Load protection circuit, electronic equipment and cascade system
By designing a load protection circuit that includes input and output protection modules, the problem of simultaneously protecting internal and external loads in existing technologies has been solved, achieving effective protection in case of reverse polarity connection and expanding the application range.
Patent Information
- Application Number
- CN202520011480.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-01-02
- Publication Date
- 2026-02-17
- Estimated Expiration
- 2035-01-02
AI Technical Summary
Existing load protection circuits cannot effectively protect both internal and external loads simultaneously, limiting their application scope, especially posing safety hazards when electronic devices are cascaded with external loads.
A load protection circuit was designed, comprising an input protection module and an output protection module, which are used to control the power supply path of the internal load and the external load when connected in the forward and reverse directions, respectively, to ensure protection of the internal and external loads when the polarity is reversed.
It achieves effective protection for internal and external loads when the input power polarity is reversed, thus improving the application range of load protection circuits and the safety of equipment.
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Figure CN223928088U_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of electronic circuit technology, and more specifically, to a load protection circuit, electronic equipment, and cascade system. Background Technology
[0002] Reverse polarity of the power supply is a common safety hazard in electronic devices, affecting their normal operation and even damaging them. In practical use, load protection circuits can protect electronic devices from damage caused by reverse connections, extending their lifespan.
[0003] However, with the rapid development of technology, the diversity and complexity of electronic devices on the market are increasing. Electronic devices can support cascading with other external load devices. In related technologies, load protection circuits can only protect electronic devices, but it is difficult to effectively protect both internal and external loads at the same time, which limits the application scope of load protection circuits. Utility Model Content
[0004] In view of the above problems, this utility model proposes a load protection circuit, electronic equipment, and cascade system to improve the above technical problems.
[0005] In a first aspect, embodiments of this application provide a load protection circuit, which includes: an input protection module, an internal load, and an output protection module; the internal load is connected between the input protection module and the output protection module; wherein, the input protection module is used to connect the connection path between the input power supply and the internal load when the connection direction with the input power supply is forward; the input protection module is also used to disconnect the connection path between the input power supply and the internal load when the connection direction with the input power supply is reverse; the output protection module is used to connect the connection path between the input power supply and the external load when the connection direction with the input protection module and the input power supply is forward; the output protection module is also used to disconnect the connection path between the input power supply and the external load when the connection direction with the input protection module and the input power supply is reverse.
[0006] Secondly, embodiments of this application also provide an electronic device that includes the load protection circuit described in the first aspect.
[0007] Thirdly, embodiments of this application also provide a cascaded system, including the electronic device described in the second aspect above and a load device; wherein the load device includes an external load, which is used to connect to the output protection module of the electronic device.
[0008] The technical solution provided by this utility model includes a load protection circuit comprising: an input protection module, an internal load, and an output protection module; the internal load is connected between the input protection module and the output protection module; the input protection module is used to connect the input power supply and the internal load when the connection direction with the input power supply is positive; the input protection module is also used to disconnect the connection path between the input power supply and the internal load when the connection direction with the input power supply is reverse; the output protection module is used to connect the input power supply and the external load when the connection direction with the input protection module is positive; the output protection module is also used to disconnect the connection path between the input power supply and the external load when the connection direction with the input protection module is reverse; thus, the load protection circuit can effectively protect both the internal and external loads even when the polarity of the input power supply is reversed, thereby improving the application range of the load protection circuit. Attached Figure Description
[0009] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments and drawings obtained by those skilled in the art without creative effort are within the scope of protection of this application.
[0010] Figure 1 A schematic diagram of a load protection circuit provided in an embodiment of this application is shown.
[0011] Figure 2 A schematic diagram of another load protection circuit provided in an embodiment of this application is shown.
[0012] Figure 3 A schematic diagram of another load protection circuit provided in an embodiment of this application is shown.
[0013] Figure 4 A schematic diagram of the structure of an input protection module provided in an embodiment of this application is shown.
[0014] Figure 5 A schematic diagram of another load protection circuit provided in an embodiment of this application is shown.
[0015] Figure 6 A schematic diagram of the structure of an output protection module provided in an embodiment of this application is shown.
[0016] Figure 7 A schematic diagram of another output protection module provided in an embodiment of this application is shown.
[0017] Figure 8 A schematic diagram of another load protection circuit provided in an embodiment of this application is shown.
[0018] Figure 9 A schematic diagram of the structure of an electronic device provided in an embodiment of this application is shown.
[0019] Figure 10 A schematic diagram of a cascaded system provided in an embodiment of this application is shown. Detailed Implementation
[0020] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings.
[0021] In the following description, when referring to the accompanying drawings, the same numbers in different drawings denote the same or similar elements unless otherwise indicated. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this application. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this application as detailed in the appended claims.
[0022] The terminology used in this application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. The singular forms “a,” “the,” and “the” used in this application and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the term “and / or” as used herein refers to and includes any or all possible combinations of one or more of the associated listed items.
[0023] Reverse polarity of the power supply is a common safety hazard in load devices, affecting the normal operation of electronic equipment and even damaging it. In practical use, load protection circuits can protect electronic equipment from damage caused by reverse connection, extending the lifespan of the equipment.
[0024] However, with the rapid development of technology, the diversity and complexity of electronic devices on the market are increasing. Electronic devices can support cascading with other load devices. In related technologies, load protection circuits can only protect electronic devices, but it is difficult to effectively protect both internal and external loads at the same time, which limits the application scope of load protection circuits.
[0025] To address the aforementioned problems, the inventors have proposed the load protection circuit, electronic device, and cascaded system provided in this application. The load protection circuit includes an input protection module, an internal load, and an output protection module. The internal load is connected between the input protection module and the output protection module. The input protection module connects the input power supply and the internal load when connected in the forward direction; it also disconnects the connection when connected in the reverse direction. The output protection module connects the input power supply and the external load when connected in the forward direction; it also disconnects the connection when connected in the reverse direction. Therefore, the load protection circuit can effectively protect both the internal and external loads even when the input power supply polarity is reversed, thus expanding the application range of the load protection circuit.
[0026] The technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings.
[0027] Please see Figure 1 , Figure 1 This is a schematic diagram of a load protection circuit disclosed in an embodiment of this application. Figure 1 As shown, the load protection circuit 100 includes an input protection module 110, an internal load 120, and an output protection module 130.
[0028] The internal load 120 is connected between the input protection module 110 and the output protection module 130. The input protection module 110 is used to connect to the input power supply, and the output protection module 130 is used to connect to the external load.
[0029] When the input protection module 110 is connected to the input power supply in the positive direction, the positive terminal of the input protection module 110 is connected to the positive terminal of the input power supply, and the negative terminal of the input protection module 110 is connected to the negative terminal of the input power supply. At this time, the polarity of the input power supply is positive. When the input power supply is connected to the internal load 120, it can provide power support for the normal operation of the internal load 120.
[0030] When the input protection module 110 and the input power supply are connected in reverse, the positive terminal of the input protection module 110 is connected to the negative terminal of the input power supply, and the negative terminal of the input protection module 110 is connected to the positive terminal of the input power supply. The polarity of the input power supply is reversed. When the input power supply is connected to the external load, the internal load 120 will be subjected to abnormal current surge, which will prevent it from working properly or even cause damage.
[0031] In the embodiments of this application, the input protection module 110 is used to connect the input power supply and the internal load 120 when the connection direction with the input power supply is forward. The input protection module 110 is also used to disconnect the connection path between the input power supply and the internal load 120 when the connection direction with the input power supply is reversed. Thus, the input protection module 110 can effectively protect the internal load 120 when the power supply is reversed.
[0032] In the embodiments of this application, the output protection module 130 can be connected to an external load to achieve device cascading, enriching product diversity and flexibility. However, there is a safety hazard when the external load is connected in reverse.
[0033] Therefore, in the embodiments of this application, when the input protection module 110 is connected to the input power supply in a forward direction, the output protection module 130 connects the input power supply to the external load. In this case, the input power supply can provide power support for the normal operation of the external load. When the input protection module 110 is connected to the input power supply in a reverse direction, the output protection module 130 disconnects the connection between the input power supply and the external load. Thus, the output protection module 110 can effectively protect the cascaded external load when the power supply is reversed.
[0034] The external load is connected to the output power supply through the output protection module 130 and the internal load 120. That is, the output power supply passes through the input protection module 110, the internal load 120 and the output protection module 130 in sequence before being connected to the external load. When the internal load 120 is connected to the input protection module 110, the output protection module 130 connects the connection path between the internal load 120 and the external load, that is, connects the connection path between the input power supply and the external load. When the output protection module 130 disconnects the connection path between the internal load 120 and the external load, that is, disconnects the connection path between the input power supply and the external load.
[0035] When the external load and the output protection module 130 are connected in the forward direction, the positive power supply terminal of the output protection module 130 is connected to the positive power supply terminal of the external load, and the negative power supply terminal of the output protection module 130 is connected to the negative power supply terminal of the external load. At this time, when the input protection module 110 and the input power supply are connected in the forward direction, the current of the input power supply can reach the external load through the input protection module 110, the internal load and the output protection module 130, providing power support for the normal operation of the external load.
[0036] When the external load and the output protection module 130 are connected in reverse, with the positive power supply terminal of the output protection module 130 connected to the negative power supply terminal of the external load, and the negative power supply terminal of the output protection module 130 connected to the positive power supply terminal of the external load, and the input protection module 110 and the input power supply are connected in forward direction, if the current from the input power supply flows to the external load, the internal load will be subjected to abnormal current surges, malfunction, or even damage. Therefore, in the load protection circuit provided in this embodiment, the output protection module 130 is also used to disconnect the connection path between the input power supply and the external load when the input protection module 110 and the input power supply are connected in forward direction and the external load and the output protection module 130 are connected in reverse direction. This allows for effective protection of the external load when it is reverse-connected.
[0037] In some implementations, when the input protection module 110 is connected to the input power supply in a forward direction and the external load is connected to the output protection module 130 in a reverse direction, the output protection module 130 periodically disconnects the connection path between the input power supply and the external load, forming a power supply hiccup state to protect the external load from damage.
[0038] In some implementations, please refer to Figure 2 , Figure 2 This is a schematic diagram of another load protection circuit disclosed in an embodiment of this application. For example... Figure 2 As shown in the embodiments of this application, the input protection module 110 includes an input switch unit 111 and an input voltage divider unit 112.
[0039] The input terminal of the input switch unit 111 is used to connect to the input power supply; the output terminal of the input switch unit 111 is connected to the internal load 120.
[0040] The first end of the input voltage divider unit 112 is connected to the control terminal of the input switch unit 111, the second end of the input voltage divider unit 112 is used for grounding, and the third end of the input voltage divider unit 112 is connected to the output terminal of the input switch unit 111.
[0041] The input switch unit 111 is used to connect the input terminal and the output terminal of the input switch unit 111 when the voltage at the control terminal is greater than or equal to the preset input threshold voltage; and to disconnect the connection between the input terminal and the output terminal of the input switch unit 111 when the voltage at the control terminal is less than the preset input threshold voltage.
[0042] The input voltage divider unit 112 is used to divide the voltage at the first terminal of the input voltage divider unit 112 to form the input control voltage.
[0043] Specifically, when the input terminal of the input switch unit 112 is connected to the positive terminal of the input power supply, the input control voltage is greater than or equal to the preset input threshold voltage; when the input terminal of the input switch unit 112 is connected to the negative terminal of the input power supply, the input control voltage is less than the preset input threshold voltage.
[0044] In some implementations, the input switching unit 111 can be implemented using a switching transistor, such as a MOS transistor (Metal-Oxide-Semiconductor Field-Effect Transistor), a triode, or other switching devices.
[0045] In some implementations, the input voltage divider unit 112 can be implemented using multiple voltage divider resistors, operational amplifiers, or diodes.
[0046] In some implementations, please refer to Figure 3 , Figure 3 This is a schematic diagram of another load protection circuit disclosed in an embodiment of this application. For example... Figure 3 As shown in the embodiments of this application, the input protection module 110 further includes an input voltage regulator unit 113, the positive terminal of which is connected to the control terminal of the input switch unit 111, and the negative terminal of which is connected to the output terminal of the input switch unit 111.
[0047] When the input terminal of the input switch unit 111 is connected to the positive terminal of the input power supply, the input voltage regulator unit 113 is in the off state, that is, the input voltage regulator unit 113 is in the open state.
[0048] When the input terminal of the input switch unit 111 is connected to the negative terminal of the input power supply, the input voltage regulator unit 113 is turned on, stabilizing the voltage at the control terminal of the input switch unit 111 to the first preset voltage regulation threshold, thereby protecting the input switch unit 111 and preventing abnormal current from impacting the input switch unit 111 when reverse connected, thus protecting the input switch unit 111.
[0049] It is understood that this application is not limited thereto. In other embodiments, the input protection module 110 may also include other components, such as a filtering unit, a power soft start unit, etc. The specific configuration can be made according to actual usage needs, and this application does not impose any restrictions on this.
[0050] Please see Figure 4 , Figure 4 This is a schematic diagram of the structure of an input protection module 110 disclosed in an embodiment of this application.
[0051] In the embodiments of this application, the input protection module 110 includes an input switch unit, an input voltage divider unit, a voltage regulator unit, a filter unit, and an input power soft-start unit.
[0052] The input switching unit includes a first switching device Q1, the drain (D) of the first switching device Q1 is used to connect to the input power supply, and the source (S) is connected to the internal load 120.
[0053] The input voltage divider unit includes a first resistor R1 and a second resistor R2. One end of the first resistor R1 is connected to the gate (G) of the first switching device Q1, and the other end of the first resistor R1 is used for grounding. One end of the second resistor R2 is connected to one end of the first resistor R1, and the other end of the second resistor R2 is connected to the internal load 120.
[0054] When the drain of the first switching device Q1 is connected to the positive terminal of the input power supply (e.g., 36V), the first resistor R1 (e.g., 200KΩ) and the second resistor R2 (e.g., 100KΩ) divide the voltage. At this time, the voltage between the gate and drain of the first switching device Q1 is -12V, the first switching device Q1 is turned on, and the input power supply can provide power support for the normal operation of the internal load 120.
[0055] The voltage regulator unit includes a Zener diode D1. The positive terminal of Zener diode D1 is connected to the gate of the first switching device Q1, and the negative terminal of Zener diode D1 is connected to the source of the first switching device Q1. Zener diode D1 can conduct when the first switching device Q1 is reverse-connected to the input power supply. When Zener diode D1 is conducting, it reduces the voltage between the gate and source of the first switching device Q1 to the forward voltage difference of Zener diode D1, thus preventing the first switching device Q1 from conducting. Therefore, it provides protection when the input power supply is reverse-connected and protects the first switching device Q1 from abnormal current surges.
[0056] Optionally, the on-state voltage difference of Zener diode D1 is 0.7V.
[0057] The filtering unit includes a first capacitor C1 and a second capacitor C2. One end of the first capacitor C1 is connected to the internal load 120, and the other end of the first capacitor C1 is grounded. One end of the second capacitor C2 is also connected to the internal load 120, and the other end of the second capacitor C2 is grounded. The first capacitor C1 and the second capacitor C2 can filter the signals flowing through them.
[0058] Optionally, the first capacitor C1 can be 1μF; the second capacitor C1 can be 1μF.
[0059] The input power soft-start unit includes a third capacitor C3. One end of the third capacitor C3 is connected to the internal load 120, and the other end of the third capacitor C3 is connected to one end of the first resistor R1. The third capacitor C3 can serve as a soft-start unit.
[0060] Optionally, the third capacitor C3 can be 0.1μF.
[0061] The input protection module 110 provided in this application embodiment is built with discrete components, which not only reduces costs but also improves circuit reliability.
[0062] In some implementations, please refer to Figure 5 , Figure 5 This is a schematic diagram of another load protection circuit disclosed in an embodiment of this application. Figure 5 As shown in the embodiments of this application, the output protection module 130 includes an output switch unit 131 and an output voltage divider unit 132.
[0063] The first end of the output voltage divider unit 132 is connected to the internal load, the second end of the output voltage divider unit 132 is used for grounding, and the third end of the output voltage divider unit 132 is connected to the control terminal of the output switch unit 131.
[0064] The input terminal of the output switch unit 131 is connected to the second terminal of the output voltage divider unit 132, and the output terminal of the output switch unit 131 is used to connect to an external load.
[0065] The output switch unit 131 is used to connect the connection path between the input terminal and the output terminal of the output switch unit 131 when the voltage at the control terminal is greater than or equal to the preset output threshold voltage; and to disconnect the connection path between the input terminal and the output terminal of the output switch unit 131 when the voltage at the control terminal is less than the preset output threshold voltage.
[0066] The output voltage divider unit 132 is used to divide the voltage at the third terminal of the output voltage divider unit 132 to form the input control voltage.
[0067] Specifically, when the input protection module 110 is connected to the positive terminal of the input power supply, the output control voltage is greater than or equal to the preset output threshold voltage; when the input protection module 110 is connected to the negative terminal of the input power supply, the output control voltage is less than the preset output threshold voltage.
[0068] In some implementations, the output switching unit 131 may be implemented using a switching transistor, such as a MOS transistor (Metal-Oxide-Semiconductor Field-Effect Transistor), a triode, or other switching devices.
[0069] In some implementations, the output voltage divider unit 132 can be implemented using multiple voltage divider resistors, operational amplifiers, or diodes.
[0070] In some implementations, please refer to Figure 6 , Figure 6 This is a schematic diagram of the structure of an output protection module 130 disclosed in an embodiment of this application. Figure 6 As shown in the embodiments of this application, the output protection module 130 further includes: a periodic switching unit 133, a periodic voltage divider unit 134, and a periodic voltage regulator unit 135.
[0071] The output voltage divider unit 132 includes a first subunit 1321 and a second subunit 1322.
[0072] The first end of the first subunit 1321 is connected to the internal load 120, and the second end of the first subunit 1321 is connected to the input end of the periodic switch unit 133; the first end of the second subunit 1321 is connected to the output end of the periodic switch unit 133 and the control end of the output switch unit 131 respectively, and the second end of the second subunit 1322 is connected to the input end of the output switch unit 131.
[0073] The first end of the periodic voltage divider unit 134 is connected to the internal load 120, and the second end of the periodic voltage divider unit 134 is connected to the control end of the periodic switch unit 133.
[0074] The negative terminal of the periodic voltage regulator unit 135 is connected to the control terminal of the periodic switch unit 133; the positive terminal of the periodic voltage regulator unit 135 is connected to the output terminal of the output switch unit 131.
[0075] The periodic voltage regulator unit 135 and the periodic voltage divider unit 134 are used to adjust the periodic control voltage of the control terminal of the periodic switch unit 133 when the connection direction between the input terminal of the output switch unit 133 and the internal load 120 is positive and the connection direction between the external load and the output terminal of the output switch unit 131 is negative. This causes the first terminal of the periodic switch unit 133 and the second terminal of the periodic switch unit 133 to be periodically disconnected, thereby periodically disconnecting the connection path between the input power supply and the external load.
[0076] When the input protection module 110 is connected to the input power supply in the forward direction, the periodic voltage regulator unit 135 is turned on, and the voltage obtained by the periodic voltage divider unit 134 is greater than or equal to the conduction threshold of the periodic switch unit, so the periodic switch unit 133 is turned on. The first sub-unit 1321 and the second sub-unit 1322 form a voltage divider. The voltage of the second sub-unit 1322 is greater than the conduction threshold of the output switch unit 131, so the output switch unit 131 is turned on.
[0077] When the input protection module 110 is connected to the input power supply in reverse, the periodic voltage regulator unit 135 is disconnected and the periodic switch unit 133 is not turned on.
[0078] When the input protection module 110 is connected to the input power supply in a forward direction, and the external load is connected to the output terminal of the output switch unit 131 in a reverse direction, the following two processes are repeated:
[0079] The first process: When the external load is short-circuited, the voltage at the first terminal of the periodic voltage divider unit 134 is pulled down. Since the voltage of the periodic voltage regulator unit 135 is constant, the voltage of the periodic voltage divider unit 134 continuously decreases. When the voltage of the periodic voltage divider unit 134 is less than the conduction threshold of the periodic switch unit 133, the periodic switch unit 133 is turned off. At this time, since the power supply is disconnected, the voltage of the second sub-unit 1322 is 0, and the output switch unit 131 is turned off.
[0080] The second process: After the output switch unit 131 disconnects from the external load, the voltage at the first end of the periodic voltage divider unit 134 gradually recovers. When the voltage of the periodic voltage divider unit 134 recovers to a value greater than the conduction threshold of the periodic switch unit 133, the periodic switch unit 133 is turned on. At this time, the voltage division of the second sub-unit 1322 causes the output switch unit 131 to be turned on again.
[0081] The above two processes repeat, forming a power supply hiccup state, protecting the external load from damage.
[0082] It is understood that this application is not limited thereto. In other embodiments, the output protection module 130 may also include other components, such as a filtering unit, a power soft-start unit, etc. The specific configuration can be made according to actual usage needs, and this application does not impose any restrictions on this.
[0083] Please see Figure 7 , Figure 7 This is a schematic diagram of another output protection module 130 disclosed in an embodiment of this application.
[0084] In embodiments of this application, the output protection module 130 includes: an output switching unit and an output voltage divider unit, a periodic switching unit, a periodic voltage divider unit, a periodic voltage regulator unit, a power supply soft-start unit, and a protection unit. The output voltage divider unit includes a first subunit and a second subunit.
[0085] The output switching unit includes a second switching device Q2, and the periodic switching unit includes a third switching device Q3.
[0086] The first switching subunit includes a third resistor R3, one end of which is connected to the internal load 120, and the other end of which is connected to the emitter of the third switching device Q3. The second switching subunit includes a fourth resistor R4, one end of which is connected to the collector of the third switching device Q3, and the other end of which is connected to the source (S) of the second switching device Q2.
[0087] The periodic voltage divider unit includes a fifth resistor R5, and the protection unit includes a sixth resistor R6. One end of the fifth resistor R5 is connected to the internal load 120, and the other end of the fifth resistor R5 is connected to one end of the sixth resistor R6. The other end of the sixth resistor R6 is connected to the base of the third switching device Q3. The protection unit can prevent the base of the third switching device Q3 from being impacted by abnormal current.
[0088] The periodic voltage regulator unit includes a second Zener diode D2. The negative terminal of the second Zener diode D2 is connected to the other end of the fifth resistor R5, and the positive terminal of the second Zener diode D2 is connected to the source of the second switching device Q2.
[0089] The power supply soft-start unit includes a fourth capacitor C4. One end of the fourth capacitor C4 is connected to the collector of the third switching device Q3, and the other end of the fourth capacitor C4 is connected to the gate of the second switching device Q2. The fourth capacitor C4 can serve as a soft-start device.
[0090] Optionally, the fourth capacitor C4 can be 0.1μF.
[0091] The drain (D) of the second switching device Q2 is used to connect to an external load.
[0092] When the input protection module 110 is connected to the input power supply in the forward direction, and the external load is connected to the output terminal of the output switch unit in the forward direction, assuming the input voltage at one end of the fifth resistor R5 is 36V, the second Zener diode D2 is turned on (e.g., regulated at 30V), the voltage of the fifth resistor R5 (e.g., 100KΩ) is 6V, thus the third switch Q3 is turned on; the third resistor R3 (e.g., 100KΩ) and the fourth resistor R4 (e.g., 100KΩ) divide the voltage, the voltage of the fourth resistor R4 is 18V, the second switch Q2 is turned on, and the external load is powered normally.
[0093] When the input protection module 110 is connected to the input power supply in the forward direction, and the external load is connected to the output terminal of the output switch unit in the reverse direction, the following two processes are repeated:
[0094] The first process: When the external load is short-circuited, the voltage at the first end of the fifth resistor R5 is pulled down. Since the voltage of the second Zener diode D2 is constant, the voltage of the fifth resistor R5 continues to decrease. When the voltage of the fifth resistor R5 is less than the conduction threshold of the third switching device Q3, the third switching device Q3 is turned off. At this time, since the power supply is disconnected, the voltage of the fourth resistor R4 is 0, and the second switching device Q2 is turned off.
[0095] The second process: After the second switching device Q2 disconnects from the external load, the voltage at one end of the fifth resistor R5 gradually recovers. When the voltage at the fifth resistor R5 recovers to a level greater than the conduction threshold of the third switching device Q3, the third switching device Q3 turns on. At this time, the voltage division of the fourth resistor R4 causes the second switching device Q2 to turn on again and connect to the external load.
[0096] The above two processes repeat, forming a power supply hiccup state, protecting the external load from damage.
[0097] The output protection module 130 provided in this application embodiment is built with discrete components, which not only reduces costs but also improves circuit reliability.
[0098] Please see Figure 8 , Figure 8 This is a schematic diagram of another load protection circuit 100 disclosed in an embodiment of this application. Figure 8 As shown, the internal load 120 includes an internal data transmission interface, and the external load includes an external data transmission interface. The internal data transmission interface is used to connect to the external data transmission interface.
[0099] When the input protection module 110 is connected to the input power supply in the forward direction and the external load is connected to the output protection module 130 in the reverse direction, the internal load and the external load are powered normally, and the internal load and the external load can transmit data.
[0100] Please see Figure 9 , Figure 9 This application provides an electronic device 200, which includes the load protection circuit 100 described above.
[0101] Electronic device 200 can be, for example, a laser module, a lighting module, an audio module, etc. Electronic device 200 can be cascaded with other external loads, and load protection circuit 100 can effectively protect internal and external loads.
[0102] Please see Figure 10 , Figure 10 This application provides a cascade system 300, which includes the aforementioned electronic device 200 and a load device 310. The load device includes an external load, which is used to connect to the output protection module of the electronic device 200.
[0103] The load devices may include lighting modules (such as light strips), audio modules, display modules, etc.
[0104] In summary, this application provides a load protection circuit, electronic device, and cascaded system. The load protection circuit includes an input protection module, an internal load, and an output protection module. The internal load is connected between the input protection module and the output protection module. The input protection module connects the input power supply and the internal load when connected in the forward direction. It also disconnects the connection when connected in the reverse direction. The output protection module connects the input power supply and an external load when connected in the forward direction. It also disconnects the connection when connected in the reverse direction. Therefore, the load protection circuit can effectively protect both the internal and external loads even when the input power supply polarity is reversed, thus expanding its application range.
[0105] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application.
Claims
1. A load protection circuit, characterized by, The load protection circuit comprises an input protection module, an internal load and an output protection module; the internal load is connected between the input protection module and the output protection module; The input protection module is configured to, when the input protection module and the input power source are connected in a forward direction, connect a connection path between the input power source and the internal load; the input protection module is further configured to, when the input protection module and the input power source are connected in a reverse direction, disconnect the connection path between the input power source and the internal load; The output protection module is configured to, when the input protection module and the input power source are connected in a forward direction, connect a connection path between the input power source and an external load; the output protection module is further configured to, when the input protection module and the input power source are connected in a reverse direction, disconnect the connection path between the input power source and the external load.
2. The load protection circuit of claim 1, wherein, The output protection module is further configured to, when the input protection module and the input power source are connected in a forward direction and the external load and the output protection module are connected in a reverse direction, disconnect the connection path between the input power source and the external load.
3. The load protection circuit of claim 2, wherein, The output protection module is further configured to, when the input protection module and the input power source are connected in a forward direction and the external load and the output protection module are connected in a reverse direction, periodically disconnect the connection path between the input power source and the external load.
4. The load protection circuit of claim 1, wherein, The input protection module comprises an input switch unit and an input voltage division unit; An input end of the input switch unit is configured to be connected to the input power source; an output end of the input switch unit is connected to the internal load; a first end of the input voltage division unit is connected to a control end of the input switch unit; a second end of the input voltage division unit is configured to be grounded; and a third end of the input voltage division unit is connected to the output end of the input switch unit; The input switch unit is configured to, when a voltage at the control end is greater than or equal to a preset input threshold voltage, connect a connection path between the input end of the input switch unit and the output end of the input switch unit; and when the voltage at the control end is less than the preset input threshold voltage, disconnect the connection path between the input end of the input switch unit and the output end of the input switch unit; The input voltage division unit is configured to divide a voltage at the first end to form an input control voltage; When the input end of the input switch unit is connected to a positive end of the input power source, the input control voltage is greater than or equal to the preset input threshold voltage; and when the input end of the input switch unit is connected to a negative end of the input power source, the input control voltage is less than the preset input threshold voltage.
5. The load protection circuit of claim 4, wherein, The input protection module further comprises an input voltage stabilizing unit; a positive end of the input voltage stabilizing unit is connected to the control end of the input switch unit; and a negative end of the input voltage stabilizing unit is connected to the output end of the input switch unit.
6. The load protection circuit of claim 1, wherein, The internal load comprises an internal data transmission interface, and the external load comprises an external data transmission interface.
7. The load protection circuit according to any one of claims 1 to 6, characterized in that, The output protection module comprises an output switch unit and an output voltage division unit. The first end of the output voltage division unit is connected to the internal load, the second end of the output voltage division unit is connected to the input end of the output switch unit, and the third end of the output voltage division unit is connected to the control end of the output switch unit. The output end of the output switch unit is used to connect the external load. The output switch unit is used to connect the input end and the output end of the output switch unit when the voltage at the control end is greater than or equal to a preset output threshold voltage, and disconnect the input end and the output end of the output switch unit when the voltage at the control end is less than the preset output threshold voltage. The output voltage division unit is used to divide the voltage at the third end of the output voltage division unit to form an output control voltage.
8. The load protection circuit of claim 7, wherein, When the connection direction of the input protection module and the input power supply is forward connection, the output control voltage is greater than or equal to the preset output threshold voltage; when the input end of the output switch unit is connected to the negative end of the input power supply, the output control voltage is less than the preset output threshold voltage. The output protection module further comprises a cycle switch unit, a cycle voltage division unit, and a cycle voltage stabilization unit; the output voltage division unit comprises a first sub-unit and a second sub-unit. The first end of the first sub-unit is connected to the internal load, and the second end of the first sub-unit is connected to the input end of the cycle switch unit; the first end of the second sub-unit is connected to the output end of the cycle switch unit and the control end of the output switch unit, and the second end of the second sub-unit is connected to the input end of the output switch unit. The first end of the cycle voltage division unit is connected to the internal load, and the second end of the cycle voltage division unit is connected to the control end of the cycle switch unit. The negative end of the cycle voltage stabilization unit is connected to the second end of the cycle voltage division unit, and the positive end of the cycle voltage stabilization unit is connected to the output end of the output switch unit.
9. An electronic device, comprising: The cycle voltage stabilization unit and the cycle voltage division unit are used to adjust the cycle control voltage at the control end of the cycle switch unit when the connection direction of the input end of the output switch unit and the internal load is forward connection and the connection direction of the external load and the output end of the output switch unit is reverse connection, so that the first end of the cycle switch unit and the second end of the cycle switch unit are periodically disconnected, thereby periodically disconnecting the connection path between the input power supply and the external load.
10. A cascaded system characterized by, The electronic device comprises the load protection circuit of any one of claims 1 to 8. The electronic device and the load device of claim 9 are included, wherein the load device comprises an external load used to be connected to the output protection module of the electronic device.