An electronic switch box with a leakage protection function

Abstract

An electronic switch box with a leakage protection function is provided with a first thyristor switch connected to the live wire and a second thyristor switch connected to the neutral wire. The first thyristor switch and the second thyristor switch are connected to a zero-sequence current transformer for controlling the current of an external load. A zero-potential detection module for detecting an electric potential signal is provided on the live wire, and the detected signal is fed back to a control module. The power supply terminal of the control module is electrically connected to the output terminal of a voltage conversion unit provided on the live wire. The zero-sequence current transformer amplifies the signal through a signal amplification module, and the amplified signal is fed back into the control module. The control module is displayed through a set indication module connected externally. The present invention can execute synchronously. Therefore, when there is a leakage sign in the overall circuit, the protection function can be instantaneously activated, the power supply can be cut off, and the leakage protection mode can be entered, thereby having the advantages of rapid start-up and response, accurate execution, and sensitive detection of leakage signs.

Description

Technical Field

[0001] The present invention relates to the technical field of electronic switches, and particularly to an electronic switch box with a leakage protection function. Background Art

[0002] An electronic switch refers to an operating unit that uses electronic circuits and power electronic devices to achieve circuit on-off, and includes at least one controllable electronic drive device, such as thyristors, transistors, field effect transistors, silicon controlled rectifiers, relays, etc. In actual use, electronic switches mainly include touch switches, induction switches, voice control switches, wireless switches, etc. A leakage protection switch is mainly a switch that can timely disconnect the circuit when a leakage fault occurs in the device or when a fatal electric shock to a person occurs.

[0003] In the prior art, there has emerged an anti-leakage electronic switch that combines the above two forms. However, the current anti-leakage electronic switches generally have the disadvantages of low sensitivity, slow response, and high cost.

[0004] Therefore, aiming at the deficiencies of the prior art, it is very necessary to provide an electronic switch box with a leakage protection function to solve the deficiencies of the prior art. Summary of the Invention

[0005] The purpose of the present invention is to avoid the deficiencies of the prior art and provide an electronic switch box with a leakage protection function. The electronic switch box with a leakage protection function has the advantages of quick start and response, so as to be sensitive in detecting leakage signs.

[0006] The above object of the present invention is achieved by the following technical means.

[0007] Provide an electronic switch box with a leakage protection function, which is provided with a first thyristor switch connected to the live wire and a second thyristor switch connected to the neutral wire. The first thyristor switch and the second thyristor switch are connected to a zero-sequence current transformer for controlling the current of an external load.

[0008] A zero-potential detection module for detecting a potential signal is arranged on the live wire. The zero-potential detection module feeds back the detected signal to the control module, and the power supply end of the control module is conducted with the output end of a voltage conversion unit arranged on the live wire.

[0009] The zero-sequence current transformer amplifies the signal through a signal amplification module, and the amplified signal is fed back into the control module. The control module displays set parameters through a connected setting indication module.

[0010] Preferably, the first thyristor switch is provided with a thyristor chip Q1, a triode Q3, a triode Q4, a resistor R6, a resistor R7, a resistor R8, a resistor R11, a resistor R12 and a resistor R13. The pin 1 of the thyristor chip Q1 is connected to the live wire, the pin 2 of the thyristor chip Q1 is connected to the zero-sequence current transformer, the pin 3 of the thyristor chip Q1 is sequentially connected to the zero-sequence current transformer through the resistor R12 and the resistor R13. The resistor R11 connected in series with the pin 3 of the thyristor chip Q1 is connected to the pin 3 of the triode Q3. The pin 2 of the triode Q3 is connected to the live wire. The pin 1 of the triode Q3 is connected to the pin 2 of the triode Q4 through the resistor R8. The pin 2 of the triode Q4 is connected to the live wire through the resistor R6. The pin 3 of the triode Q4 is grounded. The pin 1 of the triode Q4 is connected to the control module through the resistor R7.

[0011] Preferably, the second thyristor switch is provided with a thyristor chip Q2, a resistor R9 and a resistor R10. The pin 1 of the thyristor chip Q2 is connected to the zero-sequence current transformer. The pin 2 of the thyristor chip Q2 is connected to one end of the resistor R9. The other end of the resistor R9 is connected to the control module and is also connected to the neutral wire through the series-connected resistor R10. The pin 3 of the thyristor chip Q2 is connected to the neutral wire.

[0012] Preferably, the zero-potential detection module is provided with a triode Q5, a zener diode D2, a resistor R2, a resistor R1, a resistor R5 and a resistor R15. The pin 2 of the triode Q5 is connected to the input end of the zener diode D2. The pin 1 of the triode Q5 is connected to the output end of the zener diode D2. The input end of the zener diode D2 is also connected to the output end through the series-connected resistor R5. The pin 2 of the triode Q5 is grounded. The pin 3 of the triode Q5 is connected to the control module. And the pin 3 of the triode Q5 is connected to the power supply VCC5V through the resistor R15. The pin 1 of the triode Q5 is connected to the live wire through the resistors R2 and R1 in sequence.

[0013] Preferably, the pin 1 of the zero-sequence current transformer is connected to the pin 2 of the thyristor chip Q1. The pin 2 of the zero-sequence current transformer is connected to the pin 1 of the thyristor chip Q2. The pin 3 of the zero-sequence current transformer is grounded. The pin 4 of the zero-sequence current transformer is connected to the signal amplification module. The pins 5 and 6 of the zero-sequence current transformer are respectively connected to an external load.

[0014] Preferably, the above signal amplification module is provided with a dual operational amplifier U3, a capacitor C8, a capacitor C9, a capacitor C10, a resistor R17, a resistor R18, a resistor R19, a resistor R20, a resistor R21, a resistor R22, and a resistor R23. The pin 1 of the dual operational amplifier U3 is connected to the control module. The pin 1 of the dual operational amplifier U3 is connected to the ground in series with the capacitor C8. The pin 1 of the dual operational amplifier U3 is connected to the pin 2 in series with the resistor R17. The pin 2 of the dual operational amplifier U3 is connected to the pin 4 of the zero-sequence current transformer in series with the resistor R22. The pin 3 of the dual operational amplifier U3 is connected to the VCC5V power supply in series with the resistor R19 and the resistor R23 in sequence. The pin 4 of the dual operational amplifier U3 is connected to the pin 3 in series with the resistor R18. The pin 2 of the dual operational amplifier U3 is connected to the ground in series with the resistor R20 and the resistor R21 in sequence. The capacitor C10 is connected in parallel with the resistor R21. The pin 4 of the dual operational amplifier U3 is grounded. The pin 8 of the dual operational amplifier U3 is connected to the ground in series with the capacitor C9. The pin 8 of the dual operational amplifier U3 is also connected to the VCC5V power supply. The pins 5, 6, and 7 of the dual operational amplifier U3 are left floating.

[0015] Preferably, the above voltage conversion unit is provided with a voltage regulator U1, a capacitor C1, a capacitor C2, an electrolytic capacitor C3, an electrolytic capacitor C4, a capacitor C5, a diode D3, a diode D4, a zener diode D5, a thermistor RT1, a resistor R3, and a resistor R4. The pin 2 of the voltage regulator U1 is connected to the neutral line. The pin 1 of the voltage regulator U1 is connected to the VCC5V power supply. The electrolytic capacitor C4 and the capacitor C5 are connected in parallel between the pin 1 and the pin 2 of the voltage regulator U1. The pin 3 of the voltage regulator U1 is connected to the negative electrode of the diode D4. The positive electrode of the diode D4 is connected to the live wire in series with the capacitor C1 and the thermistor RT1. The capacitor C1 is connected in parallel with a resistor bank composed of the resistor R3 and the resistor R4 connected in series. The positive electrode of the diode D4 is also connected to the negative electrode of the diode D3. The positive electrode of the diode D3 is connected to the neutral line. The pin 3 of the voltage regulator U1 is also connected to the negative electrode of the zener diode D5. The positive electrode of the zener diode D5 is grounded. The pin 3 of the voltage regulator U1 is also connected to the ground in series with the capacitor C2. The pin 3 of the voltage regulator U1 is also connected to the positive electrode of the electrolytic capacitor C3. The negative electrode of the electrolytic capacitor C3 is grounded.

[0016] Preferably, the above control module is provided with a single-chip microcomputer U2, a capacitor C11, and a capacitor C12. The pin 1 of the single-chip microcomputer U2 is connected to the pin 14 in series with the capacitor C11. The pin 1 of the single-chip microcomputer U2 is connected to the pin 14 in series with the capacitor C12. The pin 1 of the single-chip microcomputer U2 is grounded. The pin 14 of the single-chip microcomputer U2 is connected to the VCC5V power supply. The pins 2, 3, 4, 7, 12, and 13 of the single-chip microcomputer U2 are connected to the setting and indicating module. The pin 5 of the single-chip microcomputer U2 is connected to the other end of the resistor R9. The pin 6 of the single-chip microcomputer U2 is connected to the resistor R7. The pin 8 of the single-chip microcomputer U2 is connected to the pin 3 of the triode Q5. The pin 9 of the single-chip microcomputer U2 is connected to the pin 1 of the dual operational amplifier U3.

[0017] Preferably, the above-mentioned setting indication module is provided with a setting switch unit, a time indicator unit, and a gear indicator unit. The setting switch unit is connected to pins 2 and 7 of the single-chip microcomputer U2. The time indicator unit is connected to pins 3 and 4 of the single-chip microcomputer U2. The gear indicator unit is connected to pins 12 and 13 of the single-chip microcomputer U2.

[0018] Preferably, the above-mentioned setting switch unit is provided with a key switch S1 and a key switch S2. Pin 2 of the single-chip microcomputer U2 is connected to the ground in series with the key switch S2. Pin 7 of the single-chip microcomputer U2 is connected to the ground in series with the key switch S1.

[0019] Preferably, the above-mentioned time indicator unit is provided with a light-emitting diode D8, a light-emitting diode D9, a resistor R25, and a resistor R26. Pin 13 of the single-chip microcomputer U2 is connected to the negative electrode of the light-emitting diode D8 in series with the resistor R25. The positive electrode of the light-emitting diode D8 is grounded. Pin 12 of the single-chip microcomputer U2 is connected to the negative electrode of the light-emitting diode D9 in series with the resistor R26. The positive electrode of the light-emitting diode D9 is grounded.

[0020] Preferably, the above-mentioned gear indicator unit is provided with a light-emitting diode D10, a light-emitting diode D11, a resistor R27, and a resistor R28. Pin 13 of the single-chip microcomputer U2 is connected to the negative electrode of the light-emitting diode D10 in series with the resistor R27. The positive electrode of the light-emitting diode D10 is grounded. Pin 12 of the single-chip microcomputer U2 is connected to the negative electrode of the light-emitting diode D11 in series with the resistor R28. The positive electrode of the light-emitting diode D11 is grounded.

[0021] Preferably, the chip model of the above-mentioned single-chip microcomputer U2 is the MC32P7030-14P chip. The models of the thyristor chips Q1 and Q2 are MAC98A8. The model of the triode Q3 is MMBTA94. The models of the triodes Q4 and Q5 are MMBTA44. The models of the diodes D3 and D4 are 1N4007. The model of the voltage regulator U1 is 78L05 or 7550. The model of the dual operational amplifier U3 is LM358.

[0022] Preferably, the winding turn number range of the above-mentioned zero-sequence current transformer is from 1 turn to 10 turns.

[0023] The electronic switch box with leakage protection function of the present invention is provided with a first thyristor switch connected to the live wire and a second thyristor switch connected to the neutral wire. The first thyristor switch and the second thyristor switch are connected to a zero-sequence current transformer for controlling the current of an external load. A zero-potential detection module for detecting potential signals is arranged on the live wire. The zero-potential detection module feeds back the detected signal to a control module. The power supply terminal of the control module is conducted with the output terminal of a voltage conversion unit arranged on the live wire. The zero-sequence current transformer amplifies the signal through a signal amplification module, and the amplified signal is fed back into the control module. The control module displays set parameters through a connected setting and indicating module. The present invention can make the first thyristor switch and the second thyristor switch execute synchronously through the control module. Therefore, when there is a leakage sign in the overall circuit, the protection function can be instantly activated, the power supply can be cut off, and the leakage protection mode can be entered, thus having the advantages of rapid startup and response, accurate execution, and sensitive detection of leakage signs. The number of turns of the zero-sequence current transformer of the present invention can be adjusted according to the amplification multiple of the signal amplification module. For dedicated electrical appliances, the number of turns can be reduced to achieve a small volume. The thyristor switch of the present invention can effectively avoid generating harmonics, effectively avoid electromagnetic mutual interference in the electrical environment, and the on-off mode of the thyristor switch makes the leakage protection function product smaller, longer-lived, and lower-noise. The present invention uses a pure electronic circuit operation for leakage protection, breaking away from the operations of traditional electromagnetic tripping, magnetic locking switches, and electric contact manual reset buttons, and is more convenient and reliable to use. After the electronic switch box of the present invention operates, it needs to be manually plugged and unplugged to cut off and then power on its internal circuit to restore normal output, thus avoiding the danger of reset power supply and keeping the overall circuit in a continuous startup state. Description of the Drawings

[0024] The present invention will be further described with reference to the accompanying drawings, but the content in the drawings does not constitute any limitation to the present invention.

[0025] Figure 1 It is a circuit diagram of the first thyristor switch, the second thyristor switch, the zero-sequence current transformer, the zero-potential detection module, and the voltage conversion unit.

[0026] Figure 2 It is a circuit diagram of the signal amplification module.

[0027] Figure 3 It is a circuit diagram of the control module.

[0028] Figure 4 It is a circuit diagram of the setting switch unit.

[0029] Figure 5 It is a circuit diagram of the time indicator unit.

[0030] Figure 6 It is a circuit diagram of the gear indicator unit.

[0031] Figures 1 to 6 In the figure, it includes:

[0032] The first thyristor switch 100, the second thyristor switch 200, the zero-sequence current transformer 300, the zero-potential detection module 400, the voltage conversion unit 500, the control module 600, the signal amplification module 700, the setting switch unit 800, the time indicator unit 900, and the gear indicator unit 1000. Detailed implementation mode

[0033] The present invention will be further described in conjunction with the following embodiments.

[0034] Embodiment 1.

[0035] An electronic switch box with a leakage protection function, such as Figures 1 to 6 , is provided with a first thyristor switch 100 connected to the live wire and a second thyristor switch 200 connected to the neutral wire. The first thyristor switch 100 and the second thyristor switch 200 are connected to a zero-sequence current transformer 300 for controlling the external load current. A zero-potential detection module 400 for detecting the potential signal is provided on the live wire, and the zero-potential detection module 400 feeds back the detected signal to the control module 600. The power supply terminal of the control module 600 is conducted with the output terminal of a voltage conversion unit 500 provided on the live wire. The zero-sequence current transformer 300 amplifies the signal through the signal amplification module 700, and the amplified signal is fed back into the control module 600. The control module 600 sets parameter display through the connected setting and indicating module.

[0036] The first thyristor switch 100 is provided with a thyristor chip Q1, a triode Q3, a triode Q4, a resistor R6, a resistor R7, a resistor R8, a resistor R11, a resistor R12, and a resistor R13. The pin 1 of the thyristor chip Q1 is connected to the live wire, the pin 2 of the thyristor chip Q1 is connected to the zero-sequence current transformer 300, the pin 3 of the thyristor chip Q1 is sequentially connected in series with the resistor R12 and the resistor R13 and then connected to the zero-sequence current transformer 300. The resistor R11 connected in series with the pin 3 of the thyristor chip Q1 is connected to the pin 3 of the triode Q3. The pin 2 of the triode Q3 is connected to the live wire, the pin 1 of the triode Q3 is connected in series with the resistor R8 and then connected to the pin 2 of the triode Q4. The pin 2 of the triode Q4 is connected in series with the resistor R6 and then connected to the live wire. The pin 3 of the triode Q4 is grounded, and the pin 1 of the triode Q4 is connected in series with the resistor R7 and then connected to the control module 600.

[0037] The second thyristor switch 200 is provided with a thyristor chip Q2, a resistor R9, and a resistor R10. The pin 1 of the thyristor chip Q2 is connected to the zero-sequence current transformer 300. The pin 2 of the thyristor chip Q2 is connected to one end of the resistor R9. The other end of the resistor R9 is connected to the control module 600, and the other end of the resistor R9 is also connected to the neutral line in series with the resistor R10. The pin 3 of the thyristor chip Q2 is connected to the neutral line.

[0038] The zero-potential detection module 400 is provided with a triode Q5, a zener diode D2, a resistor R2, a resistor R1, a resistor R5, and a resistor R15. The pin 2 of the triode Q5 is connected to the input end of the zener diode D2. The pin 1 of the triode Q5 is connected to the output end of the zener diode D2. The input end of the zener diode D2 is also connected to the output end in series with the resistor R5. The pin 2 of the triode Q5 is grounded. The pin 3 of the triode Q5 is connected to the control module 600, and the pin 3 of the triode Q5 is connected to the power supply VCC5V in series with the resistor R15. The pin 1 of the triode Q5 is connected to the live wire in series with the resistor R2 and the resistor R1 in sequence.

[0039] The pin 1 of the zero-sequence current transformer 300 is connected to the pin 2 of the thyristor chip Q1. The pin 2 of the zero-sequence current transformer 300 is connected to the pin 1 of the thyristor chip Q2. The pin 3 of the zero-sequence current transformer 300 is grounded. The pin 4 of the zero-sequence current transformer 300 is connected to the signal amplification module 700. The pins 5 and 6 of the zero-sequence current transformer 300 are respectively connected to an external load.

[0040] The signal amplification module is provided with a dual operational amplifier U3, a capacitor C8, a capacitor C9, a capacitor C10, a resistor R17, a resistor R18, a resistor R19, a resistor R20, a resistor R21, a resistor R22, and a resistor R23. The pin 1 of the dual operational amplifier U3 is connected to the control module 600. The pin 1 of the dual operational amplifier U3 is connected to the ground in series with the capacitor C8. The pin 1 of the dual operational amplifier U3 is connected to the pin 2 in series with the resistor R17. The pin 2 of the dual operational amplifier U3 is connected to the pin 4 of the zero-sequence current transformer 300 in series with the resistor R22. The pin 3 of the dual operational amplifier U3 is connected to the VCC5V power supply in series with the resistor R19 and the resistor R23 in sequence. The pin 4 of the dual operational amplifier U3 is connected to the pin 3 in series with the resistor R18. The pin 2 of the dual operational amplifier U3 is connected to the ground in series with the resistor R20 and the resistor R21 in sequence. The capacitor C10 is connected in parallel with the resistor R21. The pin 4 of the dual operational amplifier U3 is grounded. The pin 8 of the dual operational amplifier U3 is connected to the ground in series with the capacitor C9. The pin 8 of the dual operational amplifier U3 is also connected to the VCC5V power supply. The pins 5, 6, and 7 of the dual operational amplifier U3 are left floating.

[0041] The voltage conversion unit 500 is provided with a voltage regulator U1, a capacitor C1, a capacitor C2, an electrolytic capacitor C3, an electrolytic capacitor C4, a capacitor C5, a diode D3, a diode D4, a zener diode D5, a thermistor RT1, a resistor R3 and a resistor R4. The pin 2 of the voltage regulator U1 is connected to the neutral line, the pin 1 of the voltage regulator U1 is connected to the VCC 5V power supply, and the electrolytic capacitor C4 and the capacitor C5 are connected in parallel between the pin 1 and the pin 2 of the voltage regulator U1. The pin 3 of the voltage regulator U1 is connected to the negative electrode of the diode D4. The positive electrode of the diode D4 is sequentially connected in series with the capacitor C1 and the thermistor RT1 and then connected to the live wire. The resistor bank composed of the resistor R3 and the resistor R4 in series is connected in parallel with the capacitor C1. The positive electrode of the diode D4 is also connected to the negative electrode of the diode D3, and the positive electrode of the diode D3 is connected to the neutral line. The pin 3 of the voltage regulator U1 is also connected to the negative electrode of the zener diode D5, the positive electrode of the zener diode D5 is grounded, the pin 3 of the voltage regulator U1 is also connected to the capacitor C2 and then grounded, the pin 3 of the voltage regulator U1 is also connected to the positive electrode of the electrolytic capacitor C3, and the negative electrode of the electrolytic capacitor C3 is grounded.

[0042] The number of turns of the winding of the zero-sequence current transformer ranges from 1 turn to 10 turns. It should be noted that the number of turns of the zero-sequence current transformer of the present invention can be coordinated with the circuit design. By increasing the amplification factor of the signal amplification module 700 (which can be achieved by adjusting the external resistance value of the dual operational amplifier U3) or increasing the output bridging resistance of the zero-sequence current transformer 300, the number of turns of the zero-sequence current transformer 300 can be reduced. Under the premise of the same amplification factor, the number of turns of the zero-sequence current transformer 300 can also be reduced in the case of a large leakage current operation.

[0043] The function of the zero-potential detection module 400 of the present invention is to detect the state of the AC voltage at the 0 potential. If the first thyristor and the second thyristor are turned on only when in the 0 potential state, the instantaneous conduction current of the thyristor, the impact on the powered equipment and the interference to other electrical equipment can be reduced. For example, when the input alternating current is in the zero-potential state, the voltage of the pin 3 of the triode Q5 of the zero-potential detection module 400 of the present invention will change from a low level to a high level (also called a rising edge) or from a high level to a low level (also called a falling edge). These two state changes are caused by the characteristics of the alternating current. The pin 3 of the triode Q5 is connected to the pin 8 of the single-chip microcomputer, and the single-chip microcomputer will detect the level change state of this pin to determine whether it is in the zero-potential state.

[0044] The functions of the first thyristor switch 100 and the second thyristor switch 200 are to cut off the current of the neutral line and the live wire. In the present invention, the first thyristor switch 100 and the second thyristor switch 200 are respectively arranged corresponding to the neutral line and the live wire, so any leakage in either line can be cut off in time. In actual sockets, the neutral line and the live wire may not be connected according to the standard. Only when both lines can be cut off can the power supply be truly cut off in case of leakage.

[0045] The function of the zero-sequence current transformer 300 is to detect the residual current. As long as the magnitudes of the currents flowing through the neutral wire and the live wire are different, the zero-sequence current transformer 300 will output a voltage to the signal amplification module 700.

[0046] The function of the signal amplification module 700 is that since the voltage output by the zero-sequence current transformer 300 is weak and the control module 600 cannot directly process it, the voltage is amplified by the signal amplification module 700. The weak signal output by the zero-sequence current transformer 300 will be amplified to a signal that is easy for the control module 600 to process, which also improves the accuracy and timeliness of protection.

[0047] The function of the voltage conversion unit 500 is to supply power to the control module 600 and drive the thyristor to conduct.

[0048] The function of the setting switch unit 800 is to set the leakage current threshold for action and the corresponding time, which can be applied to occasions with different requirements to achieve precise actions.

[0049] The function of the time indicator unit 900 is to indicate the action time, such as 5ms, 10ms, 20ms, etc. When the detected leakage current is greater than the threshold time, the output is immediately turned off, corresponding to occasions where the output needs to be delayed to turn off.

[0050] The function of the gear indicator unit 1000 is to indicate the leakage current for action, such as 3mA, 8mA, 10mA, etc. When the detected leakage current is higher than this threshold, the output is immediately turned off, corresponding to occasions with different requirements for the magnitude of the leakage current. For example, the leakage current of high-power electrical appliances will be larger, and a higher gear of leakage current needs to be set. The electric water heater requires a lower leakage current to protect personal safety.

[0051] After multiple experimental verifications, the electronic switch box with the leakage protection function of the present invention can cut off the power supply within 30ms when the zero-sequence current appears at 10mA, enter the leakage protection mode, start more quickly, execute more accurately, and detect leakage signs more sensitively.

[0052] The electronic switch box with a leakage protection function can make the first thyristor switch 100 and the second thyristor switch 200 execute synchronously through the control module 600. Therefore, when there is a leakage sign in the overall circuit, it can instantly activate the protection function, cut off the power supply, and enter the leakage protection mode, thus having the advantages of rapid startup and response, accurate execution, and sensitive detection of leakage signs. The number of turns of the zero-sequence current transformer 300 of the present invention can be adjusted according to the amplification factor of the signal amplification module 700, and the number of turns can be reduced for dedicated electrical appliances to achieve a small volume. The thyristor switch of the present invention can effectively avoid generating harmonics, effectively avoiding electromagnetic mutual interference in the electrical environment, and the on-off mode of using the thyristor switch makes the leakage protection function product smaller, longer-lived, and lower in noise. The present invention uses a pure electronic circuit operation for leakage protection, breaking away from the traditional electromagnetic tripping, magnetic locking switch, and electrical contact manual reset button operations, making it more convenient and reliable to use. After the electronic switch box of the present invention operates, it needs to be manually plugged and unplugged to cut off and then power on the internal circuit to restore normal output, thus avoiding the danger of reset power supply and keeping the overall circuit in a continuous startup state.

[0053] Embodiment 2.

[0054] An electronic switch box with a leakage protection function, having the same other features as in Embodiment 1, except that: the chip model of the single-chip microcomputer U2 is the MC32P7030-14P chip, the models of the thyristor chips Q1 and Q2 are MAC98A8, the model of the triode Q3 is MMBTA94, the models of the triodes Q4 and Q5 are MMBTA44, the models of the diodes D3 and D4 are 1N4007, the model of the voltage regulator U1 is 78L05 or 7550, and the model of the dual operational amplifier U3 is LM358.

[0055] It should be noted that the voltage regulator U1 of the present invention can also be replaced by a three-terminal voltage stabilization circuit made of triodes. U1 assumes the responsibility of secondary voltage stabilization. Since the voltage at the positive pole of the C3 capacitor may not be stable enough, U1 is used for secondary voltage stabilization, and the voltage supplied to the control module 600 will be more stable. If the capacity of C1 is increased, the U1 part can also be cancelled. This part of the voltage conversion unit 500 is a capacitor buck method, and it can also be replaced by an AC-DC circuit for voltage conversion. A circuit that can convert 120VAC or 220VAC into 5VDC can be used.

[0056] Compared with Embodiment 1, in this embodiment, electrical components such as the single-chip microcomputer U2, the thyristor chips Q1 and Q2, the voltage regulator U1, and the dual operational amplifier U3 are all common models. Therefore, the electronic switch box with a leakage protection function in this embodiment has the advantage of low production cost.

[0057] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit the protection scope of the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention can be modified or equivalently replaced without departing from the essence and scope of the technical solutions of the present invention.

Claims

1. An electronic switch box with a leakage protection function, characterized in that: A first thyristor switch connected to the live wire and a second thyristor switch connected to the neutral wire are provided. The first thyristor switch and the second thyristor switch are connected to a zero-sequence current transformer for controlling the current of an external load. A zero-potential detection module for detecting a potential signal is provided on the live wire. The zero-potential detection module feeds back the detected signal to a control module. The power supply terminal of the control module is conducted with the output terminal of a voltage conversion unit provided on the live wire. The zero-sequence current transformer amplifies the signal through a signal amplification module, and the amplified signal is fed back to the control module. The control module displays set parameters through a connected setting indication module. The first thyristor switch is provided with a thyristor chip Q1, a triode Q3, a triode Q4, a resistor R6, a resistor R7, a resistor R8, a resistor R11, a resistor R12, and a resistor R13. The pin 1 of the thyristor chip Q1 is connected to the live wire. The pin 2 of the thyristor chip Q1 is connected to the zero-sequence current transformer. The pin 3 of the thyristor chip Q1 is sequentially connected in series with the resistor R12 and the resistor R13 and then connected to the zero-sequence current transformer. The resistor R11 connected in series with the pin 3 of the thyristor chip Q1 is connected to the pin 3 of the triode Q3. The pin 2 of the triode Q3 is connected to the live wire. The pin 1 of the triode Q3 is connected in series with the resistor R8 and then connected to the pin 2 of the triode Q4. The pin 2 of the triode Q4 is connected in series with the resistor R6 and then connected to the live wire. The pin 3 of the triode Q4 is grounded. The pin 1 of the triode Q4 is connected in series with the resistor R7 and then connected to the control module.

2. The electronic switch box with a leakage protection function according to claim 1, characterized in that: The second thyristor switch is provided with a thyristor chip Q2, a resistor R9, and a resistor R10. The pin 1 of the thyristor chip Q2 is connected to the zero-sequence current transformer. The pin 2 of the thyristor chip Q2 is connected to one end of the resistor R9. The other end of the resistor R9 is connected to the control module and is also connected in series with the resistor R10 and then connected to the neutral wire. The pin 3 of the thyristor chip Q2 is connected to the neutral wire.

3. The electronic switch box with a leakage protection function according to claim 2, characterized in that: The zero-potential detection module is provided with a triode Q5, a zener diode D2, a resistor R2, a resistor R1, a resistor R5, and a resistor R15. The pin 2 of the triode Q5 is connected to the input terminal of the zener diode D2. The pin 1 of the triode Q5 is connected to the output terminal of the zener diode D2. The input terminal of the zener diode D2 is also connected in series with the resistor R5 and then connected to the output terminal. The pin 2 of the triode Q5 is grounded. The pin 3 of the triode Q5 is connected to the control module, and the pin 3 of the triode Q5 is connected in series with the resistor R15 and then connected to the power supply VCC5V. The pin 1 of the triode Q5 is sequentially connected in series with the resistor R2 and the resistor R1 and then connected to the live wire.

4. The electronic switch box with a leakage protection function according to claim 3, characterized in that: The pin 1 of the zero-sequence current transformer is connected to the pin 2 of the thyristor chip Q1. The pin 2 of the zero-sequence current transformer is connected to the pin 1 of the thyristor chip Q2. The pin 3 of the zero-sequence current transformer is grounded. The pin 4 of the zero-sequence current transformer is connected to the signal amplification module. The pins 5 and 6 of the zero-sequence current transformer are respectively connected to an external load.

5. The electronic switch box with a leakage protection function according to claim 4, characterized in that: The signal amplification module is provided with a dual operational amplifier U3, a capacitor C8, a capacitor C9, a capacitor C10, a resistor R17, a resistor R18, a resistor R19, a resistor R20, a resistor R21, a resistor R22, and a resistor R23. The pin 1 of the dual operational amplifier U3 is connected to the control module. The pin 1 of the dual operational amplifier U3 is connected to the ground in series with the capacitor C8. The pin 1 of the dual operational amplifier U3 is connected to the pin 2 in series with the resistor R17. The pin 2 of the dual operational amplifier U3 is connected to the pin 4 of the zero-sequence current transformer in series with the resistor R22. The pin 3 of the dual operational amplifier U3 is connected to the VCC5V power supply in series with the resistor R19 and the resistor R23 in sequence. The pin 4 of the dual operational amplifier U3 is connected to the pin 3 in series with the resistor R18. The pin 2 of the dual operational amplifier U3 is connected to the ground in series with the resistor R20 and the resistor R21 in sequence. The capacitor C10 is connected in parallel with the resistor R21. The pin 4 of the dual operational amplifier U3 is grounded. The pin 8 of the dual operational amplifier U3 is connected to the ground in series with the capacitor C9. The pin 8 of the dual operational amplifier U3 is also connected to the VCC5V power supply. The pins 5, 6, and 7 of the dual operational amplifier U3 are left floating.

6. The electronic switch box with a leakage protection function according to claim 5, characterized in that: The voltage conversion unit is provided with a voltage regulator U1, a capacitor C1, a capacitor C2, an electrolytic capacitor C3, an electrolytic capacitor C4, a capacitor C5, a diode D3, a diode D4, a zener diode D5, a thermistor RT1, a resistor R3, and a resistor R4. The pin 2 of the voltage regulator U1 is connected to the neutral line. The pin 1 of the voltage regulator U1 is connected to the VCC5V power supply, and the electrolytic capacitor C4 and the capacitor C5 are connected in parallel between the pin 1 and the pin 2 of the voltage regulator U1. The pin 3 of the voltage regulator U1 is connected to the cathode of the diode D4. The anode of the diode D4 is connected to the live wire in series with the capacitor C1 and the thermistor RT1. The capacitor C1 is connected in parallel with a resistor bank composed of the resistor R3 and the resistor R4 connected in series. The anode of the diode D4 is also connected to the cathode of the diode D3. The anode of the diode D3 is connected to the neutral line. The pin 3 of the voltage regulator U1 is also connected to the cathode of the zener diode D5. The anode of the zener diode D5 is grounded. The pin 3 of the voltage regulator U1 is also connected to the ground in series with the capacitor C2. The pin 3 of the voltage regulator U1 is also connected to the anode of the electrolytic capacitor C3. The cathode of the electrolytic capacitor C3 is grounded.

7. The electronic switch box with a leakage protection function according to claim 6, characterized in that: The control module is provided with a single-chip microcomputer U2, a capacitor C11, and a capacitor C12. The pin 1 of the single-chip microcomputer U2 is connected to the pin 14 in series with the capacitor C11. The pin 1 of the single-chip microcomputer U2 is connected to the pin 14 in series with the capacitor C12. The pin 1 of the single-chip microcomputer U2 is grounded. The pin 14 of the single-chip microcomputer U2 is connected to the VCC5V power supply. The pins 2, 3, 4, 7, 12, and 13 of the single-chip microcomputer U2 are connected to the setting and indicating module. The pin 5 of the single-chip microcomputer U2 is connected to the other end of the resistor R9. The pin 6 of the single-chip microcomputer U2 is connected to the resistor R7. The pin 8 of the single-chip microcomputer U2 is connected to the pin 3 of the triode Q5. The pin 9 of the single-chip microcomputer U2 is connected to the pin 1 of the dual operational amplifier U3.

8. The electronic switch box with a leakage protection function according to claim 7, characterized in that: The setting indication module is provided with a setting switch unit, a time indicator light unit and a gear indicator light unit. The setting switch unit is connected to pins 2 and 7 of the single-chip microcomputer U2. The time indicator light unit is connected to pins 3 and 4 of the single-chip microcomputer U2. The gear indicator light unit is connected to pins 12 and 13 of the single-chip microcomputer U2. The setting switch unit is provided with a key switch S1 and a key switch S2. Pin 2 of the single-chip microcomputer U2 is connected to the ground in series with the key switch S2. Pin 7 of the single-chip microcomputer U2 is connected to the ground in series with the key switch S1. The time indicator light unit is provided with a light-emitting diode D8, a light-emitting diode D9, a resistor R25 and a resistor R26. Pin 13 of the single-chip microcomputer U2 is connected to the negative electrode of the light-emitting diode D8 in series with the resistor R25. The positive electrode of the light-emitting diode D8 is grounded. Pin 12 of the single-chip microcomputer U2 is connected to the negative electrode of the light-emitting diode D9 in series with the resistor R26. The positive electrode of the light-emitting diode D9 is grounded. The gear indicator light unit is provided with a light-emitting diode D10, a light-emitting diode D11, a resistor R27 and a resistor R28. Pin 13 of the single-chip microcomputer U2 is connected to the negative electrode of the light-emitting diode D10 in series with the resistor R27. The positive electrode of the light-emitting diode D10 is grounded. Pin 12 of the single-chip microcomputer U2 is connected to the negative electrode of the light-emitting diode D11 in series with the resistor R28. The positive electrode of the light-emitting diode D11 is grounded.

9. The electronic switch box with a leakage protection function according to claim 8, characterized in that: The chip model of the single-chip microcomputer U2 is the MC32P7030-14P chip. The models of the thyristor chips Q1 and Q2 are MAC98A8. The model of the triode Q3 is MMBTA94. The models of the triodes Q4 and Q5 are MMBTA44. The models of the diodes D3 and D4 are 1N4007. The model of the voltage regulator U1 is 78L05 or 7550. The model of the dual operational amplifier U3 is LM358. The winding turn number range of the zero-sequence current transformer is from 1 turn to 10 turns.

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