Input overvoltage protection circuit and driving power supply device

Abstract

The utility model discloses an input overvoltage protection circuit and a driving power supply device, comprising a rectification module, an overvoltage detection module, a switch module, a current limiting member and an electrolytic capacitor, the input end of the rectification module is used for being connected with a power supply, the sampling end of the overvoltage detection module is connected with the output end of the rectification module, and the output end of the rectification module is connected with the current limiting member. The switch module and the current limiting piece are connected to form at least part of a protection branch, the head end of the protection branch is connected with the output end of the rectification module, the control end of the overvoltage detection module is connected with the controlled end of the switch module, and the tail end of the protection branch is connected with the electrolytic capacitor to form a power supply output end. The design can provide overvoltage protection and suppress surge current, and is safe and reliable to use.

Description

Technical Field

[0001] The utility model relates to the technical field of electronic circuit design, and particularly relates to an input overvoltage protection circuit and a driving power supply device. Background Art

[0002] The existing power supply driving circuit can be provided with current limiting components such as thermosensitive components. The current limiting components can suppress inrush current and prevent the inrush current of charging the electrolytic capacitor behind the rectification module from being too large when the power supply is turned on, so as to avoid damage to the electrolytic capacitor and the subsequent circuit components. However, when the input voltage is too high, it will also damage the electrolytic capacitor, and the current power supply driving circuit is not compatible for the time being and cannot meet the use requirements. Content of the Utility Model

[0003] The utility model aims to at least solve one of the technical problems existing in the prior art. For this purpose, the utility model provides an input overvoltage protection circuit and a driving power supply device, which can provide overvoltage protection and suppress inrush current, and are safe and reliable to use.

[0004] An input overvoltage protection circuit according to an embodiment of the first aspect of the utility model includes: a rectification module, the input end of the rectification module is used for connecting with a power supply; an overvoltage detection module, the sampling end of the overvoltage detection module is connected with the output end of the rectification module; a switch module and a current limiting component, the switch module and the current limiting component are connected to form at least part of a protection branch, the head end of the protection branch is connected with the output end of the rectification module, and the control end of the overvoltage detection module is connected with the controlled end of the switch module; an electrolytic capacitor, the tail end of the protection branch is connected with the electrolytic capacitor and forms a power supply output end.

[0005] An input overvoltage protection circuit according to an embodiment of the utility model has at least the following beneficial effects:

[0006] In the input overvoltage protection circuit of the utility model, the input end of the rectification module is connected with the power supply. When the input voltage provided by the power supply is normal, the overvoltage detection module controls the switch module to conduct, and the current charges the electrolytic capacitor after passing through the current limiting component and outputs from the power supply output end. When the instantaneous inrush current is too large at the initial stage of charging, the current limiting component can limit the inrush current to prevent the too large inrush current from impacting the electrolytic capacitor. When the input voltage increases, the overvoltage detection module timely controls the switch module to disconnect, and the input voltage will not be applied to the electrolytic capacitor and the subsequent electronic components, preventing damage to the electrolytic capacitor and the subsequent electronic components. This design can provide overvoltage protection and suppress inrush current, and is safe and reliable to use.

[0007] According to some embodiments of the utility model, the current limiting component includes a thermistor NTC.

[0008] According to some embodiments of the present utility model, the switch module includes a semiconductor switch tube Q1, and an output end of the switch tube Q1 is connected to one end of the current limiting component.

[0009] According to some embodiments of the present utility model, a positive electrode of an output end of the rectification module is connected to a positive electrode of the electrolytic capacitor and forms a positive electrode of a power supply output end; a head end of the protection branch is connected to a negative electrode of the output end of the rectification module, and a tail end of the protection branch is connected to a negative electrode of the electrolytic capacitor and forms a negative electrode of the power supply output end.

[0010] According to some embodiments of the present utility model, the overvoltage detection module includes a voltage stabilizing power supply unit, an overvoltage triggering unit, and a switch unit. An input end of the voltage stabilizing power supply unit is connected to an output end of the rectification module. An output end of the voltage stabilizing power supply unit is respectively connected to a controlled end of the switch module and an input end of the switch unit. An output end of the switch unit is grounded. A sampling end of the overvoltage triggering unit is connected to the output end of the rectification module. An output end of the overvoltage triggering unit is connected to a controlled end of the switch unit to be able to control on / off of the switch unit.

[0011] According to some embodiments of the present utility model, the voltage stabilizing power supply unit includes a resistor R1, a resistor R4, and a voltage stabilizing diode ZD1. One end of the resistor R1 is connected to the output end of the rectification module. The other end of the resistor R1 is respectively connected to one end of the resistor R4, a negative electrode of the voltage stabilizing diode ZD1, the controlled end of the switch module, and the input end of the switch unit. The other end of the resistor R4 and a positive electrode of the voltage stabilizing diode ZD1 are both grounded.

[0012] According to some embodiments of the present utility model, the overvoltage triggering unit includes a resistive voltage dividing component. A sampling end of the resistive voltage dividing component is connected to the output end of the rectification module. A grounding end of the resistive voltage dividing component is grounded. A voltage dividing end of the resistive voltage dividing component is connected to the controlled end of the switch unit.

[0013] According to some embodiments of the present utility model, the resistive voltage dividing component includes a resistor R6 and a resistor R9. One end of the resistor R6 is connected to the output end of the rectification module. The other end of the resistor R6 is respectively connected to one end of the resistor R9, the controlled end of the switch module, and the input end of the switch unit. The other end of the resistor R9 is grounded.

[0014] A driving power supply device according to an embodiment of the second aspect of the present utility model includes an input overvoltage protection circuit disclosed in any one of the above embodiments.

[0015] The driving power supply device according to an embodiment of the present utility model has at least the following beneficial effects:

[0016] The driving power supply device of the present utility model applies an input overvoltage protection circuit disclosed in any of the above embodiments, which can provide overvoltage protection and suppress inrush current, and is safe and reliable to use.

[0017] Additional aspects and advantages of the present utility model will be partially given in the following description, partially become apparent from the following description, or be understood through the practice of the present utility model. Description of the Drawings

[0018] The above and / or additional aspects and advantages of the present utility model will become apparent and be readily understood from the description of the embodiments in conjunction with the following drawings, where:

[0019] Figure 1 is the principle structural block diagram of one embodiment of the input overvoltage protection circuit of the present utility model;

[0020] Figure 2 is the circuit schematic diagram of one embodiment of the input overvoltage protection circuit of the present utility model.

[0021] Reference Signs:

[0022] Rectification module 100; overvoltage detection module 200; voltage stabilization and power supply unit 210; overvoltage trigger unit 220; switch unit 230; switch module 300; current limiting component 400; electrolytic capacitor 500. Detailed Embodiments

[0023] The embodiments of the present utility model will be described in detail below. Examples of the embodiments are shown in the drawings, where the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by referring to the drawings are exemplary only for explaining the present utility model and should not be construed as limiting the present utility model.

[0024] In the description of the present utility model, it should be understood that with respect to the orientation description, for example, terms such as "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as limiting the present utility model.

[0025] In the description of the present utility model, the meaning of "a number of" is one or more, the meaning of "a plurality of" is two or more, and understandings such as "greater than", "less than", "exceeding", etc. do not include the base number, and understandings such as "above", "below", "within", etc. include the base number. If there is a description of "first" and "second", it is only for the purpose of distinguishing technical features and cannot be understood as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features or implicitly indicating the sequence relationship of the indicated technical features.

[0026] In the description of the present utility model, it should be noted that unless otherwise clearly specified and limited, the terms "installation", "connection", and "connection" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to specific situations.

[0027] As Figure 1 , 2 shown, an input overvoltage protection circuit according to an embodiment of the first aspect of the present utility model includes a rectification module 100, an overvoltage detection module 200, a switching module 300, a current limiting component 400, and an electrolytic capacitor 500. The input end of the rectification module 100 is used to be connected to a power supply. The sampling end of the overvoltage detection module 200 is connected to the output end of the rectification module 100. The switching module 300 and the current limiting component 400 are connected to form at least part of a protection branch. The head end of the protection branch is connected to the output end of the rectification module 100. The control end of the overvoltage detection module 200 is connected to the controlled end of the switching module 300. The tail end of the protection branch is connected to the electrolytic capacitor 500 and forms a power supply output end.

[0028] Among them, the rectification module 100 can be a full-wave rectifier bridge device or a half-wave rectifier bridge device composed of a plurality of diodes.

[0029] As Figure 2 shown, the electrolytic capacitor 500 can be selected from conventional components. The power supply can output alternating current. After the rectification module 100 rectifies the alternating current into direct current, it charges the electrolytic capacitor 500 and outputs through the power supply output end to supply power to the subsequent load.

[0030] The overvoltage protection circuit for the present utility model has the input end of the rectification module 100 connected to the power supply. Under the condition that the input voltage provided by the power supply is normal, the overvoltage detection module 200 controls the switch module 300 to conduct. The current charges the electrolytic capacitor 500 after passing through the current-limiting component 400 and is output from the power supply output terminal. When the instantaneous surge current is too large at the initial stage of charging, the current-limiting component 400 can limit the surge current to prevent the excessive surge current from impacting the electrolytic capacitor 500. And when the input voltage increases, the overvoltage detection module 200 timely controls the switch module 300 to disconnect, so that the input voltage will not be applied to the electrolytic capacitor 500 and the subsequent electronic components, preventing damage to the electrolytic capacitor 500 and the subsequent electronic components. This design can provide overvoltage protection and suppress surge current, and is safe and reliable to use.

[0031] In some embodiments of the present utility model, the current-limiting component 400 includes a thermistor NTC. The thermistor NTC is connected in series between the output end of the rectification module 100 and the power supply output terminal. When the current is too large, the resistance value of the thermistor NTC rapidly increases, thereby suppressing the surge current.

[0032] In some embodiments of the present utility model, the switch module 300 includes a semiconductor switch tube Q1. The output end of the switch tube Q1 is connected to one end of the current-limiting component 400. Among them, the switch tube Q1 can be a semiconductor component such as a triode, a MOS tube, or a thyristor.

[0033] In some embodiments of the present utility model, as Figure 2 shown, the positive pole of the output end of the rectification module 100 is connected to the positive pole of the electrolytic capacitor 500 and forms the positive pole of the power supply output terminal. The head end of the protection branch is connected to the negative pole of the output end of the rectification module 100. Specifically, the head end of the protection branch and the negative pole of the output end of the rectification module 100 are both grounded. The tail end of the protection branch is connected to the negative pole of the electrolytic capacitor 500 and forms the negative pole of the power supply output terminal. The positive pole and the negative pole of the power supply output terminal can be connected to subsequent circuit elements such as a voltage regulation circuit and a load for power supply. Among them, one end of the current-limiting component 400 can be used as the head end of the protection branch, and the other end of the current-limiting component 400 is connected to the output end of the switch tube Q1. The input end of the switch tube Q1 is used as the tail end of the protection branch.

[0034] In some embodiments of the present utility model, the positive pole of the output end of the rectification module 100 can also be connected to the head end of the protection branch. The tail end of the protection branch is connected to the positive pole of the electrolytic capacitor 500 and forms the positive pole of the power supply output terminal. The negative pole of the electrolytic capacitor 500 is respectively connected to the negative pole of the output end of the rectification module 100 and the negative pole of the power supply output terminal to be grounded.

[0035] In some embodiments of the present utility model, as Figure 1 、2 As shown, the overvoltage detection module 200 includes a voltage-stabilizing power supply unit 210, an overvoltage trigger unit 220, and a switching unit 230. The input end of the voltage-stabilizing power supply unit 210 is connected to the output end of the rectification module 100. The output end of the voltage-stabilizing power supply unit 210 is respectively connected to the controlled end of the switching module 300 and the input end of the switching unit 230. The output end of the switching unit 230 is grounded. The sampling end of the overvoltage trigger unit 220 is connected to the output end of the rectification module 100, and the output end of the overvoltage trigger unit 220 is connected to the controlled end of the switching unit 230 to be able to control the on-off of the switching unit 230.

[0036] The voltage-stabilizing power supply unit 210 provides a stable signal voltage to the controlled end of the switching module 300. The overvoltage trigger unit 220 detects the magnitude of the input voltage. When the input voltage is too large, the overvoltage trigger unit 220 controls the switching unit 230 to conduct, pulling down the voltage provided by the voltage-stabilizing power supply unit 210 to the controlled end of the switching module 300, thereby causing the switching module 300 to disconnect.

[0037] In some embodiments of the present invention, as Figure 2 shown, the voltage-stabilizing power supply unit 210 includes a resistor R1, a resistor R4, and a voltage-regulator diode ZD1. One end of the resistor R1 is connected to the output end of the rectification module 100. The other end of the resistor R1 is respectively connected to one end of the resistor R4, the negative electrode of the voltage-regulator diode ZD1, the controlled end of the switching module 300, and the input end of the switching unit 230. The other end of the resistor R4 and the positive electrode of the voltage-regulator diode ZD1 are both grounded.

[0038] The resistor R1 and the resistor R4 form a resistor voltage division, and the voltage-regulator diode ZD1 clamps the terminal voltage at the connection point of the resistor R1 and the resistor R4 to form a relatively stable signal voltage to be provided to the controlled end of the switching module 300.

[0039] In some embodiments of the present invention, as Figure 2 shown, the overvoltage trigger unit 220 includes a resistive voltage division component. The sampling end of the resistive voltage division component is connected to the output end of the rectification module 100. The grounding end of the resistive voltage division component is grounded. The voltage division end of the resistive voltage division component is connected to the controlled end of the switching unit 230.

[0040] The overvoltage trigger unit 220 uses resistor voltage division to collect the input voltage. The voltage division end of the resistive voltage division component forms a feedback signal representing the magnitude of the input voltage. When the terminal voltage of the feedback signal is too high, the switching unit 230 can be made to conduct, thereby pulling down the signal voltage and causing the switching module 300 to disconnect.

[0041] In some embodiments of the present utility model, the resistive voltage dividing component includes a resistor R6 and a resistor R9. One end of the resistor R6 is connected to the output end of the rectification module 100, and the other end of the resistor R6 is respectively connected to one end of the resistor R9, the controlled end of the switch module 300, and the input end of the switch unit 230. The other end of the resistor R9 is grounded.

[0042] The driving power supply device according to the embodiment of the second aspect of the present utility model includes an input overvoltage protection circuit disclosed in any of the above embodiments.

[0043] The overvoltage protection circuit can be used as the front-end input circuit, and the power supply output end can be connected to the back-end load, voltage regulating circuit, switching power supply circuit, etc.

[0044] The driving power supply device of the present utility model applies an input overvoltage protection circuit disclosed in any of the above embodiments, which can provide overvoltage protection and suppress inrush current, and is safe and reliable to use.

[0045] The technical features of the above embodiments can be combined arbitrarily. For the sake of brevity of description, 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, it should be considered as the scope described in this specification.

[0046] Although the embodiments of the present utility model have been shown and described, those of ordinary skill in the art can understand that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principle and spirit of the present utility model. The scope of the present utility model is defined by the claims and their equivalents.

Claims

1. An input overvoltage protection circuit, characterized in that: include: A rectifier module, wherein the input end of the rectifier module is used to be connected to a power supply; An overvoltage detection module, wherein a sampling end of the overvoltage detection module is connected to an output end of the rectifier module; A switch module and a current limiting component, wherein the switch module and the current limiting component are connected to form at least a portion of a protection branch, the head end of the protection branch is connected to the output end of the rectifier module, and the control end of the overvoltage detection module is connected to the controlled end of the switch module; An electrolytic capacitor, the tail end of the protection branch is connected to the electrolytic capacitor and forms a power supply output end.

2. The input overvoltage protection circuit according to claim 1, characterized in that: The current limiting component includes a thermistor NTC.

3. The input overvoltage protection circuit according to claim 2, characterized in that: The switch module includes a semiconductor switch tube Q1, and an output end of the switch tube Q1 is connected to one end of the current limiting component.

4. The input overvoltage protection circuit according to claim 1, characterized in that: The positive pole of the output end of the rectifier module is connected to the positive pole of the electrolytic capacitor and forms the positive pole of the power supply output end; the head end of the protection branch is connected to the negative pole of the output end of the rectifier module, and the tail end of the protection branch is connected to the negative pole of the electrolytic capacitor and forms the negative pole of the power supply output end.

5. The input overvoltage protection circuit according to claim 1, characterized in that: The overvoltage detection module includes a voltage stabilizing energy supply unit, an overvoltage trigger unit and a switch unit. The input end of the voltage stabilizing energy supply unit is connected to the output end of the rectifier module, the output end of the voltage stabilizing energy supply unit is respectively connected to the controlled end of the switch module and the input end of the switch unit, the output end of the switch unit is grounded, the sampling end of the overvoltage trigger unit is connected to the output end of the rectifier module, and the output end of the overvoltage trigger unit is connected to the controlled end of the switch unit so as to control the on and off of the switch unit.

6. The input overvoltage protection circuit according to claim 5, characterized in that: The voltage-stabilizing energy supply unit includes a resistor R1, a resistor R4 and a voltage-stabilizing tube ZD1. One end of the resistor R1 is connected to the output end of the rectifier module, and the other end of the resistor R1 is respectively connected to one end of the resistor R4, the negative electrode of the voltage-stabilizing tube ZD1, the controlled end of the switch module and the input end of the switch unit. The other end of the resistor R4 and the positive electrode of the voltage-stabilizing tube ZD1 are both grounded.

7. The input overvoltage protection circuit according to claim 5, characterized in that: The overvoltage trigger unit includes a resistive voltage divider component, a sampling end of the resistive voltage divider component is connected to the output end of the rectifier module, a grounding end of the resistive voltage divider component is grounded, and a voltage divider end of the resistive voltage divider component is connected to the controlled end of the switch unit.

8. The input overvoltage protection circuit according to claim 7, characterized in that: The resistive voltage divider component includes a resistor R6 and a resistor R9, one end of the resistor R6 is connected to the output end of the rectifier module, the other end of the resistor R6 is respectively connected to one end of the resistor R9, the controlled end of the switch module and the input end of the switch unit, and the other end of the resistor R9 is grounded.

9. A driving power supply device, characterized in that: Comprising an input overvoltage protection circuit as described in any one of claims 1 to 8.

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