Lightning protection circuit, circuit board assembly, and electronic device

Abstract

Embodiments of the present application relate to the field of circuit, and disclose a lightning protection circuit, a circuit board assembly and an electronic device. In the present application, the conduction states of the first switch and the second switch are determined according to the voltage of the first end of the first switch and the voltage of the second end of the second switch, but the conduction states of the first switch and the second switch must be opposite, and when the first switch is on and the second switch is off, the second polarity capacitor works; when the first switch is off and the second switch is on, the first polarity capacitor works; so that no matter which end of the lightning protection circuit receives a larger level of lightning surge, the residual voltage can be absorbed by a larger capacity polarity capacitor, thereby protecting the external circuit; since the polarity capacitor is used, the storage capacity is large, the number of capacitors to be set is small, the lightning protection level of the lightning protection circuit is improved at a small cost and a small circuit space.

Description

TECHNICAL FIELD

[0001] The embodiment of the present application relates to the field of circuit, in particular to a lightning protection circuit, a circuit board assembly and an electronic device. BACKGROUND

[0002] At present, with the development of the lithium battery market, the lightning protection circuit of the battery management system (BMS) with high lightning protection level becomes a key development trend of the battery management system.

[0003] In order to realize a high lightning protection level, the BMS lightning protection circuit needs to set a large-capacity polarity capacitor to absorb residual voltage. Since the setting of the polarity capacitor will cause the high lightning protection level circuit to be unable to cope with the reverse polarity lightning surge; therefore, in order to cope with the lightning surge of the positive polarity and the reverse polarity at the same time, the related art uses a non-polarity capacitor to absorb residual voltage; but since the capacity of the non-polarity capacitor is small, the residual voltage that can be absorbed is limited, and a high lightning protection level cannot be realized; therefore, in order to cope with a high lightning protection level and the lightning surge of the positive polarity and the reverse polarity at the same time, the common method in the related art is to increase the number of non-polarity capacitors to absorb more residual voltage. However, this method will inevitably increase the cost and space of the circuit. SUMMARY

[0004] The main purpose of the embodiment of the present application is to provide a lightning protection circuit, which comprises: a lightning protection circuit, a first switch, a second switch, a first polarity capacitor and a second polarity capacitor; the first input end of the lightning protection circuit is connected to the first output end of the power supply, and the second input end of the lightning protection circuit is connected to the second output end of the power supply; the first end of the first switch is connected to the first output end of the lightning protection circuit, the second end of the first switch is connected to the first end of the second switch, and the second end of the second switch is connected to the second output end of the lightning protection circuit; the first end of the first polarity capacitor is connected to the first end of the first switch and the first input end of the external circuit respectively, the second end of the first polarity capacitor is connected to the first end of the second polarity capacitor, and the second end of the second polarity capacitor is connected to the second end of the second switch and the second input end of the external circuit respectively; there is a first node between the first switch and the second switch, and there is a second node between the first polarity capacitor and the second polarity capacitor, and the first node and the second node are connected; the conduction state of the first switch and the second switch is determined according to the voltage of the first end of the first switch and the voltage of the second end of the second switch, and the conduction state of the first switch and the second switch is opposite; when the first switch is turned on, the second polarity capacitor is in a working state, and when the second switch is turned on, the first polarity capacitor is in a working state.

[0005] In order to achieve the above-mentioned purpose, the embodiment of the present application provides a circuit board assembly comprising the lightning protection circuit.

[0006] To achieve the above object, the embodiment of the present application further provides an electronic device comprising the circuit board assembly.

[0007] The lightning protection circuit provided by the embodiment of the present application determines the conduction state of the first switch and the second switch according to the voltage at the first end of the first switch and the voltage at the second end of the second switch. For example, when the voltage at the first end of the first switch is greater than the voltage at the second end of the second switch, the first switch can be turned on, or the second switch can be turned on, which can be set according to actual circuit requirements. However, the conduction states of the first switch and the second switch must be opposite, and when the first switch is turned on and the second switch is turned off, the second polarity capacitor works; when the first switch is turned off and the second switch is turned on, the first polarity capacitor works; so that no matter which end of the lightning protection circuit receives a larger level of lightning surge, the residual voltage can be absorbed by a larger capacity polarity capacitor, thereby protecting the external circuit. Since the polarity capacitor is used, the storage capacity is large, the number of capacitors to be set is small, the cost is low, and the space occupied by the circuit is also reduced. In the case of spending less cost and occupying less circuit space, the lightning protection effect and lightning protection level of the lightning protection circuit are improved. BRIEF DESCRIPTION OF DRAWINGS

[0008] One or more embodiments are illustrated by way of example with reference to the drawings, which are not limiting of the embodiments and which are merely meant to explain the embodiments. The elements in the figures are not meant to be limiting of the embodiments, unless otherwise specifically noted and described. The drawings in the figures are not to scale, except if specifically noted.

[0009] Figure 1 is a circuit structure schematic diagram of a lightning protection circuit according to the first embodiment of the present application;

[0010] Figure 2 is a circuit structure schematic diagram of a lightning protection circuit according to the first embodiment of the present application;

[0011] Figure 3 is a circuit structure schematic diagram of a lightning protection circuit according to the second embodiment of the present application;

[0012] Figure 4 is a circuit structure schematic diagram of another lightning protection circuit according to the second embodiment of the present application;

[0013] Figure 5 is a circuit structure schematic diagram of a lightning protection circuit according to the third embodiment of the present application. DETAILED DESCRIPTION

[0014] To make the purposes, technical solutions, and advantages of the embodiments of the present application clearer, the embodiments of the present application will be described in detail below with the accompanying drawings. However, those of ordinary skill in the art can understand that, in the embodiments of the present application, many technical details are presented in order to make the readers better understand the present application. However, the technical solutions claimed by the present application can be implemented even if there are no such technical details and various changes and modifications based on the following embodiments. The division of the following embodiments is for the convenience of description, and should not constitute any limitation on the specific implementation modes of the present application. The embodiments can be combined and referenced with each other without contradiction.

[0015] The first embodiment of the present application relates to a lightning protection circuit. As shown in Figure 1 , the lightning protection circuit includes a lightning protection circuit 101, a first switch 102, a second switch 103, a first polarity capacitor C1, and a second polarity capacitor C2.

[0016] In actual applications, the lightning protection circuit 101 includes protection fuses, voltage-dependent resistors, decoupling inductors, and the like. When the lightning protection circuit 101 is subjected to lightning surges, protection is performed by opening the fuses, or the voltage of the lightning surges is reduced as much as possible by the voltage-dependent resistors and the decoupling inductors, but part of the residual voltage still reaches the back-end. Therefore, the present application uses the first polarity capacitor C1 or the second polarity capacitor C2 to absorb the residual voltage and protect the external circuit.

[0017] Specifically, a first input end Vin+ of the lightning protection circuit 101 is connected to a first output end of a power supply, and a second input end Vin- of the lightning protection circuit 101 is connected to a second output end of the power supply; a first end c of the first switch 102 is connected to a first output end a of the lightning protection circuit 101, a second end d of the first switch 102 is connected to a first end e of the second switch 103, and a second end f of the second switch 103 is connected to a second output end b of the lightning protection circuit 101; a first end g of the first polarity capacitor C1 is connected to the first end c of the first switch 102 and a first input end of an external circuit, respectively, a second end h of the first polarity capacitor C1 is connected to a first end i of the second polarity capacitor C2, and a second end j of the second polarity capacitor C1 is connected to the second end f of the second switch 103 and a second input end of the external circuit, respectively; there is a first node A between the first switch 102 and the second switch 103, there is a second node B between the first polarity capacitor C1 and the second polarity capacitor C2, and the first node A and the second node B are connected.

[0018] Specifically, the conduction states of the first switch 102 and the second switch 103 are determined according to the magnitude of the voltage at the first terminal c of the first switch 102 and the voltage at the second terminal f of the second switch 103, and the conduction states of the first switch 102 and the second switch 103 are opposite; when the first switch 102 is turned on, the second polarity capacitor C2 is in a working state, and when the second switch 103 is turned on, the first polarity capacitor C1 is in a working state.

[0019] In actual application, when the voltage at the first terminal c of the first switch 102 is greater than the voltage at the second terminal f of the second switch 103, the first switch 102 can be turned on or the second switch 103 can be turned on, which can be set according to actual circuit requirements; for example, when the voltage at the first terminal c of the first switch 102 is greater than the voltage at the second terminal f of the second switch 103, the first switch 102 is set to be turned on and the second switch 103 is set to be turned off, at this time, since the first switch 102 is turned on, the second polarity capacitor C2 is in a working state, and the two terminals of the first polarity capacitor C1 form a closed loop since being connected by the first switch 102, the first polarity capacitor C1 is reversely embedded by the first switch 102 and is in a non-charging state and will not be damaged; when the voltage at the first terminal c of the first switch 102 is less than the voltage at the second terminal f of the second switch 103, the first switch 102 is turned off and the second switch 103 is turned on, at this time, since the second switch 103 is turned on, the first polarity capacitor C1 is in a working state, and the two terminals of the second polarity capacitor C2 form a closed loop since being connected by the second switch 103, the second polarity capacitor C2 is reversely embedded by the second switch 103 and is in a non-charging state and will not be damaged.

[0020] It should be noted that the conduction and turn-off states of the first switch 102 and the second switch 103 can be set according to actual circuit requirements, and the above is only an example and does not limit the technical solutions of the present embodiment.

[0021] It should be noted that no matter how the conduction and turn-off states of the first switch 102 and the second switch 103 are determined, the conduction states of the first switch 102 and the second switch 103 must be opposite, so that one of the first polarity capacitor C1 and the second polarity capacitor C2 can work normally, and no matter which input terminal of the lightning protection circuit 101 receives a larger level of lightning surge, the residual voltage can be absorbed by a larger capacity polarity capacitor, thereby protecting the external circuit; thereby improving the lightning protection level of the lightning protection circuit at a lower cost and with a smaller circuit space.

[0022] In actual application, the external circuit can be a direct current (DC / DC) circuit or other types of circuits, and different types of external circuits can be designed according to different application scenarios, and the type of the external circuit is not specifically limited in the present embodiment.

[0023] In the embodiment, the on-off states of the first switch 102 and the second switch 103 are determined according to the voltage of the first end c of the first switch 102 and the voltage of the second end f of the second switch 103; but the on-off states of the first switch 102 and the second switch 103 must be opposite, and when the first switch 102 is on and the second switch 103 is off, the second polarity capacitor C1 works; when the first switch 102 is off and the second switch 103 is on, the first polarity capacitor C1 works; so that no matter which end of the lightning protection circuit receives a larger level of lightning surge, the residual voltage can be absorbed by a larger capacity polarity capacitor, thereby protecting the external circuit; because the polarity capacitor is used, the storage capacity is large, the number of capacitors to be set is small, the cost is low, and the space occupied by the circuit is also reduced, in the case of spending small cost and occupying small circuit space, the lightning protection level of the lightning protection circuit is improved.

[0024] In one example, the lightning protection circuit further comprises an anti-reverse connection circuit; as Figure 2 shown, the lightning protection circuit of the embodiment comprises a lightning protection circuit 201, a first switch 202, a second switch 203, a first polarity capacitor C1, a second polarity capacitor C2, and an anti-reverse connection circuit 204.

[0025] Specifically, the first input end Vin+ of the lightning protection circuit 201 is connected to the first output end of the power supply, and the second input end Vin- of the lightning protection circuit 201 is connected to the second output end of the power supply; the first end c of the first switch 202 is connected to the first output end a of the lightning protection circuit 201, the second end d of the first switch 202 is connected to the first end e of the second switch 203, and the second end f of the second switch 203 is connected to the second output end b of the lightning protection circuit 201; the first end g of the first polarity capacitor C1 is connected to the first end c of the first switch 202, the second end h of the first polarity capacitor C1 is connected to the first end i of the second polarity capacitor C2, and the second end j of the second polarity capacitor C1 is connected to the second end f of the second switch 203; there is a first node A between the first switch 202 and the second switch 203, there is a second node B between the first polarity capacitor C1 and the second polarity capacitor C2, and the first node A and the second node B are connected. Wherein, the first input end k of the anti-reverse connection circuit 204 is connected to the first end g of the first polarity capacitor C1, and the second input end l of the anti-reverse connection circuit 204 is connected to the second end j of the second polarity capacitor C2; the first output end m of the anti-reverse connection circuit 204 is connected to the first input end of the external circuit, and the second output end n of the anti-reverse connection circuit 204 is connected to the second input end of the external circuit.

[0026] In practical applications, the anti-reverse polarity circuit 204 generally uses a transistor as an anti-reverse polarity element, but since the transistor can withstand a relatively small voltage, the related art uses multiple non-polarized capacitors to absorb the residual voltage under high-level lightning surges so that the residual voltage can be absorbed as much as possible. That is to say, in order for the lightning protection circuit to simultaneously achieve high lightning protection level functions and anti-reverse polarity functions in the related art, it costs a lot and occupies a large circuit space. Therefore, the present invention uses the above-mentioned connection relationship to achieve a higher lightning protection level and anti-reverse polarity functions of the lightning protection circuit at a lower cost and in a smaller circuit space.

[0027] Specifically, the capacity of the first polarity capacitor C1 and the capacity of the second polarity capacitor C2 are related to the residual voltage of the lightning protection circuit, that is, the greater the residual voltage of the lightning protection circuit, the greater the capacity of the first polarity capacitor C1 and the capacity of the second polarity capacitor C2, and the smaller the residual voltage of the lightning protection circuit, the smaller the capacity of the first polarity capacitor C1 and the capacity of the second polarity capacitor C2. Therefore, the capacity of the first polarity capacitor C1 and the capacity of the second polarity capacitor C2 can be set according to the actual application scenario, and this embodiment does not make specific limitations.

[0028] The second embodiment of the present invention relates to a lightning protection circuit. This second embodiment is substantially similar to the first embodiment, with the primary difference being that, in this second embodiment, both the first switch and the second switch are diodes. The relevant technical details of the first embodiment remain valid in this embodiment and are omitted here to avoid repetition.

[0029] The second embodiment of the present application relates to a lightning protection circuit such as Figure 3 As shown, it includes: a lightning protection circuit 301, a first switch D1, a second switch D2, a first polarity capacitor C1, and a second polarity capacitor C2.

[0030] Specifically, the first input terminal Vin+ of the lightning protection circuit 301 is connected to the first output terminal of the power supply, and the second input terminal Vin- of the lightning protection circuit 301 is connected to the second output terminal of the power supply; the first end c of the first switch D1 is connected to the first output terminal a of the lightning protection circuit 301, the second end d of the first switch D1 is connected to the first end e of the second switch D2, and the second end f of the second switch D2 is connected to the second output terminal b of the lightning protection circuit 301; the first end g of the first polarity capacitor C1 is respectively connected to the first end c of the first switch D1 and the first input terminal of the external circuit, the second end h of the first polarity capacitor C1 is connected to the first end i of the second polarity capacitor C2, and the second end j of the second polarity capacitor C1 is respectively connected to the second end f of the second switch D2 and the second input terminal of the external circuit; there is a first node A between the first switch D1 and the second switch D2, a second node B between the first polarity capacitor C1 and the second polarity capacitor C2, and the first node A is connected to the second node B.

[0031] Specifically, the first switch D1 and the second switch D2 are both diodes. Figure 3 As shown, the first end c of the first switch D1 is a cathode, and the second end d of the first switch D1 is an anode. At this time, to ensure the normal operation of the lightning protection circuit, the first end e of the second switch D2 is an anode, and the second end f of the second switch D2 is a cathode; the first end g of the first polarity capacitor C1 is an anode, and the second end h of the first polarity capacitor C1 is a cathode; the first end i of the second polarity capacitor C2 is a cathode, and the second end j of the second polarity capacitor C2 is an anode. Through this configuration, the conduction states of the first switch D1 and the second switch D2 are opposite. When the first switch D1 is on, the second polarity capacitor C2 is in an operating state, and when the second switch D2 is on, the first polarity capacitor C1 is in an operating state. Therefore, no matter which end of the lightning protection circuit receives a larger level of lightning surge, the residual voltage can be absorbed by the larger polarity capacitor, thereby protecting the external circuit.

[0032] In practical applications, such as Figure 3In the shown circuit, when the first input end Vin+ of the lightning protection circuit 301 receives a lightning surge, the voltage of the first output end Vin+ of the lightning protection circuit 301 is greater than the voltage of the second output end Vin- of the lightning protection circuit 301, according to the characteristics of the diode, at this time, the first switch D1 is off, the second switch D2 is on, the first polarity capacitor C1 is in working state, and absorbs the residual voltage through the lightning protection circuit 301, and the second polarity capacitor C2 is in non-working state due to being reversely embedded by the second switch D2; when the second input end Vin- of the lightning protection circuit 301 receives a lightning surge, the voltage of the first output end a of the lightning protection circuit 301 is less than the voltage of the second output end b of the lightning protection circuit 301, according to the characteristics of the diode, at this time, the first switch D1 is on, the second switch D2 is off, the second polarity capacitor C2 is in working state, and absorbs the residual voltage through the lightning protection circuit 301, and the first polarity capacitor C1 is in non-working state due to being reversely embedded by the first switch D1.

[0033] Another lightning protection circuit related to the embodiment is shown in Figure 4 The lightning protection circuit 401, the first switch D1, the second switch D2, the first polarity capacitor C1, and the second polarity capacitor C2.

[0034] Specifically, the first input end Vin+ of the lightning protection circuit 401 is connected to the first output end of the power supply, and the second input end Vin- of the lightning protection circuit 401 is connected to the second output end of the power supply; the first end c of the first switch D1 is connected to the first output end a of the lightning protection circuit 401, the second end d of the first switch D1 is connected to the first end e of the second switch D2, the second end f of the second switch D2 is connected to the second output end b of the lightning protection circuit 401; the first end g of the first polarity capacitor C1 is connected to the first end c of the first switch D1 and the first input end of the external circuit respectively, the second end h of the first polarity capacitor C1 is connected to the first end i of the second polarity capacitor C2, and the second end j of the second polarity capacitor C1 is connected to the second end f of the second switch D2 and the second input end of the external circuit respectively; there is a first node A between the first switch D1 and the second switch D2, there is a second node B between the first polarity capacitor C1 and the second polarity capacitor C2, and the first node A and the second node B are connected.

[0035] In the embodiment, as Figure 4As shown, the first end c of the first switch D1 is an anode, and the second end d of the first switch D1 is a cathode. At this time, to ensure the normal operation of the lightning protection circuit, the first end e of the second switch D2 is a cathode, and the second end f of the second switch D2 is an anode; the first end g of the first polarity capacitor C1 is a cathode, and the second end h of the first polarity capacitor C1 is an anode; the first end i of the second polarity capacitor C2 is an anode, and the second end j of the second polarity capacitor C2 is a cathode. Through this configuration, the conduction states of the first switch D1 and the second switch D2 are opposite. When the first switch D1 is on, the second polarity capacitor C2 is in an operating state, and when the second switch D2 is on, the first polarity capacitor C1 is in an operating state. Therefore, no matter which end of the lightning protection circuit receives a larger level of lightning surge, the residual voltage can be absorbed by the larger polarity capacitor, thereby protecting the external circuit.

[0036] In practical applications, such as Figure 4 In the circuit shown, when the first input terminal Vin+ of the lightning protection circuit 401 receives a lightning surge, the voltage at the first output terminal Vin+ of the lightning protection circuit 401 is greater than the voltage at the second output terminal Vin- of the lightning protection circuit 401. According to the characteristics of the diode, at this time, the first switch D1 is turned on, the second switch D2 is turned off, and the second polarity capacitor C2 is in a working state, absorbing the residual voltage passing through the lightning protection circuit 401. The first polarity capacitor C1 is in a non-working state due to being reversely clamped by the first switch D1. When the second input terminal Vin- of the lightning protection circuit 401 receives a lightning surge, the voltage at the first output terminal a of the lightning protection circuit 401 is less than the voltage at the second output terminal b of the lightning protection circuit 401. According to the characteristics of the diode, at this time, the second switch D2 is turned on, the first switch D1 is turned off, the first polarity capacitor C1 is in a working state, absorbing the residual voltage passing through the lightning protection circuit 401, and the second polarity capacitor C2 is in a non-working state due to being reversely clamped by the second switch D2.

[0037] It should be noted that through Figure 3 、 Figure 4 It can be seen from the structure of the lightning protection circuit that since the first switch D1 and the second switch D2 are both set as diodes, in order to ensure that the lightning protection circuit can operate normally, the polarity of the second end h of the first polarity capacitor C1 is the same as the polarity of the first end i of the second polarity capacitor C2; the polarity of the second end d of the first switch D1 is the same as the polarity of the first end e of the second switch D2; the polarity of the first end c of the first switch D1 is opposite to the polarity of the first end g of the first polarity capacitor C1; so that when the first switch D1 is turned on, the second polarity capacitor C2 is in a working state, and when the second switch D2 is turned on, the first polarity capacitor C1 is in a working state, and the conduction states of the first switch D1 and the second switch D2 are opposite.

[0038] In the embodiment, by setting the first switch D1 and the second switch D2 as diodes, the polarity of the capacitor in working state can be determined according to the voltage value of the two output terminals of the lightning protection circuit by using the characteristics of the diodes, and the structure is simple and the cost is low.

[0039] A third embodiment of the present application relates to a lightning protection circuit. The third embodiment is substantially the same as the first embodiment, and the main difference is that the lightning protection circuit further comprises a control circuit in the third embodiment. The technical details of the first embodiment are still valid in the third embodiment, and are not repeated here.

[0040] The lightning protection circuit of the third embodiment of the present application is shown in Figure 5 The lightning protection circuit of the third embodiment of the present application is shown in

[0041] Specifically, the first input terminal Vin+ of the lightning protection circuit 501 is connected to the first output terminal of the power supply, and the second input terminal Vin- of the lightning protection circuit 501 is connected to the second output terminal of the power supply; the first end c of the first switch S1 is connected to the first output terminal a of the lightning protection circuit 501, the second end d of the first switch S1 is connected to the first end e of the second switch S2, and the second end f of the second switch S2 is connected to the second output terminal b of the lightning protection circuit 501; the first end g of the first polarity capacitor C1 is connected to the first end c of the first switch S1 and the first input terminal of the external circuit, the second end h of the first polarity capacitor C1 is connected to the first end i of the second polarity capacitor C2, and the second end j of the second polarity capacitor C2 is connected to the second end f of the second switch S2 and the second input terminal of the external circuit; there is a first node A between the first switch S1 and the second switch S2, there is a second node B between the first polarity capacitor C1 and the second polarity capacitor C2, and the first node A and the second node B are connected.

[0042] The first input terminal of the control circuit 502 is connected to the first end c of the first switch S1 (i.e. the first output terminal a of the lightning protection circuit 501), and the second input terminal of the control circuit 502 is connected to the second end f of the second switch S2 (i.e. the second output terminal b of the lightning protection circuit 501); the first control terminal of the control circuit 502 is connected to the control terminal o of the first switch S1, and the second control terminal of the control circuit 502 is connected to the control terminal p of the second switch S2; the control circuit 502 is used to control the conduction and turn-off of the first switch S1 and the second switch S2 according to the voltage of the first end c of the first switch S1 and the voltage of the second end f of the second switch S2 (i.e. the voltage of the first output terminal a of the lightning protection circuit 501 and the voltage of the second output terminal b of the lightning protection circuit 501).

[0043] In one example, when the control circuit 502 detects that the voltage of the first end of the first switch S1 is greater than the voltage of the second end f of the second switch S2 (i.e. the voltage of the first output end a of the lightning protection circuit 501 is greater than the voltage of the second output end b of the lightning protection circuit 501), the control circuit 502 controls the first switch S1 to be off through the first control end and controls the second switch S2 to be on through the second control end; when the control circuit 502 detects that the voltage of the first end c of the first switch S1 is less than the voltage of the second end f of the second switch S2 (i.e. the voltage of the first output end a of the lightning protection circuit 501 is less than the voltage of the second output end b of the lightning protection circuit 501), the control circuit 502 controls the first switch S1 to be on through the first control end and controls the second switch S2 to be off through the second control end.

[0044] It should be noted that the control circuit 502 has the ability to collect voltage values, analyze the size of the voltage values, and control the on and off of the switches. In actual application, since the first input end of the control circuit 502 is connected to the first end c of the first switch S1 and the second input end of the control circuit 502 is connected to the second end f of the second switch S2, the control circuit 502 can collect the voltage value of the first end c of the first switch S1 and the voltage value of the second end f of the second switch S2; then, the control circuit 502 compares the size of the two voltage values, when the voltage value of the first end c of the first switch S1 is greater than the voltage value of the second end f of the second switch S2 (i.e. the voltage of the first output end a of the lightning protection circuit 501 is greater than the voltage of the second output end b of the lightning protection circuit 501), the control circuit 502 can control the first switch S1 to be off through the first control end and control the second switch S2 to be on through the second control end; when the control circuit 502 detects that the voltage of the first end c of the first switch S1 is less than the voltage of the second end f of the second switch S2 (i.e. the voltage of the first output end a of the lightning protection circuit 501 is less than the voltage of the second output end b of the lightning protection circuit 501), the control circuit 502 can control the first switch S1 to be on through the first control end and control the second switch S2 to be off through the second control end.

[0045] In another example, the control circuit 502 can be configured to control the first switch S1 to be turned on and the second switch S2 to be turned off when the control circuit 502 detects that the voltage at the first end c of the first switch S1 is greater than the voltage at the second end f of the second switch S2 (i.e., the voltage at the first output end a of the lightning protection circuit 501 is greater than the voltage at the second output end b of the lightning protection circuit 501); and the control circuit 502 can be configured to control the first switch S1 to be turned off and the second switch S2 to be turned on when the control circuit 502 detects that the voltage at the first end of the first switch S1 is less than the voltage at the second end of the second switch S2 (i.e., the voltage at the first output end a of the lightning protection circuit 501 is less than the voltage at the second output end b of the lightning protection circuit 501).

[0046] In one example, the first switch and the second switch are both electronic switches; the first switch S1 and the second switch S2 can be one of or a combination of any two of the following: a transistor, a relay. The transistor can be an insulated gate field effect transistor, an insulated gate bipolar transistor, etc. In this embodiment, the switches can be of the same type or different types, and the type of the switches can be set according to actual needs, which can accommodate more use scenarios.

[0047] The fourth embodiment of the present application relates to a circuit board assembly comprising the lightning protection circuit of the first embodiment, the second embodiment, or the third embodiment.

[0048] The fourth embodiment of the present application relates to a circuit board assembly comprising the lightning protection circuit of the first embodiment, the second embodiment, or the third embodiment.

[0049] The fifth embodiment of the present application relates to an electronic device comprising the circuit board assembly of the fourth embodiment.

[0050] The fifth embodiment of the present application relates to an electronic device comprising the circuit board assembly of the fourth embodiment.

[0051] Those skilled in the art can understand that the above embodiments are specific embodiments for implementing the present application, and in actual applications, various changes can be made in form and details without departing from the spirit and scope of the present application.

Claims

1. A lightning protection circuit, characterized in that: include: Lightning protection circuit, first switch, second switch, first polarity capacitor, second polarity capacitor; The first input end of the lightning protection circuit is connected to the first output end of the power supply, and the second input end of the lightning protection circuit is connected to the second output end of the power supply; A first end of the first switch is connected to a first output end of the lightning protection circuit, a second end of the first switch is connected to a first end of the second switch, and a second end of the second switch is connected to a second output end of the lightning protection circuit; The first end of the first polarity capacitor is connected to the first end of the first switch and the first input end of the external circuit respectively, the second end of the first polarity capacitor is connected to the first end of the second polarity capacitor, and the second end of the second polarity capacitor is connected to the second end of the second switch and the second input end of the external circuit respectively; There is a first node between the first switch and the second switch, there is a second node between the first polarity capacitor and the second polarity capacitor, and the first node is connected to the second node; The conduction states of the first switch and the second switch are determined according to the magnitude of the voltage at the first end of the first switch and the voltage at the second end of the second switch, and the conduction states of the first switch and the second switch are opposite; when the first switch is turned on, the second polarity capacitor is in a working state, and when the second switch is turned on, the first polarity capacitor is in a working state.

2. The lightning protection circuit according to claim 1, characterized in that: The first switch and the second switch are both diodes; The polarity of the second end of the first polarity capacitor is the same as the polarity of the first end of the second polarity capacitor; the polarity of the second end of the first switch is the same as the polarity of the first end of the second switch; the polarity of the first end of the first switch is opposite to the polarity of the first end of the first polarity capacitor.

3. The lightning protection circuit according to claim 2, characterized in that: The first end of the first switch is a cathode, and the second end of the first switch is an anode.

4. The lightning protection circuit according to claim 1, characterized in that: The lightning protection circuit also includes a control circuit; The first input terminal of the control circuit is connected to the first terminal of the first switch, and the second input terminal of the control circuit is connected to the second terminal of the second switch; The first control end of the control circuit is connected to the control end of the first switch, and the second control end of the control circuit is connected to the control end of the second switch; The control circuit is used to control the on and off of the first switch and the second switch according to the voltage of the first end of the first switch and the voltage of the second end of the second switch.

5. The lightning protection circuit according to claim 4, characterized in that: The first switch and the second switch are both electronic switches.

6. The lightning protection circuit according to claim 4, characterized in that: The first switch and the second switch may be one of the following or a combination of any two: Transistors, relays.

7. The lightning protection circuit according to any one of claims 1 to 6, characterized in that: The lightning protection circuit also includes an anti-reverse connection circuit; The first input end of the anti-reverse connection circuit is connected to the first end of the first polarity capacitor, and the second input end of the anti-reverse connection circuit is connected to the second end of the second polarity capacitor; The first output end of the anti-reverse connection circuit is connected to the first input end of the external circuit, and the second output end of the anti-reverse connection circuit is connected to the second input end of the external circuit.

8. The lightning protection circuit according to claim 4, characterized in that: When the control circuit detects that the voltage at the first end of the first switch is greater than the voltage at the second end of the second switch, the control circuit controls the first switch to be turned off through the first control end and controls the second switch to be turned on through the second control end; When the control circuit detects that the voltage at the first end of the first switch is less than the voltage at the second end of the second switch, the control circuit controls the first switch to be turned on through the first control end and controls the second switch to be turned off through the second control end.

9. A circuit board assembly, characterized in that: The lightning protection circuit comprises the lightning protection circuit according to any one of claims 1 to 8.

10. An electronic device, characterized in that: A circuit board assembly comprising the circuit board assembly of claim 9.

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