Current-limiting protection circuit applied to DC socket

Abstract

The embodiment of the utility model provides a current-limiting protection circuit applied to a DC socket, and belongs to the field of electrics, the current-limiting protection circuit comprises a DC power supply input end, a switch module, a voltage detection module, an MCU module, an output control module, a DC socket output module and a voltage comparison module, the DC power supply input end is used for accessing an external DC power supply; the switch module is electrically connected with the direct-current power supply input end; the voltage detection module is electrically connected with the output end of the switch module; the MCU module is electrically connected with the switch module, and the voltage detection module is electrically connected with the MCU module, so that the MCU module receives a first voltage value detected by the voltage detection module; the output control module is electrically connected with the MCU module and the input end of the direct-current power supply respectively; the DC socket output module is electrically connected with the output control module; the voltage comparison module is electrically connected with the DC socket output module and the MCU module, so that the current flowing through the DC socket output module can be limited, and the connection safety of the external equipment and the DC socket output module is improved.

Description

Technical Field

[0001] The present application relates to the field of electricity, and in particular to a current limiting protection circuit applied to a DC socket. Background Art

[0002] At present, there are more and more battery-equipped products on the market. Some fan products, lighting products, and mobile power products are equipped with a DC socket with a 4V output (almost synchronized with the voltage of the built-in battery terminal of the product). However, when external devices are connected to the DC interface, they are easily burned out due to the lack of current limiting protection function. In more serious cases, it is easy to cause fire and electric shock injuries. Utility Model Content

[0003] The purpose of the utility model is to solve at least one of the technical problems existing in the prior art and to provide a current limiting protection circuit applied to a DC socket, which can limit the current flowing through a DC socket output module and improve the safety of the connection between an external device and the DC socket output module.

[0004] To achieve the above-mentioned purpose, the embodiment of the present application proposes a current limiting protection circuit applied to a DC socket, comprising: a DC power supply input terminal, a switch module, a voltage detection module, an MCU module, an output control module, a DC socket output module and a voltage comparison module.

[0005] The DC power input terminal is used to connect to an external DC power supply;

[0006] The switch module is electrically connected to the DC power input terminal;

[0007] The voltage detection module is electrically connected to the output end of the switch module;

[0008] The MCU module is electrically connected to the switch module, and the voltage detection module is electrically connected to the MCU module so that the MCU module receives the first voltage value detected by the voltage detection module;

[0009] The output control module is electrically connected to the MCU module and the DC power supply input terminal respectively;

[0010] The DC socket output module is electrically connected to the output control module;

[0011] The voltage comparison module is electrically connected to the DC socket output module and the MCU module respectively;

[0012] When the first voltage value is greater than a first preset voltage value, the MCU module determines the functional state of the output control module according to the output value of the voltage comparison module.

[0013] According to the embodiment of the utility model, a current limiting protection circuit applied to a DC socket has at least the following beneficial effects: when the switch in the switch module is closed, the current flows into the switch module from the DC power input end and flows out from the output end of the switch module. Since the output end of the switch module is electrically connected to the input end of the MCU module and the input end of the voltage detection module, the MCU module and the voltage detection module are turned on and work. The output end of the voltage detection module is electrically connected to the MCU module and sends the detected first voltage value to the MCU module. The MCU module is electrically connected to the output control module and the voltage comparison module, respectively. The MCU module can detect the voltage value according to the received first voltage. The voltage comparison module determines whether to output a high level based on the voltage value and the first preset voltage value to turn on the output control module and the voltage comparison module. The output control module is electrically connected to the DC socket output module and the DC power input terminal respectively. When the output control module is turned on, the current flows from the DC power input terminal through the input terminal of the DC socket output module to start the DC socket output module. Since the voltage comparison module is electrically connected to the DC socket output module and the MCU module respectively, if the current output by the output terminal of the DC socket output module exceeds the limit value, the voltage comparison module outputs a high level, and then the MCU module determines whether the output control module remains started or turned off according to the output value of the voltage comparison module.

[0014] In some embodiments, the MCU module includes a first pin, the switch module includes a first resistor, a first PMOS tube and a self-locking switch, the source of the first PMOS tube is electrically connected to the DC power supply input end as the input end of the switch module, the drain of the first PMOS tube is electrically connected to the input end of the voltage detection module and the first pin of the MCU module as the output end of the switch module, one end of the first resistor is electrically connected to the source of the first PMOS tube, one end of the self-locking switch is electrically connected to the other end of the first resistor and the gate of the first PMOS tube, and the other end of the self-locking switch is grounded.

[0015] In some embodiments, the MCU module includes a second pin, the voltage detection module includes a second resistor and a third resistor, one end of the second resistor is electrically connected to the switch module, the other end of the second resistor is respectively electrically connected to one end of the third resistor and the second pin of the MCU module, and the other end of the third resistor is grounded.

[0016] In some embodiments, the MCU module includes a third pin, and the output control module includes: a fourth resistor, a fifth resistor, a sixth resistor, a seventh resistor, a second PMOS tube and a third PMOS tube, one end of the fourth resistor is electrically connected to the gate of the second PMOS tube, and the other end of the fourth resistor is electrically connected to the third pin of the MCU module as the input end of the output control module, one end of the fifth resistor is electrically connected to the gate of the second PMOS tube, and the other end of the fifth resistor is grounded, one end of the sixth resistor is electrically connected to the drain of the second PMOS tube, the gate of the third PMOS tube is respectively electrically connected to the other end of the sixth resistor and one end of the seventh resistor, and the DC power supply input end is respectively electrically connected to the source of the third PMOS tube and the other end of the seventh resistor.

[0017] In some embodiments, the DC socket output module includes a first DC socket, a second DC socket, an eighth resistor, and a ninth resistor. The first DC socket is connected in parallel with the second DC socket. The output end of the output control module is electrically connected to one end of the first DC socket and the second DC socket, respectively. One end of the eighth resistor is electrically connected to the other end of the first DC socket and the second DC socket, one end of the ninth resistor is electrically connected to the other end of the first DC socket and the second DC socket, respectively. The other end of the ninth resistor is grounded.

[0018] In some embodiments, the DC socket output module also includes a third DC socket, a fourth DC socket, a tenth resistor, and an eleventh resistor. The third DC socket is connected in parallel with the fourth DC socket, the output control module is electrically connected to one end of the third DC socket and the fourth DC socket, respectively, one end of the tenth resistor is electrically connected to the other end of the third DC socket and the fourth DC socket, one end of the eleventh resistor is electrically connected to the other end of the third DC socket and the fourth DC socket, respectively, and the other end of the eleventh resistor is grounded.

[0019] In some embodiments, the voltage comparison module includes a first operational amplifier, a second operational amplifier, a twelfth resistor, a thirteenth resistor, a fourteenth resistor, a fifteenth resistor, a sixteenth resistor, and a seventeenth resistor, one end of the thirteenth resistor is electrically connected to the output end of the first operational amplifier, one end of the twelfth resistor is respectively electrically connected to the other end of the thirteenth resistor and the reverse input end of the first operational amplifier, the other end of the twelfth resistor is grounded, one end of the fourteenth resistor is electrically connected to the output end of the first operational amplifier, the in-phase input end of the first operational amplifier is electrically connected to the eighth resistor, one end of the sixteenth resistor is electrically connected to the output end of the second operational amplifier, one end of the fifteenth resistor is respectively electrically connected to the other end of the sixteenth resistor and the reverse input end of the second operational amplifier, the other end of the fifteenth resistor is grounded, one end of the seventeenth resistor is electrically connected to the output end of the second operational amplifier, and the in-phase input end of the second operational amplifier is electrically connected to the tenth resistor.

[0020] In some embodiments, the MCU module includes a fourth pin, a fifth pin and a sixth pin, the fourth pin is electrically connected to the power input terminal of the first operational amplifier, the fifth pin is electrically connected to the other end of the fourteenth resistor, and the sixth pin is electrically connected to the other end of the seventeenth resistor.

[0021] In some embodiments, when the first voltage is less than a first preset voltage value, the MCU module stops working.

[0022] In some embodiments, the functional status includes running function and shutting down function. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The accompanying drawings are used to provide a further understanding of the technical solution of the utility model and constitute a part of the specification. Together with the embodiments of the utility model, they are used to explain the technical solution of the utility model and do not constitute a limitation on the technical solution of the utility model.

[0024] The utility model is further described below in conjunction with the accompanying drawings and embodiments;

[0025] Figure 1 This is a system architecture diagram of a current limiting protection circuit applied to a DC socket provided by an embodiment of the utility model;

[0026] Figure 2 It is an overall schematic diagram of a current limiting protection circuit applied to a DC socket provided by an embodiment of the utility model. DETAILED DESCRIPTION

[0027] This section will describe in detail the specific embodiments of the utility model. The preferred embodiments of the utility model are shown in the accompanying drawings. The purpose of the accompanying drawings is to supplement the description of the text part of the specification with graphics, so that people can intuitively and vividly understand each technical feature and the overall technical solution of the utility model, but it cannot be understood as a limitation on the protection scope of the utility model.

[0028] In the description of the utility model, if there is a description of first and second, it is only for the purpose of distinguishing the technical features, and cannot be understood as indicating or implying the relative importance or implicitly indicating the number of the indicated technical features or implicitly indicating the order of the indicated technical features.

[0029] In the description of the present invention, unless otherwise clearly defined, terms such as setting, installing, connecting, etc. should be understood in a broad sense, and technicians in the relevant technical field can reasonably determine the specific meanings of the above terms in the present invention based on the specific content of the technical solution.

[0030] At present, there are more and more battery-equipped products on the market. Some fan products, lighting products, and mobile power products are equipped with a DC socket with a 4V output (almost synchronized with the voltage of the built-in battery terminal of the product). However, when external devices are connected to the DC interface, they are easily burned out due to the lack of current limiting protection function. In more serious cases, it is easy to cause fire and electric shock injuries.

[0031] Based on this, an embodiment of the utility model provides a current limiting protection circuit applied to a DC socket, which can limit the current flowing through the DC socket output module and improve the safety of the connection between the external device and the DC socket output module.

[0032] The following is a further description of the embodiments of the present invention in conjunction with the accompanying drawings.

[0033] Reference Figure 1 , Figure 2 , the embodiment of the present application proposes a current limiting protection circuit applied to a DC socket, comprising: a DC power input terminal B+, a switch module 100, a voltage detection module 200, an MCU module 300, an output control module 400, a DC socket output module 500 and a voltage comparison module 600;

[0034] The DC power input terminal B+ is used to connect to an external DC power supply;

[0035] The switch module 100 is electrically connected to the DC power input terminal B+;

[0036] The voltage detection module 200 is electrically connected to the output end of the switch module 100 to detect the voltage value output by the switch module 100;

[0037] The MCU module 300 is electrically connected to the switch module 100, and the voltage detection module 200 is electrically connected to the MCU module 300 so that the MCU module 300 receives the first voltage value detected by the voltage detection module 200;

[0038] The output control module 400 is electrically connected to the MCU module 300 and the DC power input terminal B+;

[0039] The DC socket output module 500 is electrically connected to the output control module 400;

[0040] The voltage comparison module 600 is electrically connected to the DC socket output module 500 and the MCU module 300 respectively;

[0041] When the first voltage value is greater than the first preset voltage value, the MCU module 300 determines the functional state of the output control module 400 according to the output value of the voltage comparison module 600 .

[0042] According to a current limiting protection circuit applied to a DC socket provided by an embodiment of the utility model, when the switch in the switch module 100 is closed, the current flows into the switch module 100 from the DC power input terminal B+ and flows out from the output terminal of the switch module 100. Since the output terminal of the switch module 100 is electrically connected to the input terminal of the MCU module 300 and the input terminal of the voltage detection module 200, respectively, the MCU module 300 and the voltage detection module 200 are turned on and work, and the output terminal of the voltage detection module 200 is electrically connected to the MCU module 300 and sends the detected first voltage value to the MCU module 300. The MCU module 300 is electrically connected to the output control module 400 and the voltage comparison module 600, respectively. The MCU module 300 can detect the first voltage value according to the received first voltage value and the first pre- It is assumed that the voltage value determines whether to output a high level to turn on the output control module 400 and the voltage comparison module 600. The output control module 400 is electrically connected to the DC socket output module 500 and the DC power input terminal B+, respectively. When the output control module 400 is turned on, the current flows from the DC power input terminal B+ through the input terminal of the DC socket output module 500 to start the DC socket output module 500. Since the voltage comparison module 600 is electrically connected to the DC socket output module 500 and the MCU module 300, respectively, if the current output from the output terminal of the DC socket output module 500 exceeds the limit value, the voltage comparison module 600 outputs a high level, and then the MCU module 300 determines whether the output control module 400 remains started or turned off according to the output value of the voltage comparison module 600.

[0043] Reference Figure 2In some embodiments, the MCU module 300 includes a first pin 1, the switch module 100 includes a first resistor R1, a first PMOS tube Q1 and a self-locking switch SW1, the source of the first PMOS tube Q1 is electrically connected to the DC power supply input terminal B+ as the input end of the switch module 100, the drain of the first PMOS tube Q1 is electrically connected to the input end of the voltage detection module 200 and the first pin 1 of the MCU module 300 as the output end of the switch module 100, one end of the first resistor R1 is electrically connected to the source of the first PMOS tube Q1, one end of the self-locking switch is electrically connected to the other end of the first resistor R1 and the gate of the first PMOS tube Q1, and the other end of the self-locking switch is grounded.

[0044] It should be noted that when the self-locking switch SW1 is closed, the gate of the first PMOS tube Q1 is grounded, the first PMOS tube Q1 is turned on, and the DC power input terminal B+ provides power to the MCU module 300 through the output terminal of the switch module 100, that is, the drain of the first PMOS tube Q1.

[0045] It should be noted that the first pin 1 of the MCU module 300 is a power input terminal.

[0046] Preferably, the resistance of the first resistor R1 may be 10k.

[0047] In some embodiments, the MCU module 300 includes a second pin 2, the voltage detection module 200 includes a second resistor R2 and a third resistor R3, one end of the second resistor R2 is electrically connected to the switch module 100, the other end of the second resistor R2 is electrically connected to one end of the third resistor R3 and the second pin 2 of the MCU module 300, and the other end of the third resistor R3 is grounded.

[0048] It should be noted that the second resistor R2 and the third resistor R3 are connected in series to form a voltage divider circuit, and the output end is located at the common end of the second resistor R2 and the third resistor R3. The output end of the voltage detection module 200 is connected to the second pin 2 of the MCU module 300, wherein the second pin 2 of the MCU module 300 is an ADC port, and the MCU module 300 converts the received ADC value into a first voltage value. The MCU module 300 determines the working status of the output control module 400 and the voltage comparison module 600 based on the first voltage value and the first preset voltage value.

[0049] It should be noted that the first preset voltage value is set according to the battery voltage value, and due to the voltage dividing effect of the resistor R2, the measured first voltage value is smaller than the battery voltage value.

[0050] Preferably, when the battery voltage is 3.2V, a corresponding first preset voltage value is set. When the first voltage value detected by the voltage detection module 200 is greater than the first preset voltage value, the MCU module 300 controls the output control module 400 and the voltage comparison module 600 to turn on and work. The battery voltage can be appropriately adjusted within the range of 3-6V. In this application, no excessive restrictions are imposed on the value of the battery voltage.

[0051] It can be understood that when the self-locking switch SW1 is disconnected or when the first voltage value is less than the first preset voltage value, the entire current limiting protection circuit is in a low power consumption state.

[0052] Preferably, the resistance value of the second resistor R2 may be 200k, and the resistance value of the third resistor R3 may be 100k.

[0053] Reference Figure 2 In some embodiments, the MCU module 300 includes a third pin 6, and the output control module 400 includes: a fourth resistor R4, a fifth resistor R5, a sixth resistor R6, a seventh resistor R7, a second PMOS tube Q2 and a third PMOS tube Q3, one end of the fourth resistor R4 is electrically connected to the gate of the second PMOS tube Q2, the other end of the fourth resistor R4 is electrically connected to the third pin 6 of the MCU module 300 as the input end of the output control module 400, one end of the fifth resistor R5 is electrically connected to the gate of the second PMOS tube Q2, the other end of the fifth resistor R5 is grounded, one end of the sixth resistor R6 is electrically connected to the drain of the second PMOS tube Q2, the gate of the third PMOS tube Q3 is electrically connected to the other end of the sixth resistor R6 and one end of the seventh resistor R7, and the DC power input end B+ is electrically connected to the source of the third PMOS tube Q3 and the other end of the seventh resistor R7.

[0054] It should be noted that when the first voltage value is greater than the first preset voltage value, the third pin 6 of the MCU module 300 outputs a high level, so that the second PMOS tube Q2 is turned on. Furthermore, since one end of the sixth resistor R6 is electrically connected to the drain of the second PMOS tube Q2, the gate of the third PMOS tube Q3 is connected to the other end of the sixth resistor R6. When the second PMOS tube Q2 is turned on, the gate of the third PMOS tube Q3 is grounded through the sixth resistor R6 and the second PMOS tube Q2. At this time, the third PMOS tube Q3 is in an on state.

[0055] It can be understood that, since the third PMOS tube Q3 is in the on state and the DC power input terminal B+ is electrically connected to the source of the third PMOS tube Q3, the DC power input terminal B+ can supply power to the DC socket output module 500 through the third PMOS tube Q3.

[0056] Preferably, the resistance value of the fourth resistor R4 may be 1k, the resistance value of the fifth resistor R5 may be 10k, the resistance value of the sixth resistor R6 may be 100Ω, and the resistance value of the seventh resistor R7 may be 10k.

[0057] Reference Figure 2 In some embodiments, the DC socket output module 500 includes a first DC socket DC1, a second DC socket DC2, an eighth resistor R8, and a ninth resistor R9. The first DC socket DC1 is connected in parallel with the second DC socket DC2. The output end of the output control module 400 is electrically connected to one end of the first DC socket DC1 and the second DC socket DC2, respectively. One end of the eighth resistor R8 is electrically connected to the other end of the first DC socket DC1 and the second DC socket DC2, one end of the ninth resistor R9 is electrically connected to the other end of the first DC socket DC1 and the second DC socket DC2, respectively. The other end of the ninth resistor R9 is grounded.

[0058] It should be noted that when the third PMOS transistor Q3 is in the on state, the DC power input terminal B+ can supply power to the first DC socket DC1 and the second DC socket DC2 through the third PMOS transistor Q3.

[0059] It should be noted that the ninth resistor R9 is used as a current limiting resistor, and the current limiting protection function can be achieved by reasonably designing the resistance value of the ninth resistor R9.

[0060] Preferably, if the operating current of the DC socket output module 500 is limited to 800 mA, the resistance value of the ninth resistor R9 may be 0.025 k, and the resistance value of the eighth resistor R8 may be 1 k.

[0061] It should be noted that the number of the first DC sockets DC1 can be 1, 2, 3, or 4, and the number of the first DC sockets DC1 is not excessively limited in the present application.

[0062] Reference Figure 2 In some embodiments, the DC socket output module 500 also includes a third DC socket DC3, a fourth DC socket DC4, a tenth resistor R10, and an eleventh resistor R11. The third DC socket DC3 is connected in parallel with the fourth DC socket DC4. The output control module 400 is electrically connected to one end of the third DC socket DC3 and the fourth DC socket DC4 respectively. One end of the tenth resistor R10 is electrically connected to the other end of the third DC socket DC3 and the fourth DC socket DC4. One end of the eleventh resistor R11 is electrically connected to the other end of the third DC socket DC3 and the fourth DC socket DC4 respectively. The other end of the eleventh resistor R11 is grounded.

[0063] It should be noted that when the third PMOS transistor Q3 is in the on state, the DC power input terminal B+ can supply power to the third DC socket DC3 and the fourth DC socket DC4 through the third PMOS transistor Q3.

[0064] It should be noted that the eleventh resistor R11 is used as a current limiting resistor, and the current limiting protection function can be achieved by reasonably designing the resistance value of the eleventh resistor R11.

[0065] Preferably, if the operating current of the DC socket output module 500 is limited to 800 mA, the resistance value of the eleventh resistor R11 may be 0.025 k, and the resistance value of the tenth resistor R10 may be 1 k.

[0066] It should be noted that the number of the third DC sockets DC3 can be 1, 2, 3, or 4, and the number of the third DC sockets DC3 is not excessively limited in the present application.

[0067] Reference Figure 2 In some embodiments, the voltage comparison module 600 includes a first operational amplifier U1A, a second operational amplifier U1B, a twelfth resistor R12, a thirteenth resistor R13, a fourteenth resistor R14, a fifteenth resistor R15, a sixteenth resistor R16, and a seventeenth resistor R17, one end of the thirteenth resistor R13 is electrically connected to the output end of the first operational amplifier U1A, one end of the twelfth resistor R12 is electrically connected to the other end of the thirteenth resistor R13 and the reverse input end of the first operational amplifier U1A, the other end of the twelfth resistor R12 is grounded, and the fourteenth resistor R14 is electrically connected to the output end of the first operational amplifier U1A. One end is electrically connected to the output end of the first operational amplifier U1A, the non-inverting input end of the first operational amplifier U1A is electrically connected to the eighth resistor R8, one end of the sixteenth resistor R16 is electrically connected to the output end of the second operational amplifier U1B, one end of the fifteenth resistor R15 is respectively electrically connected to the other end of the sixteenth resistor R16 and the reverse input end of the second operational amplifier U1B, the other end of the fifteenth resistor R15 is grounded, one end of the seventeenth resistor R17 is electrically connected to the output end of the second operational amplifier U1B, and the non-inverting input end of the second operational amplifier U1B is electrically connected to the tenth resistor R10.

[0068] Preferably, the voltage comparison module 600 may adopt a dual operational amplifier LM358, in which the first operational amplifier U1A and the second operational amplifier U1B may be integrated simultaneously.

[0069] It should be noted that one end of the eighth resistor R8 is electrically connected to the other end of the first DC socket DC1 and the second DC socket DC2, and the non-inverting input end of the first operational amplifier U1A is electrically connected to the eighth resistor R8. If the operating current of the first DC socket DC1 and the second DC socket DC2 in the DC socket output module 500 exceeds the limiting current of 800mA, at this time, the voltage of the non-inverting input end of the first operational amplifier U1A is greater than the voltage of the reverse input end, and a high level is output at the output end of the first operational amplifier U1A.

[0070] It should be noted that one end of the tenth resistor R10 is electrically connected to the other ends of the third DC socket DC3 and the fourth DC socket DC4, and the non-inverting input end of the second operational amplifier U1B is electrically connected to the tenth resistor R10. If the operating current of the third DC socket DC3 and the fourth DC socket DC4 in the DC socket output module 500 exceeds the limiting current of 800mA, at this time, the voltage of the non-inverting input end of the second operational amplifier U1B is greater than the voltage of the reverse input end, and a high level is output at the output end of the second operational amplifier U1B.

[0071] Preferably, the resistance value of the twelfth resistor R12 can be 1k, the resistance value of the thirteenth resistor R13 can be 100k, the resistance value of the fourteenth resistor R14 can be 1k, the resistance value of the fifteenth resistor R15 can be 1k, the resistance value of the sixteenth resistor R16 can be 100k, and the resistance value of the seventeenth resistor R17 can be 1k.

[0072] Reference Figure 2 In some embodiments, the MCU module 300 includes a fourth pin 5, a fifth pin 7 and a sixth pin 8, the fourth pin 5 is electrically connected to the power input terminal of the first operational amplifier U1A, the fifth pin 7 is electrically connected to the other end of the fourteenth resistor R14, and the sixth pin 8 is electrically connected to the other end of the seventeenth resistor R17.

[0073] It should be noted that when the first operational amplifier U1A and the second operational amplifier U1B are integrated into a dual operational amplifier, the power input terminal can be set at the first operational amplifier U1A.

[0074] It should be noted that when the first voltage value is greater than the first preset voltage value, the fourth pin 5 of the MCU module 300 outputs a high level, so that the voltage comparison module 600 is turned on and works.

[0075] It should be noted that one end of the fourteenth resistor R14 is electrically connected to the output end of the first operational amplifier U1A, the fifth pin 7 is electrically connected to the other end of the fourteenth resistor R14, one end of the seventeenth resistor R17 is electrically connected to the output end of the second operational amplifier U1B, and the sixth pin 8 is electrically connected to the other end of the seventeenth resistor R17.

[0076] When the voltage at the same-direction input terminal of the first operational amplifier U1A is greater than the voltage at the reverse input terminal, a high level is output at the output terminal of the first operational amplifier U1A, and the fifth pin 7 of the MCU module 300 receives a high level signal, or when the voltage at the same-direction input terminal of the second operational amplifier U1B is greater than the voltage at the reverse input terminal, a high level is output at the output terminal of the second operational amplifier U1B, and the sixth pin 8 of the MCU module 300 receives a high level signal, and the third pin 6 of the MCU module 300 is controlled to output a low level, so that the second PMOS tube Q2 is cut off. Furthermore, since one end of the sixth resistor R6 is electrically connected to the drain of the second PMOS tube Q2, the gate of the third PMOS tube Q3 is connected to the other end of the sixth resistor R6. When the second PMOS tube Q2 is cut off, the gate of the third PMOS tube Q3 is not grounded, and the third PMOS tube Q3 is in a cut-off state.

[0077] It is understandable that, since the third PMOS transistor Q3 is in the cut-off state, the DC power input terminal B+ cannot supply power to the DC socket output module 500 through the third PMOS transistor Q3.

[0078] In some embodiments, when the first voltage is less than a first preset voltage value, the MCU module 300 stops working.

[0079] In some embodiments, the functional status includes running function and shutting down function.

[0080] It can be understood that, under the premise that the first voltage value is greater than the first preset voltage value, when the output of the voltage comparison module 600 is a high level, the third pin 6 of the MCU module 300 outputs a low level so that the output control module 400 is shut down, thereby causing the DC socket output module 500 to stop working; when the output of the voltage comparison module 600 is a low level, the third pin 6 of the MCU module 300 continues to output a high level so that the output control module 400 continues to run, thereby causing the DC socket output module 500 to keep running.

[0081] The embodiments of the present invention are described in detail above in conjunction with the accompanying drawings, but the present invention is not limited to the above embodiments, and various changes can be made within the knowledge scope of ordinary technicians in the technical field without departing from the purpose of the present invention.

Claims

1. A current limiting protection circuit applied to a DC socket, characterized in that: include: A DC power input terminal, wherein the DC power input terminal is used to connect to an external DC power supply; A switch module, wherein the switch module is electrically connected to the DC power supply input terminal; A voltage detection module, wherein an input end of the voltage detection module is electrically connected to an output end of the switch module; An MCU module, wherein the MCU module is electrically connected to the switch module, and an output end of the voltage detection module is electrically connected to the MCU module so that the MCU module receives a first voltage value detected by the voltage detection module; An output control module, the output control module is electrically connected to the MCU module and the DC power supply input terminal respectively; A DC socket output module, the DC socket output module is electrically connected to the output control module; A voltage comparison module, wherein the voltage comparison module is electrically connected to the DC socket output module and the MCU module respectively; in: The DC socket output module includes a first DC socket, a second DC socket, an eighth resistor, and a ninth resistor. The first DC socket is connected in parallel with the second DC socket. The output end of the output control module is electrically connected to one end of the first DC socket and the second DC socket, respectively. One end of the eighth resistor is electrically connected to the other end of the first DC socket and the second DC socket, one end of the ninth resistor is electrically connected to the other end of the first DC socket and the second DC socket, respectively. The other end of the ninth resistor is grounded. The DC socket output module further includes a third DC socket, a fourth DC socket, a tenth resistor, and an eleventh resistor, wherein the third DC socket is connected in parallel with the fourth DC socket, the output control module is electrically connected to one end of the third DC socket and the fourth DC socket respectively, one end of the tenth resistor is electrically connected to the other end of the third DC socket and the fourth DC socket respectively, one end of the eleventh resistor is electrically connected to the other end of the third DC socket and the fourth DC socket respectively, and the other end of the eleventh resistor is grounded; The MCU module includes a first pin, the switch module includes a first resistor, a first PMOS tube and a self-locking switch, the source of the first PMOS tube is electrically connected to the DC power supply input end as the input end of the switch module, the drain of the first PMOS tube is electrically connected to the input end of the voltage detection module and the first pin of the MCU module as the output end of the switch module, one end of the first resistor is electrically connected to the source of the first PMOS tube, one end of the self-locking switch is electrically connected to the other end of the first resistor and the gate of the first PMOS tube, and the other end of the self-locking switch is grounded; The voltage comparison module includes a first operational amplifier, a second operational amplifier, a twelfth resistor, a thirteenth resistor, a fourteenth resistor, a fifteenth resistor, a sixteenth resistor, and a seventeenth resistor, one end of the thirteenth resistor is electrically connected to the output end of the first operational amplifier, one end of the twelfth resistor is electrically connected to the other end of the thirteenth resistor and the reverse input end of the first operational amplifier, the other end of the twelfth resistor is grounded, one end of the fourteenth resistor is electrically connected to the output end of the first operational amplifier, the in-phase input end of the first operational amplifier is electrically connected to the eighth resistor, one end of the sixteenth resistor is electrically connected to the output end of the second operational amplifier, one end of the fifteenth resistor is electrically connected to the other end of the sixteenth resistor and the reverse input end of the second operational amplifier, the other end of the fifteenth resistor is grounded, one end of the seventeenth resistor is electrically connected to the output end of the second operational amplifier, and the in-phase input end of the second operational amplifier is electrically connected to the tenth resistor; When the first voltage value is greater than a first preset voltage value, the MCU module determines the functional state of the output control module according to the output value of the voltage comparison module.

2. The current limiting protection circuit according to claim 1, characterized in that: The MCU module includes a second pin, the voltage detection module includes a second resistor and a third resistor, one end of the second resistor is electrically connected to the switch module, the other end of the second resistor is respectively electrically connected to one end of the third resistor and the second pin of the MCU module, and the other end of the third resistor is grounded.

3. The current limiting protection circuit according to claim 1, characterized in that: The MCU module includes a third pin, and the output control module includes: a fourth resistor, a fifth resistor, a sixth resistor, a seventh resistor, a second PMOS tube and a third PMOS tube, one end of the fourth resistor is electrically connected to the gate of the second PMOS tube, the other end of the fourth resistor is electrically connected to the third pin of the MCU module as the input end of the output control module, one end of the fifth resistor is electrically connected to the gate of the second PMOS tube, the other end of the fifth resistor is grounded, one end of the sixth resistor is electrically connected to the drain of the second PMOS tube, the gate of the third PMOS tube is electrically connected to the other end of the sixth resistor and one end of the seventh resistor respectively, and the DC power supply input end is electrically connected to the source of the third PMOS tube and the other end of the seventh resistor respectively.

4. The current limiting protection circuit according to claim 1, characterized in that: The MCU module includes a fourth pin, a fifth pin and a sixth pin, the fourth pin is electrically connected to the power input terminal of the first operational amplifier, the fifth pin is electrically connected to the other end of the fourteenth resistor, and the sixth pin is electrically connected to the other end of the seventeenth resistor.

5. The current limiting protection circuit according to claim 1, characterized in that: When the first voltage is less than the first preset voltage value, the MCU module stops working.

6. The current limiting protection circuit according to claim 5, characterized in that: The functional status includes running function and closing function.

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