Low-voltage DC overvoltage protection circuit

Abstract

The utility model provides a low-voltage DC overvoltage protection circuit, which comprises a power supply module, a voltage detection module, a control module, a first PMOS tube and an output module, the power supply module is connected with the input end of the output module through the first PMOS tube, and the input end of the voltage detection module is connected between the power supply module and the first PMOS tube. The output end of the voltage detection module is connected with the control module, and the control module is connected with the first PMOS tube and used for controlling on-off of the first PMOS tube.

Description

Technical Field

[0001] This utility model relates to a low-voltage DC power supply module, specifically a low-voltage DC overvoltage protection circuit. Background Technology

[0002] In machine tool equipment, voltage exceeding a preset threshold often causes overvoltage in the low-voltage DC power supply, which can burn out the load circuitry. To address this issue, various methods are commonly used, such as switching power supplies, reducing power output, or switching to a backup power supply, to ensure the load is not damaged by overvoltage and achieve overvoltage protection. However, current overvoltage protection methods generally employ numerous electronic components, resulting in higher costs. Utility Model Content

[0003] The purpose of this invention is to provide a low-voltage DC overvoltage protection circuit. It mainly uses two P-MOS transistors and a Zener diode to optimize the circuit design and control logic. It can not only monitor the input voltage of the power supply, but also realize overvoltage protection in the low-voltage DC power supply. It has the advantages of low cost and high reliability.

[0004] To solve the above-mentioned technical problems, the present invention adopts the following solution:

[0005] A low-voltage DC overvoltage protection circuit includes a power supply module, a voltage detection module, a control module, a first P_MOS transistor, and an output module. The power supply module is connected to the input terminal of the output module through the first P_MOS transistor. The input terminal of the voltage detection module is connected between the power supply module and the first P_MOS transistor. The output terminal of the voltage detection module is connected to the control module. The control module is connected to the first P_MOS transistor and is used to control the on / off state of the first P_MOS transistor.

[0006] Furthermore, the voltage detection module includes a Zener diode and a voltage divider resistor, and the control module includes a second P_MOS transistor; the power supply module and the first P_MOS transistor are connected in sequence to the voltage divider resistor and the negative terminal of the Zener diode, the contact point between the negative terminal of the Zener diode and the voltage divider resistor is connected to the second P_MOS transistor, and the second P_MOS transistor is connected to the first P_MOS transistor.

[0007] Furthermore, the contact point between the negative terminal of the Zener diode and the voltage divider resistor is connected to the gate of the second P_MOS transistor, the drain of the second P_MOS transistor is connected to the gate of the first P_MOS transistor, the source of the second P_MOS transistor is connected to the source of the first P_MOS transistor, and both the source of the first P_MOS transistor and the source of the second P_MOS transistor are connected to the power supply module, and the drain of the first P_MOS transistor is connected to the output module.

[0008] Furthermore, the gate of the first P_MOS transistor and the drain of the second P_MOS transistor are grounded through a current-limiting resistor.

[0009] Furthermore, the voltage detection module includes a voltage divider resistor module, the input terminal of the voltage divider resistor module is connected between the power supply module and the first P_MOS transistor, and the output terminal of the voltage divider resistor module is connected to the control module.

[0010] Furthermore, it also includes a reset module for automatic or manual reset circuitry.

[0011] Furthermore, it also includes an alarm module, which is connected to the control module and is used to issue alarm signals.

[0012] Furthermore, it also includes a filtering module, which is connected between the power supply module and the voltage detection module, and is used to filter the voltage output by the power supply module.

[0013] The beneficial effects of this utility model are:

[0014] This invention provides a low-voltage DC overvoltage protection circuit. To reduce costs, two P_MOS transistors and a Zener diode are used to optimize the circuit design and control logic. A voltage detection circuit is designed using the Zener diode and a voltage divider resistor. This voltage detection circuit is connected to the two P_MOS transistors. While monitoring the input voltage of the power supply, the connection result of the two P_MOS transistors is used to achieve the protection function of the power supply. Furthermore, due to the design of the Zener diode and the voltage divider resistor, the protection voltage can be changed by adjusting the Zener diode's voltage regulation value. It has the advantages of low cost and high reliability. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of a low-voltage DC overvoltage protection circuit according to Embodiment 1 of this utility model;

[0016] Figure 2 This is a schematic diagram of a low-voltage DC overvoltage protection circuit in Embodiment 1 of this utility model. Detailed Implementation

[0017] To enable those skilled in the art to better understand the technical solution of this utility model, the present utility model will be further described in detail below with reference to the accompanying drawings and specific embodiments, but the embodiments of this utility model are not limited thereto.

[0018] In the description of this utility model, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "longitudinal", "lateral", "horizontal", "inner", "outer", "front", "rear", "top", "bottom", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the utility model product is in use. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0019] In the description of this utility model, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set up," "have," "install," "connect," and "connect" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0020] The present invention will now be described in detail with reference to the accompanying drawings and embodiments:

[0021] Example 1

[0022] In this embodiment, a low-voltage DC overvoltage protection circuit is provided, such as... Figure 1 As shown, it includes a power supply module, a voltage detection module, a control module, a first P_MOS transistor, and an output module. The power supply module is connected to the input terminal of the output module through the first P_MOS transistor. The input terminal of the voltage detection module is connected between the power supply module and the first P_MOS transistor. The output terminal of the voltage detection module is connected to the control module. The control module is connected to the first P_MOS transistor and is used to control the on / off state of the first P_MOS transistor.

[0023] The voltage detection module is used to monitor the input voltage of the power supply module in real time. The control module is connected to the voltage detection module and is used to determine whether overvoltage protection is required based on the detection result of the voltage detection module. The process is as follows: determine whether the input voltage in the detection result is greater than a preset threshold. If so, overvoltage protection is required. It can be seen that this process can be implemented using a comparator, which is a conventional technical means for those skilled in the art, and will not be elaborated here.

[0024] In one embodiment, the control module is a microprocessor or an application-specific integrated circuit (ASIC), and the power supply module is connected to the input terminal of the output module via a first P_MOS transistor. The control module is connected to the control terminal of the first P_MOS transistor. When the control module determines whether overvoltage protection is needed based on the detection result of the voltage detection module, it executes the corresponding action according to the determination result, that is, controlling the switching on and off of the first P_MOS transistor. By switching the first P_MOS transistor on and off, corresponding protection operations can be performed on the power supply module. The purpose is to use the first P_MOS transistor as the protection executor, and control it with the control module to switch the power supply, thereby ensuring overvoltage protection of the power supply module.

[0025] In one embodiment, the voltage detection module includes a voltage divider resistor module. The input terminal of the voltage divider resistor module is connected between the power supply module and the first P_MOS transistor. The output terminal of the voltage divider resistor module is connected to the control module. Specifically, the voltage divider resistor module is connected to a comparator, which can be used to compare the input voltage with a preset threshold to achieve overvoltage protection.

[0026] In one embodiment, a reset module is also included, which is used to automatically or manually reset the circuit after the overvoltage protection operation is completed, so that it returns to normal working state.

[0027] In one embodiment, an alarm module is also included, which is connected to the control module and is used to issue an alarm signal to alert the user when the control unit determines that overvoltage protection is required.

[0028] In one embodiment, a filtering module is further included, which is connected between the power supply module and the voltage detection module to filter the voltage output by the power supply module and improve the accuracy of voltage monitoring.

[0029] Based on the above principles, in this embodiment, the low-voltage DC overvoltage protection circuit is as follows: Figure 2 As shown, it includes a power module VIN, an output module V_OUT, a first P_MOS transistor Q11, a second P_MOS transistor Q12, a Zener diode D1, a voltage divider resistor R12, and a resistor R13.

[0030] The Zener diode D and the voltage divider resistor R12 are used for voltage detection. The second P-MOS transistor Q12 is used to control the first P-MOS transistor Q11 based on the voltage detection result. The first P-MOS transistor Q11 is used for overvoltage protection of the power module VIN.

[0031] Specifically, the power module VIN is connected in sequence to the voltage divider resistor R12 and the negative terminal of the Zener diode D1 between the first P_MOS transistor Q11 and the positive terminal of the Zener diode D1, and the contact point between the negative terminal of the Zener diode D1 and the voltage divider resistor R12 is connected to the gate of the second P_MOS transistor Q12.

[0032] The drain of the second P_MOS transistor is connected to the gate of the first P_MOS transistor, the source of the second P_MOS transistor is connected to the source of the first P_MOS transistor, and the sources of both the first and second P_MOS transistors are connected to the power supply module. The drain of the first P_MOS transistor is connected to the output module. The gate of the first P_MOS transistor and the drain of the second P_MOS transistor are grounded.

[0033] In addition, a resistor R13 is connected to the contact point between the gate of the first P_MOS transistor and the drain of the second P_MOS transistor, and the other end of the resistor R13 is grounded.

[0034] It is understood that the above embodiments are merely exemplary implementations used to illustrate the principles of this utility model, and the utility model is not limited thereto. For those skilled in the art, various modifications and improvements can be made without departing from the spirit and essence of this utility model, and these modifications and improvements are also considered to be within the protection scope of this utility model.

Claims

1. A low voltage DC overvoltage protection circuit, characterized by The application relates to a power supply module, a voltage detection module, a control module, a first P_MOS tube, and an output module, wherein the power supply module is connected with the input end of the output module through the first P_MOS tube, the input end of the voltage detection module is connected between the power supply module and the first P_MOS tube, the output end of the voltage detection module is connected with the control module, the control module is connected with the first P_MOS tube, and the control module is used for controlling the on-off of the first P_MOS tube.

2. The low voltage DC overvoltage protection circuit according to claim 1, characterized in that The voltage detection module comprises a voltage stabilizing diode and a voltage dividing resistor, the control module comprises a second P_MOS tube, the voltage dividing resistor and the negative electrode of the voltage stabilizing diode are sequentially connected between the power supply module and the first P_MOS tube, the contact point between the negative electrode of the voltage stabilizing diode and the voltage dividing resistor is connected with the second P_MOS tube, and the second P_MOS tube is connected with the first P_MOS tube.

3. The low voltage DC overvoltage protection circuit according to claim 2, characterized in that The contact point between the negative electrode of the voltage stabilizing diode and the voltage dividing resistor is connected with the gate of the second P_MOS tube, the drain of the second P_MOS tube is connected with the gate of the first P_MOS tube, the source of the second P_MOS tube is connected with the source of the first P_MOS tube, the source of the first P_MOS tube and the source of the second P_MOS tube are both connected with the power supply module, and the drain of the first P_MOS tube is connected with the output module.

4. The low voltage DC overvoltage protection circuit of claim 2, wherein, The gate of the first P_MOS tube and the drain of the second P_MOS tube are connected with the ground through a current limiting resistor.

5. The low voltage DC overvoltage protection circuit of claim 1, wherein, The voltage detection module comprises a voltage dividing resistor module, the input end of the voltage dividing resistor module is connected between the power supply module and the first P_MOS tube, and the output end of the voltage dividing resistor module is connected with the control module.

6. The low voltage DC overvoltage protection circuit of claim 1, wherein, The application further comprises a reset module which is used for automatically or manually resetting the circuit.

7. The low voltage DC overvoltage protection circuit of claim 1, wherein, The application further comprises an alarm module which is connected with the control module and is used for sending an alarm signal.

8. The low voltage DC overvoltage protection circuit of claim 1, wherein, The application further comprises a filter module which is connected between the power supply module and the voltage detection module and is used for filtering the voltage output by the power supply module.

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