Overvoltage protection device based on MOS tube input

Abstract

The utility model relates to the field of overvoltage protection, in particular to an overvoltage protection device based on MOS (Metal Oxide Semiconductor) tube input, which can cut off output in time and realize timely and effective overvoltage protection when the voltage of an input power supply is too high. According to the technical scheme, the circuit comprises a rectifier module, a discharge module, a withstand voltage module and a trigger module, the rectifier module comprises a rectifier bridge (BD1), a diode (D1) and a second MOS tube (Q2), the first input end (a) of the rectifier bridge (BD1) is connected with the zero line end (N) of an input power supply, the second input end (b) of the rectifier bridge is connected with the live line end (L) of the input power supply, and the second MOS tube (Q2) is connected with the discharge module. A first output end (d) of the rectifier bridge is connected with the withstand voltage module, a second output end (c) of the rectifier bridge is connected with a source electrode of the second MOS tube (Q2), a drain electrode of the second MOS tube (Q2) is connected with the withstand voltage module, a grid electrode of the second MOS tube (Q2) is connected with the trigger module, the first output end (d) of the rectifier bridge is further connected with an anode of the diode (D1), and a cathode of the diode (D1) is connected with the trigger module. The overvoltage protection circuit is suitable for overvoltage protection.

Description

Technical Field

[0001] The utility model relates to the field of overvoltage protection, in particular to an overvoltage protection device based on MOS tube input. Background Art

[0002] Existing overvoltage protection devices, such as a bridge protection circuit, an overvoltage protection device and a power supply system disclosed in CN206878452U, include a full-bridge rectifier circuit, an overvoltage protection device and a DC end protector. Among them, the overvoltage protection device is connected in parallel to both ends of each diode of the full-bridge rectifier circuit; the DC end protector includes a capacitor element, a resistor element and a metal oxide lightning rod, the capacitor element and the metal oxide lightning rod are connected in series and then connected in parallel to the DC output end of the full-bridge rectifier circuit, and the resistor element is connected in parallel to both ends of the capacitor element. This solution can provide effective overvoltage protection for the rectifier bridge by connecting an overvoltage protector in parallel to both ends of each diode of the full-bridge rectifier circuit and setting a DC end protector including a capacitor element, a resistor element and a metal oxide lightning rod at the DC output end of the full-bridge rectifier circuit, thereby extending the service life of the rectifier bridge.

[0003] However, the overvoltage protection effect of this solution is poor, and when the input power supply voltage is too high, the output cannot be cut off in time. Utility Model Content

[0004] The purpose of the utility model is to overcome the shortcomings of the prior art and provide an overvoltage protection device based on MOS tube input, which can cut off the output in time when the input power supply voltage is too high, thereby achieving timely and effective overvoltage protection.

[0005] The utility model adopts the following technical scheme to achieve the above-mentioned purpose. The utility model provides an overvoltage protection device based on MOS tube input, including a rectifier module, a discharge module, a withstand voltage module and a trigger module. The rectifier module includes a rectifier bridge BD1, a diode D1 and a second MOS tube Q2. The first input end a of the rectifier bridge BD1 is connected to the neutral line end N of the input power supply, the second input end b of the rectifier bridge is connected to the live line end L of the input power supply, the first output end d of the rectifier bridge is connected to the withstand voltage module, the second output end c of the rectifier bridge is connected to the source of the second MOS tube Q2, the drain of the second MOS tube Q2 is connected to the withstand voltage module, the gate of the second MOS tube Q2 is connected to the trigger module, the first output end d of the rectifier bridge is also connected to the anode of the diode D1, and the cathode of the diode D1 is connected to the trigger module.

[0006] Furthermore, the trigger module includes a first MOS tube Q1, a voltage-stabilizing diode ZD1, a first polarized capacitor EC1, a first resistor R1, a second resistor R2, a third resistor R3, a sixth resistor R6, an eighth resistor R8, a tenth resistor R10, an eleventh resistor R11, a twelfth resistor R12, and a thirteenth resistor R13. The cathode of the diode D1 is grounded through the twelfth resistor R12, the thirteenth resistor R13, the second resistor R2, and the eighth resistor R8. The cathode of the diode D1 is also grounded through the eleventh resistor R11, the tenth resistor R10, the sixth resistor R6, and the third resistor R3. The gate of the second MOS tube Q2 is connected to the drain of the first MOS tube Q1, the source of the first MOS tube Q1 is grounded, the gate of the first MOS tube Q1 is grounded through the first polarized capacitor EC1, the gate of the first MOS tube Q1 is also connected to the anode of the voltage-stabilizing diode ZD1 through the first resistor R1, and the cathode of the voltage-stabilizing diode ZD1 is connected between the sixth resistor R6 and the third resistor R3.

[0007] Furthermore, in order to improve the tolerance voltage of the charger, the tolerance voltage module includes a second polarized capacitor EC2 and a third polarized capacitor EC3, the first output end d of the rectifier bridge is respectively connected to the positive electrodes of the second polarized capacitor EC2 and the third polarized capacitor EC3, the negative electrodes of the second polarized capacitor EC2 and the third polarized capacitor EC3 are grounded, and the drain of the second MOS tube Q2 is respectively connected to the negative electrodes of the second polarized capacitor EC2 and the third polarized capacitor EC3.

[0008] Furthermore, the withstand voltage module further includes a fourteenth resistor R14 and an inductor L1 . The fourteenth resistor R14 is connected between the positive electrodes of the second polarized capacitor EC2 and the third polarized capacitor EC3 . The inductor L1 is connected in parallel to both ends of the fourteenth resistor R14 .

[0009] Furthermore, the withstand voltage module further includes a resistor RA, one end of the resistor RA is connected to the positive electrode of the third polarized capacitor EC3, and the other end of the resistor RA is connected to the negative electrode of the third polarized capacitor EC3.

[0010] Furthermore, in order to improve the discharge capacity of the device, the discharge module includes a fourth resistor R4, a fifth resistor R5, a seventh resistor R7 and a ninth resistor R9, the live wire terminal L is connected to the neutral wire terminal N through the fourth resistor R4 and the fifth resistor R5, and the live wire terminal L is also connected to the neutral wire terminal N through the seventh resistor R7 and the ninth resistor R9.

[0011] Furthermore, in order to filter the input power supply voltage, the device further includes a first capacitor C1, wherein the first capacitor C1 is connected between the live terminal L and the neutral terminal N.

[0012] Furthermore, in order to improve the safety of the device, the device also includes a fuse F1 and a thermistor NTC1, the live wire terminal L is connected to the second input terminal b of the rectifier bridge through the fuse F1, and the neutral wire terminal N is connected to the first input terminal a of the rectifier bridge BD1 through the thermistor NTC1.

[0013] The beneficial effect of the utility model is that the DC-DC negative end circuit is promptly shut down when the AC input voltage of the product reaches the set protection value, thereby protecting the product from damage caused by the AC input high voltage. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 This is a circuit structure diagram of an overvoltage protection device based on MOS tube input provided by an embodiment of the utility model. DETAILED DESCRIPTION

[0015] In order to make the purpose, technical solution and advantages of the embodiments of the present utility model clearer, the technical solution in the embodiments of the present utility model will be clearly and completely described below in conjunction with the drawings in the embodiments of the present utility model.

[0016] The utility model provides an overvoltage protection device based on MOS tube input, such as Figure 1 As shown, it includes a rectifier module, a discharge module, a withstand voltage module and a trigger module. The rectifier module includes a rectifier bridge BD1, a diode D1 and a second MOS tube Q2. The first input terminal a of the rectifier bridge BD1 is connected to the neutral terminal N of the input power supply, the second input terminal b of the rectifier bridge is connected to the live terminal L of the input power supply, the first output terminal d of the rectifier bridge is connected to the withstand voltage module, the second output terminal c of the rectifier bridge is connected to the source of the second MOS tube Q2, the drain of the second MOS tube Q2 is connected to the withstand voltage module, the gate of the second MOS tube Q2 is connected to the trigger module, the first output terminal d of the rectifier bridge is also connected to the anode of the diode D1, and the cathode of the diode D1 is connected to the trigger module. In this embodiment, the model of the rectifier bridge BD1 is 4A / 1000V, the model of the diode D1 is FR107 / 1A / 1000V, and the model of the second MOS tube Q2 is 4A / 650V. The function of the second MOS tube Q2 is to turn on and off the DC negative pole in the circuit.

[0017] In an embodiment of the utility model, the trigger module includes a first MOS tube Q1, a voltage-stabilizing diode ZD1, a first polarized capacitor EC1, a first resistor R1, a second resistor R2, a third resistor R3, a sixth resistor R6, an eighth resistor R8, a tenth resistor R10, an eleventh resistor R11, a twelfth resistor R12, and a thirteenth resistor R13. The cathode of the diode D1 is grounded through the twelfth resistor R12, the thirteenth resistor R13, the second resistor R2, and the eighth resistor R8. The cathode of the diode D1 is also grounded through the eleventh resistor R11, the tenth resistor R10, the sixth resistor R6, and the third resistor R3. The gate of the second MOS tube Q2 is connected to the drain of the first MOS tube Q1, the source of the first MOS tube Q1 is grounded, the gate of the first MOS tube Q1 is grounded through the first polarized capacitor EC1, the gate of the first MOS tube Q1 is also connected to the anode of the voltage-stabilizing diode ZD1 through the first resistor R1, and the cathode of the voltage-stabilizing diode ZD1 is connected between the sixth resistor R6 and the third resistor R3.

[0018] The sixth resistor R6, the tenth resistor R10, the eleventh resistor R11, and the third resistor R3 are used as voltage-dividing resistors in the circuit (divided to a set voltage value to break through ZD1 and turn on the first MOS tube Q1); the twelfth resistor R12, the thirteenth resistor R13, the second resistor R2, and the eighth resistor R8 are used as voltage-dividing resistors in the circuit (divided to a set voltage value to turn on the second MOS tube Q2). The function of the first resistor R1 is to stabilize the voltage to prevent the first MOS tube Q1 from being turned on by mistake. The function of the first polar capacitor EC1 is to filter out noise and form an RC circuit with R1 to provide a stable voltage to the G pole of the first MOS tube Q1. The function of the first MOS tube Q1 is to control the conduction and shutdown of the second MOS tube Q2.

[0019] In this embodiment, the specification model of the sixth resistor R6 is 510K±%1 / 1206, the specification model of the tenth resistor R10 is 1M±%1 / 1206, the specification model of the eleventh resistor R11 is 1M±%1 / 1206, the specification model of the twelfth resistor R12 and the thirteenth resistor R13 is 1M±%1 / 1206, the specification model of the second resistor R2 is 1M±%1 / 1206, the specification model of the eighth resistor R8 is 220K%1 / 1206, the specification model of the first resistor R1 is 1K / 1206, the specification model of the third resistor R3 is 36K±%1 / 1206, the model of the first MOS tube Q1 is 2N7002-N, the specification model of the first polar capacitor EC1 is 4.7uF / 50V, and the model of the Zener diode ZD1 is 5.6V / SOD-323.

[0020] In one embodiment of the utility model, the withstand voltage module includes a second polarized capacitor EC2 and a third polarized capacitor EC3, the first output end d of the rectifier bridge is respectively connected to the positive electrodes of the second polarized capacitor EC2 and the third polarized capacitor EC3, the negative electrodes of the second polarized capacitor EC2 and the third polarized capacitor EC3 are grounded, and the drain of the second MOS tube Q2 is respectively connected to the negative electrodes of the second polarized capacitor EC2 and the third polarized capacitor EC3.

[0021] In one embodiment of the utility model, the withstand voltage module further includes a fourteenth resistor R14 and an inductor L1, the fourteenth resistor R14 is connected between the positive electrodes of the second polarized capacitor EC2 and the third polarized capacitor EC3, and the inductor L1 is connected in parallel to both ends of the fourteenth resistor R14. The function of the inductor L1 is to suppress current mutation in the circuit.

[0022] In one embodiment of the present invention, the withstand voltage module further includes a resistor RA, one end of the resistor RA is connected to the positive electrode of the third polarized capacitor EC3, and the other end of the resistor RA is connected to the negative electrode of the third polarized capacitor EC3. The resistor RA is a hypothetical load.

[0023] In one embodiment of the utility model, the discharge module includes a fourth resistor R4, a fifth resistor R5, a seventh resistor R7 and a ninth resistor R9, the live wire terminal L is connected to the neutral wire terminal N through the fourth resistor R4 and the fifth resistor R5, and the live wire terminal L is also connected to the neutral wire terminal N through the seventh resistor R7 and the ninth resistor R9.

[0024] In an embodiment of the present invention, the device further comprises a first capacitor C1, wherein the first capacitor C1 is connected between the live terminal L and the neutral terminal N.

[0025] In one embodiment of the utility model, the device further comprises a fuse F1 and a thermistor NTC1, the live wire terminal L is connected to the second input terminal b of the rectifier bridge through the fuse F1, and the neutral wire terminal N is connected to the first input terminal a of the rectifier bridge BD1 through the thermistor NTC1.

[0026] The working principle of this utility model:

[0027] When 350V AC is input, the voltage is divided into 5.6V through the diode D1, the eleventh resistor R11, the sixth resistor R6, the tenth resistor R10, and the third resistor R3. At this time, the voltage zener diode ZD1 is turned on. The turned-on ZD1 passes through the first resistor R1, the first polar capacitor EC1, and then passes through the G pole of the first MSO tube Q1, so that the DS pole of the first MSO tube Q1 is in a conductive state to the ground. After the first MSO tube Q1 is in a conductive state, the voltage on the G pole pin of the second MOS tube Q2 is directly pulled to 0V. At this time, The second MOS tube Q2 changes from the on state to the off state, and the negative terminal of the circuit is in the off state after the bridge rectification, thereby forming an input high-voltage detection protection function for the entire circuit. When the input AC voltage is less than 350V, the voltage is divided into 10V through the D1 diode, the twelfth resistor R12, the thirteenth resistor R13, the second resistor R2, and the eighth resistor R3. The 10V voltage is applied to the G pole pin of the second MOS tube Q2. At this time, the second MOS tube Q2 is in a normal on state, ensuring that the product can work normally when the input voltage is less than 350V.

[0028] The above is only a preferred embodiment of the utility model. It should be understood that the utility model is not limited to the form disclosed herein, and should not be regarded as excluding other embodiments, but can be used in various other combinations, modifications and environments, and can be modified within the scope of the concept described herein through the above teachings or the technology or knowledge of the relevant field. The changes and modifications made by those skilled in the art do not deviate from the spirit and scope of the utility model, and should be within the scope of protection of the claims attached to the utility model.

Claims

1. An overvoltage protection device based on MOS tube input, characterized in that: The invention comprises a rectifier module, a discharge module, a withstand voltage module and a trigger module, wherein the rectifier module comprises a rectifier bridge (BD1), a diode (D1) and a second MOS tube (Q2), wherein a first input end (a) of the rectifier bridge (BD1) is connected to a neutral line end (N) of an input power source, a second input end (b) of the rectifier bridge is connected to a live line end (L) of the input power source, a first output end (d) of the rectifier bridge is connected to the withstand voltage module, a second output end (c) of the rectifier bridge is connected to a source of the second MOS tube (Q2), a drain of the second MOS tube (Q2) is connected to the withstand voltage module, a gate of the second MOS tube (Q2) is connected to the trigger module, the first output end (d) of the rectifier bridge is also connected to an anode of the diode (D1), and a cathode of the diode (D1) is connected to the trigger module; The trigger module comprises a first MOS tube (Q1), a voltage stabilizing diode (ZD1), a first polarized capacitor (EC1), a first resistor (R1), a second resistor (R2), a third resistor (R3), a sixth resistor (R6), an eighth resistor (R8), a tenth resistor (R10), an eleventh resistor (R11), a twelfth resistor (R12), and a thirteenth resistor (R13); the cathode of the diode (D1) is grounded through the twelfth resistor (R12), the thirteenth resistor (R13), the second resistor (R2), and the eighth resistor (R8); the cathode of the diode (D1) is also grounded through the twelfth resistor (R12), the thirteenth resistor (R13), the second resistor (R2), and the eighth resistor (R8); The gate of the second MOS tube (Q2) is connected to the drain of the first MOS tube (Q1), the source of the first MOS tube (Q1) is grounded, the gate of the first MOS tube (Q1) is grounded through a first polar capacitor (EC1), the gate of the first MOS tube (Q1) is also connected to the anode of a voltage zener diode (ZD1) through a first resistor (R1), and the cathode of the voltage zener diode (ZD1) is connected between the sixth resistor (R6) and the third resistor (R3).

2. The overvoltage protection device based on MOS tube input according to claim 1 is characterized in that: The withstand voltage module comprises a second polarized capacitor (EC2) and a third polarized capacitor (EC3), the first output end (d) of the rectifier bridge is respectively connected to the positive electrodes of the second polarized capacitor (EC2) and the third polarized capacitor (EC3), the negative electrodes of the second polarized capacitor (EC2) and the third polarized capacitor (EC3) are grounded, and the drain of the second MOS tube (Q2) is respectively connected to the negative electrodes of the second polarized capacitor (EC2) and the third polarized capacitor (EC3).

3. The overvoltage protection device based on MOS tube input according to claim 1 is characterized in that: The withstand voltage module also includes a fourteenth resistor (R14) and an inductor (L1), the fourteenth resistor (R14) is connected between the positive electrodes of the second polar capacitor (EC2) and the third polar capacitor (EC3), and the inductor (L1) is connected in parallel to both ends of the fourteenth resistor (R14).

4. The overvoltage protection device based on MOS tube input according to claim 1, characterized in that: The withstand voltage module further comprises a resistor (RA), one end of the resistor (RA) is connected to the positive electrode of the third polar capacitor (EC3), and the other end of the resistor (RA) is connected to the negative electrode of the third polar capacitor (EC3).

5. The overvoltage protection device based on MOS tube input according to claim 1, characterized in that: The discharge module includes a fourth resistor (R4), a fifth resistor (R5), a seventh resistor (R7) and a ninth resistor (R9), the live terminal (L) is connected to the neutral terminal (N) through the fourth resistor (R4) and the fifth resistor (R5), and the live terminal (L) is also connected to the neutral terminal (N) through the seventh resistor (R7) and the ninth resistor (R9).

6. The overvoltage protection device based on MOS tube input according to claim 1, characterized in that: The device also includes a first capacitor (C1), which is connected between the live terminal (L) and the neutral terminal (N).

7. The overvoltage protection device based on MOS tube input according to claim 1, characterized in that: The device also includes a fuse (F1) and a thermistor (NTC1), wherein the live wire end (L) is connected to the second input end (b) of the rectifier bridge through the fuse (F1), and the neutral wire end (N) is connected to the first input end (a) of the rectifier bridge (BD1) through the thermistor (NTC1).

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