A current limiting protection circuit

Abstract

The utility model discloses an embodiment of utility model discloses a kind of current-limiting protection circuit, comprising: switching module, detection module and self-locking module;The first input of switching module is connected with external power supply, the output of switching module is connected with the output of self-locking module, the output of switching module is connected with the first input of detection module;The first output of detection module is connected with the first input of self-locking module, and the second output of detection module exports power supply signal;Detection module is used to export detection voltage to the first input of self-locking module according to the current flowing;Self-locking module is used to control switching module to be turned off according to abnormal detection voltage.The technical scheme provided by the utility model embodiment can detect the current flowing in real time, quickly cut off circuit when current is abnormal, and switching module can be reused, improve the safety and stability of circuit, reduce maintenance cost and downtime.

Description

Technical Field

[0001] This utility model relates to the field of switching power supply technology, and in particular to a current limiting protection circuit. Background Technology

[0002] Currently, switching power supplies are widely used in various fields such as electronics, communications, aerospace, railway, energy, and medical. With the widespread application of switching power supplies, the reliability requirements for them are becoming increasingly stringent. To ensure that switching power supplies operate stably and reliably in different environments, various protection circuits need to be designed. Among these, current limiting protection is a priority function in the design, and its main purpose is to prevent the switching power supply from burning out or damaging the load due to high internal power consumption under overload or short-circuit conditions.

[0003] In existing switching power supplies, current limiting protection is achieved using fuses. However, when the current flows excessively, the fuse temperature rises, eventually melting and breaking the circuit to protect the circuit and equipment. However, fuses take time to melt and cannot be re-fused; they must be replaced according to specifications. Therefore, the slow disconnection speed and lack of reusability of existing switching power supply protection circuits have become pressing technical problems that the industry needs to solve. Utility Model Content

[0004] This invention provides a current limiting protection circuit to solve the problem of slow cut-off speed and inability to be reused in switching power supply protection circuits.

[0005] According to one aspect of this utility model, a current limiting protection circuit is provided, comprising: a switching module, a detection module, and a self-locking module;

[0006] The first input terminal of the switch module is connected to an external power supply, the second input terminal of the switch module is connected to the output terminal of the self-locking module, and the output terminal of the switch module is connected to the first input terminal of the detection module.

[0007] The first output terminal of the detection module is connected to the first input terminal of the self-locking module, and the second output terminal of the detection module outputs a power signal; the detection module is used to output a detection voltage to the first input terminal of the self-locking module according to the current flowing through it.

[0008] The self-locking module is used to control the switching module to turn off based on the abnormal detection voltage.

[0009] Optionally, the switching module includes: a first switching unit and a second switching unit;

[0010] The first terminal of the first switching unit is connected to a first power supply voltage, the second terminal of the first switching unit is connected to the first input terminal of the detection module, and the control terminal of the first switching unit is connected to the first terminal of the second switching unit; the first power supply voltage is generated based on the voltage of the external power supply.

[0011] The second terminal of the second switching unit is grounded, and the control terminal of the second switching unit is connected to the output terminal of the self-locking module.

[0012] The second switching unit is used to turn off when the output voltage of the self-locking module is the detection voltage corresponding to an abnormality, so as to turn off the first switching unit;

[0013] And when the output voltage of the self-locking module is the same as the normal detection voltage, it is turned on to turn on the first switching unit.

[0014] Optionally, the first switching unit includes a first voltage divider subunit and a first switching device, and the second switching unit includes a second voltage divider subunit and a second switching device;

[0015] The first terminal of the first voltage divider unit is connected to the first power supply voltage, the second terminal of the first voltage divider unit is connected to the first terminal of the second switching device, and the first voltage divider output terminal of the first voltage divider unit is connected to the control terminal of the first switching device; the first terminal of the first switching device is connected to the first terminal of the first voltage divider unit, and the second terminal of the first switching device is connected to the first input terminal of the detection module.

[0016] The first terminal of the second voltage divider unit is connected to the first power supply voltage or the second power supply voltage, the second terminal of the second voltage divider unit is grounded, the second voltage divider output terminal of the second voltage divider unit is connected to the control terminal of the second switching device, the control terminal of the second switching device is also connected to the output terminal of the self-locking module; the second terminal of the second switching device is grounded.

[0017] The second power supply voltage is generated based on the first power supply voltage.

[0018] Optionally, the switching module further includes a first voltage regulator unit;

[0019] The first terminal of the first voltage regulator unit is connected to the first power supply voltage, and the second terminal of the first voltage regulator unit is connected to the first voltage divider output terminal of the first voltage divider subunit.

[0020] Optionally, the self-locking module includes: a third switching unit and a fourth switching unit;

[0021] The first terminal of the third switch unit is connected to a first power supply voltage or a second power supply voltage, the second terminal of the third switch unit is connected to the control terminal of the fourth switch unit, and the control terminal of the third switch unit is connected to the first terminal of the fourth switch unit.

[0022] The first end of the fourth switch unit is also connected to the output end of the self-locking module, the second end of the fourth switch unit is grounded, and the fourth switch unit is used to turn on when the detected voltage is abnormal, so as to turn on the third switch unit. The third switch unit and the fourth switch unit are interlocked.

[0023] The first power supply voltage is generated based on the voltage of the external power supply, and the second power supply voltage is generated based on the first voltage.

[0024] Optionally, the third switching unit includes: a first current-limiting resistor, a second current-limiting resistor, and a third switching device; the fourth switching unit includes: a fourth switching device.

[0025] The first end of the first current-limiting resistor is connected to the first power supply voltage or the second power supply voltage, and the second end of the first current-limiting resistor is connected to the first end of the fourth switching device; the first end of the second current-limiting resistor is connected to the control terminal of the third switching device, and the second end of the second current-limiting resistor is connected to the first end of the fourth switching device; the first end of the third switching device is connected to the first power supply voltage or the second power supply voltage, and the second end of the third switching device is connected to the control terminal of the fourth switching device.

[0026] The first terminal of the fourth switching device is also connected to the output terminal of the self-locking module, and the second terminal of the fourth switching device is grounded.

[0027] The self-locking module also includes a third pressure-dividing subunit.

[0028] The first end of the third voltage divider unit is connected to the first output end of the detection module, the second end of the third voltage divider unit is grounded, and the third voltage divider output end of the third voltage divider unit is connected to the control end of the fourth switching device.

[0029] Optionally, the self-locking module further includes: a first unidirectional conduction unit and a second unidirectional conduction unit;

[0030] The first end of the first unidirectional conduction unit is connected to the first output end of the detection module, and the second end of the first unidirectional conduction unit is connected to the first end of the third voltage divider unit.

[0031] The first end of the second unidirectional conduction unit is connected to the first end of the fourth switching device, and the second end of the second unidirectional conduction unit is connected to the second input end of the switching module.

[0032] Optionally, the current limiting protection circuit further includes: an auxiliary power supply module;

[0033] The input terminal of the auxiliary power supply module is connected to a first power supply voltage. The auxiliary power supply module is used to regulate and / or filter the first power supply voltage and then output a second power supply voltage.

[0034] Optionally, the auxiliary power supply module includes: a second voltage regulator unit, a first filter unit, and a second filter unit;

[0035] The first terminal of the second voltage regulator unit is connected to the first power supply voltage, the second terminal of the second voltage regulator unit serves as the output terminal of the auxiliary power supply module, and the third terminal of the second voltage regulator unit is grounded.

[0036] The first terminal of the first filter unit is connected to the first power supply voltage, and the second terminal of the first filter unit is grounded.

[0037] The first end of the second filter unit is connected to the second end of the second voltage regulator unit, and the second end of the second filter unit is grounded.

[0038] Optionally, the current limiting protection circuit further includes: an input filtering module and an output filtering module;

[0039] The first end of the input filtering module is connected to the external power supply, and the second end of the input filtering module is connected to the first input end of the switching module.

[0040] The first end of the output filtering module is connected to the second output end of the detection module, and the second end of the output filtering module outputs a filtered signal according to the power signal.

[0041] The technical solution of this utility model embodiment detects the current flowing through the circuit using a detection module and outputs a detection voltage to a self-locking module. When the detected voltage is normal, the self-locking module controls the switching module to conduct; when the detected voltage is abnormal, it controls the switching module to turn off. The detection module can detect the current flowing through the circuit in real time and respond quickly to abnormal conditions. The self-locking module immediately activates protection measures upon receiving an abnormal detection voltage, enhancing circuit safety. Protection of the switching power supply is achieved through the switching of the switching module, which is reusable and improves circuit stability. Compared to existing circuits that use fuses for current limiting protection, the circuit can recover after protection action. Each module in the protection circuit can be reused, reducing maintenance costs and downtime.

[0042] It should be understood that the description in this section is not intended to identify key or essential features of the embodiments of this utility model, nor is it intended to limit the scope of this utility model. Other features of this utility model will become readily apparent from the following description. Attached Figure Description

[0043] To more clearly illustrate the technical solutions in the embodiments of this utility model, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0044] Figure 1 A schematic diagram of a current limiting protection circuit provided in an embodiment of this utility model;

[0045] Figure 2 A schematic diagram of another current-limiting protection circuit provided in this embodiment of the utility model;

[0046] Figure 3 A schematic diagram of another current-limiting protection circuit provided in this embodiment of the utility model;

[0047] Figure 4 A schematic diagram of another current-limiting protection circuit provided in this embodiment of the utility model;

[0048] Figure 5 A schematic diagram of another current-limiting protection circuit provided in this embodiment of the utility model;

[0049] Figure 6 This is a schematic diagram of another current-limiting protection circuit provided in an embodiment of the present utility model. Detailed Implementation

[0050] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the protection scope of the present invention.

[0051] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this utility model are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the utility model described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0052] Figure 1 A schematic diagram of a current-limiting protection circuit provided for an embodiment of this utility model. See also... Figure 1 The protection circuit 100 includes a switch module 10, a detection module 20, and a self-locking module 30. The first input terminal of the switch module 10 is connected to an external power supply 200, the second input terminal of the switch module 10 is connected to the output terminal of the self-locking module 30, and the output terminal of the switch module 10 is connected to the first input terminal of the detection module 20. The first output terminal of the detection module 20 is connected to the first input terminal of the self-locking module 30, and the second output terminal of the detection module 20 outputs a power signal. The detection module 20 is used to output a detection voltage to the first input terminal of the self-locking module 30 according to the current flowing through it. The self-locking module 30 is used to control the switch module 10 to turn off according to the abnormal detection voltage.

[0053] Specifically, the protection circuit 100 includes a switching module 10, a detection module 20, and a self-locking module 30. Power supply protection can be achieved by turning the switching module 10 on and off. The switching module 30 includes a switching device, such as a transistor. The first terminal of the switching module 10 is connected to an external power supply 200 to receive the voltage signal output by the external power supply 200. The output terminal of the switching module 10 is connected to the first input terminal of the detection module 20, transmitting the current output by the external power supply 200 to the detection module 20. The detection module 20 detects the received current and outputs the detected voltage to the first input terminal of the self-locking module 30 through its first output terminal. The detected voltage output by the first output terminal of the detection module 20 is positively correlated with the magnitude of the current flowing through it. When the detected voltage is greater than or equal to a threshold voltage, the current flowing through it is large, and the output detected voltage is an abnormal detected voltage. When the detected voltage is less than the threshold voltage, the current flowing through it is normal, and the output detected voltage is a normal detected voltage. For example, if the current flowing through the detection module 20 suddenly increases within a short period of time, the detection module 20 can also output an abnormal detection voltage. The output terminal of the self-locking module 30 is also connected to the second input terminal of the switch module 10. The self-locking module 30 can control the switching module 10 to turn on and off based on the detection voltage output by the detection module 20. When the detection voltage output by the detection module 20 is a normal voltage, it controls the switch module to turn on; and when the detection voltage output by the detection module 20 is an abnormal voltage, it controls the switch module 10 to turn off. When the external power supply 200 is working, the current will first pass through the switch module 10 and then through the detection module 20. The detection module 20 can detect the current flowing through it and output the detection voltage corresponding to the current flowing through itself (detection module 20) to the self-locking module. When the detection voltage is abnormal, the self-locking module 30 will control the switch module to turn off, and the current from the external voltage 200 cannot pass through the switch module, effectively protecting the downstream electronic equipment.

[0054] The technical solution provided by this utility model embodiment detects the current flowing through the circuit via a detection module and outputs a detection voltage to a self-locking module. When the detected voltage is normal, the self-locking module controls the switching module to conduct; when the detected voltage is abnormal, it controls the switching module to turn off. The detection module can detect the current flowing through the circuit in real time and respond quickly when an abnormal state is detected. The self-locking module immediately activates protection measures, enhancing safety. Protection of the switching power supply is achieved by controlling the conduction and cutoff of the switching module. This method is reusable and improves circuit stability. Compared to the current-limiting protection using fuses in existing technologies, the circuit can recover after protection action. Each module in the protection circuit can be reused, reducing maintenance costs and downtime.

[0055] Optional, Figure 2A schematic diagram of another current-limiting protection circuit provided in this embodiment of the utility model. Based on the above embodiments, see... Figure 2 The switching module 10 includes: a first switching unit 11 and a second switching unit 12; the first terminal of the first switching unit 11 is connected to a first power supply voltage, the second terminal of the first switching unit 11 is connected to the first input terminal of the detection module 20, and the control terminal of the first switching unit 11 is connected to the first terminal of the second switching unit 12; the first power supply voltage is generated based on the voltage of the external power supply 200; the second terminal of the second switching unit 12 is grounded, and the control terminal of the second switching unit 12 is connected to the output terminal of the self-locking module; the second switching unit 12 is used to turn off when the output voltage of the self-locking module 30 is a detection voltage corresponding to an abnormality, so as to turn off the first switching unit 11; and to turn on when the output voltage of the self-locking module 30 is a detection voltage corresponding to a normality, so as to turn on the first switching unit 11.

[0056] Specifically, the switch module 10 mainly protects the circuit by turning itself on and off. The first switch unit 11 of the switch module 10 is connected to a first power supply voltage, which is generated based on the voltage output by the external power supply 200. Figure 2 In the scenario shown, the first power supply voltage is equal to the voltage generated by the external power supply 200. The second terminal of the first switching unit 11 serves as the output terminal of the switching module 10 and is connected to the first input terminal of the detection module 20. The control terminal of the first switching unit 11 is connected to the first terminal of the second switching unit 12. The control terminal of the second switching unit 12 is connected to the output terminal of the self-locking module 30, and the second terminal of the second switching unit 12 is grounded. When the voltage output by the self-locking module 30 corresponds to an abnormal detection voltage, the second switching unit 12 is turned off. The second switching unit 12 controls the first switching unit 11 to turn off. When the voltage output by the self-locking module 30 corresponds to a normal detection voltage, the second switching unit 12 is turned on. The second switching unit 12 pulls down the voltage at the control terminal of the first switching unit 11, controlling the first switching unit 11 to turn on.

[0057] Optionally, based on the above embodiments, see also... Figure 2The first switching unit 11 includes a first voltage divider subunit 111 and a first switching device 112, and the second switching unit 12 includes a second voltage divider subunit 121 and a second switching device 122. The first terminal of the first voltage divider subunit 111 is connected to a first power supply voltage, the second terminal of the first voltage divider subunit 111 is connected to the first terminal of the second switching device 122, and the first voltage divider output terminal of the first voltage divider subunit 111 is connected to the control terminal of the first switching device 112. The first terminal of the first switching device 112 is connected to the first terminal of the first voltage divider subunit 111, and the second terminal of the first switching device 112 is connected to the first input terminal of the detection module 20. The first terminal of the second voltage divider subunit 121 is connected to either the first power supply voltage or the second power supply voltage, the second terminal of the second voltage divider subunit 121 is grounded, the second voltage divider output terminal of the second voltage divider subunit 121 is connected to the control terminal of the second switching device 122, and the control terminal of the second switching device 122 is also connected to the output terminal of the self-locking module 30. The second terminal of the second switching device 122 is grounded. The second power supply voltage is generated based on the first power supply voltage.

[0058] Specifically, the first voltage divider unit 11 includes a first voltage divider subunit 111 and a first switching device 112. The first voltage divider subunit 111 includes a first voltage divider resistor R1 and a second voltage divider resistor R2. The first end of the first voltage divider resistor R1 serves as the first end of the first voltage divider subunit 111 and is connected to a first power supply voltage. The second end of the first voltage divider resistor R1 is connected to the first end of the second voltage divider resistor R2, serving as the first voltage divider output terminal of the first voltage divider subunit 111, and is connected to the control terminal of the first switching device 112. The second end of the second voltage divider resistor R2 serves as the second end of the first voltage divider unit 111 and is connected to the first end of the second switching device 112. The first end of the first switching device 112 is connected to the first end of the first voltage divider resistor R1 and is connected to the first power supply voltage. The second end of the first switching device 112 serves as the output terminal of the switching module 10 and is connected to the first input terminal of the detection module 30.

[0059] Specifically, the second voltage divider unit 12 includes a second voltage divider subunit 121 and a second switching device 122. The second voltage divider subunit 121 includes a third voltage divider resistor R3 and a fourth voltage divider resistor R4. The first end of the third voltage divider resistor R3 serves as the second input terminal of the switching module 10, connected to either the first or second power supply voltage. The second end of the third voltage divider resistor R3 is connected to the first end of the fourth voltage divider resistor R4, serving as the second voltage divider output terminal of the first voltage divider subunit 12, and is connected to the control terminal of the second switching device 122. The first end of the second switching device 122 is connected to the second end of the second voltage divider resistor R2. The second end of the fourth voltage divider resistor R4 and the second end of the second switching device 122 are both grounded.

[0060] The first switching device 112 can be a P-type MOSFET, and the second switching device 122 can be an NPN transistor. The second power supply voltage can be generated based on the first power supply voltage. Figure 2 As shown, the second power supply voltage can be equal to the first power supply voltage. When the detection voltage output by the detection module 20 is abnormal, the output terminal of the self-locking module 30 outputs a low-level signal, the second switching device 122 is turned off, causing the gate and source of the first switching device 112 to be unable to form a voltage difference, and the first switching device 112 is turned off.

[0061] Optionally, based on the above embodiments, see also... Figure 2 The switching module 10 also includes a first voltage regulator unit 13; the first terminal of the first voltage regulator unit 13 is connected to the first power supply voltage, and the second terminal of the first voltage regulator unit 13 is connected to the first voltage divider output terminal of the first voltage divider subunit 11.

[0062] Specifically, the switching module 10 may further include a first voltage regulator unit 13. The first voltage regulator unit 13 may include a first Zener diode D1. The first terminal of the first Zener diode D1 is connected to the first input terminal of the switching module 10 and is connected to a first power supply voltage. The second terminal of the first Zener diode D1 is connected to the first voltage divider output terminal of the first voltage divider subunit 11 and is connected to the control terminal of the first switching device 112. The first voltage regulator unit 13 is used to limit the voltage at the control terminal of the first switching device 112 within a safe operating voltage range, effectively protecting the circuit.

[0063] Optional, Figure 3 A schematic diagram of another current-limiting protection circuit provided in this embodiment of the utility model. Based on the above embodiments, see... Figure 3 The self-locking module 30 includes a third switch unit 31 and a fourth switch unit 32. The first terminal of the third switch unit 31 is connected to a first power supply voltage or a second power supply voltage, and the second terminal of the third switch unit 31 is connected to the control terminal of the fourth switch unit 32. The control terminal of the third switch unit 31 is also connected to the first terminal of the fourth switch unit 32. The first terminal of the fourth switch unit 32 is also connected to the output terminal of the self-locking module 30, and the second terminal of the fourth switch unit 32 is grounded. The fourth switch unit 32 is used to turn on when an abnormal voltage is detected, so that the third switch unit 31 can turn on. The third switch unit 31 and the fourth switch unit 32 are interlocked. The first power supply voltage is generated based on the voltage of an external power supply, and the second power supply voltage is generated based on the first voltage.

[0064] Specifically, the self-locking module 30 is used to control the switching module 10 to turn on or off based on the detection voltage output by the detection module 20. The first terminal of the third switching unit 31 of the self-locking module 30 serves as the second input terminal of the self-locking module 30, connected to either the first or second power supply voltage. The second terminal of the third switching unit 31 is connected to the control terminal of the fourth switching unit 32, and the control terminal of the third switching unit 31 is connected to the first terminal of the fourth switching unit 32. The control terminal of the fourth switching unit 32 is also connected to the first output terminal of the detection module 20, and the first terminal of the fourth switching unit 32 is connected to the output terminal of the self-locking module 10 and the second input terminal of the switching module 10. When the fourth switching unit 32 receives an abnormal detection voltage, the fourth switching unit 32 turns on. After the fourth switching unit 32 turns on, it pulls down the potential of the control terminal of the third switching unit 31, causing the third switching unit 31 to turn on and apply either the first or second power supply signal to the control terminal of the fourth switching unit 32. The fourth switching unit 32 remains on, continuously pulling down the voltage at the control terminal of the third switching unit 31. The third switch unit 31 and the fourth switch unit 32 are interlocked. When the output terminal of the self-locking module 30 outputs a low level, the second switch unit 12 is turned off, and the second switch unit 12 controls the first switch unit 11 to be turned off.

[0065] Optionally, based on the above embodiments, see also Figure 3 The third switching unit 31 includes: a first current-limiting resistor R5, a second current-limiting resistor R6, and a third switching device 311. The fourth switching unit 32 includes: a fourth switching device 321. The first terminal of the first current-limiting resistor R5 is connected to a first power supply voltage or a second power supply voltage, and the second terminal of the first current-limiting resistor R5 is connected to the first terminal of the fourth switching device 321. The first terminal of the second current-limiting resistor R6 is connected to the control terminal of the third switching device 311, and the second terminal of the second current-limiting resistor R6 is connected to the first terminal of the fourth switching device 321. The first terminal of the third switching device 311... The first power supply voltage or the second power supply voltage is connected to the terminal. The second terminal of the third switching device 311 is connected to the control terminal of the fourth switching device 321. The first terminal of the fourth switching device 321 is also connected to the output terminal of the self-locking module 30, and the second terminal of the fourth switching device 321 is grounded. The self-locking module 30 also includes a third voltage divider sub-unit 33. The first terminal of the third voltage divider sub-unit 33 is connected to the first output terminal of the detection module 20, the second terminal of the third voltage divider sub-unit 33 is grounded, and the third voltage divider output terminal of the third voltage divider sub-unit 33 is connected to the control terminal of the fourth switching device 321.

[0066] Specifically, the third switching unit 31 includes a first current-limiting resistor R5 and a second current-limiting resistor R6. The first end of the first current-limiting resistor R5 serves as the first end of the third voltage divider unit 31, connected to either the first or second power supply voltage. The second end of the first current-limiting resistor R5 is connected to the second end of the second current-limiting resistor R6, serving as the control terminal of the third switching unit 31, and is connected to the first end of the fourth switching device 321. The first end of the second current-limiting resistor R6 is connected to the control terminal of the third switching device 311. The first end of the third switching device 311 is connected to the first end of the first current-limiting resistor R5, connected to either the first or second power supply voltage. The second end of the third switching device 311 is connected to the control terminal of the fourth switching device 321. The first end of the fourth switching device 321 serves as the output terminal of the self-locking module 30, connected to the second input terminal of the switching module 10.

[0067] Specifically, the self-locking module 30 also includes a third voltage divider sub-unit 33, which includes a fifth voltage divider resistor R7 and a sixth voltage divider resistor R8. The first end of the fifth voltage divider resistor R7 is connected to the first output end of the detection module 20, and the second end of the fifth voltage divider resistor R7 and the first end of the sixth voltage divider resistor R8 are connected to each other as the third voltage divider output end of the third voltage divider sub-unit 33, which is connected to the control end of the fourth switching device 321. The second end of the sixth voltage divider resistor R8 is grounded.

[0068] In this circuit, the third switching device 311 can be a PNP transistor, and the fourth switching device 321 can be an N-type MOSFET. When the detection voltage output by the detection module is abnormal, after being divided by the fifth voltage divider resistor R7 and the sixth voltage divider resistor R8, the detection voltage is higher than the threshold of the fourth switching device 321. The fourth switching device 321 then conducts, pulling down the voltage at the control terminal of the third switching device 311, thus turning it on. The first or second power supply voltage is output to the control terminal of the fourth switching device 321 through the third switching device 311. The conduction of the fourth switching device 321 continuously pulls down the voltage at the control terminal of the third switching device 311, keeping it on. The third switching unit 311 and the fourth switching unit 321 are interlocked. The first terminal of the fourth switching unit 321 outputs a low-potential voltage, causing the switching module 10 to turn off. When the detection voltage output by the detection module 20 is normal, after the voltage is divided by the fifth voltage divider resistor R7 and the sixth voltage divider resistor R8, the voltage after the voltage is divided by the third voltage divider subunit 33 is lower than the threshold voltage of the fourth switching device 321. The fourth switching device 321 is turned off, and the self-locking module 30 outputs a high-level voltage, which turns on the second switching unit 12. The second switching unit 12 controls the first switching unit 11 to turn on.

[0069] Optionally, based on the above embodiments, see also Figure 3The self-locking module 30 further includes: a first unidirectional conduction unit 34 and a second unidirectional conduction unit 35; the first end of the first unidirectional conduction unit 34 is connected to the first output end of the detection module 20, and the second end of the first unidirectional conduction unit 34 is connected to the first end of the third voltage divider unit 33; the first end of the second unidirectional conduction unit 35 is connected to the first end of the fourth switching device 321, and the second end of the second unidirectional conduction unit 35 is connected to the second input end of the switching module 10.

[0070] Specifically, the self-locking module 30 also includes a first unidirectional conduction unit 34 and a second unidirectional conduction unit 35. The first unidirectional conduction unit 34 and the second unidirectional conduction unit 35 can prevent reverse current flow and effectively protect the circuit. The first unidirectional conduction unit 34 includes a first unidirectional conduction diode D2. The first end of the first unidirectional conduction diode D2 serves as the first input terminal of the self-locking module 30 and is connected to the first output terminal of the detection module 20. The second unidirectional conduction unit 35 includes a second unidirectional conduction diode D3. The first end of the second unidirectional conduction diode D3 is connected to the first terminal of the fourth switching device 321, and the second end of the second unidirectional conduction diode D3 serves as the output terminal of the self-locking module 30 and is connected to the second input terminal of the switching module.

[0071] Optionally, the self-locking module 30 may further include a first capacitor C1, with its first terminal connected to the control terminal of the fourth switching device 321 and its second terminal grounded. The first capacitor C1 can filter the detection voltage output by the detection module 20.

[0072] Optional, Figure 4 A schematic diagram of another current-limiting protection circuit provided in this embodiment of the utility model. Based on the above embodiments, see... Figure 4 The protection circuit 100 also includes an auxiliary power supply module 40; the input terminal of the auxiliary power supply module 10 is connected to a first power supply voltage, and the auxiliary power supply module 40 is used to regulate and / or filter the first power supply voltage before outputting a second power supply voltage.

[0073] Specifically, the protection circuit 100 also includes an auxiliary power supply module 40. The input terminal of the auxiliary power supply module 40 is connected to the external power supply 200 to receive a first power supply voltage, and the output terminal of the auxiliary power supply module 40 outputs a second power supply voltage. The auxiliary power supply module 40 is used to receive the first power supply voltage and generate a stable second power supply voltage based on the first power supply voltage, so as to provide a stable supply to the switch module 10, the self-detection module 20, and the lock module 30.

[0074] Optionally, based on the above embodiments, see also... Figure 4The auxiliary power supply module 40 includes: a second voltage regulator unit 41, a first filter unit 42, and a second filter unit 43; the first terminal of the second voltage regulator unit 41 is connected to a first power supply voltage, the second terminal of the second voltage regulator unit 41 serves as the output terminal of the auxiliary power supply module 40, and the third terminal of the second voltage regulator unit 41 is grounded; the first terminal of the first filter unit 42 is connected to the first power supply voltage, and the second terminal of the first filter unit 42 is grounded; the first terminal of the second filter unit 43 is connected to the second terminal of the second voltage regulator unit 41, and the second terminal of the second filter unit 43 is grounded.

[0075] Specifically, the auxiliary power module 40 is mainly used for voltage regulation and filtering. The auxiliary power module 40 includes a second voltage regulator unit 41, a first filter unit 42, and a second filter unit 43. The first terminal of the second voltage regulator unit 41 is connected to the external power supply 200, receiving a first power supply voltage. After regulating the first power supply voltage, the second voltage regulator unit 41 outputs the second power supply voltage, which serves as the output terminal of the auxiliary power module 40, outputting the second power supply voltage. The first filter unit 42 includes a second capacitor C2. The first terminal of the second capacitor C2 is connected to the input terminal of the auxiliary power module 40, receiving the first power supply voltage, and the second terminal of the second capacitor C2 is grounded. The second capacitor C2 is used to filter the first power supply voltage. The second filter unit 43 includes a third capacitor C3. The first terminal of the third capacitor C3 is connected to the second terminal of the first voltage regulator unit 41, and the second terminal of the third capacitor C3 is grounded. The third capacitor C3 is used to filter the output second power supply voltage.

[0076] Optional, Figure 5 A schematic diagram of another current-limiting protection circuit provided in this embodiment of the utility model. Based on the above embodiments, see... Figure 5 The protection circuit 100 further includes an input filtering module 50 and an output filtering module 60; the first end of the input filtering module 50 is connected to an external power supply, and the second end of the input filtering module 50 is connected to the first input end of the switch module 10; the first end of the output filtering module 60 is connected to the second output end of the detection module 20, and the second end of the output filtering module 60 outputs a filtered signal according to the power supply signal.

[0077] Specifically, the protection circuit 100 also includes an input filtering module 50 and an output filtering module 60. The input filtering module 50 includes a fourth capacitor C4, with its first terminal connected to the external power supply 200 and its second terminal grounded. The fourth capacitor C4 is used to filter the first power supply voltage output from the external power supply 200. The output filtering module 60 includes a fifth capacitor C5, with its first terminal connected to the second output terminal of the detection module 20 and its second terminal grounded. The fifth capacitor C5 can filter the power supply signal output from the detection module 20 and output a filtered signal to the subsequent equipment. Figure 5 As shown, the first power supply voltage is generated based on the voltage generated by the external power supply 200, and the second power supply voltage is generated based on the first power supply voltage.

[0078] Optional, Figure 6 A schematic diagram of another current-limiting protection circuit provided in this embodiment of the utility model. Based on the above embodiments, see... Figure 6 The detection module 20 may include a sampling unit 21, a detection unit 22, and a sixth capacitor C6. The first terminal of the sampling unit 21 is connected to the output terminal of the switch module 10, and the second terminal of the sampling unit 21 serves as the second output terminal of the detection module 20, outputting a power signal. The sampling unit 21 may include a sampling resistor R9, the first terminal of which serves as the first terminal of the sampling unit 21 and is connected to the output of the switch module. The second terminal of the sampling resistor R9 is connected to the second output terminal of the detection module 20. The first terminal of the detection unit 22 serves as the first detection terminal and is connected to the first terminal of the sampling unit 21. The second terminal of the detection unit 22 serves as the second detection terminal and is connected to the second terminal of the sampling unit 21. The third terminal of the detection unit 22 serves as the first output terminal of the detection module 20 and is connected to the first input terminal of the self-locking module 30, outputting a detection voltage. The fourth terminal of the detection unit 22 serves as the second input terminal of the detection module 20 and is connected to the output terminal of the auxiliary power supply module 40. The fifth terminal of the detection unit 22 serves as a ground terminal, and the sixth terminal of the detection unit 22 serves as a reference voltage terminal, grounded. The first end of the sixth capacitor C6 is connected to the fourth end of the sampling unit 22 and to the second input end of the detection module 20. The second end of the sixth capacitor C6 is grounded. The sixth capacitor C6 is used to filter the second power supply voltage generated by the auxiliary power supply module 40.

[0079] The specific embodiments described above do not constitute a limitation on the scope of protection of this utility model. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this utility model should be included within the scope of protection of this utility model.

Claims

1. A current-limiting protection circuit, characterized in that, include: Switching module, detection module, and self-locking module; The first input terminal of the switch module is connected to an external power supply, the second input terminal of the switch module is connected to the output terminal of the self-locking module, and the output terminal of the switch module is connected to the first input terminal of the detection module. The first output terminal of the detection module is connected to the first input terminal of the self-locking module, and the second output terminal of the detection module outputs a power signal. The detection module is used to output a detection voltage to the first input terminal of the self-locking module according to the current flowing through it. The self-locking module is used to control the switching module to turn off based on the abnormal detection voltage; The switching module includes: a first switching unit and a second switching unit; The first terminal of the first switching unit is connected to a first power supply voltage, the second terminal of the first switching unit is connected to the first input terminal of the detection module, and the control terminal of the first switching unit is connected to the first terminal of the second switching unit; the first power supply voltage is generated based on the voltage of the external power supply. The second terminal of the second switching unit is grounded, and the control terminal of the second switching unit is connected to the output terminal of the self-locking module. The second switching unit is used to turn off when the output voltage of the self-locking module is the detection voltage corresponding to an abnormality, so as to turn off the first switching unit; And when the output voltage of the self-locking module is the same as the normal detection voltage, it is turned on to turn on the first switching unit.

2. The current limiting protection circuit according to claim 1, characterized in that, The first switching unit includes a first voltage divider subunit and a first switching device, and the second switching unit includes a second voltage divider subunit and a second switching device; The first terminal of the first voltage divider unit is connected to the first power supply voltage, the second terminal of the first voltage divider unit is connected to the first terminal of the second switching device, and the first voltage divider output terminal of the first voltage divider unit is connected to the control terminal of the first switching device; the first terminal of the first switching device is connected to the first terminal of the first voltage divider unit, and the second terminal of the first switching device is connected to the first input terminal of the detection module. The first terminal of the second voltage divider unit is connected to the first power supply voltage or the second power supply voltage, the second terminal of the second voltage divider unit is grounded, the second voltage divider output terminal of the second voltage divider unit is connected to the control terminal of the second switching device, the control terminal of the second switching device is also connected to the output terminal of the self-locking module; the second terminal of the second switching device is grounded. The second power supply voltage is generated based on the first power supply voltage.

3. The current limiting protection circuit according to claim 2, characterized in that, The switching module also includes a first voltage regulator unit; The first terminal of the first voltage regulator unit is connected to the first power supply voltage, and the second terminal of the first voltage regulator unit is connected to the first voltage divider output terminal of the first voltage divider subunit.

4. The current limiting protection circuit according to claim 1, characterized in that, The self-locking module includes: a third switching unit and a fourth switching unit; The first terminal of the third switch unit is connected to a first power supply voltage or a second power supply voltage, the second terminal of the third switch unit is connected to the control terminal of the fourth switch unit, and the control terminal of the third switch unit is connected to the first terminal of the fourth switch unit. The first end of the fourth switch unit is also connected to the output end of the self-locking module, the second end of the fourth switch unit is grounded, and the fourth switch unit is used to turn on when the detected voltage is abnormal, so as to turn on the third switch unit. The third switch unit and the fourth switch unit are interlocked. The first power supply voltage is generated based on the voltage of the external power supply, and the second power supply voltage is generated based on the first power supply voltage.

5. The current limiting protection circuit according to claim 4, characterized in that, The third switching unit includes: a first current-limiting resistor, a second current-limiting resistor, and a third switching device; the fourth switching unit includes: a fourth switching device. The first end of the first current-limiting resistor is connected to the first power supply voltage or the second power supply voltage, and the second end of the first current-limiting resistor is connected to the first end of the fourth switching device; the first end of the second current-limiting resistor is connected to the control terminal of the third switching device, and the second end of the second current-limiting resistor is connected to the first end of the fourth switching device; the first end of the third switching device is connected to the first power supply voltage or the second power supply voltage, and the second end of the third switching device is connected to the control terminal of the fourth switching device. The first terminal of the fourth switching device is also connected to the output terminal of the self-locking module, and the second terminal of the fourth switching device is grounded. The self-locking module also includes a third pressure-dividing subunit. The first end of the third voltage divider unit is connected to the first output end of the detection module, the second end of the third voltage divider unit is grounded, and the third voltage divider output end of the third voltage divider unit is connected to the control end of the fourth switching device.

6. The current limiting protection circuit according to claim 5, characterized in that, The self-locking module further includes: a first unidirectional conduction unit and a second unidirectional conduction unit; The first end of the first unidirectional conduction unit is connected to the first output end of the detection module, and the second end of the first unidirectional conduction unit is connected to the first end of the third voltage divider unit. The first end of the second unidirectional conduction unit is connected to the first end of the fourth switching device, and the second end of the second unidirectional conduction unit is connected to the second input end of the switching module.

7. The current limiting protection circuit according to any one of claims 1-6, characterized in that, The protection circuit also includes: an auxiliary power supply module; The input terminal of the auxiliary power supply module is connected to a first power supply voltage. The auxiliary power supply module is used to regulate and / or filter the first power supply voltage and then output a second power supply voltage.

8. The current limiting protection circuit according to claim 7, characterized in that, The auxiliary power supply module includes: a second voltage regulator unit, a first filter unit, and a second filter unit; The first terminal of the second voltage regulator unit is connected to the first power supply voltage, the second terminal of the second voltage regulator unit serves as the output terminal of the auxiliary power supply module, and the third terminal of the second voltage regulator unit is grounded. The first terminal of the first filter unit is connected to the first power supply voltage, and the second terminal of the first filter unit is grounded. The first end of the second filter unit is connected to the second end of the second voltage regulator unit, and the second end of the second filter unit is grounded.

9. The current limiting protection circuit according to claim 1, characterized in that, The protection circuit further includes: an input filtering module and an output filtering module; The first end of the input filtering module is connected to the external power supply, and the second end of the input filtering module is connected to the first input end of the switching module. The first end of the output filtering module is connected to the second output end of the detection module, and the second end of the output filtering module outputs a filtered signal according to the power signal.

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