Surge suppression circuit

Abstract

The utility model discloses a surge suppression circuit, which comprises a switch module connected with a power supply, and the output end of the switch module is connected with a post-stage load; the access control module is connected to a power supply and the switch module; the overvoltage protection module is connected with the power supply and the access control module; the overvoltage protection module is configured to control the working state of the switch module by controlling the working state of the access control module, and when the working voltage of the power supply does not exceed a preset value, the access control module is kept working, so that the switch module works normally; and when the working voltage of the power supply exceeds a preset value, the output of the switch module is closed by closing the output of the access control module. According to the circuit, the risk that post-stage equipment including circuit components are damaged by long-time voltage surge in a low-internal-resistance scene of the power supply is reduced, and meanwhile, the problem that a surge suppression circuit or a post-stage circuit is burnt out due to reverse polarity connection of the power supply is solved.

Description

Technical Field

[0001] The utility model relates to the field of surges, in particular to a surge suppression circuit of a direct current power supply with a reverse connection prevention function. Background Art

[0002] In the electrical field, surge refers to the instantaneous overvoltage in the circuit that exceeds the normal operating voltage, that is, the peak value that exceeds the stable value appears instantly, so it is also called a surge. In essence, a surge is a violent pulse that occurs in just a few millionths of a second. Its generation time is short, usually only a few nanoseconds to a few milliseconds. When a surge occurs, the amplitude of the voltage and current exceeds the normal value by more than twice.

[0003] In some DC power supply applications, the power supply of the equipment is required to be able to withstand voltage surges of several hundred milliseconds and the circuit components are not damaged. In addition, after the power supply is reversed in polarity, the circuit components are also required not to be damaged and the power supply can still output normally.

[0004] DC surge suppression circuits generally use TVS tubes or varistors, which can be used for power supply with high internal resistance. However, when the internal resistance is low, this surge suppression circuit is difficult to suppress wide pulse voltage surges of several hundred milliseconds, which will cause device damage and power supply failure. In addition, common power supply voltage surge suppression circuits generally do not have reverse connection protection function.

[0005] In view of this, it is urgent to find a surge suppression circuit with anti-reverse connection function and capable of coping with low internal resistance DC power supply scenarios. Utility Model Content

[0006] In order to solve at least one of the problems existing in the above-mentioned prior art, the utility model provides a surge suppression circuit, comprising:

[0007] A switch module connected to the power supply, wherein the output end of the switch module is connected to a subsequent load;

[0008] A passage control module connected to the power supply and the switch module;

[0009] An overvoltage protection module connected to the power supply and the access control module;

[0010] The anti-reverse connection module connected to the power supply or the subsequent load,

[0011] Among them, the overvoltage protection module is configured to control the working state of the switch module by controlling the working state of the path control module, keep the path control module working when the working voltage of the power supply does not exceed the preset value so that the switch module works normally, and turn off the output of the switch module by turning off the output of the path control module when the working voltage of the power supply exceeds the preset value.

[0012] In some implementations of the present invention, the reverse connection protection module is placed between the switch module and the subsequent load, and is located at the last stage of the surge suppression circuit.

[0013] This connection method of the anti-reverse connection module does not need to consider the relationship between the withstand voltage of the diode in the circuit and the maximum value of the surge voltage, thereby reducing the manufacturing cost.

[0014] Furthermore, the path control module and the overvoltage protection module both include an anti-reverse connection device connected to the power supply, so that the protection of the devices in the path control module and the overvoltage protection module is further guaranteed.

[0015] Alternatively, in some embodiments of the present invention, the reverse connection protection module is placed after the power supply and is located at the front stage of the surge suppression circuit.

[0016] Through such a connection method, other anti-reverse connection devices in the entire circuit can be omitted, thus simplifying the device.

[0017] Optionally, in some embodiments of the present invention, the reverse connection protection module is a diode.

[0018] Using diodes to prevent reverse connection is the simplest, most reliable and low-cost method.

[0019] Specifically, in some embodiments of the present invention, the switch module, the path control module and the overvoltage protection module respectively include a first switch device, a second switch device and a third switch device, wherein the third switch device is connected to the control end of the second switch device, and the second switch device is connected to the control end of the first switch device, so that the first switch device is turned on or off by the turning on or off of the second switch device.

[0020] Furthermore, in some embodiments of the present invention, the switch module, the path control module and the overvoltage protection module also include a first voltage divider circuit, a second voltage divider circuit and a third voltage divider circuit, respectively, wherein the first switch device, the second switch device and the third switch device are respectively turned on through the first voltage divider circuit, the second voltage divider circuit and the third voltage divider circuit.

[0021] Furthermore, in some embodiments of the present invention, the first voltage divider circuit includes a first series resistor having one end connected to the power supply and the other end grounded through a second switching device, and the connecting end of the two resistors in the first series resistor is connected to the control end of the first switching device.

[0022] In some embodiments of the present invention, the second voltage divider circuit includes a second series resistor having one end connected to the power supply and the other end directly grounded, and the connecting end of the two resistors in the second series resistor is connected to the control end of the second switch device.

[0023] In some embodiments of the present invention, the third voltage divider circuit includes a third series resistor with one end directly grounded and the other end connected to the control end of the third switch device, and the connection end of two resistors in the third series resistor is connected to the power supply.

[0024] Additionally, in some embodiments of the present invention, the switch module includes a voltage-stabilizing diode having one end connected to the power supply and the other end connected to the control end of the first switch device.

[0025] By providing a Zener diode in the switch module, the stable voltage required by the switch device can be maintained when the voltage is too high.

[0026] Additionally, in some embodiments of the present invention, the overvoltage protection module includes a voltage stabilizing diode having one end connected to the power supply and the other end connected to the connection ends of two resistors in the third series resistor.

[0027] By arranging a voltage stabilizing diode in the overvoltage protection module, a preset value of the surge voltage in the surge suppression circuit can be ensured.

[0028] In some embodiments of the present invention, the first switch device is a PMOS field effect transistor, and the second switch device and the third switch device are selected from MOS field effect transistors or triodes.

[0029] The first switch device in the switch module is set to a PMOS tube, and the voltage surge suppression effect is achieved by its on and off. This can eliminate the additional and more complex boost circuit required for the switch device being an NMOS tube in the existing circuit structure, thereby reducing manufacturing costs and system power consumption.

[0030] Specifically, in some embodiments of the present invention, the second switching device and the third switching device are NPN transistors; the source of the first switching device is connected to the power supply, and the drain is connected to the subsequent load; the collector of the second switching device is connected to the first voltage divider circuit, the emitter is grounded, and the base is connected to the collector of the third switching device; the collector of the third switching device is connected to the connecting end of two resistors in the second voltage divider circuit, the emitter is grounded, and the base is grounded through the third voltage divider circuit.

[0031] The surge suppression circuit provided by the utility model reduces the risk of damage to subsequent equipment including circuit components caused by long-term voltage surges in low-internal-resistance power supply scenarios through a specific circuit structure design, and simultaneously solves the problem of burning out of the surge suppression circuit or subsequent circuits due to reverse polarity of the power supply, thereby reducing the risk of circuit failure and making the circuit have a wider range of applications. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1A schematic structural diagram of a surge suppression circuit provided in one embodiment of the utility model is shown.

[0033] Figure 2a A schematic diagram of the structure of each module in a surge suppression circuit provided by an embodiment of the utility model is shown.

[0034] Figure 2b A schematic diagram showing the structure of each module in a surge suppression circuit provided in another embodiment of the utility model is shown.

[0035] Figure 3a Shows Figure 2a A circuit diagram of a surge suppression circuit provided in one embodiment of the utility model is shown in FIG.

[0036] Figure 3b Shows Figure 2b A circuit diagram of a surge suppression circuit provided in another embodiment of the present invention. DETAILED DESCRIPTION

[0037] In order to make the purpose, technical scheme and advantages of the utility model clearer, the utility model is further described in detail below in conjunction with the accompanying drawings and specific embodiments. Although the exemplary embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the utility model can be implemented in various forms and should not be limited by the embodiments described herein. On the contrary, these embodiments are provided to facilitate a more thorough understanding of the utility model and to fully convey the concept of the utility model to those skilled in the art.

[0038] refer to Figure 1 , shows a schematic diagram of the structure of a surge suppression circuit provided by an embodiment of the utility model. Figure 1 As shown, the surge suppression circuit 1 provided by the utility model mainly includes a switch module 10 , a path control module 20 , an overvoltage protection module 30 and an anti-reverse connection module 40 .

[0039] The switch module 10 is connected to a power supply, and the output end of the switch module 10 is connected to a subsequent load. The subsequent load may be an external device, module or circuit, etc., which will not be elaborated in detail in the present invention.

[0040] The passage control module 20 is connected to the power supply and the switch module 10 .

[0041] The overvoltage protection module 30 is connected to the power supply and the path control module 20 .

[0042] The reverse connection prevention module 40 is connected to the power supply or the subsequent load.

[0043] The overvoltage protection module 30 is configured to control the working state of the switch module 10 by controlling the working state of the path control module 20. When the working voltage of the power supply does not exceed the preset value of the surge voltage that the circuit can withstand, the overvoltage protection module 30 enables the switch module to work normally by keeping the path control module working. When the working voltage of the power supply exceeds the preset value of the surge voltage that the circuit can withstand, the overvoltage protection module 30 turns off the output of the switch module 10 by turning off the output of the path control module 20.

[0044] Therefore, when a surge voltage occurs and exceeds the threshold that the circuit can withstand, the above circuit can protect the subsequent load from being destroyed and damaged by stopping the working state of the switch module. At the same time, the anti-reverse connection module in the circuit can ensure that the power supply and other devices will not be damaged even if the power polarity is reversed.

[0045] The anti-reverse connection module 40 in the above circuit can be placed between the switch module 10 and the subsequent load, and is located at the last stage of the surge suppression circuit 1. Figure 2a shown.

[0046] Furthermore, under this structural layout, the path control module 20 and the overvoltage protection module 30 may include an anti-reverse connection device connected to the power supply.

[0047] The advantage of such a configuration is that there is no need to consider the relationship between the withstand voltage of the diode in the circuit and the maximum value of the surge voltage, thereby reducing the manufacturing cost.

[0048] Alternatively, the reverse connection protection module 40 can be placed after the power supply, at the front stage of the surge suppression circuit 1, such as Figure 2b shown.

[0049] The advantage of this arrangement is that other anti-reverse connection devices in the entire circuit can be omitted, thereby achieving the purpose of simplifying the device.

[0050] Optionally, the structure of the reverse connection protection module 40 may be a separate diode.

[0051] Connecting a diode in series in the circuit to prevent reverse connection is the simplest, most reliable and low-cost way.

[0052] In the present invention, the reverse connection prevention module may also be other circuit structures, such as using a fuse and a reverse parallel diode, or using a bridge rectifier, and the switching characteristics of the MOS tube may be used to control the conduction and disconnection of the circuit to achieve the purpose of reverse connection prevention. Those skilled in the art may understand and make corresponding settings according to the actual requirements to be achieved during the manufacture and use of the surge suppression circuit, and the present invention will not be described in detail here.

[0053] In some embodiments, the switch module 10, the path control module 20 and the overvoltage protection module 30 respectively include a first switch device 101, a second switch device 201 and a third switch device 301. Figure 2a and 2b shown.

[0054] The third switch device 301 is connected to the control end of the second switch device 201 , and the second switch device 201 is connected to the control end of the first switch device 101 , so that the first switch device 101 is turned on or off by turning on or off the second switch device 201 .

[0055] For example, in some embodiments, the switch module 10, the path control module 20 and the overvoltage protection module 30 respectively include a first voltage divider circuit 102, a second voltage divider circuit 202 and a third voltage divider circuit 302, wherein the first switch device 101, the second switch device 201 and the third switch device 301 are respectively turned on by the first voltage divider circuit 102, the second voltage divider circuit 202 and the third voltage divider circuit 302, as shown in FIG. Figure 2a and 2b shown.

[0056] Exemplarily, in some embodiments, the first voltage divider circuit 102 may include a first series resistor having one end connected to the power supply and the other end grounded through the second switch device 201, and the connection end of the two resistors in the first series resistor is connected to the control end of the first switch device 101.

[0057] The second voltage divider circuit 202 may include a second series resistor with one end connected to the power supply and the other end directly grounded, and a connection end of two resistors in the second series resistor is connected to the control end of the second switch device 201 .

[0058] The third voltage divider circuit 302 may include a third series resistor with one end directly grounded and the other end connected to the control end of the third switch device 301 , and the connection end of two resistors in the third series resistor is connected to the power supply.

[0059] Those skilled in the art can set the specific structures of the first voltage divider circuit 102, the second voltage divider circuit 202 and the third voltage divider circuit 302 accordingly according to actual needs. Those skilled in the art should understand that the path control module and the overvoltage protection module can also adopt other forms, as long as the switch module can stop working when the surge voltage exceeds the preset threshold, and the switch module can continue to work when the surge voltage is within the tolerable range of the circuit. As for the control mode of the third switch device 301 on / off the second switch device 201 and the second switch device 201 on / off the first switch device 101, it depends on the type of the selected first, second and third switch devices (NMOS, PMOS, NPN, PNP, etc.), those skilled in the art can select the corresponding appropriate device type and its output mode for the switch device according to actual needs and conditions, so as to select the control mode of the overvoltage protection module and / or the path control module on the switch module in different voltage ranges. The following text will be explained with examples of specific device types.

[0060] Furthermore, in some embodiments, the switch module 10 may include a voltage-stabilizing diode having one end connected to the power supply and the other end connected to the control end of the first switch device 101. The voltage-stabilizing diode may clamp the voltage of the switch device in the switch module, maintain the stable voltage required by the switch device, and prevent the switch device from being broken down, thereby avoiding unnecessary damage.

[0061] Similarly, the overvoltage protection module 30 may also include a voltage stabilizing diode having one end connected to the power supply and the other end connected to the connection end of the two resistors in the third series resistor. The voltage stabilizing diode can be used to preset the maximum surge voltage that the circuit can withstand, and keep the surge voltage during circuit operation within a certain range.

[0062] In some embodiments, the first switch device 101 may be a PMOS field effect transistor, and the second switch device 201 and the third switch device 301 may be selected from MOS field effect transistors or triodes.

[0063] Exemplarily, the second switching device 201 and the third switching device 301 may be NPN transistors.

[0064] In this example, the source of the first switch device 101 is connected to the power supply, and the drain is connected to the subsequent load; the collector of the second switch device 201 is connected to the first voltage divider circuit, the emitter is grounded, and the base is connected to the collector of the third switch device 301; the collector of the third switch device 301 is connected to the connection end of the two resistors in the second voltage divider circuit, the emitter is grounded, and the base is grounded through the third voltage divider circuit. The specific circuit structure can be referred to below and combined with the Figure 3a and 3b Description.

[0065] Regarding the selection of each switch device in the circuit provided by the utility model, those skilled in the art can understand that the first, second, and third switch devices in the utility model can be MOS tubes, or alternatively can be triodes. These switch devices can be switch devices of the same type, for example, all MOS tubes, or all triodes; alternatively, some of them can be MOS tubes and the other part can be triodes. Regardless of the type of switch device each switch device is, those skilled in the art can make corresponding adaptive deformations to the corresponding structures in the above circuits according to the working principles of the corresponding switch devices.

[0066] The advantage of setting the above-mentioned first switching device as a PMOS tube is that voltage surge suppression can be achieved by turning the PMOS tube on and off, which can eliminate the additional and more complex boost circuit required when the switching device is an NMOS tube in the existing circuit structure, thereby reducing manufacturing costs and system power consumption.

[0067] The circuit provided by an embodiment of the present invention is specifically described below by taking the first switch device 101 as a PMOS transistor Q1 , the second switch device 201 as an NPN transistor Q2 , and the third switch device 301 as an NPN transistor Q3 as an example.

[0068] refer to Figure 3a and Figure 3b , which shows a specific implementation of the surge suppression circuit of the utility model.

[0069] In this circuit, the power supply is VBAT and the subsequent load is VB_PR. The switch module includes a first switch device Q1 and a first voltage divider circuit composed of series resistors R5 and R6. The path control module includes a second switch device Q2 and a second voltage divider circuit composed of series resistors R3 and R4. The overvoltage protection module includes a third switch device Q3 and a third voltage divider circuit composed of series resistors R1 and R2.

[0070] Still Figure 3a and Figure 3b As shown, the switch module and the overvoltage protection module in the surge suppression circuit include voltage stabilizing diodes D4 and D2 respectively.

[0071] The connection relationship and corresponding functions of each circuit component are described in detail below.

[0072] Figure 3a and Figure 3b The circuit shown includes resistors R1-R6, transistors Q2 / Q3, diodes D1 / D2 / D3 / D4 / D5 and a PMOS transistor Q1.

[0073] The positive electrode of D1 is connected to the DC power supply VBAT, one end of R5, the positive electrode of D3, the negative electrode of D4, and the source of Q1, and the negative electrode is connected to the negative electrode of D2. As a common diode, the function of D1 is to prevent Q3 from burning out when the power supply is reversely connected.

[0074] The cathode of D2 is connected to the cathode of D1, and the anode is connected to one end of R1 and one end of R2. As a voltage stabilizing diode, its function is to provide a reference voltage for the voltage surge suppression circuit.

[0075] One end of R1 is connected to the positive pole of D2 and one end of R1, and the other end is directly connected to GND. Its function is that when the voltage surge exceeds the set value of D2, the current passes through R1 and generates a voltage VR1 on it. When the VR1 voltage is greater than the Vbe of Q3, Q3 is turned on.

[0076] One end of R2 is connected to the positive electrode of D2 and one end of R1, and the other end is connected to the base of Q3. Its function is to provide base limiting current for Q3 to ensure the safety of Q3.

[0077] Q3 is a triode, whose base is connected to one end of R2, the emitter is directly connected to GND, and the collector is connected to one end of R3, R4 and the base of Q2. Its function is that when the surge voltage is too high and exceeds the overvoltage threshold, Q3 is turned on to connect the base of Q2 to GND, maintaining a low level, so that Q2 can be reliably turned off.

[0078] One end of R3 is connected to the cathode of D3, and the other end is connected to the collector of Q3, the base of Q2, and one end of R4. Its function is to provide the base limiting current of Q2 and the collector limiting current when Q3 is effective.

[0079] One end of R4 is connected to the collector of Q3, one end of R3, and the base of Q2, and the other end is directly connected to GND. Its function is to ensure the stability of the base state of Q2, and to form a voltage divider circuit with R3 to ensure that Q2 can be reliably turned on when the voltage is normal.

[0080] Q2 is a triode, with the base connected to one end of R4 / R3 and the collector of Q3, the emitter directly connected to GND, and the collector connected to one end of R6. Its function is to ensure that the gate level of Q1 is low and the PMOS is reliably turned on when the voltage is normal.

[0081] One end of R6 is connected to the collector of Q2, and the other end is connected to one end of R5, the positive electrode of D4, and the gate of Q1. Its function is to form a voltage divider circuit with R5. When Q2 is effective, it ensures that the gate voltage of Q1 is less than the source voltage, so as to achieve the purpose of reliably turning on Q1.

[0082] One end of R5 is connected to the power supply VBAT, the source of Q1, the negative electrode of D4, the positive electrode of D1, and the positive electrode of D3, and the other end is connected to the positive electrode of D4, the gate of Q1, and one end of R6. Its function is the same as that of R6.

[0083] D4 is a voltage stabilizing diode. Its cathode is connected to one end of R5, VBAT, and the source of Q1, and its anode is connected to one end of R5, one end of R6, and the gate of Q1. Its function is to prevent the gate and source voltage of Q1 from being clamped to the voltage stabilizing value of D4 when the voltage is too high, so as to ensure that it does not exceed the maximum withstand voltage of VGS of Q1.

[0084] Q1 is a PMOS tube, whose source is connected to VBAT, one end of R1, the negative electrode of D4, and the positive electrode of D1 / D3, the gate is connected to one end of R6 and R5, and the positive electrode of D4, and the drain is connected to the positive electrode of D5. It acts as the main power switch device of the voltage surge suppression circuit.

[0085] The positive electrode of D3 is connected to the power supply VBAT, the positive electrode of D1, one end of R5, the negative electrode of D4 and the source of Q1. The negative electrode of D3 is connected to one end of R3. It acts as an ordinary diode to prevent Q2 from burning out when the power supply is reversed.

[0086] The positive pole of D5 is connected to the drain of Q1, and the negative pole is connected to the subsequent load VB_PR. Its main function is to provide anti-reverse connection protection for the subsequent load circuit.

[0087] The circuit working principle of the above embodiment is as follows:

[0088] When VBAT is powered on and the voltage does not exceed the surge voltage value, Q3 is in the off state, and Q2 is in the on state under the voltage division of D1 and R3 / R4. In this way, the gate of Q1 is also in a reliably on state due to the voltage division of R5 / R6, and the subsequent load is in a normal working state.

[0089] When the voltage surge of VBAT exceeds the overvoltage threshold, the D2 Zener diode is in the avalanche region. When the current passing through R1 reaches a certain value, VR1 is greater than the base turn-on level of Q3, Q3 is turned on, and the base of Q2 is connected to GND. When Q2 is turned off, Q1 will also be turned off, thereby protecting Q1 and the load of the subsequent circuit of Q1.

[0090] It should be noted that for switching devices, those skilled in the art can understand that for NPN transistors, the current relationship flowing through the collector (c), base (b), and emitter (e) is: Ie=Ib+Ic, Ic=β*Ib. When Ube>0.7V, that is, the emitter junction voltage Ube is forward biased, the transistor is turned on. When Ube<0.7V, that is, the emitter junction voltage Ube is reverse biased, the transistor is in a cut-off state, which is equivalent to the switch being disconnected. Among them, the transistor conduction voltage and other parameters are determined by the specific device selected. Correspondingly, the parameters of each voltage divider circuit are also selected according to the specification requirements of the device. This is common sense for those skilled in the art and will not be repeated. Similarly, for PNP transistors, when Ube<-0.7V, the transistor is turned on. When Ube>-0.7V, the transistor is turned off. Similarly, the specific circuit parameters need to be determined with reference to the specification requirements of the selected transistor.

[0091] It should be understood by those skilled in the art that the MOS tube needs to meet the condition of |Vg-Vs|>|Vgs(TH)| for it to be turned on. Specifically, for NMOS tubes, Vg-Vs>Vgs(TH), Vgs(TH) is the threshold voltage of the MOS tube, that is, the voltage difference between the G pole (gate) and the S pole (source) is greater than a certain value, the MOS tube will be turned on, but the voltage difference cannot be too large, otherwise the MOS tube will be burned out. Among them, the turn-on voltage and other parameters need to refer to the relevant specifications according to the specific device selected. Similarly, for PMOS tubes, Vg-Vs<Vgs(TH), that is, the voltage difference between the G pole and the S pole is less than a certain value, the MOS tube will be turned on (for PMOS tubes, Vgs(TH) is a negative value). Similarly, the specific parameters need to refer to the specifications of the specific device.

[0092] The utility model provides a surge suppression circuit, which reduces the risk of damage to subsequent equipment including circuit components caused by long-term voltage surges in a low internal resistance scenario of the power supply through a specific circuit structure design, and simultaneously solves the problem of burning of the surge suppression circuit or the subsequent circuit caused by reverse polarity of the power supply, reduces the risk of circuit failure, and makes the circuit have a wider range of applications.

[0093] Therefore, the surge suppression circuit provided by the utility model has at least the following beneficial effects:

[0094] 1. Can suppress long-term voltage surges;

[0095] 2. It is built with fewer discrete components and the cost is very low;

[0096] 3. Added power supply polarity reverse protection, wide applicability, can be used in DC circuits.

[0097] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "embodiment", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0098] In the present invention, the terms "connected", "connection", etc. should be understood in a broad sense. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; "connection" can be a direct connection or an indirect connection through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0099] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the utility model and are not restrictive. Although the utility model is described in detail with reference to the embodiments, it should be understood by those skilled in the art that any modification or equivalent replacement of the technical solution of the utility model does not deviate from the spirit and scope of the technical solution of the utility model, and should be included in the scope of the claims of the utility model.

Claims

1. A surge suppression circuit, characterized in that: include: A switch module connected to the power supply, wherein the output end of the switch module is connected to a subsequent load; A passage control module connected to the power supply and the switch module; An overvoltage protection module connected to the power supply and the access control module; The anti-reverse connection module connected to the power supply or the subsequent load, Among them, the overvoltage protection module is configured to control the working state of the switch module by controlling the working state of the path control module, keep the path control module working when the working voltage of the power supply does not exceed the preset value so that the switch module works normally, and turn off the output of the switch module by turning off the output of the path control module when the working voltage of the power supply exceeds the preset value.

2. The surge suppression circuit according to claim 1, characterized in that: The reverse connection protection module is placed between the switch module and the subsequent load, and is located at the last stage of the surge suppression circuit.

3. The surge suppression circuit according to claim 2, characterized in that: The path control module and the overvoltage protection module both include an anti-reverse connection device connected to the power supply.

4. The surge suppression circuit according to claim 1, characterized in that: The reverse connection protection module is placed after the power supply and at the front stage of the surge suppression circuit.

5. The surge suppression circuit according to claim 1, characterized in that: The reverse connection prevention module is a diode.

6. The surge suppression circuit according to any one of claims 1 to 5, characterized in that: The switch module, the path control module and the overvoltage protection module include a first switch device, a second switch device and a third switch device respectively. The third switch device is connected to the control end of the second switch device, and the second switch device is connected to the control end of the first switch device, so that the first switch device is turned on or off by turning on or off the second switch device.

7. The surge suppression circuit according to claim 6, characterized in that: The switch module, the path control module and the overvoltage protection module also include a first voltage divider circuit, a second voltage divider circuit and a third voltage divider circuit respectively, wherein the first switch device, the second switch device and the third switch device are respectively turned on through the first voltage divider circuit, the second voltage divider circuit and the third voltage divider circuit.

8. The surge suppression circuit according to claim 7, characterized in that: The first voltage divider circuit includes a first series resistor having one end connected to the power supply and the other end grounded via a second switch device, a connecting end of two resistors in the first series resistor being connected to a control end of the first switch device, and / or The second voltage divider circuit includes a second series resistor with one end connected to the power supply and the other end directly grounded, the connecting end of two resistors in the second series resistor is connected to the control end of the second switch device, and / or The third voltage divider circuit includes a third series resistor with one end directly grounded and the other end connected to the control end of the third switch device, and the connection end of two resistors in the third series resistor is connected to the power supply.

9. The surge suppression circuit according to claim 8, characterized in that: The switch module includes a voltage stabilizing diode having one end connected to the power supply and the other end connected to the control end of the first switch device, and / or The overvoltage protection module includes a voltage stabilizing diode, one end of which is connected to the power supply, and the other end of which is connected to the connection end of two resistors in the third series resistor.

10. The surge suppression circuit according to any one of claims 7 to 9, characterized in that: The first switch device is a PMOS field effect transistor, and the second switch device and the third switch device are selected from MOS field effect transistors or triodes.

11. The surge suppression circuit according to claim 10, characterized in that: in, The second switch device and the third switch device are NPN type transistors; The source of the first switching device is connected to the power supply, and the drain is connected to the subsequent load; the collector of the second switching device is connected to the first voltage divider circuit, the emitter is grounded, and the base is connected to the collector of the third switching device; the collector of the third switching device is connected to the connection end of the two resistors in the second voltage divider circuit, the emitter is grounded, and the base is grounded through the third voltage divider circuit.

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