Silicon controlled rectifier drive circuit, electrical isolation circuit and electronic equipment

Abstract

The utility model relates to a silicon controlled rectifier drive circuit, an electrical isolation circuit and electronic equipment, silicon controlled rectifiers are connected in series in a direct current path, the drive circuit comprises a first switch tube, an isolator, a second switch tube and a third switch tube, and the first end of the first switch tube is connected with a first power supply; the control end is used for receiving a pulse trigger signal and is connected with the second end of the first switching tube, and the second end is grounded; the first end of the primary side of the isolator is connected with a first power supply, the second end of the primary side is connected with the first end of the first switching tube, and the first end of the secondary side is connected with a second power supply; the control end of the second switch tube is connected with the second end of the secondary side and is also connected with the second end of the second switch tube, and the second end is grounded; and the control end of the third switch tube is connected with the first end of the second switch tube, the first end is connected with the second power supply and the first end of the second switch tube, and the second end is connected with the control end of the silicon controlled rectifier, so that the circuit cost is reduced on the premise of satisfying electrical isolation.

Description

Technical Field

[0001] The present application relates to the technical field of drive circuits, and in particular to a thyristor drive circuit, an electrical isolation circuit and an electronic device. Background Art

[0002] Thyristor is an active switching element, which usually remains in a non-conducting state until it is triggered by a control signal, then the thyristor is turned on. Once the thyristor is triggered, it will remain in the conducting state even if the trigger signal is removed. To turn it off, a reverse voltage can be added between its anode and cathode or the current flowing through the thyristor diode can be reduced to below a certain value. Thyristors are widely used in automatic control, electromechanical fields, industrial electrical and household appliances.

[0003] Currently, thyristor drive circuits used in high-voltage circuits often use separate drive chips in conjunction with relays to control thyristors in order to achieve electrical isolation on circuit boards. The drive circuits are expensive and occupy a large area of ​​the circuit board, making circuit board design more difficult. Utility Model Content

[0004] Based on this, it is necessary to provide a thyristor drive circuit, an electrical isolation circuit and an electronic device to address the problems in the above-mentioned background technology. While meeting the electrical isolation requirements, the starting current required by the thyristor can be provided, while saving the use of relays, reducing the cost of the drive circuit, reducing the occupied area of ​​the circuit, and improving the driving efficiency of the drive circuit.

[0005] To achieve the above-mentioned purpose and other purposes, according to various embodiments of the present application, the first aspect of the present application provides a thyristor drive circuit, the thyristor is connected in series in a DC path, the drive circuit includes a first switch tube, an isolator, a second switch tube and a third switch tube, the first switch tube is configured as follows: the first end is connected to the first power supply via a first voltage-dividing resistor, the control end is used to receive a pulse trigger signal and is connected to the second end of the first switch tube via a first bias resistor, and the second end is grounded; the isolator is configured as follows: the first end of the primary side is connected to the first power supply via a second voltage-dividing resistor, the second end of the primary side is connected to the first end of the first switch tube, and the first end of the secondary side is connected to the second power supply; the second switch tube is configured as follows: the control end is connected to the second end of the secondary side via a first current-limiting resistor, the control end is also connected to the second end of the second switch tube via a second bias resistor, and the second end is grounded; the third switch tube is configured as follows: the control end is connected to the first end of the second switch tube via a second current-limiting resistor, the first end is connected to the second power supply and connected to the first end of the second switch tube via a third voltage-dividing resistor, and the second end is connected to the control end of the thyristor via the third current-limiting resistor.

[0006] The thyristor drive circuit in the above embodiment connects the thyristor in series in the DC path, and controls the thyristor to be turned on through a drive circuit including a first switch tube, a second switch tube of the isolator, and a third switch tube. The first end of the first switch tube is connected to the first power supply via a first voltage-dividing resistor, the control end receives a pulse trigger signal and is connected to the second end of the first switch tube via a first bias resistor, and the second end is grounded, so as to realize the first switch tube being turned on and the driving current is amplified for the first time; the first end of the primary side of the isolator is connected to the first power supply via a second voltage-dividing resistor, the second end of the primary side is connected to the first end of the first switch tube, and the first end of the secondary side is connected to the second power supply. The first power supply is connected to the second power supply source to realize electrical isolation in the driving circuit; the control end of the second switch tube is connected to the second end of the secondary side via the first current limiting resistor, and the control end is also connected to the second end of the second switch tube via the second bias resistor, and the second end is grounded to realize the conduction of the second switch tube, and the driving current is amplified again; the control end of the third switch tube is connected to the first end of the second switch tube via the second current limiting resistor, the first end is connected to the second power supply and connected to the first end of the second switch tube via the third voltage dividing resistor, and the second end is connected to the control end of the thyristor via the third current limiting resistor, and the driving current amplified multiple times flows into the thyristor to control the conduction of the thyristor. At present, in order to realize electrical isolation on the circuit board, the related thyristor driving circuit used in the strong power circuit usually uses a separate driving chip to increase the driving top current, and the driving chip cooperates with the relay to control the conduction of the thyristor, which increases the manufacturing cost of the driving circuit and increases the occupied area on the circuit board, thereby increasing the difficulty of circuit design, or using a single switch tube to drive the thyristor, which cannot meet the needs of strong and weak current isolation of the circuit. The thyristor drive circuit in the embodiment of the present application increases the drive current by arranging a first switch tube, a second switch tube and a third switch tube in the drive circuit to form a multi-stage amplifier circuit, and realizes electrical isolation between strong current and weak current in the circuit through an isolator, thereby avoiding adding relays, reducing the cost of the circuit, and reducing the occupied area. Under the premise of ensuring electrical isolation, the drive current is increased and the thyristor is controlled to be turned on.

[0007] In some embodiments, the above-mentioned thyristor driving circuit also includes a diode, which is configured as: the anode is connected to the second end of the third switch tube, and the cathode is connected to the first end of the third switch tube. By setting the diode, the control electrode voltage of the thyristor is prevented from being greater than the second power supply voltage, thereby preventing circuit failure.

[0008] In some embodiments, the thyristor driving circuit further includes a controller, which is connected to the control end of the first switch tube and is used to generate a pulse trigger signal.

[0009] In some embodiments, the thyristor driving circuit further includes a fourth current limiting resistor, and the controller is connected to the control end of the first switch tube via the fourth current limiting resistor.

[0010] In some embodiments, the first switching tube includes a first transistor, which is configured as follows: the first end is connected to the first power supply via a first voltage-dividing resistor, the control end is used to receive a pulse trigger signal and is connected to the second end of the first transistor via a first bias resistor, and the second end is grounded.

[0011] In some embodiments, the second switch tube includes a second transistor, which is configured as follows: the control end is connected to the second end of the secondary side via a first current limiting resistor, the control end is also connected to the second end of the second transistor via a second bias resistor, and the second end is grounded.

[0012] In some embodiments, the third switching tube includes a third transistor, and the third transistor is configured as follows: the control end is connected to the first end of the second transistor via a second current limiting resistor, the first end is connected to the second power supply and connected to the first end of the second transistor via a third voltage dividing resistor, and the second end is connected to the control end of the thyristor via the third current limiting resistor.

[0013] In some embodiments, the isolator includes an optocoupler isolator, which is configured as follows: the first end of the primary side is connected to the first power supply via a second voltage divider resistor, the second end of the primary side is connected to the first end of the first switch tube, and the first end of the secondary side is connected to the second power supply.

[0014] A second aspect of the present application provides an electrical isolation circuit, comprising a thyristor, the thyristor being connected in series in a DC path; and a thyristor drive circuit according to any one of the above embodiments, for driving the thyristor.

[0015] A third aspect of the present application provides an electronic device, comprising an electrical isolation circuit.

[0016] The electrical isolation circuit and the electronic device in the above-mentioned embodiment are configured such that the first end of the first triode is connected to the first power supply via the first voltage-dividing resistor, the control end receives the pulse trigger signal and is connected to the second end of the first switch tube via the first bias resistor, and the second end is grounded, so as to realize the conduction of the first triode and amplify the driving current for the first time; the first end of the primary side of the optocoupler isolator is connected to the first power supply via the second voltage-dividing resistor, the second end of the primary side is connected to the first end of the first switch tube, and the first end of the secondary side is connected to the second power supply, so as to realize the electrical isolation between the strong current and the weak current in the driving circuit; the control end of the second triode is connected to the second end of the secondary side via the first current-limiting resistor, and the control end is connected to the second end of the secondary side via the first current-limiting resistor. The first end is also connected to the second end of the second switch tube via the second bias resistor, and the second end is grounded to realize the conduction of the second triode and amplify the driving current again; by setting the control end of the third triode to be connected to the first end of the second triode via the second current limiting resistor, the first end is connected to the second power supply and connected to the first end of the second triode via the third voltage dividing resistor, and the second end is connected to the control end of the thyristor via the third current limiting resistor, the driving current amplified multiple times flows into the thyristor to control the conduction of the thyristor, and while meeting the electrical isolation requirements, the driving current is increased, the use of relays is saved, the cost of the driving circuit is reduced, the occupied area of ​​the circuit is reduced, and the driving efficiency of the driving circuit is improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the related technologies, the drawings required for use in the embodiments or the related technical descriptions are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0018] Figure 1 Schematic diagram of the circuit structure of a thyristor drive circuit provided in one embodiment of the present application.

[0019] Description of reference numerals:

[0020] 100, thyristor drive circuit; 110, first switch tube; 120, second switch tube; 130, third switch tube; 140, isolator; 150, controller; 20, thyristor; Q1, first transistor; Q2, second transistor; Q3, third transistor; U1, optocoupler isolator; D1, diode; R1, fourth current limiting resistor; R2, first bias resistor; R3, first voltage dividing resistor; R4, second voltage dividing resistor; R5, first current limiting resistor; R6, second bias resistor; R7, third voltage dividing resistor; R8, second current limiting resistor; R9, third current limiting resistor; VCC, first power supply; VDD, second power supply. DETAILED DESCRIPTION

[0021] In order to facilitate understanding of the present application, the present application will be described more fully below with reference to the relevant drawings. Embodiments of the present application are provided in the drawings. However, the present application can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the application content of the present application more thorough and comprehensive.

[0022] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application belongs. The terms used herein in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application.

[0023] It is understood that the terms "first", "second", etc. used in this application may be used herein to describe various elements, but these elements are not limited by these terms. These terms are only used to distinguish a first element from another element. For example, without departing from the scope of this application, a first resistor may be referred to as a second resistor, and similarly, a second resistor may be referred to as a first resistor. Both the first resistor and the second resistor are resistors, but they are not the same resistor.

[0024] In the case of using “including”, “having”, and “comprising” described herein, another component may be added unless a clear limiting term such as “only”, “consisting of”, etc. is used. Unless mentioned otherwise, a term in the singular form may include a plural form and should not be understood as being one in number.

[0025] It can be understood that the “connection” in the following embodiments should be understood as “electrical connection”, “communication connection”, etc. if the connected circuits, modules, units, etc. have electrical signals or data transmission between each other.

[0026] It can be understood that “at least one” means one or more, “plurality” means two or more, and “at least a portion of an element” means a part or all of an element.

[0027] When used herein, the singular forms "a", "an", and "said / the" may also include plural forms, unless the context clearly indicates otherwise. It should also be understood that the terms "include / comprise" or "have" and the like specify the presence of stated features, wholes, steps, operations, components, parts, or combinations thereof, but do not exclude the possibility of the presence or addition of one or more other features, wholes, steps, operations, components, parts, or combinations thereof. At the same time, the term "and / or" used in this specification includes any and all combinations of the relevant listed items.

[0028] Silicon Controlled Rectifier (SCR) is the abbreviation of silicon controlled rectifier, which is a high-power semiconductor device with a four-layer structure of three PN junctions, also known as thyristor. It has the characteristics of small size, relatively simple structure, and strong functions, and is one of the more commonly used semiconductor devices. This device is widely used in various electronic equipment and electronic products, mostly for controlled rectification, inversion, frequency conversion, voltage regulation, contactless switch, etc. Dimming lamps, speed-adjustable fans, air conditioners, televisions, refrigerators, washing machines, cameras, combination audio systems, sound and light circuits, timing controllers, toy devices, radio remote controls, cameras and industrial control in household appliances all use thyristor devices in large quantities.

[0029] In SCR triggering, various aspects are important, including gate drive requirements (using gate triggering), triggering time (the applied triggering excitation needs to be maintained for a certain time in order for the circuit to latch), etc. The importance of various parameters depends on the SCR triggering form used. At present, for SCR gate drive in high-voltage circuits, in order to achieve electrical isolation, the main method is to use a driver chip in conjunction with a relay to control the conduction of the SCR. The addition of a relay increases the circuit manufacturing cost, and the driver circuit is placed on the circuit board.

[0030] Based on this, please refer to Figure 1 The embodiment of the present application provides a thyristor drive circuit 100, wherein the thyristor 20 is connected in series in a DC path, and the drive circuit includes a first switch tube 110, an isolator 140, a second switch tube 120, and a third switch tube 130. The first switch tube 110 is configured as follows: a first end is connected to a first power supply VCC via a first voltage-dividing resistor R3, a control end is used to receive a pulse trigger signal and is connected to a second end of the first switch tube 110 via a first bias resistor R2, and a second end is grounded; the isolator 140 is configured as follows: a first end of the primary side is connected to the first power supply VCC via a second voltage-dividing resistor R4, and a second end of the primary side is connected to the first switch The first end of the secondary side of the switch tube 110 is connected, and the first end of the secondary side is connected to the second power supply VDD; the second switch tube 120 is configured as follows: the control end is connected to the second end of the secondary side via the first current limiting resistor R5, the control end is also connected to the second end of the second switch tube 120 via the second bias resistor R6, and the second end is grounded; the third switch tube 130 is configured as follows: the control end is connected to the first end of the second switch tube 120 via the second current limiting resistor R8, the first end is connected to the second power supply VDD and connected to the first end of the second switch tube 120 via the third voltage dividing resistor R7, and the second end is connected to the control end of the thyristor 20 via the third current limiting resistor R9.

[0031] As an example, please refer to Figure 1The thyristor drive circuit 100 connects the thyristor 20 in series in a DC path, and uses a drive circuit including a first switch tube 110, an isolator 140, a second switch tube 120, and a third switch tube 130 to control the thyristor 20 to turn on. The first end of the first switch tube 110 is connected to the first power supply VCC via a first voltage-dividing resistor R3, the control end receives a pulse trigger signal and is connected to the second end of the first switch tube 110 via a first bias resistor R2, and the second end is grounded, so that the first switch tube 110 is turned on and the drive current is amplified for the first time; the first end of the primary side of the isolator 140 is connected to the first power supply VCC via a second voltage-dividing resistor R4, the second end of the primary side is connected to the first end of the first switch tube 110, and the first end of the secondary side is connected to the second The power supply VDD is connected to realize electrical isolation in the driving circuit; the control end of the second switch tube 120 is connected to the second end of the secondary side via the first current limiting resistor R5, and the control end is also connected to the second end of the second switch tube 120 via the second bias resistor R6, and the second end is grounded, so as to realize the conduction of the second switch tube 120 and amplify the driving current again; the control end of the third switch tube 130 is connected to the first end of the second switch tube 120 via the second current limiting resistor R8, the first end is connected to the second power supply VDD and is connected to the first end of the second switch tube 120 via the third voltage dividing resistor R7, and the second end is connected to the control end of the thyristor 20 via the third current limiting resistor R9, so that the driving current amplified multiple times flows into the thyristor 20, and the thyristor 20 is controlled to be turned on. At present, in order to achieve electrical isolation on the circuit board, the related thyristor drive circuit used in the strong current circuit usually uses a separate drive chip to increase the drive top current, and the drive chip cooperates with the relay to control the thyristor conduction, which increases the manufacturing cost of the drive circuit and increases the occupied area on the circuit board, thereby increasing the difficulty of circuit design, or using a single switch tube to drive the thyristor, which cannot meet the needs of strong and weak current isolation of the circuit. The thyristor drive circuit 100 in the embodiment of the present application increases the drive current by setting the first switch tube 110, the second switch tube 120 and the third switch tube 130 in the drive circuit to form a multi-stage amplifier circuit, and realizes the electrical isolation between the strong current and the weak current in the circuit through the isolator 140, thereby avoiding the addition of relays, reducing the cost of the circuit, reducing the occupied area, and increasing the drive current to control the thyristor 20 to conduct while ensuring electrical isolation.

[0032] In some embodiments, please refer to Figure 1 The thyristor drive circuit 100 also includes a diode D1, which is configured as follows: an anode connected to the second end of the third switch tube 130, and a cathode connected to the first end of the third switch tube 130. By setting the diode D1, the control electrode voltage of the thyristor 20 is prevented from being greater than the second power supply VDD voltage, thereby preventing circuit failure.

[0033] In some embodiments, the voltage amplitude of the DC path is greater than the maximum voltage of the pulse trigger signal.

[0034] In some embodiments, please refer to Figure 1 The thyristor drive circuit 100 also includes a controller 150, which is connected to the control end of the first switch tube 110 and is used to generate a pulse trigger signal. After detecting that a strong current passes between the DC+ end and the DC- end of the thyristor 20, the controller 150 generates a pulse trigger signal, thereby generating a drive current to control the thyristor 20 to turn on.

[0035] It should be noted that when the strong current between the DC+ and DC- terminals of the thyristor decays to a certain extent, the thyristor is turned off. For example, when the forward voltage from the anode to the cathode of the thyristor decreases, making the anode current less than the minimum holding current of the thyristor, the thyristor is turned off. Even if the strong current between the DC+ and DC- terminals of the thyristor is restored to its original state, the thyristor will not turn on again, and the controller needs to give a pulse trigger signal again to control the thyristor to turn on.

[0036] In some embodiments, the controller includes at least one of a single chip microcomputer, an ARM, a DSP and an FPGA.

[0037] In some embodiments, please refer to Figure 1 The thyristor driving circuit 100 further includes a fourth current limiting resistor R1 , and the controller 150 is connected to the control end of the first switch tube 110 via the fourth current limiting resistor R1 .

[0038] In some embodiments, please refer to Figure 1 The first switch tube includes a first transistor Q1, and the first transistor Q1 is configured as follows: a first end is connected to a first power supply VCC via a first voltage-dividing resistor R3, a control end is used to receive a pulse trigger signal and is connected to a second end of the first transistor Q1 via a first bias resistor R2, and a second end is grounded.

[0039] In some embodiments, please refer to Figure 1 The second switch tube includes a second transistor Q2, and the second transistor Q2 is configured as follows: the control end is connected to the second end of the secondary side via the first current limiting resistor R5, the control end is also connected to the second end of the second transistor Q2 via the second bias resistor R6, and the second end is grounded.

[0040] In some embodiments, please refer to Figure 1 The third switch tube includes a third transistor Q3, and the third transistor Q3 is configured as follows: the control end is connected to the first end of the second transistor Q2 via the second current limiting resistor R8, the first end is connected to the second power supply VDD and connected to the first end of the second transistor Q2 via the third voltage dividing resistor R7, and the second end is connected to the control end of the thyristor 20 via the third current limiting resistor R9.

[0041] In some embodiments, please refer to Figure 1 The isolator includes an optocoupler isolator U1, which is configured as follows: the first end of the primary side is connected to the first power supply VCC via the second voltage-dividing resistor R4, the second end of the primary side is connected to the first end of the first switch tube, and the first end of the secondary side is connected to the second power supply VDD, so as to realize electrical isolation between strong and weak electricity in the driving circuit.

[0042] In some embodiments, an electrical isolation circuit is provided, comprising a thyristor, the thyristor being connected in series in a DC path; and the thyristor driving circuit of any one of the above embodiments, for driving the thyristor.

[0043] In some embodiments, an electronic device is provided that includes an electrical isolation circuit.

[0044] In some embodiments, the electrical isolation circuit and the electronic device are configured such that the first end of the first transistor is connected to the first power supply via a first voltage-dividing resistor, the control end receives a pulse trigger signal and is connected to the second end of the first switch tube via a first bias resistor, and the second end is grounded, so as to realize the conduction of the first transistor and amplify the driving current for the first time; the first end of the primary side of the optocoupler isolator is configured to be connected to the first power supply via a second voltage-dividing resistor, the second end of the primary side is connected to the first end of the first switch tube, and the first end of the secondary side is connected to the second power supply, so as to realize the electrical isolation between the strong current and the weak current in the driving circuit; the control end of the second transistor is configured to be connected to the second end of the secondary side via a first current-limiting resistor, and the control end is configured to be connected to the second end of the secondary side via a first current-limiting resistor, so as to realize the electrical isolation between the strong current and the weak current in the driving circuit. The first end is also connected to the second end of the second switch tube via the second bias resistor, and the second end is grounded to realize the conduction of the second triode and amplify the driving current again; by setting the control end of the third triode to be connected to the first end of the second triode via the second current limiting resistor, the first end is connected to the second power supply and connected to the first end of the second triode via the third voltage dividing resistor, and the second end is connected to the control end of the thyristor via the third current limiting resistor, the driving current amplified multiple times flows into the thyristor to control the conduction of the thyristor, and while meeting the electrical isolation requirements, the driving current is increased, the use of relays is saved, the cost of the driving circuit is reduced, the occupied area of ​​the circuit is reduced, and the driving efficiency of the driving circuit is improved.

[0045] In the description of this specification, the description with reference to the terms "some embodiments", "other embodiments", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic description of the above terms does not necessarily refer to the same embodiment or example.

[0046] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0047] The above-described embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the present application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the attached claims.

Claims

1. A thyristor drive circuit, characterized in that: The thyristor is connected in series in a DC path, and the driving circuit comprises: A first switch tube is configured as follows: a first end is connected to a first power supply via a first voltage-dividing resistor, a control end is used to receive a pulse trigger signal and is connected to a second end of the first switch tube via a first bias resistor, and the second end is grounded; The isolator is configured as follows: a first end of the primary side is connected to the first power supply via a second voltage-dividing resistor, a second end of the primary side is connected to the first end of the first switch tube, and a first end of the secondary side is connected to the second power supply; A second switch tube is configured as follows: a control end is connected to the second end of the secondary side via a first current limiting resistor, the control end is further connected to the second end of the second switch tube via a second bias resistor, and the second end is grounded; The third switch tube is configured as follows: the control end is connected to the first end of the second switch tube via the second current limiting resistor, the first end is connected to the second power supply and connected to the first end of the second switch tube via the third voltage dividing resistor, and the second end is connected to the control end of the thyristor via the third current limiting resistor.

2. The thyristor drive circuit according to claim 1, characterized in that: Also includes: The diode is configured as follows: an anode connected to the second end of the third switch tube, and a cathode connected to the first end of the third switch tube.

3. The thyristor drive circuit according to claim 1, characterized in that: Also includes: A controller is connected to the control end of the first switch tube and is used to generate the pulse trigger signal.

4. The thyristor drive circuit according to claim 3, characterized in that: Also includes: A fourth current limiting resistor, wherein the controller is connected to the control end of the first switch tube via the fourth current limiting resistor.

5. The thyristor drive circuit according to any one of claims 1 to 4, characterized in that: The first switch tube comprises: The first transistor is configured as follows: a first end is connected to a first power supply via a first voltage-dividing resistor, a control end is used to receive a pulse trigger signal and is connected to a second end of the first transistor via a first bias resistor, and the second end is grounded.

6. The thyristor drive circuit according to any one of claims 1 to 4, characterized in that: The second switch tube comprises: The second transistor is configured as follows: a control end is connected to the second end of the secondary side via a first current limiting resistor, the control end is also connected to the second end of the second transistor via a second bias resistor, and the second end is grounded.

7. The thyristor drive circuit according to claim 6, characterized in that: The third switch tube comprises: The third transistor is configured as follows: the control end is connected to the first end of the second transistor via the second current limiting resistor, the first end is connected to the second power supply and connected to the first end of the second transistor via the third voltage dividing resistor, and the second end is connected to the control end of the thyristor via the third current limiting resistor.

8. The thyristor drive circuit according to any one of claims 1 to 4, characterized in that: The isolator comprises: The optocoupler isolator is configured as follows: the first end of the primary side is connected to the first power supply via the second voltage-dividing resistor, the second end of the primary side is connected to the first end of the first switch tube, and the first end of the secondary side is connected to the second power supply.

9. An electrical isolation circuit, characterized in that: include: Thyristor, used to be connected in series in the DC path; as well as The thyristor driving circuit according to any one of claims 1 to 8 is used to drive the thyristor.

10. An electronic device, characterized in that: include: The electrical isolation circuit of claim 9.

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