3. The residual current protector according to claim 1 or 2, characterized in that the residual current protector further comprises: a reverse incoming line circuit;

The reverse incoming line circuit is respectively and electrically connected with the transistor driving circuit and the double-thyristor driving circuit, and is used for preventing the tripping mechanism from being damaged when the input end of the residual current protector is electrically connected with a load.

4. The residual current protector according to claim 1 or 2, characterized in that the residual current protector further comprises: an alarm output circuit;

The alarm output circuit is electrically connected with the transistor driving circuit;

The alarm output circuit is used for early warning that the input end of the residual current protector has leakage current.

5. The residual current protector according to claim 1 or 2, characterized in that the residual current protector further comprises: a test trip circuit;

The test trip circuit is electrically connected with the tripping mechanism;

the test trip circuit is used for determining whether the tripping mechanism can work normally.

6. A residual current protector according to claim 1 or 2, characterized in that the power supply circuit comprises: a surge protection circuit and a rectifying circuit;

The surge protection circuit comprises an ABC three-phase power input end, a first piezoresistor, a second piezoresistor and a third piezoresistor; the rectifying circuit comprises a first diode, a second diode, a third diode and a fourth diode;

The first piezoresistor is electrically connected in parallel between the A-phase power input end and the B-phase power input end, the third piezoresistor is electrically connected in parallel between the B-phase power input end and the C-phase power input end, the second piezoresistor is electrically connected in parallel between a third connection point and a fourth connection point, the third connection point is arranged between the A-phase power input end and the first piezoresistor, and the fourth connection point is arranged between the C-phase power input end and the third piezoresistor;

The positive pole of first diode with fifth tie point electricity is connected, the fifth tie point sets up the third tie point with between the first piezo-resistor, the positive pole of second diode with the negative pole of third diode all is connected with the seventh tie point electricity, the seventh tie point sets up between first piezo-resistor with between the third piezo-resistor, the negative pole of fourth diode is connected with the sixth tie point electricity, the sixth tie point sets up between the fourth tie point with the third piezo-resistor, the negative pole of first diode with the negative pole of second diode all with tripping device's input electricity is connected, the positive pole of third diode with the positive pole of fourth diode all ground connection.

7. The residual current protector according to claim 1 or 2, characterized in that the residual current protector further comprises: a current threshold adjustment circuit;

The current threshold adjusting circuit is electrically connected with the current sampling circuit;

The current threshold adjustment circuit is configured to provide different current comparison thresholds to the current sampling circuit.

8. An electronic device, comprising: a residual current protector as claimed in any one of claims 1-7.

9. The electronic device of claim 8, wherein the types of electronic devices include low voltage appliances and molded case circuit breakers.

10. A power supply system, comprising: a power supply, a load and a residual current protector as claimed in any one of claims 1 to 7;

The power supply is electrically connected with a power circuit in the residual current protector, and a zero sequence current transformer in the residual current protector is electrically connected with the load.