High voltage surge protection circuit

Abstract

The utility model provides a kind of high voltage surge protection circuit, high voltage surge protection circuit includes: input, ground end and output, high voltage surge suppressor, field effect transistor, detection resistance and anti-oscillation resistance, first resistance and second resistance;Field effect transistor and detection resistance are connected in series between input and output, the gate of field effect transistor is electrically connected with the gate pin of high voltage surge suppressor by anti-oscillation resistance, current detection pin is electrically connected with one end of detection resistance connected with input, output pin is electrically connected with the other end of detection resistance connected with output, one end of first resistance is electrically connected with the other end of detection resistance, the other end of first resistance is electrically connected with one end of second resistance and feedback pin, the other end of second resistance is electrically connected with ground end.The utility model can effectively suppress high voltage surge, and reduce the influence of circuit oscillation on high voltage surge suppressor.

Description

Technical Field

[0001] This utility model relates to the field of integrated circuit technology, and in particular to a high-voltage surge protection circuit. Background Technology

[0002] In modern electronic systems, such as industrial control, electronic equipment, and communication power supplies, high-voltage surges and overcurrents are the main factors leading to system damage and unstable operation. To ensure long-term stable operation of circuits and improve reliability and immunity, effective surge suppression and current limiting protection mechanisms must be introduced.

[0003] While existing high-voltage surge protection circuits can effectively suppress high-voltage surges, they ignore the impact of circuit oscillations on the high-voltage surge suppressor. Utility Model Content

[0004] To solve the above problems, the high-voltage surge protection circuit provided by this utility model can effectively suppress high-voltage surges and reduce the impact of circuit oscillations on the high-voltage surge suppressor by setting a high-voltage surge suppressor, a field-effect transistor, a detection resistor and an anti-oscillation resistor, a first resistor and a second resistor in the protection circuit module.

[0005] This utility model provides a high voltage surge protection circuit, which includes: an input terminal, a protection circuit module, a grounding terminal, and an output terminal;

[0006] The protection circuit module includes: a high-voltage surge suppressor, a field-effect transistor, a sensing resistor and an anti-oscillation resistor, a first resistor and a second resistor;

[0007] A field-effect transistor (FET) and a sensing resistor are connected in series between the input and output terminals. The gate of the FET is electrically connected to the gate pin of the high-voltage surge suppressor through an anti-oscillation resistor. The current sensing pin of the high-voltage surge suppressor is electrically connected to the end of the sensing resistor connected to the input terminal. The output pin of the high-voltage surge suppressor is electrically connected to the other end of the sensing resistor connected to the output terminal. One end of the first resistor is electrically connected to the other end of the sensing resistor. The other end of the first resistor is electrically connected to one end of the second resistor and the feedback pin of the high-voltage surge suppressor. The other end of the second resistor is electrically connected to the ground terminal.

[0008] Optionally, the protection circuit module further includes: a first capacitor;

[0009] One end of the first capacitor is electrically connected to the ground terminal, and the other end of the first capacitor is electrically connected to the other end of the sensing resistor.

[0010] Optionally, the protection circuit module may further include: a fourth resistor and a fifth resistor;

[0011] One end of the fourth resistor is electrically connected to the first terminal of the field-effect transistor, which is electrically connected to the input terminal. The second terminal of the field-effect transistor is electrically connected to one end of the detection resistor. The other end of the fourth resistor is electrically connected to the overvoltage pin of the high-voltage surge suppressor and one end of the fifth resistor, respectively. The other end of the fifth resistor is electrically connected to the ground terminal.

[0012] Optionally, the protection circuit module may also include: a third resistor and a second capacitor;

[0013] One end of the third resistor is electrically connected to the first terminal of the field-effect transistor, and the other end of the third resistor is electrically connected to the power input pin of the high-voltage surge suppressor. One end of the fourth resistor is electrically connected to the other end of the third resistor. One end of the second capacitor is electrically connected to the other end of the third resistor, and the other end of the second capacitor is electrically connected to the ground terminal.

[0014] Optionally, the protection circuit module may also include: a Zener diode;

[0015] The anode of the Zener diode is electrically connected to the ground terminal, and the cathode of the Zener diode is electrically connected to the other end of the third resistor.

[0016] Optionally, the protection circuit module also includes: a sixth resistor and a seventh resistor;

[0017] One end of the sixth resistor is electrically connected to the other end of the third resistor. The other end of the sixth resistor is electrically connected to the undervoltage pin of the high voltage surge suppressor and one end of the seventh resistor. The other end of the seventh resistor is electrically connected to the ground terminal.

[0018] The ratio of the resistance of the fourth resistor to the resistance of the fifth resistor is greater than the ratio of the resistance of the sixth resistor to the resistance of the seventh resistor.

[0019] Optionally, the high-voltage surge protection circuit also includes: an input status indication module;

[0020] The input status indicator module includes: a positive pressure indicator and a negative pressure indicator;

[0021] One end of the input status indicator module is electrically connected to the input terminal and the first terminal of the field-effect transistor, the second terminal of the field-effect transistor is electrically connected to one end of the sensing resistor, and the other end of the input status indicator module is electrically connected to the ground terminal.

[0022] The input status indicator module is used to illuminate the positive voltage indicator and extinguish the negative voltage indicator when a positive voltage is input to the input terminal, and illuminate the negative voltage indicator and extinguish the positive voltage indicator when a negative voltage is input to the input terminal.

[0023] Optionally, the input status indication module further includes: an eighth resistor, a ninth resistor, a tenth resistor, a first transistor, a second transistor, and a clamping diode;

[0024] One end of the eighth resistor, the anode of the positive voltage indicator, and the cathode of the negative voltage indicator are electrically connected to the input terminal and the first connection terminal, respectively. The other end of the eighth resistor is electrically connected to the base of the first transistor and the collector of the second transistor, respectively. The cathode of the positive voltage indicator and the anode of the negative voltage indicator are electrically connected to the collector of the first transistor, respectively. The emitter of the first transistor and the base of the second transistor are both electrically connected to one end of the ninth resistor. The other end of the ninth resistor and the emitter of the second transistor are both electrically connected to the anode of the clamping diode and one end of the tenth resistor, respectively. The cathode of the clamping diode and the other end of the tenth resistor are both electrically connected to the ground terminal.

[0025] Optionally, the high-voltage surge protection circuit also includes: an output indicator light and an eleventh resistor;

[0026] The anode of the output indicator light is electrically connected to the other end of the detection resistor and the output terminal. The cathode of the output indicator light is electrically connected to one end of the eleventh resistor, and the other end of the eleventh resistor is electrically connected to the ground terminal.

[0027] Optionally, the high-voltage surge suppressor is model TL4363.

[0028] The high-voltage surge protection circuit provided in this embodiment effectively suppresses high-voltage surges and reduces the impact of circuit oscillations on the high-voltage surge suppressor by setting a high-voltage surge suppressor, a field-effect transistor, a detection resistor, an anti-oscillation resistor, a first resistor, and a second resistor in the protection circuit module. The field-effect transistor and the detection resistor are connected in series between the input and output terminals. The gate of the field-effect transistor is electrically connected to the gate pin of the high-voltage surge suppressor through the anti-oscillation resistor. The current detection pin of the high-voltage surge suppressor is electrically connected to one end of the detection resistor connected to the input terminal. The output pin of the high-voltage surge suppressor is electrically connected to the other end of the detection resistor connected to the output terminal. One end of the first resistor is electrically connected to the other end of the detection resistor. The other end of the first resistor is electrically connected to one end of the second resistor and the feedback pin of the high-voltage surge suppressor. The other end of the second resistor is electrically connected to the ground terminal. Attached Figure Description

[0029] To more clearly illustrate the technical solutions in the embodiments of this application or the conventional technology, the drawings used in the description of the embodiments or the conventional technology will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0030] Figure 1 This is a schematic circuit diagram of a high-voltage surge protection circuit according to an embodiment of this application.

[0031] Figure label:

[0032] INPUT, Input Terminal; 1, Protection Circuit Module; U1, High Voltage Surge Suppressor; Q3, Field Effect Transistor; R11, Sensing Resistor; R5, Anti-oscillation Resistor; R12, First Resistor; R13, Second Resistor;

[0033] R4, third resistor; R8, fourth resistor; R9, fifth resistor; C9, first capacitor; C7, second capacitor; D2, Zener diode; R6, sixth resistor; R7, seventh resistor; C8, third capacitor; OUTPUT, output terminal; 2, input status indicator module; LED1-G, positive voltage indicator; LED2-R, negative voltage indicator;

[0034] R1, eighth resistor; R3, ninth resistor; R2, tenth resistor; Q1, first transistor; Q2, second transistor; D1, clamping diode; LED3-G, output indicator light; R14, eleventh resistor. Detailed Implementation

[0035] To facilitate understanding of this application, a more complete description will be provided below with reference to the accompanying drawings, which illustrate embodiments of the present application. However, the present application can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided so that the disclosure of this application will be thorough and complete.

[0036] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.

[0037] This utility model provides a high-voltage surge protection circuit, see [link to relevant documentation]. Figure 1 The high-voltage surge protection circuit includes: input terminal INPUT, protection circuit module 1, ground terminal, and output terminal OUTPUT.

[0038] The protection circuit module 1 includes: a high-voltage surge suppressor U1, a field-effect transistor Q3, a detection resistor R11 and an anti-oscillation resistor R5, a first resistor R12 and a second resistor R13.

[0039] A field-effect transistor Q3 and a sensing resistor R11 are connected in series between the input terminal INPUT and the output terminal OUTPUT. The gate of the field-effect transistor Q3 is electrically connected to the gate pin of the high-voltage surge suppressor U1 through an anti-oscillation resistor R5. The current sensing SNS pin of the high-voltage surge suppressor U1 is electrically connected to the end of the sensing resistor R11 connected to the input terminal INPUT. The output terminal OUT pin of the high-voltage surge suppressor U1 is electrically connected to the other end of the sensing resistor R11 connected to the output terminal OUTPUT. One end of the first resistor R12 is electrically connected to the other end of the sensing resistor R11. The other end of the first resistor R12 is electrically connected to one end of the second resistor R13 and the feedback FB pin of the high-voltage surge suppressor U1. The other end of the second resistor R13 is electrically connected to the ground terminal.

[0040] In this embodiment, by setting an anti-oscillation resistor R5 in the protection circuit module 1, the high voltage surge is effectively suppressed, and the impact of circuit oscillation on the high voltage surge suppressor U1 is also reduced.

[0041] In this embodiment, the high-voltage surge suppressor U1 is a TL4363; the field-effect transistor Q3 is an N-type metal-oxide-semiconductor field-effect transistor.

[0042] In a further optional embodiment of this invention, the protection circuit module 1 further includes a first capacitor C9. One end of the first capacitor C9 is electrically connected to the ground terminal, and the other end of the first capacitor C9 is electrically connected to the other end of the detection resistor R11. The first capacitor C9, in conjunction with the high-voltage surge suppressor U1, can buffer high-voltage surges or voltage spikes in the circuit, thereby increasing the filtering and buffering function of the output side of the protection circuit module 1, and thus improving the protection circuit module 1's ability to withstand high-voltage surges and enhancing the stability of the protection circuit module 1.

[0043] In a further optional embodiment of this embodiment, the protection circuit module 1 further includes: a fourth resistor R8 and a fifth resistor R9.

[0044] The first terminal of the field-effect transistor Q3 is electrically connected to the input terminal INPUT. The second terminal of the field-effect transistor Q3 is electrically connected to one end of the sensing resistor R11. One end of the fourth resistor R8 is electrically connected to the first terminal of the field-effect transistor Q3. The other end of the fourth resistor R8 is electrically connected to the overvoltage (OV) pin of the high-voltage surge suppressor U1 and one end of the fifth resistor R9. The other end of the fifth resistor R9 is electrically connected to the ground terminal.

[0045] The fourth resistor R8 and the fifth resistor R9 are connected in series to achieve voltage division. By connecting the OV pin between R8 and R9, the OV pin of the high-voltage surge suppressor U1 can determine whether the internal reference voltage is exceeded. Specifically, when the voltage at the OV pin exceeds its internal reference voltage, the high-voltage surge suppressor U1 will determine it as an overvoltage. At this time, the high-voltage surge suppressor U1 will quickly turn off Q3, that is, by reducing the voltage of the GATE pin, the connection between the first and second terminals is disconnected. In this way, the protection circuit module 1 can realize overvoltage detection of the high-voltage surge protection circuit and disconnect the connection between the input terminal INPUT and the output terminal OUTPUT when an overvoltage occurs, thereby protecting the high-voltage surge protection circuit.

[0046] The internal reference voltage is a preset safe voltage range for the high-voltage surge protection circuit, which is obtained through the internal structure of the high-voltage surge suppressor U1. This embodiment does not specifically limit this voltage.

[0047] In a further optional embodiment of this embodiment, the protection circuit module 1 further includes: a third resistor R4 and a second capacitor C7. One end of the third resistor R4 is electrically connected to the first terminal of the field-effect transistor Q3, and the other end of the third resistor R4 is electrically connected to the power input (VCC) pin of the high-voltage surge suppressor U1 and one end of the fourth resistor R8. One end of the second capacitor C7 is electrically connected to the other end of the third resistor R4, and the other end of the second capacitor C7 is electrically connected to the ground terminal.

[0048] In this embodiment, the second capacitor C7 serves as a decoupling capacitor for the VCC pin, enabling the input terminal INPUT to provide a stable and clean power supply to the high-voltage surge suppressor U1. Specifically, the third resistor R4 and the second capacitor C7 form a simple low-pass filter circuit, thereby reducing high-frequency noise at the VCC pin.

[0049] In a further optional embodiment of this example, the protection circuit module 1 further includes a Zener diode D2 and a protection resistor R10. The anode of the Zener diode D2 is electrically connected to ground, and the cathode of the Zener diode D2 and the protection resistor R10 are electrically connected to the other end of the third resistor R4. By placing the Zener diode D2 between the VCC pin and the GND pin, the voltage of the VCC pin can be clamped, preventing the surge voltage at the input terminal INPUT from damaging U1 through the protection resistor R10.

[0050] In a further optional embodiment of this embodiment, the protection circuit module 1 further includes: a sixth resistor R6 and a seventh resistor R7.

[0051] One end of the sixth resistor R6 is electrically connected to the other end of the third resistor R4. The other end of the sixth resistor R6 is electrically connected to the UV pin of the high voltage surge suppressor U1 and one end of the seventh resistor R7. The other end of the seventh resistor R7 is electrically connected to the ground terminal.

[0052] The ratio of the resistance of the fourth resistor R8 to the resistance of the fifth resistor R9 is greater than the ratio of the resistance of the sixth resistor R6 to the resistance of the seventh resistor R7. For example, if the resistances of the fifth resistor R9 and the seventh resistor R7 are the same, the resistance of the fourth resistor R8 is greater than the resistance of the sixth resistor R6. In this embodiment, the resistance of the fourth resistor R8 is 140k ohms, the resistance of the fifth resistor R9 is 10k ohms, the resistance of the sixth resistor R6 is 23k ohms, and the resistance of the seventh resistor R7 is 10k ohms.

[0053] In this embodiment, by connecting the UV pin between the sixth resistor R6 and the seventh resistor R7, when the voltage of the UV pin is lower than its internal reference voltage, the controller in the high voltage surge suppressor U1 determines that there is an undervoltage. The high voltage surge suppressor U1 will also turn off the field-effect transistor Q3, that is, by reducing the voltage of the GATE pin, the first connection terminal and the second connection terminal are disconnected. In this way, the protection circuit module 1 can realize undervoltage detection of the high voltage surge protection circuit, and disconnect the connection between the input terminal INPUT and the output terminal OUTPUT when undervoltage occurs, thereby protecting the high voltage surge protection circuit.

[0054] In a further optional embodiment of this example, the high-voltage surge protection circuit further includes an input status indication module 2. The input status indication module 2 includes a positive pressure indicator LED1-G and a negative pressure indicator LED2-R.

[0055] One end of the input status indicator module 2 is electrically connected to the input terminal INPUT and the first terminal of the field-effect transistor Q3. The second terminal of the field-effect transistor Q3 is electrically connected to one end of the detection resistor R11. The other end of the input status indicator module 2 is electrically connected to the ground terminal.

[0056] The input status indicator module 2 illuminates the positive voltage indicator LED1-G and extinguishes the negative voltage indicator LED2-R when a positive voltage is input to the input terminal INPUT, and illuminates the negative voltage indicator LED2-R and extinguishes the positive voltage indicator LED1-G when a negative voltage is input to the input terminal INPUT. The positive voltage indicator LED1-G and the negative voltage indicator LED2-R are a green LED and a red LED, respectively.

[0057] By setting the input status indicator module 2, the voltage status of the input terminal INPUT can be effectively monitored, and the current high voltage surge protection circuit can be intuitively indicated as to whether it is working properly.

[0058] Input status indicator module 2 is a dual-color LED indicator circuit used to illuminate either a green or red LED based on the status of the input terminal INPUT. When the voltage at the input terminal INPUT is positive (INPUT>0V), the green LED is on and the red LED is off; when the voltage at the input terminal INPUT is negative (INPUT<0V), the red LED is on and the green LED is off.

[0059] Furthermore, the input status indication module 2 also includes: an eighth resistor R1, a ninth resistor R3, a tenth resistor R2, a first transistor Q1, a second transistor Q2, and a clamping diode D1.

[0060] One end of the eighth resistor R1, the anode of the positive voltage indicator LED1-G, and the cathode of the negative voltage indicator LED2-R are electrically connected to the input terminal INPUT and the first terminal of the field-effect transistor Q3, respectively. The other end of the eighth resistor R1 is electrically connected to the base of the first transistor Q1 and the collector of the second transistor Q2, respectively. The cathode of the positive voltage indicator LED1-G and the anode of the negative voltage indicator LED2-R are electrically connected to the collector of the first transistor Q1, respectively. The emitter of the first transistor Q1 and the base of the second transistor Q2 are both electrically connected to one end of the ninth resistor R3. The other end of the ninth resistor R3 and the emitter of the second transistor Q2 are both electrically connected to the anode of the clamping diode D1 and one end of the tenth resistor R2, respectively. The cathode of the clamping diode D1 and the other end of the tenth resistor R2 are both electrically connected to the ground terminal.

[0061] In this circuit, Q1, R3, and D1 form a constant current source, stably supplying power to the negative voltage indicator LED1-G when INPUT is positive. Q2, R2, D1, and R3 form a second constant current loop, stably supplying power to the negative voltage indicator LED2-R when INPUT is negative. The eighth resistor, R1, is a base bias network and does not participate in the main current loop. The clamping diode D1 provides minimum voltage clamping, ensuring that the LED current remains relatively stable and similar in both constant current source states under the high-voltage surge protection circuit. Thus, within the withstand range of the high-voltage surge protection circuit, regardless of the magnitude of the positive or negative voltage input to INPUT, the same signal line can be used to achieve automatic switching and constant current driving of dual-color LEDs, i.e., green and red LEDs.

[0062] Specifically, when the voltage input at the input terminal INPUT is positive, the eighth resistor R1 provides a positive bias voltage to the base of the first transistor Q1, turning on the first transistor Q1. At this time, the green LED lights up and the red LED turns off. The voltage rise at the emitter of the first transistor Q1 turns on the base and emitter of the second transistor Q2. The second transistor Q2 pulls back part of the voltage at the base of the first transistor Q1 to stabilize the voltage of the first transistor Q1 within the voltage range of the operating state.

[0063] When the voltage input at the input terminal INPUT is negative, the first transistor Q1 is cut off because there is no positive bias voltage at the base of the first transistor Q1, and the second transistor Q2 is also cut off because the voltage at the base of the second transistor Q2 is not high. At this time, the circuit composed of the tenth resistor R2, the ninth resistor R3, and the clamping diode D1 raises the collector of the first transistor Q1, so that the red LED is turned on and the green LED is turned off.

[0064] In a further optional embodiment of this embodiment, the high-voltage surge protection circuit further includes: output indicator LED3-G and eleventh resistor R14.

[0065] The anode of the output indicator LED3-G is electrically connected to the other end of the sensing resistor R11 and the output terminal OUTPUT. The cathode of the output indicator LED3-G is electrically connected to one end of the eleventh resistor R14, and the other end of the eleventh resistor R14 is electrically connected to the ground terminal. The output indicator LED3-G is a green LED that emits light when normally powered on.

[0066] The output indicator LED3-G displays whether the voltage at the output terminal OUTPUT is normal. The eleventh resistor R14 acts as a current-limiting protection, effectively preventing excessive current from burning out LED3-G.

[0067] In a further optional embodiment of this example, the protection circuit module 1 further includes a third capacitor C8. One end of the third capacitor C8 is electrically connected to the timing capacitor charging (TMR) pin of the high-voltage surge suppressor U1, and the other end of the third capacitor C8 is electrically connected to the ground terminal. The ground (GND) pin of the high-voltage surge suppressor U1 is grounded, serving as the reference ground for the protection circuit module 1.

[0068] The TMR pin charges the third capacitor C8 by monitoring the drain-source voltage (VDS) of the field-effect transistor Q3. When the voltage across the third capacitor C8 reaches 1.275V, the high-voltage surge suppressor U1 issues a warning, effectively preventing the field-effect transistor Q3 from being damaged due to overvoltage.

[0069] In the high-voltage surge protection circuit provided in this embodiment, the high-voltage surge suppressor U1 monitors whether the input voltage is within the safe voltage range through the UV and OV pins; the FB pin is used to set an output voltage clamping value. When a surge occurs at the input terminal INPUT, the high-voltage surge suppressor U1 will stabilize the output terminal OUTPUT voltage at the set clamping value by controlling the conduction level of the field-effect transistor Q3, instead of allowing the surge to be directly transmitted to the output terminal OUTPUT.

[0070] Specifically, when a surge voltage occurs at the input terminal INPUT, even if the surge voltage exceeds the 0V threshold, the high-voltage surge protection circuit will not immediately shut down. Instead, the high-voltage surge suppressor U1 will control the field-effect transistor Q3 as a linear regulator through the feedback loop of the FB pin. Specifically, the high-voltage surge protection circuit will sacrifice the field-effect transistor Q3, subjecting it to a large voltage drop, to ensure that the output voltage is stabilized at the set clamping value.

[0071] Understandably, when a surge voltage occurs at the input terminal INPUT, the GATE pin of the high-voltage surge suppressor U1 outputs a continuously adjustable DC voltage. This DC voltage value determines the degree to which the field-effect transistor Q3 is turned on, effectively controlling the resistance of Q3 within the linear region. In other words, the field-effect transistor Q3 has two operating modes: "switching" and "linear." In switching mode, Q3 operates in only two states: fully on and fully off. In linear mode, Q3 operates in an intermediate state between fully on and fully off, functioning as an adjustable resistor. The resistance of Q3 is controlled by the GATE pin of U1 outputting a continuously adjustable DC voltage, which determines the degree to which Q3 is turned on, i.e., the magnitude of its equivalent resistance.

[0072] In this embodiment, taking a clamping value V_OUT of 24V as an example, the clamping value V_OUT = 1.25V * (R12 + R13) / R13 = 1.25V * (182k + 10k) / 10k = 24V. This allows the downstream load to continue operating during surges without damage. Here, 1.25V is the preset reference voltage inside U1. The 0V threshold = internal reference voltage * (R8 + R9) / R9.

[0073] In the high-voltage surge protection circuit provided in this embodiment, when faced with an extreme situation of a sudden spike in input voltage, the high-voltage surge protection circuit does not simply shut down. Instead, it clamps the output voltage to a safe preset value by using the field-effect transistor Q3 as a linear regulator. This allows the load devices downstream of the high-voltage surge protection circuit to operate continuously and uninterruptedly throughout the surge event, making it particularly suitable for systems that cannot tolerate restarts. Simultaneously, this high-voltage surge protection circuit can precisely limit the load current to a set value, effectively preventing damage to downstream load devices due to load abnormalities or short circuits. Unlike traditional one-time fuses, the high-voltage surge protection circuit can automatically attempt to restore power after the overcurrent or short-circuit fault is cleared, reducing manual intervention and system downtime.

[0074] In the description of this specification, the references to terms such as "some embodiments," "other embodiments," "ideal embodiments," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example that are included in at least one embodiment or example of this application. In this specification, the illustrative descriptions of the above terms do not necessarily refer to the same embodiments or examples.

[0075] The technical features of the above embodiments can be combined in any way. For the sake of brevity, 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 of this specification.

[0076] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of this patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A high voltage surge protection circuit, characterized by, The high-voltage surge protection circuit includes: an input terminal, a protection circuit module, a grounding terminal, and an output terminal; The protection circuit module includes: a high-voltage surge suppressor, a field-effect transistor, a detection resistor and an anti-oscillation resistor, a first resistor and a second resistor; The field-effect transistor and the sensing resistor are connected in series between the input terminal and the output terminal. The gate of the field-effect transistor is electrically connected to the gate pin of the high-voltage surge suppressor through the anti-oscillation resistor. The current sensing pin of the high-voltage surge suppressor is electrically connected to one end of the sensing resistor connected to the input terminal. The output pin of the high-voltage surge suppressor is electrically connected to the other end of the sensing resistor connected to the output terminal. One end of the first resistor is electrically connected to the other end of the sensing resistor. The other end of the first resistor is electrically connected to one end of the second resistor and the feedback pin of the high-voltage surge suppressor. The other end of the second resistor is electrically connected to the ground terminal.

2. The high voltage surge protection circuit of claim 1, wherein, The protection circuit module further includes: a first capacitor; One end of the first capacitor is electrically connected to the ground terminal, and the other end of the first capacitor is electrically connected to the other end of the detection resistor.

3. The high voltage surge protection circuit of claim 1, wherein, The protection circuit module further includes: a fourth resistor and a fifth resistor; One end of the fourth resistor is electrically connected to the first terminal of the field-effect transistor, the first terminal is electrically connected to the input terminal, the second terminal of the field-effect transistor is electrically connected to one end of the detection resistor, the other end of the fourth resistor is electrically connected to the overvoltage pin of the high-voltage surge suppressor and one end of the fifth resistor, and the other end of the fifth resistor is electrically connected to the ground terminal.

4. The high voltage surge protection circuit of claim 3, wherein, The protection circuit module also includes: a third resistor and a second capacitor; One end of the third resistor is electrically connected to the first terminal of the field-effect transistor, and the other end of the third resistor is electrically connected to the power input pin of the high-voltage surge suppressor. One end of the fourth resistor is electrically connected to the other end of the third resistor. One end of the second capacitor is electrically connected to the other end of the third resistor, and the other end of the second capacitor is electrically connected to the ground terminal.

5. The high voltage surge protection circuit of claim 4, wherein, The protection circuit module also includes: a Zener diode; The anode of the Zener diode is electrically connected to the ground terminal, and the cathode of the Zener diode is electrically connected to the other end of the third resistor.

6. The high voltage surge protection circuit of claim 4, wherein, The protection circuit module further includes: a sixth resistor and a seventh resistor; One end of the sixth resistor is electrically connected to the other end of the third resistor, the other end of the sixth resistor is electrically connected to the undervoltage pin of the high voltage surge suppressor and one end of the seventh resistor, and the other end of the seventh resistor is electrically connected to the ground terminal. The ratio of the resistance of the fourth resistor to the resistance of the fifth resistor is greater than the ratio of the resistance of the sixth resistor to the resistance of the seventh resistor.

7. The high voltage surge protection circuit of claim 1, wherein, The high-voltage surge protection circuit also includes: an input status indication module; The input status indication module includes: a positive pressure indicator and a negative pressure indicator; One end of the input status indicator module is electrically connected to the input terminal and the first connection terminal of the field-effect transistor, the second connection terminal of the field-effect transistor is electrically connected to one end of the detection resistor, and the other end of the input status indicator module is electrically connected to the ground terminal; The input status indicator module is used to illuminate the positive voltage indicator and extinguish the negative voltage indicator when a positive voltage is input to the input terminal, and illuminate the negative voltage indicator and extinguish the positive voltage indicator when a negative voltage is input to the input terminal.

8. The high voltage surge protection circuit of claim 7, wherein, The input status indication module further includes: an eighth resistor, a ninth resistor, a tenth resistor, a first transistor, a second transistor, and a clamping diode; One end of the eighth resistor, the anode of the positive voltage indicator, and the cathode of the negative voltage indicator are electrically connected to the input terminal and the first connection terminal, respectively. The other end of the eighth resistor is electrically connected to the base of the first transistor and the collector of the second transistor, respectively. The cathode of the positive voltage indicator and the anode of the negative voltage indicator are electrically connected to the collector of the first transistor, respectively. The emitter of the first transistor and the base of the second transistor are both electrically connected to one end of the ninth resistor. The other end of the ninth resistor and the emitter of the second transistor are both electrically connected to the anode of the clamping diode and one end of the tenth resistor, respectively. The cathode of the clamping diode and the other end of the tenth resistor are both electrically connected to the ground terminal.

9. The high voltage surge protection circuit of claim 1, wherein, The high-voltage surge protection circuit also includes: an output indicator light and an eleventh resistor; The anode of the output indicator light is electrically connected to the other end of the detection resistor and the output terminal, the cathode of the output indicator light is electrically connected to one end of the eleventh resistor, and the other end of the eleventh resistor is electrically connected to the ground terminal.

10. The high-voltage surge protection circuit according to any one of claims 1 to 9, characterized in that, The high-voltage surge suppressor is model TL4363.

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