A power surge protection circuit

Abstract

This application provides a power surge protection circuit. When a differential-mode surge occurs between the positive and negative input terminals of the power supply, a second surge protection module and a third surge protection module cooperate to discharge the differential-mode surge energy for differential-mode surge protection. When a common-mode surge occurs between the positive input terminal and the ground terminal, a first surge protection module and a second surge protection module cooperate to discharge the common-mode surge energy for common-mode surge protection. Similarly, when a common-mode surge occurs between the negative input terminal and the ground terminal, a first surge protection module and a third surge protection module cooperate to discharge the common-mode surge energy for common-mode surge protection. In other words, the power surge protection circuit provided in this application utilizes modules from the differential-mode surge protection circuit for common-mode surge protection, thereby saving on the number of components and PCB layout space required for common-mode surge protection, and resulting in a shorter discharge path for common-mode surge protection.

Description

Technical Field

[0001] This application relates to the field of power protection technology, and in particular to a power surge protection circuit. Background Technology

[0002] Some terminal devices used outdoors (such as monitoring equipment) may be subject to lightning surge hazards in thunderstorm weather. A surge refers to a signal that instantaneously exceeds the stable value. It is a spike pulse with a high rise rate and short duration. Therefore, it is necessary to protect against potential surges.

[0003] Current surge protection methods generally involve adding differential mode surge protection devices between the positive and negative power lines of the equipment to discharge differential mode surge energy. In addition, common mode surge protection devices need to be added between the power line and the grounding line to discharge common mode surge energy.

[0004] However, the above-mentioned surge protection methods require a large number of components to be placed on the printed circuit board (PCB), which occupies a large area and results in a small layout space. Summary of the Invention

[0005] This application provides a power surge protection circuit to save on the number of surge protection devices and PCB layout space.

[0006] In a first aspect, embodiments of this application provide a power surge protection circuit, including: a first surge protection module, a second surge protection module, a third surge protection module, a first filtering module, and a first residual voltage processing module;

[0007] The first terminal of the third surge protection module is connected to the positive input terminal of the power supply and the first terminal of the second surge protection module, the second terminal of the third surge protection module is connected to the negative input terminal of the power supply, the third terminal of the third surge protection module is connected to the second terminal of the second surge protection module and the first terminal of the first surge protection module, and the second terminal of the first surge protection module is connected to the ground terminal; the first terminal of the first filter module is connected to the positive input terminal of the power supply, the second terminal of the first filter module is connected to the negative input terminal of the power supply, the third terminal of the first filter module is connected to the first terminal of the first residual voltage processing module, and the fourth terminal of the first filter module is connected to the second terminal of the first residual voltage processing module.

[0008] The first surge protection module is used to cooperate with the second surge protection module to open the path between the first end of the second surge protection module and the second end of the first surge protection module when a common-mode surge is generated between the positive input terminal of the power supply and the ground terminal; and to cooperate with the third surge protection module to open the path between the second end of the third surge protection module and the second end of the first surge protection module when a common-mode surge is generated between the negative input terminal of the power supply and the ground terminal, thereby dissipating the common-mode surge energy.

[0009] The second surge protection module is used to cooperate with the third surge protection module to open the path between the first end of the second surge protection module and the second end of the third surge protection module when a differential mode surge is generated between the positive input terminal and the negative input terminal of the power supply, thereby dissipating the differential mode surge energy and generating residual voltage.

[0010] The first filtering module is used to filter out noise;

[0011] The first residual pressure processing module is used to reduce the residual pressure.

[0012] In some embodiments, the second surge protection module includes a gas discharge tube and a first capacitor connected in parallel, and the third surge protection module includes: M gas discharge tubes and (M-1) first capacitors;

[0013] The first end of the gas discharge tube and the first capacitor connected in parallel serves as the first end of the second surge protection module, and the second end of the gas discharge tube and the first capacitor connected in parallel serves as the second end of the second surge protection module.

[0014] The M gas discharge tubes are connected in series between the second end of the second surge protection module and the negative input terminal of the power supply. One end of the gas discharge tube connected to the second end of the second surge protection module serves as the third end of the third surge protection module, and one end of the gas discharge tube connected to the negative input terminal of the power supply serves as the second end of the third surge protection module. The first end of the (M-1) first capacitors serves as the first end of the third surge protection module, and the second end of the (M-1) first capacitors is connected to each node respectively. The nodes are the (M-1) midpoints of the M gas discharge tubes connected in series, where M is a positive integer greater than or equal to 2.

[0015] In some embodiments, the first surge protection module includes: a first varistor;

[0016] The first end of the first varistor serves as the first end of the first surge protection module, and the second end of the first varistor serves as the second end of the first surge protection module.

[0017] In some embodiments, it further includes: a second varistor;

[0018] The other end of the gas discharge tube connected to the negative input terminal of the power supply is connected to the first end of the second varistor, and the second end of the second varistor is connected to the ground terminal.

[0019] In some embodiments, the first filtering module includes: a second capacitor and a common-mode inductor;

[0020] The first end of the second capacitor serves as the first end of the first filter module and is connected to the first end of the common-mode inductor. The second end of the second capacitor serves as the second end of the first filter module and is connected to the second end of the common-mode inductor. The third end of the common-mode inductor serves as the third end of the first filter module, and the fourth end of the common-mode inductor serves as the fourth end of the first filter module.

[0021] In some embodiments, the first residual voltage processing module includes a first bidirectional transient suppression diode;

[0022] The first end of the first bidirectional transient suppression diode serves as the first end of the first residual voltage processing module, and the second end of the first bidirectional transient suppression diode serves as the second end of the first residual voltage processing module.

[0023] In some embodiments, it further includes: a second filtering module and a second residual voltage processing module;

[0024] The first end of the second filtering module is connected to the first end of the first residual voltage processing module, the second end of the second filtering module is connected to the second end of the first residual voltage processing module, the third end of the second filtering module is connected to the first end of the second residual voltage processing module, and the fourth end of the second filtering module is connected to the second end of the second residual voltage processing module.

[0025] The second filtering module is used to reduce electromagnetic radiation;

[0026] The second residual pressure processing module is used to further reduce the residual pressure.

[0027] In some embodiments, the second filtering module includes: a third capacitor, a fourth capacitor, and a differential-mode inductor;

[0028] The first terminal of the third capacitor serves as the first terminal of the second filter module and is connected to the first terminal of the differential mode inductor. The second terminal of the third capacitor serves as the second terminal of the second filter module. The first terminal of the fourth capacitor serves as the third terminal of the second filter module and is connected to the second terminal of the differential mode inductor. The second terminal of the fourth capacitor serves as the fourth terminal of the second filter module and is connected to the second terminal of the third capacitor.

[0029] In some embodiments, the second residual voltage processing module includes a second bidirectional transient suppression diode;

[0030] The first end of the second bidirectional transient suppression diode serves as the first end of the second residual voltage processing module, and the second end of the second bidirectional transient suppression diode serves as the second end of the second residual voltage processing module.

[0031] In some embodiments, a first fuse and a second fuse are also included;

[0032] The first end of the first filter module is connected to the positive input terminal of the power supply through the first fuse, and the second end of the first filter module is connected to the negative input terminal of the power supply through the second fuse.

[0033] The power surge protection circuit provided in this application embodiment utilizes modules from differential mode surge protection. When a differential mode surge occurs between the positive and negative input terminals of the power supply, the second and third surge protection modules cooperate to dissipate the differential mode surge energy for differential mode surge protection. When a common mode surge occurs between the positive input terminal and the ground terminal, the first and second surge protection modules cooperate to dissipate the common mode surge energy for common mode surge protection. Furthermore, when a common mode surge occurs between the negative input terminal and the ground terminal, the first and third surge protection modules cooperate to dissipate the common mode surge energy for common mode surge protection. In other words, the power surge protection circuit provided in this application embodiment borrows modules from differential mode surge protection for common mode surge protection, thereby saving on the number of common mode surge protection components and PCB layout space, and providing a shorter discharge path for common mode surge protection. Attached Figure Description

[0034] To more clearly illustrate the technical solutions of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0035] Figure 1 A schematic diagram of a power surge protection circuit provided in an embodiment of this application;

[0036] Figure 2a A schematic diagram of another power surge protection circuit provided in this application embodiment;

[0037] Figure 2b A schematic diagram of another power surge protection circuit provided in this application embodiment;

[0038] Figure 3A schematic diagram of another power surge protection circuit provided in this application embodiment;

[0039] Figure 4 A schematic diagram of another power surge protection circuit provided in this application embodiment;

[0040] Figure 5 A schematic diagram of another power surge protection circuit provided in this application embodiment;

[0041] Figure 6 A schematic diagram of another power surge protection circuit provided in this application embodiment;

[0042] Figure 7 A schematic diagram of another power surge protection circuit provided in an embodiment of this application. Detailed Implementation

[0043] To make the objectives, technical solutions, and advantages 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. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art are within the scope of protection of this application.

[0044] With the development of digital operation and maintenance services, and driven by the needs of telecommunications, power, and farmland protection, PTZ cameras are increasingly being installed in high-altitude environments such as steel towers. Most steel towers are built in mountainous areas, suburbs, and uninhabited regions. In recent years, global warming and increased thunderstorms have made equipment on these towers more susceptible to lightning surges. Inadequate on-site wiring and protection further exacerbate the damage caused by lightning surges.

[0045] Because there are many surge protection devices currently used for power supply protection, the layout space on the PCB is small. Therefore, this application provides a power surge protection circuit to save PCB layout space for power surge protection.

[0046] like Figure 1 As shown, a power surge protection circuit provided in an embodiment of this application includes: a first surge protection module 101, a second surge protection module 102, a third surge protection module 103, a first filtering module 104, and a first residual voltage processing module 105.

[0047] The first terminal of the third surge protection module 103 is connected to the positive power input terminal VIN_IN and the first terminal of the second surge protection module 102, respectively. The second terminal of the third surge protection module 103 is connected to the negative power input terminal VIN_GND. The third terminal of the third surge protection module 103 is connected to the second terminal of the second surge protection module 102 and the first terminal of the first surge protection module 101, respectively. The second terminal of the first surge protection module 101 is connected to the ground terminal PE. The first terminal of the first filter module 104 is connected to the positive power input terminal VIN_IN. The second terminal of the first filter module 104 is connected to the negative power input terminal VIN_GND. The third terminal of the first filter module 104 is connected to the first terminal of the first residual voltage processing module 105. The fourth terminal of the first filter module 104 is connected to the second terminal of the first residual voltage processing module 105.

[0048] The first surge protection module 101 is used to cooperate with the second surge protection module 102 to open the path between the first terminal of the second surge protection module 102 and the second terminal of the first surge protection module 101 when a common-mode surge is generated between the positive input terminal VIN_IN of the power supply and the ground terminal PE; and to cooperate with the third surge protection module 103 to open the path between the second terminal of the third surge protection module 103 and the second terminal of the first surge protection module 101 when a common-mode surge is generated between the negative input terminal VIN_GND of the power supply and the ground terminal PE, thereby dissipating the common-mode surge energy.

[0049] The second surge protection module 102 is used to cooperate with the third surge protection module 103 to conduct the path between the first end of the second surge protection module 102 and the second end of the third surge protection module 103 when a differential mode surge is generated between the positive power input terminal VIN_IN and the negative power input terminal VIN_GND, thereby dissipating the differential mode surge energy and generating residual voltage.

[0050] The first filtering module 104 is used to filter out noise;

[0051] The first residual pressure processing module 105 is used to reduce residual pressure.

[0052] The power surge protection circuit provided in this application embodiment utilizes modules from differential mode surge protection. When a differential mode surge occurs between the positive and negative input terminals of the power supply, the second and third surge protection modules cooperate to dissipate the differential mode surge energy for differential mode surge protection. When a common mode surge occurs between the positive input terminal and the ground terminal, the first and second surge protection modules cooperate to dissipate the common mode surge energy for common mode surge protection. Furthermore, when a common mode surge occurs between the negative input terminal and the ground terminal, the first and third surge protection modules cooperate to dissipate the common mode surge energy for common mode surge protection. In other words, the power surge protection circuit provided in this application embodiment borrows modules from differential mode surge protection for common mode surge protection, thereby saving on the number of common mode surge protection components and PCB layout space, and providing a shorter discharge path for common mode surge protection.

[0053] In specific implementation, the second surge protection module 102 includes a gas discharge tube GDT1 and a first capacitor C1 connected in parallel, and the third surge protection module 103 includes M gas discharge tubes GDT1 and (M-1) first capacitors C1.

[0054] The first end of the gas discharge tube GDT1 and the first capacitor C1 connected in parallel serves as the first end of the second surge protection module 102, and the second end of the gas discharge tube GDT1 and the first capacitor C1 connected in parallel serves as the second end of the second surge protection module 102.

[0055] M gas discharge tubes GDT1 are connected in series between the second terminal of the second surge protection module 102 and the negative power input terminal VIN_GND. One end of the gas discharge tube GDT1 connected to the second terminal of the second surge protection module 102 serves as the third terminal of the third surge protection module 103, and one end of the gas discharge tube GDT1 connected to the negative power input terminal VIN_GND serves as the second terminal of the third surge protection module 103. The first terminals of (M-1) first capacitors C1 serve as the first terminals of the third surge protection module 103, and the second terminals of (M-1) first capacitors C1 are connected to each node respectively. Each node is one of the (M-1) midpoints of the M gas discharge tubes GDT1 connected in series, where M is a positive integer greater than or equal to 2.

[0056] As an example, when M=2, the power surge protection circuit structure diagram provided in this application embodiment is as follows: Figure 2aAs shown, when a differential-mode surge occurs between the positive input terminal VIN_IN and the negative input terminal VIN_GND, each of the first capacitors C1 conducts, accelerating the breakdown and conduction of each gas discharge tube GDT1. The breakdown and conduction sequence of each gas discharge tube GDT1 is generally from bottom to top. This method can reduce the residual voltage as a whole. Compared with the traditional gas discharge tube series varistor, the residual voltage after differential-mode surge protection is smaller, allowing the subsequent circuit to withstand the residual voltage level.

[0057] In addition, compared to differential mode surge protection in the form of a single varistor, the above structure is less likely to cause a fire due to a short circuit, and when the power supply is low voltage, it is many times the follow current sustaining voltage of a single gas discharge tube GDT1, so it will not cause follow current problems when a surge occurs.

[0058] Furthermore, in the embodiments of this application, multiple gas discharge tubes GDT1 can be connected in series, or a pre-assembled cascaded gas discharge tube can be used, and the two have the same effect.

[0059] In specific implementation, such as Figure 2a As shown, the first surge protection module 101 may include: a first varistor RV1; the first end of the first varistor RV1 serves as the first end of the first surge protection module 101, and the second end of the first varistor RV1 serves as the second end of the first surge protection module 101.

[0060] When a common-mode surge occurs between the positive power input terminal VIN_IN and the ground terminal PE, the surge energy flows through two paths. The first path flows through the uppermost gas discharge tube GDT1 (connected to the positive power input terminal VIN_IN) and the first varistor RV1, thus dissipating the common-mode surge energy. The second path flows through the uppermost first capacitor C1 and the first varistor RV1, thus dissipating the common-mode surge energy. Since the common-mode protection also uses differential-mode protection devices, it saves on device cost and quantity, and also eliminates the risk of varistor short-circuit failure.

[0061] Because the varistor has a high operating voltage, the embodiment of this application has a high operating voltage when performing common mode protection, which can meet the requirements of power line splicing and also meet the AC500V insulation withstand voltage requirement.

[0062] It is worth noting that, Figure 2a This is just one example; any modifications can be made based on the same inventive idea, such as... Figure 2b The circuit structure shown can also be connected to other gas discharge tubes GDT1 to achieve the same circuit function, which will not be described in detail here.

[0063] In a specific implementation, it may also include: a second varistor RV2; the other end of the gas discharge tube GDT1 connected to the negative input terminal VIN_GND of the power supply is connected to the first end of the second varistor RV2, and the second end of the second varistor RV2 is connected to the ground terminal PE.

[0064] As an example, when M=5, the power surge protection circuit structure diagram provided in this application embodiment is as follows: Figure 3 As shown, when a differential-mode surge occurs between the positive input terminal VIN_IN and the negative input terminal VIN_GND, each of the first capacitors C1 conducts, accelerating the breakdown and conduction of each gas discharge tube GDT1. The breakdown and conduction sequence of each gas discharge tube GDT1 is generally from bottom to top. This method can reduce the residual voltage as a whole, enabling the subsequent circuits to withstand the residual voltage level, thereby improving the reliability of the equipment's power surge protection.

[0065] When a common-mode surge occurs between the positive power input terminal VIN_IN and the ground terminal PE, the surge energy flows through the uppermost gas discharge tube GDT1 (i.e., the gas discharge tube GDT1 connected to the positive power input terminal VIN_IN) and the first varistor RV1, as well as through the uppermost first capacitor C1 and the first varistor RV1, thereby dissipating the surge energy. When a common-mode surge occurs between the negative power input terminal VIN_GND and the ground terminal PE, the surge energy flows through the lowermost gas discharge tube GDT1 (i.e., the gas discharge tube GDT1 connected to the negative power input terminal VIN_GND) and the second varistor RV2, thereby dissipating the surge energy.

[0066] In other words, based on the above circuit structure, the common-mode surge protection is a symmetrical design. Whether a common-mode surge occurs between the positive power input terminal VIN_IN and the ground terminal PE, or between the negative power input terminal VIN_GND and the ground terminal PE, the surge energy can be effectively discharged. Furthermore, the surge energy discharge paths from the positive power input terminal VIN_IN to the ground terminal PE and from the negative power input terminal VIN_GND to the ground terminal PE are basically equal, thereby improving the stability of the surge protection.

[0067] In specific implementation, such as Figure 4 As shown, the first filtering module 104 may include: a second capacitor C2 and a common-mode inductor FIL1; the first end of the second capacitor C2 serves as the first end of the first filtering module 104 and is connected to the first end of the common-mode inductor FIL1; the second end of the second capacitor C2 serves as the second end of the first filtering module 104 and is connected to the second end of the common-mode inductor FIL1; the third end of the common-mode inductor FIL1 serves as the third end of the first filtering module 104; and the fourth end of the common-mode inductor FIL1 serves as the fourth end of the first filtering module 104.

[0068] The second capacitor C2 can be an X capacitor, which can perform differential mode filtering. The common mode inductor FIL1 can filter out common mode noise and also play a decoupling role, which can limit the overcurrent of lightning strikes.

[0069] In specific implementation, such as Figure 4 As shown, the first residual voltage processing module 105 may include a first bidirectional transient suppression diode D1; the first end of the first bidirectional transient suppression diode D1 serves as the first end of the first residual voltage processing module 105, and the second end of the first bidirectional transient suppression diode D1 serves as the second end of the first residual voltage processing module 105.

[0070] The first bidirectional transient suppression diode D1 can reduce the residual voltage. Of course, other methods to reduce the residual voltage can also be chosen, such as using a varistor or a semiconductor discharge tube.

[0071] In specific implementation, such as Figure 5 As shown, it may further include: a second filtering module 106 and a second residual voltage processing module 107; the first end of the second filtering module 106 is connected to the first end of the first residual voltage processing module 105, the second end of the second filtering module 106 is connected to the second end of the first residual voltage processing module 105, the third end of the second filtering module 106 is connected to the first end of the second residual voltage processing module 107, and the fourth end of the second filtering module 106 is connected to the second end of the second residual voltage processing module 107; the second filtering module 106 is used to reduce electromagnetic radiation; the second residual voltage processing module 107 is used to further reduce residual voltage.

[0072] Specifically, such as Figure 6 As shown, the second filter module 106 may include: a third capacitor C3, a fourth capacitor C4, and a differential mode inductor L1;

[0073] The first terminal of the third capacitor C3 serves as the first terminal of the second filter module 106 and is connected to the first terminal of the differential mode inductor L1. The second terminal of the third capacitor C3 serves as the second terminal of the second filter module 106. The first terminal of the fourth capacitor C4 serves as the third terminal of the second filter module 106 and is connected to the second terminal of the differential mode inductor L1. The second terminal of the fourth capacitor C4 serves as the fourth terminal of the second filter module and is connected to the second terminal of the third capacitor C3.

[0074] Among them, the third capacitor C3 and the fourth capacitor C4 can be ceramic capacitors. The ceramic capacitors and the differential mode inductor L1 form a π filter circuit, which can optimize EMC radiation and conduction problems.

[0075] The second residual voltage processing module 107 may include a second bidirectional transient suppression diode D2;

[0076] The first end of the second bidirectional transient suppression diode D2 serves as the first end of the second residual voltage processing module 107, and the second end of the second bidirectional transient suppression diode D2 serves as the second end of the second residual voltage processing module 107. Of course, other methods to reduce residual voltage can also be selected, such as using a varistor or a semiconductor discharge tube.

[0077] The power surge protection circuit provided in this application embodiment can at least meet the high-level surge design requirements of differential mode 10KA / common mode 10KA and differential mode 20KV / common mode 20KV, and the device size is relatively small, which is friendly to PCB layout.

[0078] In specific implementation, such as Figure 7 As shown, it may also include a first fuse F1 and a second fuse F2; the first terminal of the first filter module 104 is connected to the positive input terminal VIN_IN of the power supply through the first fuse F1, and the second terminal of the first filter module 104 is connected to the negative input terminal VIN_GND of the power supply through the second fuse F2. Its function is to blow the fuses and disconnect the entire circuit when a circuit fault occurs, such as a short-circuit failure of the subsequent bidirectional transient suppression diode, thus providing circuit protection.

[0079] To meet the design requirements for surge testing of 1.2 / 50us (voltage wave) combined differential mode 20KV / common mode 20KV and 8 / 20us (current wave) combined differential mode 10KA / common mode 10KA surge tests, the following requirements apply to component selection: the gas discharge tube GDT1 and varistors RV1 and RV2 must at least meet the 10KA current carrying capacity of the 8 / 20us lightning strike test waveform; the peak pulse power of the bidirectional TVS diodes D1 and D2 must be at least 5000W; and the PCB traces of the first surge protection module, the second surge protection module, and the third surge protection module must at least meet the requirement of 1OZ trace width 200mil (2OZ trace width 100mil) or higher.

[0080] In order to meet the requirements of power line splicing and AC500V insulation withstand voltage of power supply port, the combined operating voltage of varistor RV1, RV2 and gas discharge tube GDT1 should be higher than DC707V. For example, varistor 20D821 can be selected, and the breakdown voltage of each gas discharge tube GDT1 can be selected between 140V and 250V.

[0081] It should be noted that the above parameters are merely an example, and this application does not impose any limitations on them.

[0082] Those skilled in the art can make various modifications and variations to this application without departing from the spirit and scope of this application. Therefore, if such modifications and variations fall within the scope of the claims of this application and their equivalents, this application also intends to include such modifications and variations.

Claims

1. A power surge protection circuit, characterized in that, include: The system comprises a first surge protection module, a second surge protection module, a third surge protection module, a first filtering module, and a first residual voltage processing module. The first terminal of the third surge protection module is connected to the positive input terminal of the power supply and the first terminal of the second surge protection module, the second terminal of the third surge protection module is connected to the negative input terminal of the power supply, the third terminal of the third surge protection module is connected to the second terminal of the second surge protection module and the first terminal of the first surge protection module, and the second terminal of the first surge protection module is connected to the ground terminal; the first terminal of the first filter module is connected to the positive input terminal of the power supply, the second terminal of the first filter module is connected to the negative input terminal of the power supply, the third terminal of the first filter module is connected to the first terminal of the first residual voltage processing module, and the fourth terminal of the first filter module is connected to the second terminal of the first residual voltage processing module. The first surge protection module is used to cooperate with the second surge protection module to open the path between the first end of the second surge protection module and the second end of the first surge protection module when a common-mode surge is generated between the positive input terminal of the power supply and the ground terminal; and to cooperate with the third surge protection module to open the path between the second end of the third surge protection module and the second end of the first surge protection module when a common-mode surge is generated between the negative input terminal of the power supply and the ground terminal, thereby dissipating the common-mode surge energy. The second surge protection module is used to cooperate with the third surge protection module to open the path between the first end of the second surge protection module and the second end of the third surge protection module when a differential mode surge is generated between the positive input terminal and the negative input terminal of the power supply, thereby dissipating the differential mode surge energy and generating residual voltage. The first filtering module is used to filter out noise; The first residual pressure processing module is used to reduce the residual pressure; The second surge protection module includes a gas discharge tube and a first capacitor connected in parallel, and the third surge protection module includes M gas discharge tubes and (M-1) first capacitors. The first end of the gas discharge tube and the first capacitor connected in parallel serves as the first end of the second surge protection module, and the second end of the gas discharge tube and the first capacitor connected in parallel serves as the second end of the second surge protection module. The M gas discharge tubes are connected in series between the second end of the second surge protection module and the negative input terminal of the power supply. One end of the gas discharge tube connected to the second end of the second surge protection module serves as the third end of the third surge protection module, and one end of the gas discharge tube connected to the negative input terminal of the power supply serves as the second end of the third surge protection module. The first end of the (M-1) first capacitors serves as the first end of the third surge protection module, and the second end of the (M-1) first capacitors is connected to each node respectively. The nodes are the (M-1) midpoints of the M gas discharge tubes connected in series, and M is a positive integer greater than or equal to 2.

2. The power surge protection circuit as described in claim 1, characterized in that, The first surge protection module includes: a first varistor; The first end of the first varistor serves as the first end of the first surge protection module, and the second end of the first varistor serves as the second end of the first surge protection module.

3. The power surge protection circuit as described in claim 2, characterized in that, Also includes: Second varistor; The other end of the gas discharge tube connected to the negative input terminal of the power supply is connected to the first end of the second varistor, and the second end of the second varistor is connected to the ground terminal.

4. The power surge protection circuit as described in claim 1, characterized in that, The first filtering module includes: a second capacitor and a common-mode inductor; The first end of the second capacitor serves as the first end of the first filter module and is connected to the first end of the common-mode inductor. The second end of the second capacitor serves as the second end of the first filter module and is connected to the second end of the common-mode inductor. The third end of the common-mode inductor serves as the third end of the first filter module, and the fourth end of the common-mode inductor serves as the fourth end of the first filter module.

5. The power surge protection circuit as described in claim 1, characterized in that, The first residual voltage processing module includes a first bidirectional transient suppression diode; The first end of the first bidirectional transient suppression diode serves as the first end of the first residual voltage processing module, and the second end of the first bidirectional transient suppression diode serves as the second end of the first residual voltage processing module.

6. The power surge protection circuit as described in claim 1, characterized in that, Also includes: Second filtering module and second residual voltage processing module; The first end of the second filtering module is connected to the first end of the first residual voltage processing module, the second end of the second filtering module is connected to the second end of the first residual voltage processing module, the third end of the second filtering module is connected to the first end of the second residual voltage processing module, and the fourth end of the second filtering module is connected to the second end of the second residual voltage processing module. The second filtering module is used to reduce electromagnetic radiation; The second residual pressure processing module is used to further reduce the residual pressure.

7. The power surge protection circuit as described in claim 6, characterized in that, The second filtering module includes: a third capacitor, a fourth capacitor, and a differential-mode inductor; The first terminal of the third capacitor serves as the first terminal of the second filter module and is connected to the first terminal of the differential mode inductor. The second terminal of the third capacitor serves as the second terminal of the second filter module. The first terminal of the fourth capacitor serves as the third terminal of the second filter module and is connected to the second terminal of the differential mode inductor. The second terminal of the fourth capacitor serves as the fourth terminal of the second filter module and is connected to the second terminal of the third capacitor.

8. The power surge protection circuit as described in claim 6, characterized in that, The second residual voltage processing module includes a second bidirectional transient suppression diode; The first end of the second bidirectional transient suppression diode serves as the first end of the second residual voltage processing module, and the second end of the second bidirectional transient suppression diode serves as the second end of the second residual voltage processing module.

9. The power surge protection circuit as described in any one of claims 1-8, characterized in that, It also includes a first fuse and a second fuse; The first end of the first filter module is connected to the positive input terminal of the power supply through the first fuse, and the second end of the first filter module is connected to the negative input terminal of the power supply through the second fuse.

Images