Anti-surge circuit and system

Abstract

The invention relates to the technical field of electronic circuit design, in particular to an anti-surge circuit and system.The first end of a first resistor is electrically connected with a power interface and a load positive interface, and the second end of the first resistor is electrically connected with the first end of a first capacitor; the first end of the first capacitor is electrically connected with the positive input end of the oscillation charging sub-circuit, and the second end of the first capacitor is electrically connected with the load negative interface; the negative input end of the oscillation charging electronic circuit is electrically connected with the second end of the first capacitor, the positive output end of the oscillation charging electronic circuit is electrically connected with the base electrode of the NPN triode, and the negative output end of the oscillation charging electronic circuit is electrically connected with the collector electrode of the NPN triode; the positive input end of the oscillation discharging circuit is electrically connected with the base electrode of the NPN triode, the negative input end of the oscillation discharging circuit is electrically connected with the emitting electrode of the NPN triode, and the output end of the oscillation discharging circuit is grounded. The circuit can protect the precision load from being damaged by surge voltage and transient overcurrent possibly occurring at the moment of power-on.

Description

Technical Field

[0001] The present invention relates to the technical field of electronic circuit design, and in particular to a surge protection circuit and system. Background Art

[0002] With the development of modern electronic technology, electronic equipment and electronic components have become more sophisticated and miniaturized, and their operating conditions have become more demanding and sensitive. A slightly larger current or voltage may damage these precision electronic components. Even a transient overvoltage or transient overcurrent that lasts only tens of microseconds can cause irreversible and serious impacts on them. On this basis, current power supply technology may cause surge voltage and transient overcurrent at the moment of powering on the load, causing irreversible damage to the precision load and posing a serious threat to the safety and service life of the precision load. Summary of the invention

[0003] The object of the present invention is to provide a surge protection circuit, which can protect precision loads from being damaged by surge voltage and transient overcurrent that may occur at the moment of power-on.

[0004] In order to achieve the above-mentioned purpose, the first aspect of the present invention provides a surge protection circuit, including an oscillation charging sub-circuit, an oscillation discharging sub-circuit, a first resistor, a first capacitor, an NPN transistor, a power supply interface, a load positive interface and a load negative interface; the first end of the first resistor is electrically connected to the power supply interface and the load positive interface respectively, and the second end of the first resistor is electrically connected to the first end of the first capacitor; the first end of the first capacitor is electrically connected to the positive input end of the oscillation charging sub-circuit, and the second end of the first capacitor is electrically connected to the load negative interface; the negative input end of the oscillation charging sub-circuit is electrically connected to the second end of the first capacitor, the positive output end of the oscillation charging sub-circuit is electrically connected to the base of the NPN transistor, and the oscillation charging sub-circuit is electrically connected to the base of the NPN transistor. The negative output end of the circuit is electrically connected to the collector of the NPN transistor; the positive input end of the oscillation discharge sub-circuit is electrically connected to the base of the NPN transistor, the negative input end of the oscillation discharge sub-circuit is electrically connected to the emitter of the NPN transistor, and the output end of the oscillation discharge sub-circuit is grounded, wherein: the oscillation charging sub-circuit is used to charge the oscillation discharge sub-circuit when the NPN transistor is cut off; the oscillation discharge sub-circuit turns on the NPN transistor briefly and releases the stored voltage when the stored voltage reaches a preset voltage threshold; the first capacitor is used to charge slowly, so that when the stored voltage reaches the voltage threshold, the NPN transistor is continuously turned on, and then the surge protection circuit is continuously turned on.

[0005] In the above-mentioned surge protection circuit, the first capacitor, the oscillation charging sub-circuit, the oscillation discharge sub-circuit and the base of the NPN transistor are in parallel. Under the initial condition, the base has no voltage and the NPN transistor is in a cut-off state. When the power interface receives the supply voltage, the first capacitor begins to charge slowly; at the same time, the oscillation charging sub-circuit begins to charge the oscillation discharge sub-circuit. When the voltage stored in the oscillation discharge sub-circuit reaches the preset voltage threshold, its parallel base also reaches the voltage threshold, thereby making the NPN transistor forward biased. When the NPN transistor is forward biased, the oscillation charging sub-circuit cannot charge the oscillation discharge sub-circuit, and the oscillation discharge sub-circuit releases its stored voltage to the ground terminal through the output terminal, so that its parallel base has no voltage, thereby making the NPN transistor cut off. When the NPN transistor is cut off, the oscillation charging sub-circuit can continue to charge the oscillation discharge sub-circuit. Through the process of repeated charging and discharging of the above-mentioned oscillating charging sub-circuit and oscillating discharging sub-circuit, the surge voltage and transient overcurrent in the power supply voltage received by the power interface are released through the ground terminal, thereby protecting the load positive interface terminal and the load negative interface terminal. Finally, when the voltage stored in the first capacitor reaches the voltage threshold, the NPN transistor is continuously turned on, thereby continuously turning on the surge protection circuit. At this time, there is no surge voltage and transient overcurrent in the power supply voltage, the oscillating charging sub-circuit and the oscillating discharging sub-circuit stop the charging and discharging process, and the power supply voltage received by the power interface is normally output to the external device connected to the load positive interface and the load negative interface through the surge protection circuit.

[0006] In a possible implementation, the oscillation charging sub-circuit includes a first diode, a second voltage-stabilizing diode, and a second resistor, wherein: the cathode of the first diode serves as the positive input terminal of the oscillation charging sub-circuit, and the anode of the first diode is electrically connected to the anode of the second voltage-stabilizing diode; the cathode of the second voltage-stabilizing diode serves as the negative input terminal and the negative output terminal of the oscillation charging sub-circuit; the first end of the second resistor is electrically connected to the cathode of the first diode, and the second end of the second resistor serves as the positive output terminal of the oscillation charging sub-circuit.

[0007] In this implementation, based on the unidirectional conduction characteristic of the first diode, the cathode of the first diode is used as the positive input terminal of the oscillation charging sub-circuit, and the cathode of the first diode is electrically connected to the second resistor, so that when the oscillation charging sub-circuit charges the oscillation discharge sub-circuit, the current can flow from the positive output terminal of the oscillation charging sub-circuit to the positive input terminal of the oscillation discharge sub-circuit through the second resistor; and when the oscillation discharge sub-circuit releases its stored voltage, the discharge current cannot flow from the positive input terminal of the oscillation discharge sub-circuit to the positive output terminal of the oscillation charging sub-circuit, and can only be released to the ground terminal through the output terminal of the oscillation discharge sub-circuit. On this basis, the first diode makes the charging and discharging process between the oscillation charging sub-circuit and the oscillation discharge sub-circuit unable to affect the slow charging process of the first capacitor, realizes the isolation effect of the oscillation circuit and the first capacitor charging circuit, ensures that the slow charging process of the first capacitor will not be disturbed by the voltage and current fluctuations of the oscillation charging and discharging process, thereby ensuring the startup time of the surge protection circuit and improving the safety of the surge protection circuit.

[0008] It should also be noted that when the base reaches the voltage threshold and the NPN transistor is forward biased, the cathode of the second voltage zener diode is directly connected to the collector of the NPN transistor, resulting in the positive electrode voltage of the second voltage zener diode being pulled down to the saturation voltage drop value when the NPN transistor is forward biased. At this time, since the positive electrode voltage of the second voltage zener diode is pulled down, the charging path for charging the oscillating discharge sub-circuit through the second resistor cannot maintain an effective forward bias, thereby interrupting the charging process of the oscillating charging sub-circuit to the oscillating discharge sub-circuit, creating conditions for the oscillating discharge sub-circuit to enter the discharge stage and release its stored voltage.

[0009] In a possible implementation, the oscillation discharge sub-circuit includes a third resistor and a second capacitor, wherein: the first end of the third resistor serves as the positive input end of the oscillation discharge sub-circuit, and the second end of the third resistor serves as the negative input end and the output end of the oscillation discharge sub-circuit; the first end of the second capacitor is electrically connected to the first end of the third resistor, and the second end of the second capacitor is electrically connected to the second end of the third resistor.

[0010] In this implementation, the second capacitor is used to store the voltage input from the oscillation charging sub-circuit to the oscillation discharging sub-circuit, and when the NPN transistor is forward-biased and the oscillation charging sub-circuit stops charging, it discharges through the third resistor, so that the released voltage flows to the ground terminal through the output terminal.

[0011] It should also be noted that, by designing the capacitance value of the second capacitor and the resistance value of the third resistor, the charging and discharging time of the second capacitor is much shorter than the slow charging time of the first capacitor, so that during the period when the first capacitor is charged until the voltage threshold is reached, the oscillation charging sub-circuit and the oscillation discharging sub-circuit can repeat the charging and discharging process multiple times, thereby releasing the surge voltage and transient overcurrent in the power supply voltage received by the power interface through the ground terminal during multiple charging and discharging processes.

[0012] In one possible implementation, the surge protection circuit also includes a filtering subcircuit, wherein the positive input terminal of the filtering subcircuit is electrically connected to the first end of the first resistor, the negative input terminal of the filtering subcircuit is electrically connected to the second end of the first capacitor, the positive output terminal of the filtering subcircuit is electrically connected to the load positive interface, and the negative output terminal of the filtering subcircuit is electrically connected to the load negative interface, wherein: the filtering subcircuit is used to stabilize the voltage between the load positive interface and the load negative interface.

[0013] In this implementation, the filtering subcircuit processes the fluctuating voltage generated by the repeated conduction and cutoff of the NPN transistor during the charging and discharging of the oscillation circuit into a smooth DC voltage, stabilizes the voltage between the load positive interface and the load negative interface, protects the electrical equipment external to the load positive interface and the load negative interface, and improves the safety of the surge protection circuit.

[0014] In a possible implementation, the filtering subcircuit includes a first inductor and a third capacitor, wherein: the first end of the first inductor serves as a positive input end of the filtering subcircuit, and the second end of the first inductor serves as a positive output end of the filtering subcircuit; the first end of the third capacitor is electrically connected to the second end of the first inductor, and the second end of the third capacitor serves as a negative input end and a negative output end of the filtering subcircuit.

[0015] In this implementation, when the NPN transistor is repeatedly turned on and off so that the current flowing through the filter subcircuit changes, the first inductor generates a reverse electromotive force, thereby making the current change tend to be smooth, thereby stabilizing the current between the load positive interface and the load negative interface; when the NPN transistor is repeatedly turned on and off so that the voltage of the filter subcircuit increases instantaneously, the third capacitor absorbs excess charge by storing energy, and when the voltage of the filter subcircuit decreases instantaneously, the third capacitor releases the stored charge to compensate for the decreased voltage, thereby stabilizing the voltage between the load positive interface and the load negative interface, protecting the electrical equipment connected to the load positive interface and the load negative interface, and improving the safety of the surge protection circuit.

[0016] In one possible implementation, the surge protection circuit also includes a third diode, the anode of the third diode is electrically connected to the first end of the first capacitor, and the cathode of the third diode is electrically connected to the positive input end of the oscillation charging sub-circuit, wherein: the third diode is used to cut off the surge protection circuit when the power interface receives a preset reverse voltage.

[0017] In this implementation, when the power interface receives reverse power supply with opposite polarity, the third diode is cut off based on its unidirectional conduction characteristics, and the NPN transistor is also cut off, thereby cutting off the surge protection circuit, thereby protecting the load positive interface and the load negative interface from the influence of reverse voltage power supply, protecting the electrical equipment connected to the load positive interface and the load negative interface; preventing reverse connection of the power supply, and improving the safety of the surge protection circuit.

[0018] A second aspect of the present invention provides a surge protection system, comprising a power supply, a surge protection circuit and a load; the surge protection circuit comprises an oscillation charging sub-circuit, an oscillation discharging sub-circuit, a first resistor, a first capacitor, an NPN transistor, a power supply interface, a load positive interface and a load negative interface; the first end of the first resistor is electrically connected to the power supply interface and the load positive interface, and the second end of the first resistor is electrically connected to the first end of the first capacitor; the first end of the first capacitor is electrically connected to the positive input end of the oscillation charging sub-circuit, and the second end of the first capacitor is electrically connected to the load negative interface; the negative input end of the oscillation charging sub-circuit is electrically connected to the second end of the first capacitor, the positive output end of the oscillation charging sub-circuit is electrically connected to the base of the NPN transistor, and the negative output end of the oscillation charging sub-circuit is electrically connected to the collector of the NPN transistor; the positive input end of the oscillation discharging sub-circuit is electrically connected to the NPN transistor The base of the tube, the negative input end of the oscillating discharge sub-circuit is electrically connected to the emitter of the NPN transistor, and the output end of the oscillating discharge sub-circuit is grounded, wherein: the output end of the power supply is electrically connected to the power supply interface, which is used to output the power supply voltage to the anti-surge circuit; the anti-surge circuit is used to transmit the power supply voltage of the power supply to the load when it is turned on; the positive electrode of the load is electrically connected to the positive interface of the load, and the negative electrode of the load is electrically connected to the negative interface of the load; the oscillating charging sub-circuit is used to charge the oscillating discharge sub-circuit when the NPN transistor is cut off; the oscillating discharge sub-circuit turns on the NPN transistor briefly and releases the stored voltage when the stored voltage reaches a preset voltage threshold; the first capacitor is used to charge slowly, so that when the stored voltage reaches the voltage threshold, the NPN transistor is continuously turned on, and then the anti-surge circuit is continuously turned on.

[0019] In the above-mentioned surge protection system, the first capacitor, the oscillation charging sub-circuit, the oscillation discharge sub-circuit and the base of the NPN transistor are in parallel. Under the initial condition, the base has no voltage and the NPN transistor is in a cut-off state. When the power interface receives the supply voltage, the first capacitor begins to charge slowly; at the same time, the oscillation charging sub-circuit begins to charge the oscillation discharge sub-circuit. When the voltage stored in the oscillation discharge sub-circuit reaches the preset voltage threshold, its parallel base also reaches the voltage threshold, thereby making the NPN transistor forward biased and turned on. When the NPN transistor is forward biased and turned on, the oscillation charging sub-circuit cannot charge the oscillation discharge sub-circuit, and the oscillation discharge sub-circuit releases its stored voltage to the ground terminal through the output terminal, so that its parallel base has no voltage, thereby making the NPN transistor turned off. When the NPN transistor is turned off, the oscillation charging sub-circuit can continue to charge the oscillation discharge sub-circuit. Through the process of repeated charging and discharging of the above-mentioned oscillating charging sub-circuit and oscillating discharging sub-circuit, the surge voltage and transient overcurrent in the power supply voltage received by the power interface are released through the ground terminal, thereby protecting the load positive interface terminal and the load negative interface terminal. Finally, when the voltage stored in the first capacitor reaches the voltage threshold, the NPN transistor is continuously turned on, thereby continuously turning on the surge protection circuit. At this time, there is no surge voltage and transient overcurrent in the power supply voltage, the oscillating charging sub-circuit and the oscillating discharging sub-circuit stop the charging and discharging process, and the power supply voltage received by the power interface is normally output to the external device connected to the load positive interface and the load negative interface through the surge protection circuit.

[0020] In a possible implementation, the oscillation charging sub-circuit includes a first diode, a second voltage-stabilizing diode, and a second resistor, wherein: the cathode of the first diode serves as the positive input terminal of the oscillation charging sub-circuit, and the anode of the first diode is electrically connected to the anode of the second voltage-stabilizing diode; the cathode of the second voltage-stabilizing diode serves as the negative input terminal and the negative output terminal of the oscillation charging sub-circuit; the first end of the second resistor is electrically connected to the cathode of the first diode, and the second end of the second resistor serves as the positive output terminal of the oscillation charging sub-circuit.

[0021] In this implementation, based on the unidirectional conduction characteristic of the first diode, the cathode of the first diode is used as the positive input terminal of the oscillation charging sub-circuit, and the cathode of the first diode is electrically connected to the second resistor, so that when the oscillation charging sub-circuit charges the oscillation discharge sub-circuit, the current can flow from the positive output terminal of the oscillation charging sub-circuit to the positive input terminal of the oscillation discharge sub-circuit through the second resistor; and when the oscillation discharge sub-circuit releases its stored voltage, the discharge current cannot flow from the positive input terminal of the oscillation discharge sub-circuit to the positive output terminal of the oscillation charging sub-circuit, and can only be released to the ground terminal through the output terminal of the oscillation discharge sub-circuit. On this basis, the first diode makes the charging and discharging process between the oscillation charging sub-circuit and the oscillation discharge sub-circuit unable to affect the slow charging process of the first capacitor, realizes the isolation effect of the oscillation circuit and the first capacitor charging circuit, ensures that the slow charging process of the first capacitor will not be disturbed by the voltage and current fluctuations of the oscillation charging and discharging process, thereby ensuring the startup time of the surge protection circuit and improving the safety of the surge protection circuit.

[0022] It should also be noted that when the base reaches the voltage threshold and the NPN transistor is forward biased, the cathode of the second voltage zener diode is directly connected to the collector of the NPN transistor, resulting in the positive electrode voltage of the second voltage zener diode being pulled down to the saturation voltage drop value when the NPN transistor is forward biased. At this time, since the positive electrode voltage of the second voltage zener diode is pulled down, the charging path for charging the oscillating discharge sub-circuit through the second resistor cannot maintain an effective forward bias, thereby interrupting the charging process of the oscillating charging sub-circuit to the oscillating discharge sub-circuit, creating conditions for the oscillating discharge sub-circuit to enter the discharge stage and release its stored voltage.

[0023] In a possible implementation, the oscillation discharge sub-circuit includes a third resistor and a second capacitor, wherein: the first end of the third resistor serves as the positive input end of the oscillation discharge sub-circuit, and the second end of the third resistor serves as the negative input end and the output end of the oscillation discharge sub-circuit; the first end of the second capacitor is electrically connected to the first end of the third resistor, and the second end of the second capacitor is electrically connected to the second end of the third resistor.

[0024] In this implementation, the second capacitor is used to store the voltage input from the oscillation charging sub-circuit to the oscillation discharging sub-circuit, and when the NPN transistor is forward-biased and the oscillation charging sub-circuit stops charging, it discharges through the third resistor, so that the released voltage flows to the ground terminal through the output terminal.

[0025] It should also be noted that, by designing the capacitance value of the second capacitor and the resistance value of the third resistor, the charging and discharging time of the second capacitor is much shorter than the slow charging time of the first capacitor, so that during the period when the first capacitor is charged until the voltage threshold is reached, the oscillation charging sub-circuit and the oscillation discharging sub-circuit can repeat the charging and discharging process multiple times, thereby releasing the surge voltage and transient overcurrent in the power supply voltage received by the power interface through the ground terminal during multiple charging and discharging processes.

[0026] In a possible implementation, the surge protection circuit also includes a filtering subcircuit, the positive input terminal of the filtering subcircuit is electrically connected to the first end of the first resistor, the negative input terminal of the filtering subcircuit is electrically connected to the second end of the first capacitor, the positive output terminal of the filtering subcircuit is electrically connected to the positive interface of the load, and the negative output terminal of the filtering subcircuit is electrically connected to the negative interface of the load, wherein: the filtering subcircuit is used to stabilize the voltage of the load.

[0027] In this implementation, the filtering subcircuit processes the fluctuating voltage generated by the repeated conduction and cutoff of the NPN transistor during the charging and discharging of the oscillation circuit into a smooth DC voltage, stabilizes the voltage between the load positive interface and the load negative interface, protects the electrical equipment external to the load positive interface and the load negative interface, and improves the safety of the surge protection circuit.

[0028] A surge protection circuit and system provided by the present invention has at least the following advantages compared with the prior art:

[0029] The present invention releases the surge voltage and transient overcurrent in the power supply voltage received by the power interface through the ground terminal through the process of repeated charging and discharging of the oscillating charging sub-circuit and the oscillating discharging sub-circuit, thereby protecting the load positive interface terminal and the load negative interface terminal. Finally, when the voltage stored in the first capacitor reaches the voltage threshold, the NPN transistor is continuously turned on, thereby continuously turning on the anti-surge circuit. At this time, there is no surge voltage and transient overcurrent in the power supply voltage, the oscillating charging sub-circuit and the oscillating discharging sub-circuit stop the charging and discharging process, and the power supply voltage received by the power interface is normally output to the external device connected to the load positive interface and the load negative interface through the anti-surge circuit. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 is a circuit structure diagram of a surge protection circuit provided by an embodiment of the present invention;

[0031] Figure 2 It is a circuit structure diagram of a surge protection circuit and an oscillation charging sub-circuit provided in an embodiment of the present invention;

[0032] Figure 3It is a circuit structure diagram of a surge protection circuit, an oscillation charging sub-circuit and an oscillation discharging sub-circuit provided in an embodiment of the present invention;

[0033] Figure 4 is a circuit structure diagram of another surge protection circuit provided by an embodiment of the present invention;

[0034] Figure 5 is a circuit structure diagram of another surge protection circuit provided by an embodiment of the present invention;

[0035] Figure 6 It is a circuit structure diagram of a surge protection circuit, an oscillation charging sub-circuit, an oscillation discharging sub-circuit and a filtering sub-circuit provided in an embodiment of the present invention;

[0036] Figure 7 is a structural diagram of a surge protection system provided by an embodiment of the present invention;

[0037] Among them: 110, oscillation charging sub-circuit; 120, oscillation discharging sub-circuit; 130, power supply interface; 140, load positive interface; 150, load negative interface; 160, filtering sub-circuit. DETAILED DESCRIPTION

[0038] The present invention will be described in detail below with reference to the accompanying drawings and in combination with embodiments. It should be noted that the embodiments and features in the embodiments of the present invention can be combined with each other without conflict.

[0039] The following detailed descriptions are all exemplary descriptions, and are intended to provide further detailed descriptions of the present invention. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by technicians in the technical field of the present application; the terms used in the specification of the application herein are only for the purpose of describing specific embodiments, and are not intended to limit the present application; the terms "including" and "having" in the specification and claims of the present application and the above-mentioned drawings and any variations thereof are intended to cover non-exclusive inclusions. The terms "first", "second", etc. in the specification and claims of the present application or the above-mentioned drawings are used to distinguish different objects, not to describe a specific order.

[0040] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0041] See also Figure 1In a first aspect, an embodiment of the present invention provides a surge protection circuit, comprising an oscillation charging subcircuit 110, an oscillation discharge subcircuit 120, a first resistor R1, a first capacitor C1, an NPN transistor V1, a power interface, a load positive interface 140 and a load negative interface 150; the first end of the first resistor R1 is electrically connected to the power interface and the load positive interface 140 respectively, and the second end of the first resistor R1 is electrically connected to the first end of the first capacitor C1; the first end of the first capacitor C1 is electrically connected to the positive input end of the oscillation charging subcircuit 110, and the second end of the first capacitor C1 is electrically connected to the load negative interface 150; the negative input end of the oscillation charging subcircuit 110 is electrically connected to the second end of the first capacitor C1, the positive output end of the oscillation charging subcircuit 110 is electrically connected to the base of the NPN transistor V1, and the oscillation The negative output terminal of the charging sub-circuit 110 is electrically connected to the collector of the NPN transistor V1; the positive input terminal of the oscillating discharge sub-circuit 120 is electrically connected to the base of the NPN transistor V1, the negative input terminal of the oscillating discharge sub-circuit 120 is electrically connected to the emitter of the NPN transistor V1, and the output terminal of the oscillating discharge sub-circuit 120 is grounded, wherein: the oscillating charging sub-circuit 110 is used to charge the oscillating discharge sub-circuit 120 when the NPN transistor V1 is cut off; the oscillating discharge sub-circuit 120 turns on the NPN transistor V1 briefly and releases the stored voltage when the stored voltage reaches a preset voltage threshold; the first capacitor C1 is used to charge slowly, so that the NPN transistor V1 is continuously turned on when the stored voltage reaches the voltage threshold, thereby continuously turning on the surge protection circuit.

[0042] In the above-mentioned surge protection circuit, the first capacitor C1, the oscillation charging subcircuit 110, the oscillation discharge subcircuit 120 and the base of the NPN transistor V1 are in parallel. Under the initial condition, the base has no voltage and the NPN transistor V1 is in a cut-off state. When the power interface 130 receives the supply voltage, the first capacitor C1 starts to charge slowly; at the same time, the oscillation charging subcircuit 110 starts to charge the oscillation discharge subcircuit 120. When the voltage stored in the oscillation discharge subcircuit 120 reaches the preset voltage threshold, its parallel base also reaches the voltage threshold, thereby making the NPN transistor V1 forward biased and turned on. When the NPN transistor V1 is forward biased and turned on, the oscillation charging subcircuit 110 cannot charge the oscillation discharge subcircuit 120, and the oscillation discharge subcircuit 120 releases its stored voltage to the ground terminal through the output terminal, so that its parallel base has no voltage, thereby making the NPN transistor V1 cut off. When the NPN transistor V1 is turned off, the oscillation charging sub-circuit 110 can continue to charge the oscillation discharge sub-circuit 120. Through the repeated charging and discharging process of the above-mentioned oscillation charging sub-circuit 110 and the oscillation discharge sub-circuit 120, the surge voltage and transient overcurrent in the power supply voltage received by the power interface 130 are released through the ground terminal, protecting the load positive interface 140 and the load negative interface 150. Finally, when the voltage stored in the first capacitor C1 reaches the voltage threshold, the NPN transistor V1 is continuously turned on, thereby continuously turning on the surge protection circuit. At this time, there is no surge voltage and transient overcurrent in the power supply voltage, the oscillation charging sub-circuit 110 and the oscillation discharge sub-circuit 120 stop the charging and discharging process, and the power supply voltage received by the power interface 130 is normally output to the external device connected to the load positive interface 140 and the load negative interface 150 through the surge protection circuit.

[0043] See also Figure 2 In a possible embodiment, the oscillation charging sub-circuit 110 includes a first diode D1, a second voltage-stabilizing diode D2, and a second resistor R2, wherein: the cathode of the first diode D1 serves as the positive input terminal of the oscillation charging sub-circuit 110, and the anode of the first diode D1 is electrically connected to the anode of the second voltage-stabilizing diode D2; the cathode of the second voltage-stabilizing diode D2 serves as the negative input terminal and the negative output terminal of the oscillation charging sub-circuit 110; the first end of the second resistor R2 is electrically connected to the cathode of the first diode D1, and the second end of the second resistor R2 serves as the positive output terminal of the oscillation charging sub-circuit 110.

[0044] In this embodiment, based on the unidirectional conduction characteristic of the first diode D1, the cathode of the first diode D1 is used as the positive input terminal of the oscillation charging sub-circuit 110, and the cathode of the first diode D1 is electrically connected to the second resistor R2, so that when the oscillation charging sub-circuit 110 charges the oscillation discharging sub-circuit 120, the current can flow from the positive output terminal of the oscillation charging sub-circuit 110 to the positive input terminal of the oscillation discharging sub-circuit 120 through the second resistor R2; and when the oscillation discharging sub-circuit 120 releases its stored voltage, the discharge current cannot flow from the positive input terminal of the oscillation discharging sub-circuit 120 to the positive output terminal of the oscillation charging sub-circuit 110, and can only be released to the ground terminal through the output terminal of the oscillation discharging sub-circuit 120. On this basis, the first diode D1 makes the charging and discharging process between the oscillating charging sub-circuit 110 and the oscillating discharging sub-circuit 120 unable to affect the slow charging process of the first capacitor C1, thereby realizing the isolation effect of the oscillating circuit and the charging circuit of the first capacitor C1, ensuring that the slow charging process of the first capacitor C1 will not be disturbed by the voltage and current fluctuations of the oscillating charging and discharging process, thereby ensuring the startup time of the surge protection circuit and improving the safety of the surge protection circuit.

[0045] It should also be noted that when the base reaches the voltage threshold and the NPN transistor V1 is forward biased, the cathode of the second voltage zener diode D2 is directly connected to the collector of the NPN transistor V1, resulting in the positive electrode voltage of the second voltage zener diode D2 also being pulled down to the saturation voltage drop value when the NPN transistor V1 is forward biased. At this time, since the positive electrode voltage of the second voltage zener diode D2 is pulled down, the charging path for charging the oscillating discharge sub-circuit 120 through the second resistor R2 cannot maintain an effective forward bias, thereby interrupting the charging process of the oscillating charging sub-circuit 110 to the oscillating discharge sub-circuit 120, creating conditions for the oscillating discharge sub-circuit 120 to enter the discharge stage and release its stored voltage.

[0046] See also Figure 3 In a possible embodiment, the oscillation discharge sub-circuit 120 includes a third resistor R3 and a second capacitor C2, wherein: the first end of the third resistor R3 serves as the positive input end of the oscillation discharge sub-circuit 120, and the second end of the third resistor R3 serves as the negative input end and the output end of the oscillation discharge sub-circuit 120; the first end of the second capacitor C2 is electrically connected to the first end of the third resistor R3, and the second end of the second capacitor C2 is electrically connected to the second end of the third resistor R3.

[0047] In this embodiment, the second capacitor C2 is used to store the voltage input from the oscillation charging sub-circuit 110 to the oscillation discharging sub-circuit 120, and when the NPN transistor V1 is forward biased and turned on and the oscillation charging sub-circuit 110 stops charging, the second capacitor C2 is discharged through the third resistor R3, so that the released voltage flows to the ground terminal through the output terminal.

[0048] It should also be noted that, by designing the capacitance value of the second capacitor C2 and the resistance value of the third resistor R3, the charging and discharging time of the second capacitor C2 is much shorter than the slow charging time of the first capacitor C1, so that during the period when the first capacitor C1 is charged until the voltage threshold is reached, the oscillation charging sub-circuit 110 and the oscillation discharging sub-circuit 120 can repeat the charging and discharging process multiple times, thereby releasing the surge voltage and transient overcurrent in the power supply voltage received by the power interface 130 through the ground terminal during multiple charging and discharging processes.

[0049] See also Figure 5 In a possible embodiment, the surge protection circuit further includes a filtering subcircuit 160, the positive input end of the filtering subcircuit 160 is electrically connected to the first end of the first resistor R1, the negative input end of the filtering subcircuit 160 is electrically connected to the second end of the first capacitor C1, the positive output end of the filtering subcircuit 160 is electrically connected to the load positive interface 140, and the negative output end of the filtering subcircuit 160 is electrically connected to the load negative interface 150, wherein: the filtering subcircuit 160 is used to stabilize the voltage between the load positive interface 140 and the load negative interface 150.

[0050] In this embodiment, the filtering subcircuit 160 processes the fluctuating voltage generated by the repeated turning on and off of the NPN transistor V1 during the charging and discharging of the oscillation circuit into a smooth DC voltage, thereby stabilizing the voltage between the load positive interface 140 and the load negative interface 150, protecting the electrical equipment external to the load positive interface 140 and the load negative interface 150, and improving the safety of the surge protection circuit.

[0051] See also Figure 6 In a possible embodiment, the filtering subcircuit 160 includes a first inductor L1 and a third capacitor C3, wherein: the first end of the first inductor L1 serves as the positive input end of the filtering subcircuit 160, and the second end of the first inductor L1 serves as the positive output end of the filtering subcircuit 160; the first end of the third capacitor C3 is electrically connected to the second end of the first inductor L1, and the second end of the third capacitor C3 serves as the negative input end and the negative output end of the filtering subcircuit 160.

[0052] In this embodiment, when the NPN transistor V1 is repeatedly turned on and off so that the current flowing through the filter subcircuit 160 changes, the first inductor L1 generates a reverse electromotive force, thereby making the current change tend to be gentle, thereby stabilizing the current between the load positive interface 140 and the load negative interface 150; when the NPN transistor V1 is repeatedly turned on and off so that the voltage of the filter subcircuit 160 increases instantaneously, the third capacitor C3 absorbs excess charge by storing energy, and when the voltage of the filter subcircuit 160 decreases instantaneously, the third capacitor C3 releases the stored charge to compensate for the decreased voltage, thereby stabilizing the voltage between the load positive interface 140 and the load negative interface 150, protecting the electrical equipment external to the load positive interface 140 and the load negative interface 150, and improving the safety of the surge protection circuit.

[0053] See also Figure 4 In a possible embodiment, the surge protection circuit further includes a third diode D3, an anode of the third diode D3 is electrically connected to the first end of the first capacitor C1, and a cathode of the third diode D3 is electrically connected to the positive input end of the oscillation charging sub-circuit 110, wherein: the third diode D3 is used to cut off the surge protection circuit when the power interface 130 receives a preset reverse voltage.

[0054] In this embodiment, when the power interface 130 receives reverse power supply with opposite polarity, the third diode D3 is cut off based on its unidirectional conduction characteristic, and the NPN transistor V1 is also cut off, so that the surge protection circuit is cut off, thereby protecting the load positive interface 140 and the load negative interface 150 from the influence of reverse voltage power supply, protecting the electrical equipment connected to the load positive interface 140 and the load negative interface 150; preventing the power supply from being reversed, and improving the safety of the surge protection circuit.

[0055] See also Figure 7In a second aspect, an embodiment of the present invention provides a surge protection system, including a power supply DC, a surge protection circuit and a load RL; the surge protection circuit includes an oscillation charging subcircuit 110, an oscillation discharge subcircuit 120, a first resistor R1, a first capacitor C1, an NPN transistor V1, a power interface 130, a load positive interface 140 and a load negative interface 150; the first end of the first resistor R1 is electrically connected to the power interface 130 and the load positive interface 140, and the second end of the first resistor R1 is electrically connected to the first end of the first capacitor C1; the first end of the first capacitor C1 is electrically connected to the positive input end of the oscillation charging subcircuit 110, and the second end of the first capacitor C1 is electrically connected to the load negative interface 150; the negative input end of the oscillation charging subcircuit 110 is electrically connected to the second end of the first capacitor C1, the positive output end of the oscillation charging subcircuit 110 is electrically connected to the base of the NPN transistor V1, and the negative output end of the oscillation charging subcircuit 110 is electrically connected to the collector of the NPN transistor V1; the positive input end of the oscillation discharge subcircuit 120 The negative input terminal of the oscillating discharge sub-circuit 120 is electrically connected to the base of the NPN transistor V1, the negative input terminal of the oscillating discharge sub-circuit 120 is electrically connected to the emitter of the NPN transistor V1, and the output terminal of the oscillating discharge sub-circuit 120 is grounded, wherein: the output terminal of the power supply DC is electrically connected to the power supply interface 130, which is used to output the power supply voltage to the surge protection circuit; the surge protection circuit is used to transmit the power supply voltage of the power supply DC to the load RL when it is turned on; the positive electrode of the load RL is electrically connected to the load positive interface 140, and the load RL The negative electrode is electrically connected to the load negative interface 150; the oscillation charging sub-circuit 110 is used to charge the oscillation discharge sub-circuit 120 when the NPN transistor V1 is cut off; the oscillation discharge sub-circuit 120 makes the NPN transistor V1 temporarily turned on when the stored voltage reaches a preset voltage threshold, and releases the stored voltage; the first capacitor C1 is used to charge slowly, so that when the stored voltage reaches the voltage threshold, the NPN transistor V1 is continuously turned on, and then the surge protection circuit is continuously turned on.

[0056] In the above-mentioned surge protection system, the first capacitor C1, the oscillation charging subcircuit 110, the oscillation discharge subcircuit 120 and the base of the NPN transistor V1 are in parallel. Under the initial condition, the base has no voltage and the NPN transistor V1 is in a cut-off state. When the power interface 130 receives the supply voltage, the first capacitor C1 starts to charge slowly; at the same time, the oscillation charging subcircuit 110 starts to charge the oscillation discharge subcircuit 120. When the voltage stored in the oscillation discharge subcircuit 120 reaches the preset voltage threshold, its parallel base also reaches the voltage threshold, thereby making the NPN transistor V1 forward biased and turned on. When the NPN transistor V1 is forward biased and turned on, the oscillation charging subcircuit 110 cannot charge the oscillation discharge subcircuit 120, and the oscillation discharge subcircuit 120 releases its stored voltage to the ground terminal through the output terminal, so that its parallel base has no voltage, thereby making the NPN transistor V1 cut off. When the NPN transistor V1 is turned off, the oscillation charging sub-circuit 110 can continue to charge the oscillation discharge sub-circuit 120. Through the repeated charging and discharging process of the above-mentioned oscillation charging sub-circuit 110 and the oscillation discharge sub-circuit 120, the surge voltage and transient overcurrent in the power supply voltage received by the power interface 130 are released through the ground terminal, protecting the load positive interface 140 and the load negative interface 150. Finally, when the voltage stored in the first capacitor C1 reaches the voltage threshold, the NPN transistor V1 is continuously turned on, thereby continuously turning on the surge protection circuit. At this time, there is no surge voltage and transient overcurrent in the power supply voltage, the oscillation charging sub-circuit 110 and the oscillation discharge sub-circuit 120 stop the charging and discharging process, and the power supply voltage received by the power interface 130 is normally output to the load RL connected to the load positive interface 140 and the load negative interface 150 through the surge protection circuit.

[0057] In a possible embodiment, the oscillation charging sub-circuit 110 includes a first diode D1, a second voltage-stabilizing diode D2, and a second resistor R2, wherein: the cathode of the first diode D1 serves as the positive input terminal of the oscillation charging sub-circuit 110, and the anode of the first diode D1 is electrically connected to the anode of the second voltage-stabilizing diode D2; the cathode of the second voltage-stabilizing diode D2 serves as the negative input terminal and the negative output terminal of the oscillation charging sub-circuit 110; the first end of the second resistor R2 is electrically connected to the cathode of the first diode D1, and the second end of the second resistor R2 serves as the positive output terminal of the oscillation charging sub-circuit 110.

[0058] In this embodiment, based on the unidirectional conduction characteristic of the first diode D1, the cathode of the first diode D1 is used as the positive input terminal of the oscillation charging sub-circuit 110, and the cathode of the first diode D1 is electrically connected to the second resistor R2, so that when the oscillation charging sub-circuit 110 charges the oscillation discharging sub-circuit 120, the current can flow from the positive output terminal of the oscillation charging sub-circuit 110 to the positive input terminal of the oscillation discharging sub-circuit 120 through the second resistor R2; and when the oscillation discharging sub-circuit 120 releases its stored voltage, the discharge current cannot flow from the positive input terminal of the oscillation discharging sub-circuit 120 to the positive output terminal of the oscillation charging sub-circuit 110, and can only be released to the ground terminal through the output terminal of the oscillation discharging sub-circuit 120. On this basis, the first diode D1 makes the charging and discharging process between the oscillating charging sub-circuit 110 and the oscillating discharging sub-circuit 120 unable to affect the slow charging process of the first capacitor C1, thereby realizing the isolation effect of the oscillating circuit and the charging circuit of the first capacitor C1, ensuring that the slow charging process of the first capacitor C1 will not be disturbed by the voltage and current fluctuations of the oscillating charging and discharging process, thereby ensuring the startup time of the surge protection circuit and improving the safety of the surge protection circuit.

[0059] It should also be noted that when the base reaches the voltage threshold and the NPN transistor V1 is forward biased, the cathode of the second voltage zener diode D2 is directly connected to the collector of the NPN transistor V1, resulting in the positive electrode voltage of the second voltage zener diode D2 also being pulled down to the saturation voltage drop value when the NPN transistor V1 is forward biased. At this time, since the positive electrode voltage of the second voltage zener diode D2 is pulled down, the charging path for charging the oscillating discharge sub-circuit 120 through the second resistor R2 cannot maintain an effective forward bias, thereby interrupting the charging process of the oscillating charging sub-circuit 110 to the oscillating discharge sub-circuit 120, creating conditions for the oscillating discharge sub-circuit 120 to enter the discharge stage and release its stored voltage.

[0060] In a possible embodiment, the oscillation discharge sub-circuit 120 includes a third resistor R3 and a second capacitor C2, wherein: the first end of the third resistor R3 serves as the positive input end of the oscillation discharge sub-circuit 120, and the second end of the third resistor R3 serves as the negative input end and the output end of the oscillation discharge sub-circuit 120; the first end of the second capacitor C2 is electrically connected to the first end of the third resistor R3, and the second end of the second capacitor C2 is electrically connected to the second end of the third resistor R3.

[0061] In this embodiment, the second capacitor C2 is used to store the voltage input from the oscillation charging sub-circuit 110 to the oscillation discharging sub-circuit 120, and when the NPN transistor V1 is forward biased and turned on and the oscillation charging sub-circuit 110 stops charging, the second capacitor C2 is discharged through the third resistor R3, so that the released voltage flows to the ground terminal through the output terminal.

[0062] It should also be noted that, by designing the capacitance value of the second capacitor C2 and the resistance value of the third resistor R3, the charging and discharging time of the second capacitor C2 is much shorter than the slow charging time of the first capacitor C1, so that during the period when the first capacitor C1 is charged until the voltage threshold is reached, the oscillation charging sub-circuit 110 and the oscillation discharging sub-circuit 120 can repeat the charging and discharging process multiple times, thereby releasing the surge voltage and transient overcurrent in the power supply voltage received by the power interface 130 through the ground terminal during multiple charging and discharging processes.

[0063] In a possible embodiment, the surge protection circuit also includes a filtering subcircuit 160, the positive input end of the filtering subcircuit 160 is electrically connected to the first end of the first resistor R1, the negative input end of the filtering subcircuit 160 is electrically connected to the second end of the first capacitor C1, the positive output end of the filtering subcircuit 160 is electrically connected to the load positive interface 140, and the negative output end of the filtering subcircuit 160 is electrically connected to the load negative interface 150, wherein: the filtering subcircuit 160 is used to stabilize the voltage of the load.

[0064] In this embodiment, the filtering subcircuit 160 processes the fluctuating voltage generated by the repeated conduction and cutoff of the NPN transistor V1 during the charging and discharging of the oscillation circuit into a smooth DC voltage, stabilizes the voltage between the load positive interface 140 and the load negative interface 150, protects the load RL externally connected to the load positive interface 140 and the load negative interface 150, and improves the safety of the surge protection circuit.

[0065] In a possible embodiment, the charge of the first capacitor C1 reaches the voltage threshold, so that the NPN transistor V1 is continuously turned on for about 60 seconds; the time for the third capacitor C3 to discharge through the third resistor R3 is much less than 60 seconds. By adjusting the resistance value of the third resistor R3, the second resistor R2 and the capacitance value of the third capacitor C3, the oscillation charging and discharging frequency of the oscillation charging sub-circuit 110 and the oscillation discharge sub-circuit 120 can be changed, and the effect of the surge protection circuit on releasing the surge voltage and transient overcurrent in the power supply voltage can be adjusted. By adjusting the resistance value of the first resistor R1 and the capacitance value of the first capacitor C1, the charge of the first capacitor C1 can be adjusted to reach the voltage threshold, so that the NPN transistor V1 is continuously turned on, thereby adjusting the time for the surge protection circuit to start stably.

[0066] In a possible embodiment, a plurality of the NPN transistors V1 may be connected in parallel to adjust the load capacity of the surge protection circuit.

[0067] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope recorded in this specification.

[0068] The above-described embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be construed as limiting the scope of the present application. It should be noted that, for a person of ordinary skill in the art, several improvements and substitutions may be made without departing from the concept of the present application, and these improvements and substitutions shall also be regarded as the protection scope of the present invention. Therefore, the protection scope of the present application shall be subject to the attached claims.

Claims

1. A surge protection circuit, characterized in that: It includes an oscillating charging subcircuit, an oscillating discharging subcircuit, a first resistor, a first capacitor, an NPN transistor, a power interface, a load positive interface and a load negative interface; the first end of the first resistor is electrically connected to the power interface and the load positive interface respectively, and the second end of the first resistor is electrically connected to the first end of the first capacitor; the first end of the first capacitor is electrically connected to the positive input end of the oscillating charging subcircuit, and the second end of the first capacitor is electrically connected to the load negative interface; the negative input end of the oscillating charging subcircuit is electrically connected to the second end of the first capacitor, the positive output end of the oscillating charging subcircuit is electrically connected to the base of the NPN transistor, and the negative output end of the oscillating charging subcircuit is electrically connected to the collector of the NPN transistor; the positive input end of the oscillating discharging subcircuit is electrically connected to the base of the NPN transistor, the negative input end of the oscillating discharging subcircuit is electrically connected to the emitter of the NPN transistor, and the output end of the oscillating discharging subcircuit is grounded, wherein: The oscillation charging sub-circuit is used to charge the oscillation discharging sub-circuit when the NPN transistor is cut off; The oscillating discharge subcircuit causes the NPN transistor to be temporarily turned on and releases the stored voltage when the stored voltage reaches a preset voltage threshold; The first capacitor is used for slowly charging, so that when the voltage stored in the first capacitor reaches the voltage threshold, the NPN transistor is continuously turned on, thereby causing the surge protection circuit to be continuously turned on.

2. A surge protection circuit according to claim 1, characterized in that: The oscillating charging subcircuit comprises a first diode, a second voltage stabilizing diode and a second resistor, wherein: The cathode of the first diode serves as the positive input terminal of the oscillation charging sub-circuit, and the anode of the first diode is electrically connected to the anode of the second voltage stabilizing diode; The cathode of the second voltage stabilizing diode serves as the negative input terminal and the negative output terminal of the oscillation charging subcircuit; The first end of the second resistor is electrically connected to the cathode of the first diode, and the second end of the second resistor serves as the positive output end of the oscillation charging sub-circuit.

3. The surge protection circuit according to claim 1, characterized in that: The oscillating discharge subcircuit comprises a third resistor and a second capacitor, wherein: The first end of the third resistor serves as the positive input end of the oscillating discharge sub-circuit, and the second end of the third resistor serves as the negative input end and the output end of the oscillating discharge sub-circuit; A first end of the second capacitor is electrically connected to a first end of the third resistor, and a second end of the second capacitor is electrically connected to a second end of the third resistor.

4. The surge protection circuit according to claim 1, characterized in that: It also includes a filter subcircuit, wherein the positive input end of the filter subcircuit is electrically connected to the first end of the first resistor, the negative input end of the filter subcircuit is electrically connected to the second end of the first capacitor, the positive output end of the filter subcircuit is electrically connected to the positive interface of the load, and the negative output end of the filter subcircuit is electrically connected to the negative interface of the load, wherein: The filtering subcircuit is used to stabilize the voltage between the load positive interface and the load negative interface.

5. A surge protection circuit according to claim 4, characterized in that: The filtering subcircuit comprises a first inductor and a third capacitor, wherein: The first end of the first inductor serves as a positive input end of the filter subcircuit, and the second end of the first inductor serves as a positive output end of the filter subcircuit; The first end of the third capacitor is electrically connected to the second end of the first inductor, and the second end of the third capacitor serves as a negative input end and a negative output end of the filter subcircuit.

6. The surge protection circuit according to claim 1, characterized in that: It also includes a third diode, wherein the anode of the third diode is electrically connected to the first end of the first capacitor, and the cathode of the third diode is electrically connected to the positive input end of the oscillation charging sub-circuit, wherein: The third diode is used to cut off the surge protection circuit when the power interface receives a preset reverse voltage.

7. A surge protection system, characterized in that: It includes a power supply, a surge protection circuit and a load; the surge protection circuit includes an oscillation charging subcircuit, an oscillation discharge subcircuit, a first resistor, a first capacitor, an NPN transistor, a power interface, a load positive interface and a load negative interface; the first end of the first resistor is electrically connected to the power interface and the load positive interface, and the second end of the first resistor is electrically connected to the first end of the first capacitor; the first end of the first capacitor is electrically connected to the positive input end of the oscillation charging subcircuit, and the second end of the first capacitor is electrically connected to the load negative interface; the negative input end of the oscillation charging subcircuit is electrically connected to the second end of the first capacitor, the positive output end of the oscillation charging subcircuit is electrically connected to the base of the NPN transistor, and the negative output end of the oscillation charging subcircuit is electrically connected to the collector of the NPN transistor; the positive input end of the oscillation discharge subcircuit is electrically connected to the base of the NPN transistor, the negative input end of the oscillation discharge subcircuit is electrically connected to the emitter of the NPN transistor, and the output end of the oscillation discharge subcircuit is grounded, wherein: The output end of the power supply is electrically connected to the power interface, which is used to output a power supply voltage to the surge protection circuit; The surge protection circuit is used to transmit the supply voltage of the power supply to the load when it is turned on; The positive electrode of the load is electrically connected to the load positive interface, and the negative electrode of the load is electrically connected to the load negative interface; The oscillation charging sub-circuit is used to charge the oscillation discharging sub-circuit when the NPN transistor is cut off; The oscillating discharge subcircuit causes the NPN transistor to be temporarily turned on and releases the stored voltage when the stored voltage reaches a preset voltage threshold; The first capacitor is used for slowly charging, so that when the voltage stored in the first capacitor reaches the voltage threshold, the NPN transistor is continuously turned on, thereby causing the surge protection circuit to be continuously turned on.

8. A surge protection system according to claim 7, characterized in that: The oscillating charging subcircuit comprises a first diode, a second voltage stabilizing diode and a second resistor, wherein: The cathode of the first diode serves as the positive input terminal of the oscillation charging sub-circuit, and the anode of the first diode is electrically connected to the anode of the second voltage stabilizing diode; The cathode of the second voltage stabilizing diode serves as the negative input terminal and the negative output terminal of the oscillation charging subcircuit; The first end of the second resistor is electrically connected to the cathode of the first diode, and the second end of the second resistor serves as the positive output end of the oscillation charging sub-circuit.

9. A surge protection system according to claim 7, characterized in that: The oscillating discharge subcircuit comprises a third resistor and a second capacitor, wherein: The first end of the third resistor serves as the positive input end of the oscillating discharge sub-circuit, and the second end of the third resistor serves as the negative input end and the output end of the oscillating discharge sub-circuit; A first end of the second capacitor is electrically connected to a first end of the third resistor, and a second end of the second capacitor is electrically connected to a second end of the third resistor.

10. A surge protection system according to claim 7, characterized in that: The surge protection circuit further includes a filter subcircuit, wherein the positive input end of the filter subcircuit is electrically connected to the first end of the first resistor, the negative input end of the filter subcircuit is electrically connected to the second end of the first capacitor, the positive output end of the filter subcircuit is electrically connected to the positive interface of the load, and the negative output end of the filter subcircuit is electrically connected to the negative interface of the load, wherein: The filtering subcircuit is used to stabilize the voltage of the load.

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