Power supply protection circuit and device

Abstract

The utility model relates to a power supply protection circuit and device, belongs to the technical field of power supplies, and aims to solve the problem that a power supply is easily damaged by a surge high-voltage prevention mode of an existing power supply. The utility model provides a power supply protection circuit and device, the power supply protection circuit comprises a power supply input end, a power supply output end, an anti-surge circuit, a current limiting circuit, a transient high voltage limiting circuit and a slow start protection circuit, and the anti-surge circuit, the current limiting circuit, the transient high voltage limiting circuit and the slow start protection circuit are sequentially connected between the power supply input end and the power supply output end. The power output end is connected with the input end of the power circuit; the current limiting circuit is used for carrying out overcurrent protection when the current of the power supply input end exceeds a preset current, and the transient high-voltage limiting circuit is used for limiting voltage. The anti-surge circuit suppresses voltage surge at the input end of the power supply, the current limiting circuit prevents overload of the power supply, the transient high-voltage limiting circuit limits the voltage of the power supply and prevents the power supply from generating overhigh voltage, and the slow start protection circuit controls the starting speed of the power supply, so that the power supply protection effect is improved.

Description

Technical Field

[0001] This application relates to the technical field of power supplies, and specifically, to a power supply protection circuit and device. Background Art

[0002] As the reliability requirements of current electronic devices for electronic systems or circuit boards are getting higher and higher, higher requirements are also put forward for the power supply safety of the power supply. At present, there are still some deficiencies in the protection of the docking input power supply. For the docking input power supply circuits on the market, the protection level is relatively low, and there are still some problems with insufficient protection of the power supply circuit. For example, when there is a relatively high surge voltage in the external power supply, the traditional surge protection scheme uses a varistor to absorb the surge energy. When the input voltage of the surge energy is large but not enough to make the leakage current of the varistor very large, the ability of the varistor to absorb the surge energy is insufficient, and at this time, the main power transistor may have been damaged due to excessive energy. Summary of the Utility Model

[0003] The purpose of this application is to provide a power supply protection circuit and device to solve the problem of power supply damage caused by high surge voltage.

[0004] To solve the above problems, the following technical solutions are adopted in this application for implementation:

[0005] The first aspect of this application provides a power supply protection circuit, including: a power input terminal, a power output terminal, a surge protection circuit, a current limiting circuit, a transient high voltage limiting circuit, and a soft start protection circuit. The surge protection circuit, the current limiting circuit, the transient high voltage limiting circuit, and the soft start protection circuit are sequentially connected between the power input terminal and the power output terminal, and the power output terminal is connected to the input terminal of the power supply circuit;

[0006] Among them, the current limiting circuit is used for overcurrent protection when the current at the power input terminal exceeds a preset current, and the transient high voltage limiting circuit is used for voltage limiting.

[0007] The surge protection circuit can effectively suppress the voltage surge at the power input terminal. The current limiting circuit can avoid power overload and protect the power supply circuit from damage. The transient high voltage limiting circuit can limit the voltage of the power supply to prevent too high a voltage at the power output terminal. The soft start protection circuit can control the start-up speed of the power supply and avoid the voltage surge caused by too fast start-up of the power supply, thereby improving the power supply protection effect.

[0008] Further, the power supply protection circuit further includes a first filter circuit, and the first filter circuit is located between the power input terminal and the surge protection circuit, and the first filter circuit is used for filtering the power input terminal.

[0009] By adding a first filter circuit between the power input terminal and the surge circuit, the power input terminal can be filtered more effectively, removing the noise and interference at the power input terminal and ensuring that the signal at the power input terminal is more stable.

[0010] Further, the soft start protection circuit includes a MOS module, and the MOS module is respectively connected to the power output terminal and the transient high voltage limiting circuit.

[0011] By providing a MOS module, the soft start protection circuit can be quickly started when the voltage at the power output terminal is too high, preventing voltage surges at the power output terminal and realizing the soft start protection function.

[0012] Further, the surge protection circuit includes a TVS tube, one end of the TVS tube is connected to the power input terminal, and the other end of the TVS tube is grounded.

[0013] By adopting a TVS tube in the surge protection circuit, the voltage surge at the power input terminal can be quickly suppressed, protecting the power circuit from damage. At the same time, the TVS tube has a fast response time and can act quickly when a voltage surge occurs, reducing the damage to the power circuit.

[0014] Further, the power protection circuit includes an inductor component, one end of the inductor component is connected to the power input terminal, and the other end of the inductor component is connected to the transient high voltage limiting circuit. By connecting the inductor component to the transient high voltage limiting circuit, impedance can be provided during a voltage surge, thereby protecting the circuit from damage, reducing the influence of electromagnetic interference on the power circuit, and improving the reliability of the circuit.

[0015] Further, the current limiting circuit includes a fuse, and the fuse is located between the inductor component and the power input terminal. Due to the provision of the fuse, it can melt when the current exceeds its rated value, thereby cutting off the circuit and protecting the inductor component and the power input terminal from overcurrent damage.

[0016] Further, the transient high voltage limiting circuit includes a polarized capacitor, one end of the polarized capacitor is connected to the inductor component, and the other end of the polarized capacitor is grounded.

[0017] By adding a polarized capacitor to the transient high voltage limiting circuit, the polarized capacitor can suppress the voltage spikes at the power input terminal, reduce voltage fluctuations, thereby protecting circuit components from damage and improving the anti-interference ability of the power supply to transient voltages.

[0018] Further, the power protection circuit further includes a second filter circuit, and the second filter circuit is located between the transient high voltage limiting circuit and the soft start protection circuit. The second filter circuit is used to filter the voltage after passing through the transient high voltage limiting circuit.

[0019] Since the second filtering circuit is located between the transient high-voltage limiting circuit and the soft-start protection circuit, it can perform additional filtering on the voltage processed by the transient high-voltage limiting circuit, further reducing voltage fluctuations and ripples, and improving the stability of the power supply output voltage. The second filtering circuit finely filters the voltage, removes the noise and ripples at the power supply output end, and enhances the protection ability of the circuit.

[0020] Furthermore, the power supply protection circuit further includes a pulse absorption circuit. One end of the pulse absorption circuit is connected to the second filtering circuit, and the other end of the pulse absorption circuit is grounded.

[0021] When the power supply starts or the load is switched, the pulse absorption circuit can absorb the pulse voltage at the power supply output end, protect the circuit from damage by the pulse voltage, reduce the pulse voltage and voltage spikes at the power supply output end, and improve the stability of the power supply output.

[0022] On the other hand, the present application provides a power supply protection device, including a housing with a receiving cavity formed therein, and the power supply protection circuit according to any one of the above, which is disposed in the housing.

[0023] Compared with the prior art, the beneficial effects of the present application are as follows: The surge protection circuit can effectively suppress the voltage surge at the power supply input end. The current limiting circuit can perform over-current protection when the current at the power supply input end exceeds the preset current, avoiding power supply overload. The transient high-voltage limiting circuit can limit the voltage of the power supply to prevent excessive voltage at the power supply output end. The soft-start protection circuit can control the start-up speed of the power supply to avoid voltage surges caused by too fast start-up of the power supply. Through the surge protection circuit, current limiting circuit, transient high-voltage limiting circuit and soft-start protection circuit, the power supply can be comprehensively and effectively protected. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 is a circuit diagram of a power supply protection circuit provided by an embodiment of the present application; and

[0025] Figure 2 is a schematic structural diagram of a power supply protection circuit provided by an embodiment of the present application.

[0026] Description of the Reference Numerals:

[0027] 100, power supply protection circuit; 110, surge protection circuit; 120, current limiting circuit; 130, transient high-voltage limiting circuit; 140, soft-start protection circuit; 141, MOS module; 150, first filtering circuit; 160, inductor component; 170, second filtering circuit; 180, pulse absorption circuit; 200, power supply circuit; 300, external power supply. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0028] The following will describe in detail the specific embodiments of the present application with reference to the accompanying drawings.

[0029] It should be noted that, without conflict, the embodiments in the present application and the technical features in the embodiments can be combined with each other. The detailed description in the specific embodiments should be understood as an explanatory illustration of the purpose of the present application and should not be regarded as an improper limitation of the present application.

[0030] It should be understood that the orientation or positional relationship is based on the orientation or positional relationship shown in the accompanying drawings. These orientation terms are only for the convenience of describing the present application 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 a limitation of the present application.

[0031] Figure 1 It is a circuit diagram of a power protection circuit provided for an embodiment of the present application. Figure 2 It is a structural schematic diagram of a power protection circuit provided for an embodiment of the present application. As Figure 1 and Figure 2 shown, an embodiment of the present application provides a power protection circuit 100, including a power input terminal I, a power output terminal O, a surge protection circuit 110, a current limiting circuit 120, a transient high voltage limiting circuit 130, and a soft start protection circuit 140. The surge protection circuit 110, the current limiting circuit 120, the transient high voltage limiting circuit 130, and the soft start protection circuit 140 are sequentially connected between the power input terminal I and the power output terminal 0, and the power output terminal O is connected to the input terminal of the power circuit 200.

[0032] Among them, the current limiting circuit 120 is used to perform overcurrent protection when the current at the power input terminal I exceeds a preset current, and the transient high voltage limiting circuit 130 is used to limit the voltage.

[0033] Specifically, the power input terminal I is connected to an external power supply 300, so that the external power supply 300 is connected to the power circuit 200 through the power input terminal I, the power protection circuit 100, and the power output terminal O. The power protection circuit 100 processes and protects the external power supply 300, making the input voltage of the power circuit 200 stable and reliable. For example, the external power supply 300 includes a power device DCIN1, and the input port of the power circuit 200 is P24V (see Figure 1) The power input terminal I is connected to an external power supply 300, and the power output terminal O is connected to a power supply circuit 200. For example, the external power supply 300 is a power socket, and the power supply circuit 200 is an electronic device. To protect the electronic device, a power protection circuit 100 is provided between the power socket and the electronic device to perform functions such as surge protection, filtering, and transient voltage absorption. Among them, the surge protection circuit 110 can adopt a gas plasma protector, a silicon-controlled rectifier circuit, or other forms of surge protection means. The surge protection circuit 110 is connected between the power input terminal I and the power output terminal O to suppress the surge voltage in the power grid and protect the circuit from the influence of power grid fluctuations. The current limiting circuit 120 can adopt a fuse, an overcurrent protector. The current limiting circuit 120 is connected between the power input terminal I and the power output terminal O and is used for overcurrent protection when the current at the power input terminal I exceeds a preset current. The transient high voltage limiting circuit 130 can adopt a silicon-controlled rectifier circuit, a gas plasma protector. The transient high voltage limiting circuit 130 is connected between the power input terminal I and the power output terminal O and is used for voltage limiting to prevent the transient high voltage in the power grid from damaging the circuit. The soft start protection circuit 140 can adopt a soft start protection circuit composed of components such as inductors and capacitors. The soft start protection circuit 140 is connected between the power input terminal I and the power output terminal O and is used to limit the current during power startup to prevent damage to the circuit caused by the current impact during power startup.

[0034] Through the surge protection circuit 110, the voltage surge at the power input terminal I can be effectively suppressed. The current limiting circuit 120 can avoid power overload and protect the power supply circuit from being damaged. The transient high voltage limiting circuit 130 can limit the voltage of the power supply to prevent an excessive voltage at the power output terminal. The soft start protection circuit 140 can control the startup speed of the power supply and avoid voltage surges caused by too fast power startup, thereby improving the power protection effect.

[0035] In some embodiments, the power protection circuit 100 further includes a first filter circuit 150. The first filter circuit 150 is located between the power input terminal I and the surge protection circuit 110, and the first filter circuit 150 is used to filter the power input terminal I.

[0036] Specifically, the first filter circuit 150 includes a capacitor C1. One end of the capacitor C1 is grounded, and the other end is connected to the external power supply 300. For example, one end of the capacitor C1 is grounded, and the other end is connected to pin 2 of CDIN1. The first filter circuit 150 is located between the power input terminal I and the surge protection circuit 110, and the surge protection circuit 110 is connected between the first filter circuit 150 and the power output terminal O. The first filter circuit 150 suppresses the noise and interference in the power grid and improves the quality of the power input signal.

[0037] In some embodiments, the soft-start protection circuit 140 includes a MOS module 141, and the MOS module 141 is respectively connected to the power output terminal O and the transient high-voltage limiting circuit 130.

[0038] Specifically, the MOS module 141 includes MOSFET transistors, which can quickly switch states according to the change of the control signal to realize the connection and disconnection between the power output terminal O and the transient high-voltage limiting circuit 130; after the MOS module 141 receives the control signal, the MOS module 141 conducts and cuts off to realize the soft-start connection between the power output terminal O and the transient high-voltage limiting circuit 130.

[0039] When the circuit starts up, the MOS module 141 receives the start signal and conducts, connecting the power output terminal O to the transient high-voltage limiting circuit 130. After the circuit operates stably, the voltage of the power output terminal is continuously monitored. When it is detected that the voltage of the power output terminal O exceeds the set threshold, the control unit immediately sends a protection signal to the MOS module 141, causing the MOS module 141 to quickly cut off, thereby disconnecting the connection between the power output terminal O and the transient high-voltage limiting circuit 130.

[0040] By providing the MOS module 141, the soft-start protection circuit 140 can quickly start when the voltage of the power output terminal O is too high, prevent voltage surges at the power output terminal O, and realize the soft-start protection function.

[0041] In some embodiments, the surge protection circuit 110 includes a TVS tube, one end of the TVS tube is connected to the power input terminal I, and the other end of the TVS tube is grounded.

[0042] Specifically, when the circuit is working normally, the voltage at the power input terminal I is maintained within the rated voltage range of the TVS tube. At this time, the TVS tube is in a high-resistance state and does not affect the normal operation of the circuit; when the power input terminal I is subjected to a voltage surge impact and the voltage instantaneously rises and exceeds the breakdown voltage of the TVS tube, the TVS tube quickly changes from the high-resistance state to the low-resistance state, conducts the circuit, and releases the excess voltage energy to the ground through its own dissipation mechanism, thereby protecting the subsequent circuit from surge damage; when the voltage surge disappears and the voltage at the power input terminal I returns to the normal level, the TVS tube becomes a high-resistance state again.

[0043] During the operation of the electronic device, it may be subjected to voltage surge impacts from the power cord, which may damage electronic components and affect the normal operation of the device. The TVS tube (Transient Voltage Suppressor) can quickly conduct when the voltage exceeds its breakdown voltage, absorb the excess voltage energy, thereby protecting the circuit from surge damage.

[0044] By adopting a TVS tube in the surge protection circuit 110, the voltage surge at the power input terminal I can be quickly suppressed, protecting the power circuit 200 from damage. At the same time, the TVS tube has a fast response time and can act quickly when a voltage surge occurs, reducing the damage to the power circuit.

[0045] In some embodiments, the power protection circuit 100 includes an inductor component 160. One end of the inductor component 160 is connected to the power input terminal I, and the other end of the inductor component 160 is connected to the transient high voltage limiting circuit 130.

[0046] Specifically, both ends of the inductor component 160 are respectively connected to the current limiting circuit 120 and the transient high voltage limiting circuit 130.

[0047] When the power input terminal I is subjected to a voltage surge impact and the voltage instantaneously rises, the inductor component 160 can limit the sudden change of current through its self-inductance effect, slowing down the impact of the voltage surge on the subsequent circuit. The transient high voltage limiting circuit 130 monitors the voltage of the power input terminal I. When the voltage exceeds its set threshold, the transient high voltage limiting circuit 130 is activated and protects the circuit from high voltage surges through its internal protection mechanism. When the voltage surge disappears and the voltage of the power input terminal I returns to the normal level, the inductor component 160 and the transient high voltage limiting circuit 130 return to the normal working state.

[0048] By connecting the inductor component 160 to the transient high voltage limiting circuit 130, impedance can be provided during a voltage surge, thereby protecting the circuit from damage, reducing the impact of electromagnetic interference on the power circuit 200, and improving the reliability of the circuit.

[0049] In some embodiments, the current limiting circuit 120 includes a fuse F1, and the fuse F1 is located between the inductor component 160 and the power input terminal I.

[0050] Specifically, in an electronic device, an overcurrent phenomenon may cause circuit components to overheat, be damaged, or even catch fire. To prevent this from happening, a current limiting component needs to be added to the circuit to limit the current within a safe range. The current limiting circuit 120 includes a fuse F1, and the fuse F1 is located between the inductor component 160 and the surge protection circuit 110. When the circuit is operating normally, the current passes through the inductor component 160, and the fuse F1 is in a conducting state, and the circuit operates normally. When the current exceeds the rated current of the fuse F1, the fuse F1 will quickly heat up due to the increase in its own resistance, melt after reaching the melting point, and cut off the circuit to provide overcurrent protection.

[0051] Since the fuse F1 is provided, it can melt when the current exceeds its rated value, thereby cutting off the circuit and protecting the inductor component 160 and the power input terminal I from overcurrent damage.

[0052] In some embodiments, the transient high-voltage limiting circuit 130 includes a polarized capacitor C4. One end of the polarized capacitor C4 is connected to the inductor component 160, and the other end of the polarized capacitor C4 is grounded.

[0053] Specifically, when the power input terminal I is subjected to a voltage surge impact and the voltage instantaneously rises, the inductor component 160 can limit the sudden change of current through its self-inductance effect and slow down the impact of the voltage surge on the subsequent circuit. Since the other end of the polarized capacitor C4 is grounded, the overvoltage surge can be guided to the ground, thereby protecting the circuit from damage caused by the high-voltage surge.

[0054] By adding the polarized capacitor C4 to the transient high-voltage limiting circuit 130, the polarized capacitor C4 can suppress the voltage spike at the power input terminal I, reduce the voltage fluctuation, thereby protecting the circuit components from damage and improving the anti-interference ability of the power supply to transient voltages.

[0055] In some embodiments, the power protection circuit 100 further includes a second filter circuit 170. The second filter circuit 170 is located between the transient high-voltage limiting circuit 130 and the soft-start protection circuit 140, and the second filter circuit 170 is used to filter the voltage after passing through the transient high-voltage limiting circuit 130.

[0056] Specifically, the power protection circuit 100 includes a transient high-voltage limiting circuit 130, a second filter circuit 170, and a soft-start protection circuit 140. The second filter circuit 170 is located between the transient high-voltage limiting circuit 130 and the soft-start protection circuit 140 and is used to filter the voltage processed by the transient high-voltage limiting circuit 130. The voltage processed by the transient high-voltage limiting circuit 130 is output to the second filter circuit 170. The second filter circuit 170 includes a capacitor C3, and the capacitor C3 is used to filter the voltage waveform. The filtered voltage is output to the soft-start protection circuit 140, and the soft-start protection circuit 140 further protects the electronic device from damage caused by voltage fluctuations.

[0057] Since the second filter circuit 170 is located between the transient high-voltage limiting circuit 130 and the soft-start protection circuit 140, it can perform additional filtering on the voltage processed by the transient high-voltage limiting circuit 130, further reducing the voltage fluctuation and ripple, and improving the stability of the power supply output voltage. The second filter circuit 170 finely filters the voltage, removes the noise and ripple at the power output terminal O, and enhances the protection ability for the circuit.

[0058] In some embodiments, the power protection circuit 100 further includes a pulse absorption circuit 180. One end of the pulse absorption circuit 180 is connected to the second filter circuit 170, and the other end of the pulse absorption circuit 180 is grounded.

[0059] Specifically, the power protection circuit 100 includes a transient high voltage limiting circuit 130, a second filtering circuit 170, and a pulse absorption circuit 180. The pulse absorption circuit 180 includes a resistor R6 and a capacitor C2. One end of the capacitor C2 is connected to the resistor R6, the other end of the capacitor C2 is connected to the ground, and the resistor R6 is connected to the second filtering circuit 170.

[0060] After passing through the second filtering circuit 170, the second filtering circuit 170 filters the voltage to reduce the impact of voltage fluctuations on the electronic device. The filtered voltage is output to the pulse absorption circuit 180. The pulse absorption circuit 180 can absorb the remaining voltage pulses. The other end of the pulse absorption circuit 180 is grounded to direct the absorbed voltage pulses to the ground, thereby protecting the electronic device from damage.

[0061] When the power supply is started or the load is switched, the pulse absorption circuit 180 can absorb the pulse voltage at the power output terminal O, protect the circuit from damage by the pulse voltage, reduce the pulse voltage and voltage spikes at the power output terminal O, and improve the stability of the power output.

[0062] The embodiment of the present application also provides a power protection device, including a housing with a receiving cavity formed therein, and the above-mentioned power protection circuit 100. The power protection circuit 100 is disposed in the housing.

[0063] The above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them; although the present application has been described in detail with reference to the foregoing embodiments, for those skilled in the art, it is still possible to modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions required to be protected by the present application.

Claims

1. A power protection circuit, characterized in that, Comprising: A power input terminal, a power output terminal, a surge protection circuit, a current limiting circuit, a transient high voltage limiting circuit, and a soft start protection circuit. The surge protection circuit, the current limiting circuit, the transient high voltage limiting circuit, and the soft start protection circuit are sequentially connected between the power input terminal and the power output terminal, and the power output terminal is connected to the input terminal of the power circuit; Wherein, the current limiting circuit is used for overcurrent protection when the current at the power input terminal exceeds a preset current, and the transient high voltage limiting circuit is used for voltage limiting.

2. The power protection circuit according to claim 1, wherein The power protection circuit further includes a first filter circuit, which is located between the power input terminal and the surge protection circuit, and the first filter circuit is used for filtering the power input terminal.

3. The power protection circuit according to claim 1, characterized in that The soft start protection circuit includes a MOS module, and the MOS module is respectively connected to the power output terminal and the transient high voltage limiting circuit.

4. A power protection circuit according to claim 1, characterized in that, The surge protection circuit includes a TVS tube, one end of the TVS tube is connected to the power input terminal, and the other end of the TVS tube is grounded.

5. A power protection circuit according to claim 1, characterized in that, The power protection circuit includes an inductor component, one end of the inductor component is connected to the power input terminal, and the other end of the inductor component is connected to the transient high voltage limiting circuit.

6. The power protection circuit according to claim 5, wherein The current limiting circuit includes a fuse, and the fuse is located between the inductor component and the power input terminal.

7. A power protection circuit according to claim 5, characterized in that, The transient high voltage limiting circuit includes a polar capacitor, one end of the polar capacitor is connected to the inductor component, and the other end of the polar capacitor is grounded.

8. The power supply protection circuit according to claim 1, characterized in that, The power protection circuit further includes a second filter circuit, which is located between the transient high voltage limiting circuit and the soft start protection circuit, and the second filter circuit is used for filtering the voltage after passing through the transient high voltage limiting circuit.

9. The protection circuit for serial communication according to claim 8, characterized in that The power protection circuit further includes a pulse absorption circuit, one end of the pulse absorption circuit is connected to the second filter circuit, and the other end of the pulse absorption circuit is grounded.

10. A power protection device, characterized in that, A housing with a receiving cavity formed therein, and the power protection circuit according to any one of claims 1-9 is disposed in the housing.

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