A bidirectional switch circuit and a bidirectional electronic switch

Abstract

The present application provides a bidirectional switch circuit and a bidirectional electronic switch. The bidirectional switch circuit includes a first switch transistor, a second switch transistor, a first resistor, a second resistor, a first unidirectional semiconductor, a second unidirectional semiconductor, and a first capacitor, which form a full-wave rectifier circuit. When the alternating current passing through the bidirectional switch circuit passes through zero and the first switch transistor and the second switch transistor are in the cut-off state, the alternating current passes through the chip diode of the first switch transistor, the first unidirectional semiconductor, the chip diode of the second switch transistor, and the second unidirectional semiconductor, and supplies power to the switch buck unit through the constant current power supply terminal. Through the two relatively arranged switch transistors, the switching control and current detection of the positive and negative half-cycle alternating current are realized, which helps to prevent the problem of partial direct current in the circuit, indirectly improves the safety and protection performance of power consumption and the service life of the product.

Description

Technical Field

[0001] The present application relates to the technical field of electronic switches, and in particular to a bidirectional switch circuit and a bidirectional electronic switch. Background Art

[0002] Home intelligentization is an important and indispensable part of modern intelligent life, and intelligent electrical switches are a category of smart home products. Any electronic product requires power supply to maintain its normal operation. As one of the electronic products, intelligent electrical switches are naturally no exception. The intelligent electrical switches that need to access the alternating current (AC) neutral wire and live wire to obtain power are called "zero-fire version intelligent switches" in the industry. The intelligent electrical switches that do not need to access the AC neutral wire to obtain power are called "single-fire version intelligent switches" in the industry.

[0003] Currently, single-fire version intelligent electrical switches generally use a single low-voltage withstand single-tube unidirectional power supply taking method in the powered-on state. Its power supply taking method is equivalent to half-wave rectification. Only half of the AC cycle is throttled, and the other half is equivalent to direct connection, resulting in an obvious DC component in the current flowing through the intelligent electrical switch in the on state. The problem of DC bias in AC will endanger the normal operation of electrical appliances, power transmission systems, and power grids. The safety problem of DC bias caused by DC bias in AC cannot be ignored. Summary of the Invention

[0004] In view of this, the purpose of the present application is to provide a bidirectional switch circuit and a bidirectional electronic switch. By two relatively arranged switching tubes, the on-off control and current detection of positive and negative half-cycle alternating current are realized, which helps to prevent the problem of DC bias in the circuit, indirectly improves the safety and protection performance of electricity use, and the service life of the product.

[0005] The embodiment of the present application provides a bidirectional switch circuit, and the bidirectional switch circuit includes: a first switching tube, a second switching tube, a first resistor, a second resistor, a first unidirectional semiconductor, a second unidirectional semiconductor, and a first capacitor;

[0006] The drain of the first switching tube is connected to the positive electrode of the first unidirectional semiconductor, the source of the first switching tube is connected to the first end of the first resistor, and the gate of the first switching tube is connected to the gate of the second switching tube; the source of the second switching tube is connected to the first end of the second resistor, and the drain of the second switching tube is connected to the positive electrode of the second unidirectional semiconductor; the second end of the first resistor and the second end of the second resistor are connected to the ground terminal;

[0007] The negative electrode of the first unidirectional semiconductor and the negative electrode of the second unidirectional semiconductor are connected to the first end of the first capacitor as the constant current power supply terminal of the bidirectional switch circuit, and the second end of the first capacitor is connected to the ground terminal;

[0008] When the alternating current passing through the bidirectional switch circuit passes through zero and the first switch transistor and the second switch transistor are cut off, the alternating current passes through the chip diode of the first switch transistor, the first unidirectional semiconductor, the chip diode of the second switch transistor, and the second unidirectional semiconductor, and supplies power to the switching buck unit through the constant current power supply terminal.

[0009] Further, the bidirectional switch circuit further includes a switch drive circuit;

[0010] The first end of the switch drive circuit serves as the low-voltage power supply terminal of the bidirectional switch circuit, the second end of the switch drive circuit serves as the logic control interface of the bidirectional switch circuit and is connected to the logic control unit, the third end of the switch drive circuit is connected to the ground terminal, and the fourth end of the switch drive circuit is connected to the gate of the first switch transistor and the gate of the second switch transistor;

[0011] The switch drive circuit is used to control the conduction or cut-off of the first switch transistor and the second switch transistor.

[0012] Further, the switch drive circuit includes a third switch transistor, a third resistor, a fourth resistor, a fifth resistor, and a second capacitor;

[0013] The collector of the third switch transistor is connected to the first end of the third resistor, the base of the third switch transistor is connected to the first end of the fifth resistor, and the emitter of the third switch transistor serves as the third end of the switch drive circuit;

[0014] The second end of the third resistor is connected to the first end of the fourth resistor and serves as the first end of the switch drive circuit; the second end of the fourth resistor is connected to the second end of the fifth resistor, and the second end of the switch drive circuit is led out between the second end of the fourth resistor and the second end of the fifth resistor;

[0015] The first end of the second capacitor is connected between the first end of the third resistor and the collector of the third switch transistor and serves as the fourth end of the switch drive circuit; the fifth end of the switch drive circuit is led out between the collector of the third switch transistor and the first end of the third resistor; the second end of the second capacitor is connected to the emitter of the third switch transistor;

[0016] When the logic control unit inputs a high level to the bidirectional switch circuit through the logic control interface, the third switch transistor conducts, the voltages of the gates of the first switch transistor and the second switch transistor are zero, and the first switch transistor and the second switch transistor are cut off;

[0017] When the logic control unit inputs a low level to the bidirectional switch circuit through the logic control interface, the third switching tube is turned off, and the voltages of the gates of the first switching tube and the second switching tube charge the second capacitor through the third resistor via the low-voltage power supply terminal. As the voltages of the gates of the first switching tube and the second switching tube increase, the first switching tube and the second switching tube are turned on.

[0018] Further, the bidirectional switch circuit further includes a constant current circuit;

[0019] The first constant current pin of the constant current circuit is connected to the negative electrodes of the first unidirectional semiconductor and the second unidirectional semiconductor. The second constant current pin of the constant current circuit is connected to the first end of the first capacitor. The third constant current pin of the constant current circuit is connected to the second constant current pin;

[0020] When the first switching tube and the second switching tube are turned off, the current in the bidirectional switch circuit is controlled within a preset range through the constant current circuit.

[0021] Further, the constant current circuit includes a constant current integrated block and a sixth resistor;

[0022] The first pin of the constant current integrated block serves as the first constant current pin of the constant current circuit. The second pin of the constant current integrated block serves as the second constant current pin of the constant current circuit. The third pin of the constant current integrated block is connected to the first end of the sixth resistor. The second end of the sixth resistor serves as the third constant current pin of the constant current circuit.

[0023] Further, the bidirectional switch circuit further includes a temperature-sensitive resistor;

[0024] The first end of the temperature-sensitive resistor is connected to the second end of the second resistor. The second end of the temperature-sensitive resistor serves as the temperature sampling terminal of the bidirectional switch circuit and is connected to the logic control unit;

[0025] The logic control unit converts the voltage value of the temperature-sensitive resistor collected through the temperature sampling terminal into a temperature value. When the temperature value is greater than a preset temperature threshold, the logic control unit outputs a high level to the logic control interface.

[0026] Further, a first current sampling terminal is led out between the source of the first switching tube and the first end of the first resistor; a second current sampling terminal is led out between the source of the second switching tube and the first end of the second resistor;

[0027] The logic control unit collects the first current load value of the positive half cycle of the alternating current in the bidirectional switch circuit through the first current sampling terminal. When the first current load value is greater than a preset current threshold, the logic control unit outputs a high level to the logic control interface;

[0028] The logic control unit collects the second current load value of the negative half cycle of the alternating current in the bidirectional switch circuit through the second current sampling terminal. When the second current load value is greater than a preset current threshold, the logic control unit outputs a high level to the logic control interface.

[0029] Further, a live wire input terminal is led out between the drain of the first switching tube and the positive electrode of the first unidirectional semiconductor; a live wire output terminal is led out between the drain of the second switching tube and the positive electrode of the second unidirectional semiconductor;

[0030] When the alternating current in the bidirectional switch circuit passes through zero, the logic control unit outputs a high level to the logic control interface.

[0031] The embodiment of the present application further provides a bidirectional electronic switch, which includes the above-mentioned bidirectional switch circuit, and further includes a logic control unit, a switching buck unit, and a communication unit;

[0032] The high voltage in the bidirectional switch circuit is converted into a low voltage through the switching buck unit and used as the working voltage of the logic control unit, the bidirectional switch circuit, and the communication unit;

[0033] The logic control unit outputs a level signal to the bidirectional switch circuit;

[0034] The communication unit sends the received control instruction to the logic control unit.

[0035] Further, the bidirectional electronic switch further includes a branch power supply circuit;

[0036] The first power supply terminal of the branch power supply circuit is connected to the positive electrode of the first capacitor in the bidirectional switch circuit; the second power supply terminal of the branch power supply circuit is connected to the negative electrode of the second unidirectional semiconductor in the bidirectional switch circuit; the branch power supply circuit includes a plurality of branch output terminals.

[0037] Further, the branch power supply circuit includes a plurality of branch power supply sub-circuits; each branch power supply sub-circuit includes a branch power supply unidirectional semiconductor and a branch power supply switch;

[0038] For the multiple branch power-taking electronic circuits, the negative electrode of the branch power-taking unidirectional semiconductor in the first branch power-taking electronic circuit is used as the first power-taking end of the branch power-taking circuit; the first contact of the branch power-taking switch in the second branch power-taking electronic circuit among the multiple branch power-taking electronic circuits is used as the second power-taking end of the branch power-taking circuit; the first contacts of the branch power-taking switches in the other branch power-taking electronic circuits except the branch power-taking switch in the second branch power-taking electronic circuit among the multiple branch power-taking electronic circuits are connected to the first contact of the branch power-taking switch in the second branch power-taking electronic circuit; the second contacts of the branch power-taking switches in each branch power-taking electronic circuit are used as the branch output ends of the branch power-taking circuit.

[0039] For each branch power-taking electronic circuit, the positive electrode of the branch power-taking unidirectional semiconductor in the branch power-taking electronic circuit is connected to the second contact of the branch power-taking switch in the branch power-taking electronic circuit.

[0040] The negative electrodes of the branch power-taking unidirectional semiconductors in the other branch power-taking electronic circuits except the negative electrode of the branch power-taking unidirectional semiconductor in the first branch power-taking electronic circuit among the multiple branch power-taking electronic circuits are connected to the negative electrode of the branch power-taking unidirectional semiconductor in the first branch power-taking electronic circuit.

[0041] When the bidirectional switch circuit is closed, the branch power-taking switches in the branch power-taking circuit are all closed.

[0042] The bidirectional switch circuit and the bidirectional electronic switch provided by the embodiments of the present application include a first switch tube, a second switch tube, a first resistor, a second resistor, a first unidirectional semiconductor, a second unidirectional semiconductor, and a first capacitor, which constitute a full-wave rectification circuit. When the alternating current passing through the bidirectional switch circuit passes through zero and the first switch tube and the second switch tube are in the cut-off state, the alternating current passes through the chip diode of the first switch tube, the first unidirectional semiconductor, the chip diode of the second switch tube, and the second unidirectional semiconductor, and supplies power to the switch buck unit through the constant current power supply terminal. Through the two relatively arranged switch tubes, the on-off control and current detection of the positive and negative half-cycle alternating currents are realized, which helps to prevent the problem of partial direct current in the circuit, and indirectly improves the safety and protection performance of power consumption and the service life of the product.

[0043] To make the above objects, features, and advantages of the present application more obvious and understandable, the following specifically gives preferred embodiments and, in conjunction with the accompanying drawings, makes a detailed description as follows. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] To more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings required in the embodiments. It should be understood that the following drawings only show some embodiments of the present application and should not be regarded as limiting the scope. For those of ordinary skill in the art, without creative efforts, other relevant drawings can also be obtained based on these drawings.

[0045] Figure 1 One of the schematic structural diagrams of a bidirectional electronic switch provided by an embodiment of the present application;

[0046] Figure 2 Another schematic structural diagram of a bidirectional electronic switch provided by an embodiment of the present application;

[0047] Figure 3 For Figure 1 One of the schematic circuit diagrams of the bidirectional switch circuit shown;

[0048] Figure 4 For Figure 1 Another schematic circuit diagram of the bidirectional switch circuit shown;

[0049] Figure 5 For Figure 4 The schematic circuit diagram of the switch drive circuit shown;

[0050] Figure 6 For Figure 1 Another schematic circuit diagram of the bidirectional switch circuit shown;

[0051] Figure 7 For Figure 6 The schematic circuit diagram of the constant current circuit shown;

[0052] Figure 8 For Figure 1 Another schematic circuit diagram of the bidirectional switch circuit shown;

[0053] Figure 9 For Figure 1 Another schematic circuit diagram of the bidirectional switch circuit shown;

[0054] Figure 10 For Figure 2 The schematic circuit diagram of the branch power supply circuit shown. Detailed implementation manners

[0055] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of this application. Obviously, the described embodiments are only some, but not all, of the embodiments of this application. Components of the embodiments of this application usually described and illustrated in the accompanying drawings here can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely represents selected embodiments of this application. Based on the embodiments of this application, every other embodiment obtained by those skilled in the art without creative efforts falls within the scope of protection of this application.

[0056] Through research, it has been found that currently, in the powered-on state, a single-fire version intelligent electrical switch generally uses a single-tube unidirectional power extraction with low withstand voltage. Its power extraction method is equivalent to half-wave rectification, where only half a cycle of the alternating current is throttled, and the other half cycle is equivalent to a direct pass, resulting in an obvious DC component in the current flowing through the intelligent electrical switch in the on state. The problem of DC bias in the alternating current will endanger the normal operation of electrical appliances, power transmission systems, and power grids. The safety problem of DC bias caused by DC bias in the alternating current cannot be ignored.

[0057] Based on this, the embodiments of this application provide a bidirectional switch circuit, which fully realizes the switch control and current detection of positive and negative half-cycle alternating currents, thereby helping to prevent the problem of DC bias in the circuit and indirectly improving the safety and protection performance of power consumption and the service life of the product.

[0058] Please refer to Figure 1 , Figure 1 which is one of the schematic structural diagrams of a bidirectional electronic switch provided by the embodiments of this application. As shown in Figure 1 , the bidirectional electronic switch 100 provided by the embodiments of this application includes: a bidirectional switch circuit 110, a logic control unit 120, a switching step-down unit 130, and a communication unit 140.

[0059] Among them, the high voltage flowing through the bidirectional switch circuit 110 is stepped down by the switching step-down unit 130 and converted into a low voltage to serve as the working voltage of the logic control unit 120, the bidirectional switch circuit 110, and the communication unit 140.

[0060] The logic control unit 120 can determine the level signal output to the bidirectional switch circuit 110 based on the current signal output from the synchronous signal sampling terminal of the bidirectional switch circuit 110, the first current load value output from the first current sampling terminal, and the second current load value output from the second current sampling terminal.

[0061] The logic control unit 120 can also determine the level signal output to the bidirectional switch circuit 110 according to the control instruction sent by the communication unit 140.

[0062] Specifically, when the current signal collected by the logic control unit 120 indicates that the alternating current in the bidirectional switch circuit 110 passes through zero, the logic control unit 120 outputs a high level to the bidirectional switch circuit 110 to turn off the bidirectional switch circuit 110 and establish the working condition for the first capacitor to charge.

[0063] When the current signal indicates that the alternating current in the bidirectional switch circuit 110 passes through zero and the logic control unit 120 receives an on instruction, the logic control unit 120 outputs a low level to the bidirectional switch circuit 110 after a delay when the alternating current passes through zero to turn on the bidirectional switch circuit 110.

[0064] When the current signal indicates that the alternating current in the bidirectional switch circuit 110 passes through zero and the logic control unit 120 receives an off instruction, after the alternating current passes through zero, the logic control unit 120 outputs a high level to the bidirectional switch circuit 110 for a long time, so that the bidirectional switch circuit 110 is turned off for a long time.

[0065] Further, as Figure 2 shown, Figure 2 FIG. 2 is a second structural schematic diagram of a bidirectional electronic switch provided by an embodiment of the present application. The bidirectional electronic switch 100 further includes a branch power supply circuit 150. In this way, the bidirectional electronic switch provided by the embodiment of the present application can detect and judge the current state in the electronic switch circuit at the microsecond level, and realize the control of the on and off of the first switch tube and the second switch tube in the bidirectional switch circuit through the logic control unit. Furthermore, it ensures rapid power-off, avoids the fuse from burning out, and can be manually restarted after troubleshooting, greatly extending the service life of the product and reducing the maintenance cost of users.

[0066] Further, as Figure 3 shown, Figure 3 FIG. 3 Figure 1 is a first circuit schematic diagram of the bidirectional switch circuit shown. The bidirectional switch circuit 110 includes a first switch tube 1101, a second switch tube 1102, a first resistor 1103, a second resistor 1104, a first unidirectional semiconductor 1105, a second unidirectional semiconductor 1106, and a first capacitor 1107.

[0067] Among them, the drain of the first switching transistor 1101 is connected to the positive electrode of the first unidirectional semiconductor 1105, the source of the first switching transistor 1101 is connected to the first end of the first resistor 1103, and the gate of the first switching transistor 1101 is connected to the gate of the second switching transistor 1102; the source of the second switching transistor 1102 is connected to the first end of the second resistor 1104, and the drain of the second switching transistor 1102 is connected to the positive electrode of the second unidirectional semiconductor 1106; the second end of the first resistor 1103 and the second end of the second resistor 1104 are connected to the ground terminal.

[0068] The negative electrode of the first unidirectional semiconductor 1105 and the negative electrode of the second unidirectional semiconductor 1106 are connected to the first end of the first capacitor 1107 as the constant current power supply terminal of the bidirectional switching circuit 110, and the second end of the first capacitor 1107 is connected to the ground terminal.

[0069] When the alternating current passing through the bidirectional switching circuit 110 passes through zero, and the first switching transistor 1101 and the second switching transistor 1102 are in the cut-off state, the chip diode in the first switching transistor 1101, the chip diode in the second switching transistor 1102, the first unidirectional semiconductor 1105 and the second unidirectional semiconductor 1106 form a bridge full-wave rectifier circuit. At this time, the alternating current passes through the chip diode in the first switching transistor 1101, the chip diode in the second switching transistor 1102, the first unidirectional semiconductor 1105 and the second unidirectional semiconductor 1106, and supplies power to the switching buck unit 130 through the constant current power supply terminal of the bidirectional switching circuit 110.

[0070] Here, the current input to the bidirectional switching circuit 110 is alternating current, which is divided into a positive half-cycle and a negative half-cycle. When the alternating current is in the positive half-cycle, the current flows in through the live wire input terminal of the bidirectional switching circuit 110. Since the first switching transistor 1101 is cut off, the current passes through the first unidirectional semiconductor 1105, then through the first capacitor 1107, the second resistor 1104 and the second switching transistor 1102 to the live wire output terminal of the bidirectional switching circuit 110, and then flows from the live wire output terminal to the load, through the load to the neutral line, forming a positive half-cycle current loop.

[0071] When the alternating current is in the negative half-cycle, the current flows into the load through the neutral line, and into the second unidirectional semiconductor 1106 and the second switching transistor 1102 through the live wire output terminal. Since the second switching transistor 1102 is cut off, the current passes through the second unidirectional semiconductor 1106, then through the first capacitor 1107, the first resistor 1103 and the first switching transistor 1101 to the live wire input terminal, forming a negative half-cycle current loop.

[0072] At this time, the current passing through the bidirectional switching circuit 110 charges the first capacitor 1107.

[0073] Further, as Figure 4 shown, Figure 4As Figure 1 Figure 2 of the circuit schematic diagram of the bidirectional switch circuit shown. The bidirectional switch circuit 110 further includes a switch driving circuit 1108.

[0074] Among them, the first end of the switch driving circuit 1108 serves as the low-voltage power supply end of the bidirectional switch circuit 110, the second end of the switch driving circuit 1108 serves as the logic control interface of the bidirectional switch circuit 110 and is connected to the logic control unit 120, the third end of the switch driving circuit 1108 is connected to the ground end, the fourth end of the switch driving circuit 1108 is connected to the gate of the first switching transistor 1101, the fifth end of the switch driving circuit 1108 is connected to the gate of the second switching transistor 1102, and the switch driving circuit is used to control the conduction or cut-off of the first switching transistor 1101 and the second switching transistor 1102 according to the input signal of the logic control unit 120.

[0075] Here, the first switching transistor 1101 and the second switching transistor 1102 can be MOSFETs, or can be switching triodes such as IGBTs. When using switching triodes without the parasitic diode of the chip body, a diode or a unidirectional TVS can be connected in parallel between the collector and the emitter to replace the parasitic diode of the chip body.

[0076] The first resistor 1103 and the second resistor 1104 can be current sampling resistors, or can also be current sensors for realizing AC current sampling.

[0077] The first unidirectional semiconductor 1105 and the second unidirectional semiconductor 1106 are rectifier diodes, or can also be semiconductors with unidirectional conductivity.

[0078] Further, as Figure 5 shown, Figure 5 As Figure 4 Figure of the circuit schematic diagram of the switch driving circuit shown. The switch driving circuit 1108 includes a third switching transistor 1108a, a third resistor 1108b, a fourth resistor 1108c, a fifth resistor 1108d, and a second capacitor 1108e.

[0079] Among them, the collector of the third switching transistor 1108a is connected to the first end of the third resistor 1108b, the base of the third switching transistor 1108a is connected to the first end of the fifth resistor 1108d, and the emitter of the third switching transistor 1108a serves as the third end of the switch driving circuit 1108.

[0080] The second end of the third resistor 1108b is connected to the first end of the fourth resistor 1108c, serving as the first end of the switch driving circuit 1108.

[0081] The second terminal of the fourth resistor 1108c is connected to the second terminal of the fifth resistor 1108d, and the second terminal of the switch driving circuit 1108 is led out between the second terminals of the fourth resistor 1108c and the fifth resistor 1108d.

[0082] The first terminal of the second capacitor 1108e is connected between the first terminal of the third resistor 1108b and the collector of the third switching transistor 1108a, serving as the fourth terminal of the switch driving circuit 1108, and the second terminal of the second capacitor 1108e is connected to the emitter of the third switching transistor 1108a.

[0083] The fifth terminal of the switch driving circuit 1108 is led out between the collector of the third switching transistor 1108a and the first terminal of the third resistor 1108b.

[0084] When the logic control unit 120 inputs a high level to the bidirectional switch circuit 110 through the logic control interface, the third switching transistor 1108a is turned on, and the voltages of the gates of the first switching transistor 1101 and the second switching transistor 1102 are zero, and the first switching transistor 1101 and the second switching transistor 1102 are turned off.

[0085] When the logic control unit 120 inputs a low level to the bidirectional switch circuit 110 through the logic control interface, the third switching transistor 1108a is turned off, and the voltages of the gates of the first switching transistor 1101 and the second switching transistor 1102 are charged to the second capacitor 1108e through the third resistor 1108b by the low-voltage power supply terminal. And as the voltages of the gates of the first switching transistor 1101 and the second switching transistor 1102 increase, the first switching transistor 1101 and the second switching transistor 1102 are gradually turned on.

[0086] Here, the third switching transistor 1108a can be an NPN triode or other types of logic control devices.

[0087] Therefore, the switch driving circuit 1108 provided in the present application can control the conduction speed of the first switch tube 1101 and the second switch tube 1102. When the logic control unit 120 inputs a low level to the bidirectional switch circuit 110 through the logic control interface, the first switch tube 1101 and the second switch tube 1102 are gradually turned on. The alternating current is input to the bidirectional switch circuit 110 through the live wire input terminal, and flows to the live wire output terminal through the first switch tube 1101, the first resistor 1103, the second resistor 1104, and the second switch tube 1102, and then flows to the load through the live wire output terminal and returns to the zero line through the load, forming a current loop for the alternating current to turn on. Here, since the on-resistances of the first switch tube 1101 and the second switch tube 1102 are in the milliohm level, the magnitude of the current in the turn-on loop depends on the internal resistance of the load; at the same time, since the first switch tube 1101 and the second switch tube 1102 form a bidirectional structure, their conduction characteristics remain the same when the current direction changes. In this state, the voltage between the live wire input terminal and the live wire output terminal is close to 0, the first unidirectional semiconductor 1105 and the second unidirectional semiconductor 1106 are turned off, the constant current circuit stops charging the first capacitor 1107, and the working electrical energy of the switching buck unit 130 is maintained by the discharge of the first capacitor 1107.

[0088] When the bidirectional electronic switch 100 is powered on, the logic control unit 120 and the communication unit 140 are not yet working. The switch driving circuit 1108, the third switch tube 1108a, the fourth resistor 1108c, the fifth resistor 1108d, and the second capacitor 1108e in the bidirectional switch circuit 110 pull down the gate voltages of the first switch tube 1101 and the second switch tube 1102 to make the bidirectional electronic switch 100 work in the off state, ensuring safety during power-on.

[0089] Further, as Figure 6 shown, Figure 6 is Figure 1 the schematic diagram of the circuit of the bidirectional switch circuit shown in FIG. The bidirectional switch circuit 110 further includes a constant current circuit 1109.

[0090] The first constant current pin of the constant current circuit 1109 is connected to the negative electrodes of the first unidirectional semiconductor 1105 and the second unidirectional semiconductor 1106, the second constant current pin of the constant current circuit 1109 is connected to the first end of the first capacitor 1107, and the third constant current pin of the constant current circuit 1109 is connected to the second constant current pin of the constant current circuit 1109.

[0091] When the bidirectional switch circuit 110 includes the constant current circuit 1109, it works in cooperation with the branch power-taking circuit 151 in the branch power-taking circuit 150. The working principle of the full-wave rectifier circuit is as follows:

[0092] When the bidirectional switch circuit 110 is disconnected and any one of the branch power-taking circuits 151 in the branch power-taking circuit 150 is connected, when the alternating current is in the positive half-cycle, the current flows in through the live wire input terminal of the bidirectional switch circuit 110. Since the first switching tube 1101 is cut off, the current passes through the first unidirectional semiconductor 1105 and the constant current circuit 1109, then through the first capacitor 1107, the second resistor 1104 and the second switching tube 1102 to the live wire output terminal of the bidirectional switch circuit 110, and then from the live wire output terminal through the branch power-taking circuit 150 to the load, through the load to the neutral wire, forming a positive half-cycle current loop.

[0093] When the alternating current is in the negative half-cycle, the current flows in through the neutral wire to the load, through the branch power-taking circuit 150 into the second unidirectional semiconductor 1106 and the second switching tube 1102. Since the second switching tube 1102 is cut off, the current passes through the second unidirectional semiconductor 1106 and the constant current circuit 1109, then through the first capacitor 1107, the first resistor 1103 and the first switching tube 1101 to the live wire input terminal, forming a negative half-cycle current loop.

[0094] When the bidirectional switch circuit 110 is disconnected and all the branch power-taking circuits 151 are disconnected, when the alternating current is in the positive half-cycle, since all the branch power-taking circuits 151 are disconnected, there is no current loop in the bidirectional switch circuit 110.

[0095] When the alternating current is in the negative half-cycle, the current flows in through the neutral wire to the load, through the branch power-taking unidirectional semiconductor 1511 in any one of the branch power-taking circuits 151 to the first constant current pin of the constant current circuit 1109, and then through the constant current circuit 1109 to the live wire input terminal, forming a negative half-cycle current loop.

[0096] At this time, when the first switching tube 1101 and the second switching tube 1102 are cut off, the current in the bidirectional switch circuit 110 is controlled within a preset range by the constant current circuit 1109, thus avoiding the phenomenon that a working voltage is instantaneously generated at both ends of the load. When the load is an LED lamp, the instantaneously generated working voltage will cause the LED lamp to light up instantaneously and then go out as the charging current decreases.

[0097] When constant current power supply is not required in the bidirectional switch circuit 110, the constant current circuit 1109 can be replaced with a unidirectional semiconductor.

[0098] Further, as Figure 7 shown, Figure 7 is Figure 6 the circuit schematic diagram of the constant current circuit shown. The constant current circuit 1109 includes a constant current integrated block 1109a and a sixth resistor 1109b.

[0099] Among them, the first pin of the constant current integrated circuit 1109a serves as the first constant current pin of the constant current circuit 1109, the second pin of the constant current integrated circuit 1109a serves as the second constant current pin of the constant current circuit 1109, the third pin of the constant current integrated circuit 1109a is connected to the first end of the sixth resistor 1109b, and the second end of the sixth resistor 1109b serves as the third constant current pin of the constant current circuit 1109.

[0100] Further, as Figure 8 shown, Figure 8 is Figure 1 the fourth circuit schematic diagram of the bidirectional switch circuit shown. The bidirectional switch circuit 110 further includes a temperature sensing resistor 1110.

[0101] The first end of the temperature sensing resistor 1110 is connected to the second end of the second resistor 1104, and the second end of the temperature sensing resistor 1110 serves as the temperature sampling end of the bidirectional switch circuit 110 and is connected to the logic control unit 120.

[0102] The logic control unit 120 converts the voltage value of the temperature sensing resistor 1110 collected through the temperature sampling end into a temperature value. When the temperature value is greater than the preset temperature threshold, the logic control unit 120 outputs a high level to the logic control interface.

[0103] For the processing of over-temperature protection by the logic control unit 120, the ADC module is used to convert the voltage of the temperature sensing resistor 1110 into a temperature value digital signal.

[0104] Further, as Figure 9 shown, Figure 9 is Figure 1 the fifth circuit schematic diagram of the bidirectional switch circuit shown. A first current sampling end is led out between the source electrode of the first switch tube 1101 and the first end of the first resistor 1103; a second current sampling end is led out between the source electrode of the second switch tube 1102 and the first end of the second resistor 1104.

[0105] The logic control unit 120 collects the first current load value in the positive half cycle of the alternating current in the bidirectional switch circuit 110 through the first current sampling end. When the first current load value is greater than the preset current threshold, at this time, if the first current load value is greater than the preset current threshold of the load, it indicates that the power supply circuit is in an overloaded state. The logic control unit 120 outputs a high level to the logic control interface to turn off the bidirectional electronic switch.

[0106] The logic control unit 120 collects the second current load value in the negative half cycle of the alternating current in the bidirectional switch circuit 110 through the second current sampling end. When the second current load value is greater than the preset current threshold, it also indicates that the power supply circuit is in an overloaded state. The logic control unit 120 outputs a high level to the logic control interface.

[0107] Specifically, the logic control unit 120 uses an ADC module to convert the voltage value collected through the first current sampling terminal / the second current sampling terminal into a digital signal of the load current. After the logic control unit 120 compares the positive and negative half-cycle load currents, when an overload state occurs, the logic control unit 120 outputs a high level to the bidirectional switch circuit through the logic control interface to turn off the bidirectional electronic switch.

[0108] Further, as Figure 9 shown, a live wire input terminal is led out between the drain of the first switching transistor 1101 and the positive pole of the first unidirectional semiconductor 1105; a live wire output terminal is led out between the drain of the second switching transistor 1102 and the positive pole of the second unidirectional semiconductor 1106; a synchronization signal sampling terminal is led out between the first power-taking terminal of the branch power-taking circuit 150 and the first constant-current pin of the constant-current circuit 1109.

[0109] When the current signal output by the synchronization signal sampling terminal indicates that the alternating current in the bidirectional switch circuit 110 passes through zero, the logic control unit 120 outputs a high level to the logic control interface.

[0110] The bidirectional switch circuit provided by the embodiment of the present application includes a first switching transistor, a second switching transistor, a first resistor, a second resistor, a first unidirectional semiconductor, a second unidirectional semiconductor, and a first capacitor, which constitute a full-wave rectifier circuit. When the alternating current passing through the bidirectional switch circuit passes through zero and the first switching transistor and the second switching transistor are in the cut-off state, the alternating current passes through the chip diode of the first switching transistor, the first unidirectional semiconductor, the chip diode of the second switching transistor, and the second unidirectional semiconductor, and supplies power to the switching buck unit through the constant-current power supply terminal. Through the two relatively arranged switching transistors, the switching control and current detection of the positive and negative half-cycle alternating current are realized, which helps to prevent the problem of partial direct current in the circuit, and indirectly improves the safety and protection performance of power consumption and the service life of the product.

[0111] Further, the first power-taking terminal of the branch power-taking circuit 150 is connected to the positive pole of the first capacitor 1107 in the bidirectional switch circuit 110; the second power-taking terminal of the branch power-taking circuit 150 is connected to the drain of the second unidirectional semiconductor 1106 in the bidirectional switch circuit 110; the branch power-taking circuit 150 includes a plurality of branch output terminals; a synchronization signal sampling terminal is led out between the first power-taking terminal of the branch power-taking circuit 150 and the first constant-current pin of the constant-current circuit 1109 in the bidirectional switch circuit 110.

[0112] Further, as Figure 10 shown, Figure 10 For Figure 2Schematic diagram of the branch power extraction circuit shown. The branch power extraction circuit 150 includes a plurality of branch power extraction subcircuits 151; each branch power extraction subcircuit 151 includes a branch power extraction unidirectional semiconductor 1511 and a branch power extraction switch 1512.

[0113] The negative pole of the branch power extraction unidirectional semiconductor 1511 in the first branch power extraction subcircuit among the plurality of branch power extraction subcircuits 151 serves as the first power extraction end of the branch power extraction circuit 150; the first contact of the branch power extraction switch 1512 in the second branch power extraction subcircuit among the plurality of branch power extraction subcircuits 151 serves as the second power extraction end of the branch power extraction circuit 150; the first contacts of the branch power extraction switches 1512 in the other branch power extraction subcircuits among the plurality of branch power extraction subcircuits 151 except for the branch power extraction switch 1512 in the second branch power extraction subcircuit are connected to the first contact of the branch power extraction switch 1512 in the second branch power extraction subcircuit; the second contacts of the branch power extraction switches 1512 in each branch power extraction subcircuit 151 serve as the branch output end of the branch power extraction circuit 150;

[0114] For each branch power extraction subcircuit 151, the positive pole of the branch power extraction unidirectional semiconductor 1511 in the branch power extraction subcircuit 151 is connected to the second contact of the branch power extraction switch 1512 in the branch power extraction subcircuit 151;

[0115] The negative poles of the branch power extraction unidirectional semiconductors 1511 in the other branch power extraction subcircuits among the plurality of branch power extraction subcircuits 151 except for the negative pole of the branch power extraction unidirectional semiconductor 1511 in the first branch power extraction subcircuit 151 are connected to the negative pole of the branch power extraction unidirectional semiconductor 1511 in the first branch power extraction subcircuit 151. Among them, the branch power extraction switch 1512 can be a switch device such as a relay or a triac.

[0116] Those skilled in the art can clearly understand that for the convenience and simplicity of description, the specific working processes of the above-described systems, devices, and units can refer to the corresponding processes in the foregoing method embodiments, and will not be elaborated herein.

[0117] In several embodiments provided in the present application, it should be understood that the disclosed systems, devices, and methods can be implemented in other ways. The device embodiments described above are merely illustrative. For example, the division of the units is only a logical function division, and there can be other division methods in actual implementation. For another example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point, the displayed or discussed couplings or direct couplings or communication connections to each other can be through some communication interfaces. The indirect couplings or communication connections of the devices or units can be in electrical, mechanical, or other forms.

[0118] The unit described as a separation component may or may not be physically separated. The component shown as a unit may or may not be a physical unit, that is, it may be located in one place or distributed over multiple network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0119] In addition, each functional unit in various embodiments of the present application may be integrated into one processing unit, may exist separately as individual physical units, or two or more units may be integrated into one unit.

[0120] Finally, it should be noted that: the above-described embodiments are only specific implementation manners of the present application, used to illustrate the technical solutions of the present application, rather than limiting them. The protection scope of the present application is not limited thereto. Although the present application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: any person skilled in the art within the technical scope disclosed by the present application can still modify the technical solutions recorded in the foregoing embodiments or can easily think of changes, or perform equivalent replacements on some of the technical features; and these modifications, changes or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application, and should all be covered by the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A bidirectional switch circuit, characterized in that, The bidirectional switch circuit includes: a first switch transistor, a second switch transistor, a first resistor, a second resistor, a first unidirectional semiconductor, a second unidirectional semiconductor, and a first capacitor; the first resistor and the second resistor are current sampling resistors; The drain of the first switch transistor is connected to the positive electrode of the first unidirectional semiconductor, the source of the first switch transistor is connected to the first end of the first resistor, and the gate of the first switch transistor is connected to the gate of the second switch transistor; the source of the second switch transistor is connected to the first end of the second resistor, and the drain of the second switch transistor is connected to the positive electrode of the second unidirectional semiconductor; the second end of the first resistor and the second end of the second resistor are connected to the ground terminal; The negative electrode of the first unidirectional semiconductor and the negative electrode of the second unidirectional semiconductor are connected to the first end of the first capacitor as the constant current power supply terminal of the bidirectional switch circuit, and the second end of the first capacitor is connected to the ground terminal; When the alternating current passing through the bidirectional switch circuit passes through zero and the first switch transistor and the second switch transistor are cut off, the alternating current passes through the chip diode of the first switch transistor, the first unidirectional semiconductor, the chip diode of the second switch transistor, and the second unidirectional semiconductor, and supplies power to the switch buck unit through the constant current power supply terminal; The bidirectional switch circuit further includes a constant current circuit; The first constant current pin of the constant current circuit is connected to the negative electrode of the first unidirectional semiconductor and the negative electrode of the second unidirectional semiconductor, the second constant current pin of the constant current circuit is connected to the first end of the first capacitor, and the third constant current pin of the constant current circuit is connected to the second constant current pin; When the first switch transistor and the second switch transistor are cut off, the current in the bidirectional switch circuit passes through the constant current circuit to control the current value within a preset range; The constant current circuit includes a constant current integrated block and a sixth resistor; The first pin of the constant current integrated block serves as the first constant current pin of the constant current circuit, the second pin of the constant current integrated block serves as the second constant current pin of the constant current circuit, the third pin of the constant current integrated block is connected to the first end of the sixth resistor, and the second end of the sixth resistor serves as the third constant current pin of the constant current circuit.

2. The bidirectional switch circuit according to claim 1, wherein The bidirectional switch circuit further includes a switch drive circuit; The first end of the switch drive circuit serves as the low-voltage power supply terminal of the bidirectional switch circuit, the second end of the switch drive circuit serves as the logic control interface of the bidirectional switch circuit and is connected to the logic control unit, the third end of the switch drive circuit is connected to the ground terminal, and the fourth end of the switch drive circuit is connected to the gate of the first switch transistor and the gate of the second switch transistor; The switch drive circuit is used to control the conduction or cut-off of the first switch transistor and the second switch transistor.

3. The two-way switch circuit according to claim 2, wherein The switch drive circuit includes a third switch transistor, a third resistor, a fourth resistor, a fifth resistor, and a second capacitor; The collector of the third switch transistor is connected to the first end of the third resistor, the base of the third switch transistor is connected to the first end of the fifth resistor, and the emitter of the third switch transistor serves as the third end of the switch drive circuit; The second terminal of the third resistor is connected to the first terminal of the fourth resistor, serving as the first terminal of the switch driving circuit; the second terminal of the fourth resistor is connected to the second terminal of the fifth resistor, and the second terminal of the switch driving circuit is led out between the second terminal of the fourth resistor and the second terminal of the fifth resistor; The first terminal of the second capacitor is connected between the first terminal of the third resistor and the collector of the third switching transistor, serving as the fourth terminal of the switch driving circuit; the fifth terminal of the switch driving circuit is led out between the collector of the third switching transistor and the first terminal of the third resistor; the second terminal of the second capacitor is connected to the emitter of the third switching transistor; When the logic control unit inputs a high level to the bidirectional switch circuit through the logic control interface, the third switching transistor conducts, and the voltages of the gates of the first switching transistor and the second switching transistor are zero, and the first switching transistor and the second switching transistor are cut off; When the logic control unit inputs a low level to the bidirectional switch circuit through the logic control interface, the third switching transistor is cut off, and the voltages of the gates of the first switching transistor and the second switching transistor charge the second capacitor through the third resistor from the low-voltage power supply terminal, and as the voltages of the gates of the first switching transistor and the second switching transistor increase, the first switching transistor and the second switching transistor conduct.

4. The two-way switch circuit according to claim 2, characterized in that, The bidirectional switch circuit further includes a temperature-sensitive resistor; The first terminal of the temperature-sensitive resistor is connected to the second terminal of the second resistor, and the second terminal of the temperature-sensitive resistor serves as the temperature sampling terminal of the bidirectional switch circuit and is connected to the logic control unit; The logic control unit converts the voltage value of the temperature-sensitive resistor collected through the temperature sampling terminal into a temperature value. When the temperature value is greater than a preset temperature threshold, the logic control unit outputs a high level to the logic control interface.

5. The bidirectional switch circuit according to claim 2, characterized in that, A first current sampling terminal is led out between the source of the first switching transistor and the first terminal of the first resistor; a second current sampling terminal is led out between the source of the second switching transistor and the first terminal of the second resistor; The logic control unit collects the first current load value in the positive half-cycle of the alternating current in the bidirectional switch circuit through the first current sampling terminal. When the first current load value is greater than a preset current threshold, the logic control unit outputs a high level to the logic control interface; The logic control unit collects the second current load value in the negative half-cycle of the alternating current in the bidirectional switch circuit through the second current sampling terminal. When the second current load value is greater than a preset current threshold, the logic control unit outputs a high level to the logic control interface.

6. The two-way switch circuit according to claim 2, wherein A live wire input terminal is led out between the drain of the first switching transistor and the positive pole of the first unidirectional semiconductor; a live wire output terminal is led out between the drain of the second switching transistor and the positive pole of the second unidirectional semiconductor; When the alternating current in the bidirectional switch circuit passes through zero, the logic control unit outputs a high level to the logic control interface.

7. A bidirectional electronic switch, characterized in that, The bidirectional electronic switch includes the bidirectional switch circuit according to any one of claims 1-6, and further includes a logic control unit, a switching step-down unit, and a communication unit; The high voltage in the bidirectional switch circuit is converted into a low voltage through the switching step-down unit and used as the operating voltage of the logic control unit, the bidirectional switch circuit, and the communication unit; The logic control unit outputs a level signal to the bidirectional switch circuit; The communication unit sends the received control instruction to the logic control unit.

8. The bidirectional electronic switch according to claim 7, characterized in that The bidirectional electronic switch further includes a branch power-taking circuit; The first power-taking end of the branch power-taking circuit is connected to the positive electrode of the first capacitor in the bidirectional switch circuit; the second power-taking end of the branch power-taking circuit is connected to the negative electrode of the second unidirectional semiconductor in the bidirectional switch circuit; the branch power-taking circuit includes a plurality of branch output ends; a synchronization signal sampling end is led out between the first power-taking end of the branch power-taking circuit and the first constant current pin of the constant current circuit in the bidirectional switch circuit.

9. The bidirectional electronic switch according to claim 8, characterized in that, The branch power-taking circuit includes a plurality of branch power-taking sub-circuits; each branch power-taking sub-circuit includes a branch power-taking unidirectional semiconductor and a branch power-taking switch; The negative electrode of the branch power-taking unidirectional semiconductor in the first branch power-taking sub-circuit among the plurality of branch power-taking sub-circuits serves as the first power-taking end of the branch power-taking circuit; the first contact of the branch power-taking switch in the second branch power-taking sub-circuit among the plurality of branch power-taking sub-circuits serves as the second power-taking end of the branch power-taking circuit; the first contacts of the branch power-taking switches in the other branch power-taking sub-circuits except the branch power-taking switch in the second branch power-taking sub-circuit among the plurality of branch power-taking sub-circuits are connected to the first contact of the branch power-taking switch in the second branch power-taking sub-circuit; the second contacts of the branch power-taking switches in each branch power-taking sub-circuit serve as the branch output ends of the branch power-taking circuit; For each branch power-taking sub-circuit, the positive electrode of the branch power-taking unidirectional semiconductor in the branch power-taking sub-circuit is connected to the second contact of the branch power-taking switch in the branch power-taking sub-circuit; The negative electrodes of the branch power-taking unidirectional semiconductors in the other branch power-taking sub-circuits except the negative electrode of the branch power-taking unidirectional semiconductor in the first branch power-taking sub-circuit among the plurality of branch power-taking sub-circuits are connected to the negative electrode of the branch power-taking unidirectional semiconductor in the first branch power-taking sub-circuit; When the bidirectional switch circuit is turned off, the branch power-taking switches in the branch power-taking circuit are all turned off.

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