Surge protection circuit, equipment and air conditioner

Abstract

The utility model relates to a surge protection circuit, equipment and an air conditioner, and relates to the technical field of equipment, the surge protection circuit comprises a discharge tube group and at least two RC circuits; one end of the discharge tube group is connected with a ground wire, the other end of the discharge tube group is respectively connected with a power line, the discharge tube group comprises at least two discharge tubes, the at least two discharge tubes are connected in series, the number of the at least two discharge tubes is the same as that of the at least two RC circuits, and the discharge tubes are connected in series. The two sides of each discharge tube are connected with one RC circuit in parallel. Under the condition that the power line generates surge voltage, a first target branch is conducted; and under the condition that the voltage at the two ends of the other discharge tubes is higher than the target voltage threshold value, the second target branch is switched on. Therefore, by optimizing the structure of the discharge tube, the surge impact resistance of the whole circuit can be effectively improved, and the reliability of the circuit is improved.

Description

Technical Field

[0001] The present disclosure relates to the technical field of equipment, and in particular to a surge protection circuit, equipment and air conditioner. Background Art

[0002] Household appliances are becoming more and more indispensable in people's daily lives. In order to meet people's requirements for high reliability and stable operation of electronic products, it is often necessary to perform reliability processing on product design. At present, commonly used tests include surge testing. During the surge test, the discharge tube in the equipment is usually required to discharge the surge voltage applied by the surge to detect the reliability of the equipment in a harsh power environment. However, in actual application scenarios, the discharge tube will generate a large surge residual voltage at both ends of itself while discharging the surge voltage, which will cause abnormal operation or reset of the subsequent circuit. Utility Model Content

[0003] To overcome the problems existing in the related art, the present disclosure provides a surge protection circuit, a device and an air conditioner.

[0004] According to a first aspect of an embodiment of the present disclosure, a surge protection circuit is provided, the surge protection circuit comprising: a discharge tube group and at least two RC circuits; one end of the discharge tube group is connected to a ground line, and the other end of the discharge tube group is respectively connected to a power line, the discharge tube group comprises at least two discharge tubes, the at least two discharge tubes are connected in series, the number of the at least two discharge tubes is the same as the number of the at least two RC circuits, and one RC circuit is connected in parallel on both sides of each discharge tube;

[0005] In the case where a surge voltage is generated on the power line, the first target branch is turned on; wherein the first target branch includes at least one discharge tube and a branch where the remaining RC circuits are located, the remaining RC circuits are RC circuits in parallel with the remaining discharge tubes in the at least two RC circuits, and the remaining discharge tubes are discharge tubes in the discharge tube group except the at least one discharge tube;

[0006] When the voltage across the remaining discharge tubes is higher than the target voltage threshold, the second target branch is turned on; wherein the second target branch is the branch where the at least two discharge tubes are located.

[0007] Optionally, when the first target branch is turned on, the surge voltage is discharged through the first target branch.

[0008] Optionally, when the second target branch is turned on, the surge voltage is discharged through the second target branch.

[0009] Optionally, the at least two discharge tubes include a first discharge tube and a second discharge tube, and the at least two RC circuits include a first RC circuit and a second RC circuit; the first discharge tube is connected in series with the second discharge tube, the first RC circuit is connected in parallel at both ends of the first discharge tube, and the second RC circuit is connected in parallel at both ends of the second discharge tube.

[0010] Optionally, the first RC circuit includes a first resistor and a first capacitor, and the second RC circuit includes a second resistor and a second capacitor.

[0011] Optionally, the first resistor is greater than the second resistor, and a first difference between the first resistor and the second resistor is greater than a preset resistance threshold;

[0012] The first target branch includes a branch where a first discharge tube and a second RC circuit are located.

[0013] Optionally, the second target branch includes a branch where the first discharge tube and the second discharge tube are located;

[0014] When the first voltage across the second discharge tube is higher than the target voltage threshold, the second target branch is turned on.

[0015] Optionally, the second resistor is greater than the first resistor, and a second difference between the second resistor and the first resistor is greater than a preset resistance threshold;

[0016] The first target branch includes a branch where the second discharge tube and the first RC circuit are located.

[0017] Optionally, the second target branch includes a branch where the first discharge tube and the second discharge tube are located;

[0018] When the second voltage across the first discharge tube is higher than the target voltage threshold, the second target branch is turned on.

[0019] According to a second aspect of an embodiment of the present disclosure, a surge protection device is provided. The surge protection device includes the surge protection circuit provided by the first aspect of the present disclosure.

[0020] According to a third aspect of an embodiment of the present disclosure, an air conditioner is provided, wherein the air conditioner includes the surge protection device provided by the second aspect of the present disclosure.

[0021] The technical solution provided by the embodiments of the present disclosure may have the following beneficial effects:

[0022] The present disclosure provides a surge protection circuit, which includes: a discharge tube group and at least two RC circuits; one end of the discharge tube group is connected to the ground line, and the other end of the discharge tube group is respectively connected to the power line, the discharge tube group includes at least two discharge tubes, the at least two discharge tubes are connected in series, the number of the at least two discharge tubes is the same as the number of the at least two RC circuits, and one RC circuit is connected in parallel on both sides of each discharge tube; in the case where a surge voltage is generated on the power line, the first target branch is turned on; wherein the first target branch includes at least one discharge tube and a branch where the remaining RC circuits are located, the remaining RC circuit is an RC circuit in parallel with the remaining discharge tubes in the at least two RC circuits, and the remaining discharge tubes are discharge tubes other than the at least one discharge tube in the at least two discharge tubes; in the case where the voltage at both ends of the remaining discharge tubes is higher than the target voltage threshold, the second target branch is turned on; wherein the second target branch is the branch where the at least two discharge tubes are located. Through the above scheme, the discharge tube group composed of at least two discharge tubes replaces the existing scheme of only using one discharge tube, which can effectively share the voltage generated at both ends of the discharge tube when the pressure is discharged by only one discharge tube. At least two RC circuits connected in parallel with the discharge tubes are used to enable the discharge tubes in the discharge tube group to be turned on one by one, thereby further reducing the voltage generated by the discharge tube group as a whole during the discharge of the surge voltage. In this way, by optimizing the discharge tube structure, the surge impact resistance of the entire circuit can be effectively improved, and the reliability of the circuit can be improved.

[0023] It is to be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present disclosure and, together with the description, serve to explain the principles of the present disclosure.

[0025] Figure 1 The figure is a schematic diagram showing voltage variation on a power line according to an exemplary embodiment.

[0026] Figure 2 It is a circuit diagram of a surge protection circuit shown in the related art.

[0027] Figure 3 is a circuit diagram of another surge protection circuit shown in the related art.

[0028] Figure 4 The figure is a schematic structural diagram of a surge protection circuit according to an exemplary embodiment.

[0029] Figure 5is a circuit diagram showing a surge protection circuit according to an exemplary embodiment.

[0030] Figure 6 The figure is a diagram showing the voltage variation amplitude at both ends of a discharge tube according to a surge protection circuit in the related art.

[0031] Figure 7 The figure is a diagram showing a voltage variation amplitude across a discharge tube according to an exemplary embodiment.

[0032] Figure 8 is a block diagram of a surge protection device according to an exemplary embodiment.

[0033] Fig. 9 is a block diagram of an air conditioner according to an exemplary embodiment.

[0034] Description of Reference Numerals

[0035] Surge protection circuit-100; surge protection device-200; air conditioner-300; discharge tube group-101; discharge tube-1011; RC circuit-102;

[0036] The first resistor-R1; the second resistor-R2; the first discharge tube-DSA1; the second discharge tube-DSA2; the third discharge tube-DSA3; the first varistor-ZR1; the second varistor-ZR2; the third varistor-ZR3; the fourth varistor-ZR4; the first capacitor-C1; the second capacitor-C2; the third capacitor-C3; the fourth capacitor-C4; the rectifier bridge-BR; the poor grounding impedance-Ra; the circuit board grounding impedance-Rb; the protection component-FUSE1. DETAILED DESCRIPTION

[0037] Exemplary embodiments will be described in detail herein, examples of which are shown in the accompanying drawings. When the following description refers to the drawings, the same numbers in different drawings represent the same or similar elements unless otherwise indicated. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present disclosure. Instead, they are merely examples of devices and methods consistent with some aspects of the present disclosure as detailed in the appended claims.

[0038] The embodiments described in some embodiments of the present disclosure below do not represent all embodiments consistent with the present disclosure. Instead, they are merely examples of devices and methods consistent with some aspects of the present disclosure as detailed in the appended claims.

[0039] The terms "first", "second", etc. in the specification and claims of this application and the above drawings are used to distinguish similar objects and do not have to be understood as a specific order or sequence. In addition, in the description with reference to the drawings, the same symbols in different drawings represent the same elements.

[0040] The term "including" and its variations used herein are open inclusions, i.e., "including but not limited to". The term "based on" means "based at least in part on". The term "one embodiment" means "at least one embodiment"; the term "another embodiment" means "at least one additional embodiment"; the term "some embodiments" means "at least some embodiments". The relevant definitions of other terms will be given in the following description.

[0041] In the description of the present disclosure, unless otherwise specified, "plurality" refers to two or more than two, and other quantifiers are similar thereto; "at least one item", "one or more items" or similar expressions refer to any combination of these items, including any combination of single items or plural items. For example, at least one item a can represent any number of a; for another example, one or more items among a, b and c can represent: a, b, c, ab, ac, bc, or abc, where a, b, c can be single or plural.

[0042] Before introducing the surge protection circuit, device and air conditioner provided by the present disclosure, the application scenarios involved in each embodiment of the present disclosure are first introduced. The present disclosure is applied in the scenario where the device generates a surge voltage. Usually in the actual application scenario of the device, lightning may cause a transient large voltage (i.e., a surge voltage) to be generated on the power line of the device, thereby damaging the device. Figure 1 As shown, Figure 1 The solid line in the figure shows the voltage change on the power line when the device is in normal working condition. When the device is struck by lightning, a surge voltage will be generated, i.e. Figure 1 The dashed part in the middle. It can be clearly seen that when a surge voltage is generated on the device, the voltage on the power line undergoes a sudden change. Compared with the voltage peak value Vd under normal working conditions, the surge voltage is significantly greater than the voltage peak value Vd, which will have a serious impact on the normal operation of the device. In order to detect the reliability of the device in a harsh power environment, surge tests are often performed on the device to simulate the device's tolerance to instantaneous high voltages.

[0043] During the product design phase, in order to ensure that the device can withstand instantaneous high voltage, a surge protection circuit will be added to the device. Existing surge protection circuits such as Figure 2As shown, it is composed of a first varistor ZR1, a second varistor ZR2, and a third discharge tube DSA3. The first varistor ZR1 is connected to the neutral line (i.e. Figure 2 AC-N in the figure, the second varistor ZR2 is connected to the live wire (i.e. Figure 2 AC-L in the figure, one end of the third discharge tube DSA3 (such as Figure 1 The other end of the third discharge tube DSA3 (such as Figure 2 The principle of surge testing is to simulate the generation of surge voltage and introduce the surge voltage into the ground wire through the surge protection circuit on the equipment to discharge the surge voltage.

[0044] However, the inventors have found in long-term practice that due to the complex grounding environment of the actual application of the equipment, sometimes there will be a poor grounding situation, which will generate a large grounding impedance (such as Figure 3 When a surge voltage is generated, the third discharge tube DSA3 will generate a large surge residual voltage at both ends while discharging the surge voltage, and act on the subsequent circuits connected to the surge protection circuit (for example, Figure 3 In the subsequent circuit composed of the rectifier bridge BR, the third capacitor C3 and the circuit board ground impedance Rb, a large current disturbance is generated, causing the subsequent circuit to work abnormally or reset.

[0045] In order to solve the above technical problems, the present invention provides a surge protection circuit, device and air conditioner, which uses a discharge tube group composed of at least two discharge tubes to replace the existing solution of using only one discharge tube, and can effectively share the surge residual pressure generated at both ends of the discharge tube when the pressure is discharged by only one discharge tube. And through at least two RC circuits connected in parallel with the discharge tube, the discharge tubes in the discharge tube group can be turned on one by one, thereby further reducing the surge residual pressure generated by the discharge tube group as a whole during the process of discharging the surge voltage. In this way, by optimizing the discharge tube structure, the surge impact resistance of the entire circuit can be effectively improved, and the reliability of the circuit is improved.

[0046] The specific embodiments of the present disclosure are described in detail below with reference to the accompanying drawings.

[0047] Figure 4 is a schematic diagram of a surge protection circuit according to an exemplary embodiment. Figure 4As shown, the circuit 100 includes: a discharge tube group 101 and at least two RC circuits 102; one end of the discharge tube group 101 is connected to the ground line, and the other end of the discharge tube group 101 is respectively connected to the power line, the discharge tube group 101 includes at least two discharge tubes 1011, the at least two discharge tubes 1011 are connected in series, the number of the at least two discharge tubes 1011 is the same as the number of the at least two RC circuits 102, and one RC circuit 102 is connected in parallel on both sides of each discharge tube 1011.

[0048] The power line includes a live line and a neutral line, and each RC circuit 102 includes a capacitor and a resistor.

[0049] The working principle of the discharge tube 1011 is that when the voltage at both ends of the discharge tube 1011 is higher than its protection specification value, the gap between the two poles will discharge and break down, and the discharge tube 1011 changes from an insulating state to a conducting state, and discharges the input voltage. In the application scenario of the present disclosure, the surge voltage usually has the characteristics of high frequency and large voltage value. Therefore, in order to effectively protect the entire circuit, the protection specification value of the discharge tube 1011 can be selected according to the characteristics of the surge voltage. For example, a discharge tube 1011 with a protection specification value of 3000V can be selected. When the surge voltage at both ends of the discharge tube 1011 is greater than 3000V, it will be turned on and the surge voltage will be discharged. However, the inventor has found in long-term practice that the larger the protection specification value of the discharge tube 1011, the greater the surge residual voltage it may generate. In other words, the surge residual voltage generated at both ends of the two discharge tubes 1011 with a protection specification value of 1500V in series is less than the surge residual voltage generated at both ends of the discharge tube 1011 with a protection specification value of 3000V. Based on the above findings, in the present disclosure, the original single discharge tube with a large protection specification value can be split into at least two discharge tubes with small protection specification values ​​1011 to reduce the surge residual pressure generated by the discharge tube 1011 itself, thereby improving the reliability of the subsequent circuit. The subsequent circuit can be, for example, a control circuit connected to the surge protection circuit.

[0050] In the case where a surge voltage is generated on the power line, the first target branch is turned on; wherein the first target branch includes at least one discharge tube and a branch where the remaining RC circuits are located, the remaining RC circuits are the RC circuits 102 connected in parallel with the remaining discharge tubes in the at least two RC circuits 102, and the remaining discharge tubes are the discharge tubes 1011 in the discharge tube group 101 except the at least one discharge tube;

[0051] When the voltage across the remaining discharge tubes is higher than the target voltage threshold, the second target branch is turned on; wherein the second target branch is the branch where the at least two discharge tubes 1011 are located.

[0052] The present disclosure can be applied in the scenario of surge testing or in the scenario of lightning. In other words, the surge voltage can be simulated by a surge test device or generated by lightning in an actual scenario, and the present disclosure does not specifically limit this. The target voltage threshold is the protection specification value corresponding to the discharge tube.

[0053] In some embodiments, when a surge voltage is generated in the power line, the first target branch is turned on, at which time at least one discharge tube included in the first target branch is turned on, while the remaining discharge tubes are still in an insulating state (also known as a withstand voltage state), and the surge voltage can be discharged through at least one discharge tube included in the first target branch. In addition, in the process of discharging the surge voltage through at least one discharge tube included in the first target branch, the voltages at both ends of the remaining discharge tubes are also rising. When the voltages at both ends are higher than the target voltage threshold, the remaining discharge tubes will also be turned on. At this time, the surge voltage can be discharged through the discharge tube 1011 included in the second target branch. In this way, the one-by-one conduction of at least two discharge tubes 1011 can be achieved through the RC circuit 102. Since at least two discharge tubes 1011 are turned on one by one, the surge voltage is first discharged through the discharge tube 1011 in the first target branch, and then discharged through the discharge tube 1011 in the second target branch. Since the first target branch only includes some discharge tubes 1011, the surge residual voltage generated by them is less than the surge residual voltage generated by all the discharge tubes 1011, which can further reduce the surge residual voltage generated by the entire discharge tube group 101. By optimizing the structure of the discharge tube 1011, the surge residual voltage at both ends of the discharge tube group 101 is effectively reduced, ensuring that the subsequent circuit is not affected by the surge residual voltage, and improving the surge impact resistance of the entire circuit.

[0054] Optionally, when the first target branch is turned on, the surge voltage is discharged through the first target branch.

[0055] Optionally, when the second target branch is turned on, the surge voltage is discharged through the second target branch.

[0056] That is, first, the surge voltage can be discharged through the first target branch, and then the surge voltage can be discharged through the second target branch when the remaining discharge tubes are turned on, so that the discharge tubes 1011 in the discharge tube group 101 can be turned on one by one to reduce the surge residual voltage.

[0057] For ease of understanding, the above solution is described in detail below by taking the example that the at least two discharge tubes 1011 include a first discharge tube DSA1 and a second discharge tube DSA2, and the at least two RC circuits 102 include a first RC circuit and a second RC circuit. Figure 5As shown, the first discharge tube DSA1 and the second discharge tube DSA2 are connected in series, the first RC circuit is connected in parallel at both ends of the first discharge tube DSA1, and the second RC circuit is connected in parallel at both ends of the second discharge tube DSA2.

[0058] Specifically, the first RC circuit includes a first resistor R1 and a first capacitor C1, and the second RC circuit includes a second resistor R2 and a second capacitor C2.

[0059] In a possible implementation, the first resistor R1 is greater than the second resistor R2, and a first difference between the first resistor R1 and the second resistor R2 is greater than a preset resistance threshold; the first target branch includes a branch where the first discharge tube DSA1 and the second RC circuit are located.

[0060] For example, the first resistor R1 may also be a preset multiple of the second resistor R2, such as 10 times. That is, in this implementation, the first resistor R1 needs to be much larger than the second resistor R2.

[0061] It is well known that the capacitor in the RC circuit 102 has the working characteristic of passing high frequencies and blocking low frequencies, and the surge voltage is usually a high-frequency voltage. That is to say, when the circuit is in a normal working state (low-frequency voltage), the branch where the RC circuit 102 is located is not conductive, and the discharge tube group 101 is also in an insulating state, and the impedance corresponding to the discharge tube group 101 is much larger than the impedance of the RC circuit 102. When a surge voltage (high-frequency voltage) is generated on the power line, the RC circuit 102 is turned on, but at this time, since the first resistor R1 is much larger than the second resistor R2, the voltage division between the first RC circuit and the second RC circuit will be uneven. At this time, the first discharge tube DSA1 connected in parallel with the first RC circuit where the first resistor R1 is located is turned on. At this time, the surge voltage can be discharged through the first discharge tube DSA1 and the first target branch where the second RC circuit is located.

[0062] Optionally, the second target branch includes a branch where the first discharge tube DSA1 and the second discharge tube DSA2 are located; when the first voltage across the second discharge tube DSA2 is higher than the target voltage threshold, the second target branch is turned on.

[0063] Furthermore, in the process of discharging the surge voltage through the first target branch, the voltage across the second discharge tube DSA2 is also rising, and when the first voltage across the second discharge tube DSA2 is higher than the target voltage threshold, the second discharge tube DSA2 is turned on. When the second discharge tube DSA2 is turned on, the second RC circuit is equivalent to being short-circuited, and at this time, the surge voltage can be discharged through the second target branch.

[0064] In this way, by setting the first resistor R1 in the first RC circuit to be much larger than the second resistor R2 in the second RC circuit, it is possible to first turn on the first discharge tube DSA1 and then turn on the first discharge tube DSA1 and the second discharge tube DSA2, thereby greatly reducing the surge residual voltage generated at both ends of the discharge tube group 101 as a whole and improving the reliability of the subsequent circuit.

[0065] In another possible implementation, the second resistor R2 is greater than the first resistor R1, and a second difference between the second resistor R2 and the first resistor R1 is greater than a preset resistance threshold; the first target branch includes the branch where the second discharge tube DSA2 and the first RC circuit are located.

[0066] For example, the second resistor R2 may also be a preset multiple of the first resistor R1, such as 10 times. That is, in this implementation, the second resistor R2 needs to be much larger than the first resistor R1.

[0067] Similarly, when the circuit is in a normal working state (low-frequency voltage), the branch where the RC circuit 102 is located is not conducting, and the discharge tube group 101 is also in an insulating state, and the impedance corresponding to the discharge tube group 101 is much greater than the impedance of the RC circuit 102. When a surge voltage (high-frequency voltage) is generated on the power line, the RC circuit 102 is turned on, but at this time, since the second resistor R2 is much greater than the first resistor R1, the voltage division between the first RC circuit and the second RC circuit will be uneven. At this time, the second discharge tube DSA2 connected in parallel with the second RC circuit where the second resistor R2 is located is turned on. At this time, the surge voltage can be discharged through the first target branch where the first RC circuit and the second discharge tube DSA2 are located.

[0068] Optionally, the second target branch includes a branch where the first discharge tube DSA1 and the second discharge tube DSA2 are located; when the second voltage across the first discharge tube DSA1 is higher than the target voltage threshold, the second target branch is turned on.

[0069] Furthermore, in the process of discharging the surge voltage through the first target branch, the voltage across the first discharge tube DSA1 is also rising, and when the second voltage across the first discharge tube DSA1 is higher than the target voltage threshold, the first discharge tube DSA1 is turned on. When the first discharge tube DSA1 is turned on, the first RC circuit is equivalent to being short-circuited, and at this time, the surge voltage can be discharged through the second target branch.

[0070] In this way, by setting the second resistor R2 in the second RC circuit to be much larger than the first resistor R1 in the first RC circuit, the second discharge tube DSA2 can be turned on first, and then the first discharge tube DSA1 and the second discharge tube DSA2 can be turned on, which greatly reduces the surge residual pressure generated at both ends of the discharge tube group 101 as a whole and improves the reliability of the subsequent circuit.

[0071] In addition, if Figure 5 As shown, the surge protection circuit provided by the present disclosure may also include a protection component FUSE1 (for example, a fuse or a fusible wire), which is connected to the live wire and is used to protect the circuit from overcurrent and overheating. It also includes a fourth capacitor C4, a third varistor ZR3 and a fourth varistor ZR4 connected to the live wire and the neutral wire, wherein the varistor is used to clamp the voltage when the circuit is subjected to overvoltage, absorb excess current to protect sensitive devices, and discharge the surge voltage together with the first discharge tube DSA1 and the second discharge tube DSA2.

[0072] Figure 6 This is the change of voltage at both ends of the discharge tube when the surge protection circuit in the related art is used for surge testing. It can be seen that when the surge voltage is generated, the voltage at both ends of the discharge tube has an obvious sudden change, and then the surge residual voltage at both ends also increases significantly. It can be seen from the test data that the surge residual voltage at both ends of the discharge tube reaches 1.620kV at this time. Figure 7 The voltage change at both ends of the discharge tube during the surge test of the surge protection circuit provided by this solution. It can be seen that when the surge voltage is generated, the voltage at both ends of the discharge tube has an obvious sudden change, but then the amplitude of the surge residual voltage at both ends gradually tends to be flat. It can be seen from the test data that the surge residual voltage at both ends of the discharge tube reaches 1.250kV at this time. Figure 6 The surge residual voltage in the discharge tube can be effectively reduced by the surge protection circuit provided by the present invention when the surge voltage is generated, thereby ensuring the working stability of the subsequent circuit and improving the surge impact resistance of the entire circuit.

[0073] Through the above scheme, a discharge tube group composed of at least two discharge tubes replaces the existing scheme of using only one discharge tube, which can effectively share the surge residual pressure generated at both ends of the discharge tube when the pressure is discharged by only one discharge tube. And through at least two RC circuits connected in parallel with the discharge tube, the discharge tubes in the discharge tube group can be turned on one by one, thereby further reducing the surge residual pressure generated by the discharge tube group as a whole during the process of discharging the surge voltage. In this way, by optimizing the discharge tube structure, the surge impact resistance of the entire circuit can be effectively improved, and the reliability of the circuit is improved.

[0074] Figure 8 is a block diagram of a surge protection device according to an exemplary embodiment. Figure 8 As shown, the device 200 includes the surge protection circuit 100 described above.

[0075] Fig. 9 An air conditioner is shown according to an exemplary embodiment. Fig. 9As shown, the air conditioner 300 includes the above Figure 8 A surge protection device 200 is shown.

[0076] It should be understood that, unless otherwise clearly specified and limited, the terms "joining", "attaching", "installing", "connecting", "connecting", "fixing" and the like used in the embodiments of the present disclosure should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral one; it can be a mechanical connection, an electrical connection, or communication with each other; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly limited. For ordinary technicians in this field, the specific meanings of the above terms in this article can be understood according to specific circumstances.

[0077] It should be understood that spatially relative terms such as "above", "upper", "below", and "lower" are used herein to describe the relationship of one element to another element shown in the figures. In addition to the orientation depicted in the drawings, such spatially relative terms are also intended to include different orientations of the device in use or operation. For example, if the device in the drawings is turned over, the element described as being "above" or "upper" relative to another element will be "below" or "lower" relative to the other element. Therefore, depending on the spatial orientation of the device, the term "above" includes both upper and lower orientations. The device may have other orientations (e.g., rotated 90 degrees or in other orientations), and the spatially relative terms used herein should be interpreted accordingly.

[0078] In addition, the word "exemplary" is used herein to indicate serving as an example, instance, or diagram. Any aspect or design described as "exemplary" in this article is not necessarily understood to be advantageous compared to other aspects or designs. On the contrary, the use of the word exemplary is intended to present concepts in a specific way. As used herein, the term "or" is intended to represent an inclusive "or" rather than an exclusive "or". That is, unless otherwise specified or clear from the context, "X applies A or B" is intended to represent any one of the natural inclusive arrangements. That is, if X applies A; X applies B; or X applies both A and B, "X applies A or B" is satisfied under any of the aforementioned examples. In addition, unless otherwise specified or clearly pointed to a singular form from the context, the articles "one" and "an" as used in this application and the appended claims are generally understood to mean "one or more".

[0079] Likewise, although the present disclosure has been shown and described with respect to one or more implementations, equivalent variations and modifications will occur to those skilled in the art after reading and understanding the specification and drawings. The present disclosure includes all such modifications and variations and is limited only by the scope of the claims. In particular, with respect to the various functions performed by the components (e.g., elements, resources, etc.) described above, unless otherwise noted, the terms used to describe such components are intended to correspond to any component (functionally equivalent) that performs the specific functions of the described components, even if the structure is not equivalent to the disclosed structure. In addition, although the specific features of the present disclosure may have been disclosed with respect to only one of several implementations, such features may be combined with one or more other features of other implementations as may be desired and conducive to any given or specific application. In addition, with respect to "including", "having", "having", "having", or variations thereof used in the specific embodiments or claims, such terms are intended to be inclusive in a manner similar to the term "comprising".

[0080] Those skilled in the art will readily appreciate other embodiments of the present disclosure after considering the specification and practicing the utility model disclosed herein. This application is intended to cover any variations, uses or adaptations of the present disclosure, which follow the general principles of the present disclosure and include common knowledge or customary technical means in the art that are not disclosed in the present disclosure. The specification and examples are intended to be exemplary only, and the true scope and spirit of the present disclosure are indicated by the appended claims.

[0081] It should be understood that the present disclosure is not limited to the exact structures that have been described above and shown in the drawings, and that various modifications and changes may be made without departing from the scope thereof. The scope of the present disclosure is limited only by the appended claims.

Claims

1. A surge protection circuit, characterized in that: The surge protection circuit (100) comprises: a discharge tube group (101) and at least two RC circuits (102); one end of the discharge tube group (101) is connected to a ground line, and the other end of the discharge tube group (101) is respectively connected to power lines; the discharge tube group (101) comprises at least two discharge tubes (1011); the at least two discharge tubes (1011) are connected in series; the number of the at least two discharge tubes (1011) is the same as the number of the at least two RC circuits (102); and one RC circuit (102) is connected in parallel to both sides of each discharge tube (1011); In the case where a surge voltage is generated on the power line, a first target branch is turned on; wherein the first target branch includes at least one discharge tube and a branch where the remaining RC circuits are located, the remaining RC circuits are RC circuits (102) connected in parallel with the remaining discharge tubes in the at least two RC circuits (102), and the remaining discharge tubes are discharge tubes (1011) in the discharge tube group (101) except for the at least one discharge tube; When the voltage across the remaining discharge tubes is higher than a target voltage threshold, a second target branch is turned on; wherein the second target branch is the branch where the at least two discharge tubes (1011) are located.

2. The circuit according to claim 1, characterized in that When the first target branch is turned on, the surge voltage is discharged through the first target branch.

3. The circuit according to claim 1, characterized in that When the second target branch is turned on, the surge voltage is discharged through the second target branch.

4. The circuit according to claim 1, characterized in that The at least two discharge tubes (1011) include a first discharge tube (DSA1) and a second discharge tube (DSA2), and the at least two RC circuits (102) include a first RC circuit and a second RC circuit; the first discharge tube (DSA1) and the second discharge tube (DSA2) are connected in series, the first RC circuit is connected in parallel at both ends of the first discharge tube (DSA1), and the second RC circuit is connected in parallel at both ends of the second discharge tube (DSA2).

5. The circuit according to claim 4, characterized in that The first RC circuit includes a first resistor (R1) and a first capacitor (C1), and the second RC circuit includes a second resistor (R2) and a second capacitor (C2).

6. The circuit according to claim 5, characterized in that The first resistor (R1) is greater than the second resistor (R2), and a first difference between the first resistor (R1) and the second resistor (R2) is greater than a preset resistance threshold; The first target branch includes a branch where a first discharge tube (DSA1) and a second RC circuit are located.

7. The circuit according to claim 6, characterized in that The second target branch includes a branch where the first discharge tube (DSA1) and the second discharge tube (DSA2) are located; When the first voltage across the second discharge tube (DSA2) is higher than the target voltage threshold, the second target branch is turned on.

8. The circuit according to claim 5, characterized in that The second resistor (R2) is greater than the first resistor (R1), and a second difference between the second resistor (R2) and the first resistor (R1) is greater than a preset resistance threshold; The first target branch includes a branch where a second discharge tube (DSA2) and a first RC circuit are located.

9. The circuit according to claim 8, characterized in that The second target branch includes a branch where the first discharge tube (DSA1) and the second discharge tube (DSA2) are located; When the second voltage across the first discharge tube (DSA1) is higher than the target voltage threshold, the second target branch is turned on.

10. A surge protection device, characterized in that: The surge protection device (200) comprises the surge protection circuit (100) according to any one of claims 1 to 9.

11. An air conditioner, characterized in that: The air conditioner (300) comprises the surge protection device (200) according to claim 10.

Images