Load detection circuit and electronic device

Abstract

This invention relates to the field of electronic circuit technology, and discloses a load detection circuit and electronic device. The load detection circuit includes a first switching subcircuit, a second switching subcircuit, and a control subcircuit. The control subcircuit is connected to the first switching subcircuit, and the first switching subcircuit is connected to the second switching subcircuit. The second switching subcircuit is used to connect a load. The control subcircuit controls the switching state of the first switching subcircuit, causing the switching state of the second switching subcircuit to switch in accordance with the switching state of the first switching subcircuit. When a load connection signal is received through the second switching subcircuit, the first switching subcircuit controls the second switching subcircuit to turn off. This invention detects whether a load is connected by controlling the structure of the switching circuit. When a load is connected, the entire load detection circuit is in a dormant state, and the virtual voltage formed by the connected load is grounded, thus eliminating the virtual voltage formed by the load connection.

Description

Technical Field

[0001] This invention relates to the field of electronic circuit technology, and in particular to a load detection circuit and electronic device. Background Technology

[0002] In physics, a load refers to an electronic component connected to both ends of a power source in a circuit. It is a device that uses electrical energy to operate, also known as an "electrical appliance." The function of a load (electrical appliance) is to convert electrical energy into other forms of energy. For example, an electric furnace converts electrical energy into heat energy, and an electric motor converts electrical energy into mechanical energy.

[0003] When a load is connected to the circuit, a virtual voltage is generated. The circuit system cannot determine whether the load is properly connected, which may lead to false alarms from the equipment or make the circuit structure unsafe.

[0004] To address the aforementioned issues, existing technologies employ mechanical structures or complex circuits to detect whether a load is connected, while also incorporating additional circuitry to eliminate virtual voltage. However, these methods are impractical, costly, and have poor reliability. Summary of the Invention

[0005] The purpose of this invention is to provide a load detection circuit and electronic device to solve one or more technical problems existing in the prior art, and at least provide a beneficial option or create conditions.

[0006] In a first aspect, a load detection circuit is provided, comprising a first switching sub-circuit, a second switching sub-circuit, and a control sub-circuit;

[0007] The control sub-circuit is connected to the first switch sub-circuit, the first switch sub-circuit is connected to the second switch sub-circuit, and the second switch sub-circuit is used to connect the load.

[0008] The control subcircuit is used to control the switching state of the first switch subcircuit, so that the switching state of the second switch subcircuit follows the switching state of the first switch subcircuit, and when the second switch subcircuit receives the load access signal, the first switch subcircuit controls the second switch subcircuit to turn off.

[0009] In some embodiments, the control sub-circuit is provided with a detection terminal, an on / off terminal and a driving terminal. The driving terminal is used to connect to the load, and the control sub-circuit outputs voltage to the load through the driving terminal.

[0010] The on / off terminal is connected to the control terminal of the first switch sub-circuit. The first terminal of the first switch sub-circuit is connected to the control terminal of the second switch sub-circuit. The second terminal of the first switch sub-circuit is connected to the potential reference point. The first terminal of the second switch sub-circuit is connected to the detection terminal. The second terminal of the second switch sub-circuit is used to connect to the load.

[0011] In some embodiments, the first switching sub-circuit includes a first resistor, a second resistor, a first diode, and a first switching device;

[0012] One end of the first resistor is connected to the control terminal of the first switching device, and the other end of the first resistor is connected to the on / off terminal.

[0013] One end of the second resistor is connected to the control terminal of the first switching device, and the other end of the second resistor is connected to the second terminal of the first switching device and the potential reference point.

[0014] The anode of the first diode is connected to the control terminal of the second switch sub-circuit, and the cathode of the first diode is connected to the first terminal of the first switch sub-circuit.

[0015] In some embodiments, the second switching sub-circuit includes a third resistor, a fourth resistor, a first Zener diode, and a second switching device.

[0016] One end of the third resistor is connected to the control terminal of the second switching device, and the other end of the third resistor is connected to the first terminal of the first switching sub-circuit.

[0017] One end of the fourth resistor is connected to the control terminal of the second switching device, and the other end of the fourth resistor is connected to the second terminal of the second switching device.

[0018] The anode of the first Zener diode is connected to the detection terminal, and the cathode of the first Zener diode is connected to the first terminal of the second switching device;

[0019] The second terminal of the second switching device is used to connect the load.

[0020] In some embodiments, the load detection circuit further includes a third switching sub-circuit;

[0021] The first terminal of the second switch sub-circuit is connected to the control terminal of the third switch sub-circuit. The first terminal of the third switch sub-circuit is connected to the DC voltage and control sub-circuit. The second terminal of the third switch sub-circuit is connected to the potential reference point.

[0022] In some embodiments, the third switching sub-circuit includes a fifth resistor, a sixth resistor, a seventh resistor, a second diode, and a third switching device;

[0023] The anode of the second diode is connected to the first terminal of the second switch sub-circuit, the cathode of the second diode is connected to one end of the fifth resistor, and the other end of the fifth resistor is connected to the control terminal of the third switch device.

[0024] One end of the sixth resistor is connected to the control terminal of the third switching device, and the other end of the sixth resistor is connected to the second terminal of the third switching device and the potential reference point.

[0025] One end of the seventh resistor is connected to a DC voltage, and the other end of the seventh resistor is connected to the first terminal of the third switching device and the control sub-circuit.

[0026] In some embodiments, the third switching device is an NPN transistor or an N-type field-effect transistor.

[0027] In some embodiments, the first switching device is an NPN transistor and the second switching device is a PNP transistor.

[0028] In some embodiments, the first switching device is an N-type field-effect transistor (FET), and the second switching device is a P-type field-effect transistor (FET).

[0029] In a second aspect, an electronic device is provided, including a load detection circuit as described in the first aspect.

[0030] The beneficial effects of the present invention are as follows: the first switch sub-circuit triggers the second switch sub-circuit to conduct, so that the entire load detection circuit is in the open state. When the conducted second switch sub-circuit detects the load connection, it transmits the connection signal to the control sub-circuit. The control sub-circuit that receives the connection signal triggers the second switch sub-circuit to turn off through the first switch sub-circuit, so that the entire load detection circuit is in the sleep state. The virtual voltage formed by the load connection is connected to the ground, thus eliminating the virtual voltage formed by the load connection. Attached Figure Description

[0031] Figure 1 This is a schematic diagram of the load detection circuit according to the first embodiment of the present invention.

[0032] Figure 2 This is a schematic diagram of the load detection circuit according to the second embodiment of the present invention.

[0033] Figure 3 This is a schematic diagram of the load detection circuit according to the third embodiment of the present invention. Detailed Implementation

[0034] The embodiments of this application are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application. In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "connected" or "linked" should be interpreted broadly, for example, it can be an electrical connection or the ability to communicate with each other; it can be a direct connection or an indirect connection through an intermediate medium; it can be the internal connection of two elements or the interaction relationship between two elements. It should be understood that when an element is said to be "coupled to" another element, an intermediate element exists. For those skilled in the art, the specific meaning of the above terms in this application can be understood according to the specific circumstances.

[0035] The following disclosure provides different implementations or examples for carrying out different structures of this application. To simplify the disclosure, specific examples of components and arrangements are described below. Of course, these are merely examples and are not intended to limit the scope of this application. Furthermore, reference numerals and / or letters may be repeated in different examples; such repetition is for simplification and clarity and does not in itself indicate a relationship between the various implementations and / or arrangements discussed.

[0036] When a load is connected to a circuit, a virtual voltage is created. The circuit system cannot determine whether the load is properly connected, which may lead to false alarms or unsafe circuit structures. To solve the technical problem of virtual voltage created when a load is connected to a circuit, existing technologies use mechanical structures or complex circuits to detect whether the load is connected, while also using additional circuit structures to eliminate virtual voltage. However, this approach is impractical, too costly, and has poor reliability.

[0037] Based on this, the present invention provides a load detection circuit and electronic device, which determines whether a load is connected by detecting the connection signal generated when a load is connected, and at the same time eliminates virtual voltage with the structure of the load detection circuit itself, thereby improving circuit safety.

[0038] According to a first aspect of the present invention, a load detection circuit is provided.

[0039] Figure 1 This is a schematic diagram of the load detection circuit according to the first embodiment of the present invention.

[0040] like Figure 1 As shown, the load detection circuit includes a first switch sub-circuit 100, a second switch sub-circuit 200, and a control sub-circuit 300.

[0041] Specifically, the control sub-circuit 300 is connected to the first switch sub-circuit 100, the first switch sub-circuit 100 is connected to the second switch sub-circuit 200, and the second switch sub-circuit 200 is used to connect the load R0.

[0042] In actual use, the control sub-circuit 300 is used to control the switching state of the first switch sub-circuit 100, so that the switching state of the second switch sub-circuit 200 follows the switching state of the first switch sub-circuit 100. When the second switch sub-circuit 200 receives the access signal of the load R0, the first switch sub-circuit 100 controls the second switch sub-circuit 200 to be turned off.

[0043] The load detection circuit has two states: on and sleep. In the on state, the control subcircuit 300 outputs a control signal to the first switch subcircuit 100, adjusting its switching state to enable the second switch subcircuit 200 to conduct. When a load R0 is connected, it receives a driving voltage. The second switch subcircuit 200, which is in the conducting state, receives this driving voltage, thus confirming the connection of load R0; the driving voltage received by load R0 serves as its connection signal. After receiving the connection signal from the second switch subcircuit 200, the control subcircuit 300 determines that a load R0 is currently connected. It then outputs a control signal to the first switch subcircuit 100, switching its state from one state to another, while the second switch subcircuit 200 switches from the conducting state to the cutoff state. The load detection circuit then enters the sleep state, thereby eliminating the dummy voltage.

[0044] For example, when the first switch sub-circuit 100 switches its state, the second switch sub-circuit 200 switches its state accordingly. This can be because the second switch sub-circuit 200 is also turned on when the first switch sub-circuit 100 is turned off, or the second switch sub-circuit 200 is also turned off when the first switch sub-circuit 100 is turned off. When no load R0 is connected, the control sub-circuit 300 controls the first switch sub-circuit 100 to remain on, thus turning on the second switch sub-circuit 200. When the load R0 is connected, the control sub-circuit 300 receives the connection signal of the load R0 through the second switch sub-circuit 200, and then controls the first switch sub-circuit 100 to turn off, thus turning off the second switch sub-circuit 200. The load detection circuit enters a sleep state, thereby eliminating the virtual voltage formed by the connection of the load R0.

[0045] It should be noted that the load R0 can be powered by the control sub-circuit 300 or by an external drive circuit. In this embodiment, the control sub-circuit 300 powers the load R0. When the load R0 is connected, it is connected to both the control sub-circuit 300 and the second switch sub-circuit 200. The control sub-circuit 300 outputs a drive voltage to power the load R0. The second switch sub-circuit 200 receives the connection signal of the load R0 by directly or indirectly connecting to it. For example, the second switch sub-circuit 200 can be directly connected to the end of the load R0 furthest from the control sub-circuit 300, and this end is also connected to ground. The second switch sub-circuit 200 collects the voltage signal at the end of the load R0 furthest from the control sub-circuit 300, using this as the connection signal of the load R0.

[0046] Based on the above-disclosed technical solution, the control sub-circuit 300 triggers the second switch sub-circuit 200 to conduct through the first switch sub-circuit 100, so that the entire load detection circuit is in the open state. When the conducting second switch sub-circuit 200 detects the connection of load R0, it transmits the connection signal to the control sub-circuit 300. The control sub-circuit 300, which receives the connection signal, triggers the second switch sub-circuit 200 to turn off through the first switch sub-circuit 100, so that the entire load detection circuit is in the sleep state. The virtual voltage formed by the connection of load R0 is connected to the ground, thus eliminating the virtual voltage formed by the connection of load R0.

[0047] See again Figure 1 In this embodiment, the control sub-circuit 300 is provided with a detection terminal in, an on / off terminal en, and a driving terminal out.

[0048] Among them, the drive terminal out is used to connect to the load R0, the control sub-circuit 300 outputs voltage to the load R0 through the drive terminal out, the on / off terminal en is connected to the control terminal of the first switch sub-circuit 100, the first terminal of the first switch sub-circuit 100 is connected to the control terminal of the second switch sub-circuit 200, the second terminal of the first switch sub-circuit 100 is connected to the potential reference point, the first terminal of the second switch sub-circuit 200 is connected to the detection terminal in, and the second terminal of the second switch sub-circuit 200 is used to connect to the load R0.

[0049] One end of the load R0 is connected to ground, and the other end of the load R0 is connected to the drive terminal out of the control sub-circuit 300. The second switch sub-circuit 200 is connected to the end of the load R0 furthest from the control sub-circuit 300. The control sub-circuit 300 outputs a drive voltage to the load R0 through its drive terminal out. The second switch sub-circuit 200, which is in the on state, collects the voltage signal of the load R0 as the load R0 access signal and sends it to the detection terminal in of the control sub-circuit 300. The control sub-circuit 300 determines whether the load R0 is connected by the voltage change at the detection terminal in, and when it determines that the load R0 is connected, it outputs an on / off control signal through the on / off terminal en to adjust the switching state of the first switch sub-circuit 100, thereby turning off the second switch sub-circuit 200 and putting the load detection circuit into a sleep state.

[0050] It should be noted that a potential reference point (i.e., a zero potential point) is a point in a circuit where the potential is defined as zero. In electronic circuits, a specific common line or chassis is often chosen as the potential reference point. In this embodiment, the potential reference point is the reference ground, and connecting to the potential reference point is equivalent to grounding, and the same applies below.

[0051] Figure 2 This is a schematic diagram of the load detection circuit according to the second embodiment of the present invention.

[0052] Combination Figure 1 and Figure 2 In some embodiments, the first switch sub-circuit 100 includes a first resistor R1, a second resistor R2, a first diode D1, and a first switching device Q1.

[0053] Specifically, one end of the first resistor R1 is connected to the control terminal of the first switching device Q1, and the other end of the first resistor R1 is connected to the on / off terminal en; one end of the second resistor R2 is connected to the control terminal of the first switching device Q1, and the other end of the second resistor R2 is connected to the second terminal of the first switching device Q1 and the potential reference point; the anode of the first diode D1 is connected to the control terminal of the second switching sub-circuit 200, and the cathode of the first diode D1 is connected to the first terminal of the first switching sub-circuit 100.

[0054] The first resistor R1 serves as a voltage divider resistor to protect the first switching device Q1.

[0055] The second resistor R2 serves as a bias resistor to enhance the driving capability of the first switching device Q1.

[0056] The first diode D1 serves as a rectifier.

[0057] The control terminal of the first switching device Q1 receives the on / off control signal from the on / off terminal en through the first resistor R1. When the on / off control signal triggers the first switching device Q1 to conduct, it connects the control terminal of the second switching sub-circuit 200 and the potential reference point, pulling down the level of the control terminal of the second switching sub-circuit 200. Conversely, when the on / off control signal triggers the first switching device Q1 to turn off, the control terminal of the second switching sub-circuit 200 and the potential reference point fail to connect, and the level state of the control terminal of the second switching sub-circuit 200 remains unchanged.

[0058] In some embodiments, the second switching sub-circuit 200 includes a third resistor R3, a fourth resistor R4, a first Zener diode ZD1, and a second switching device Q2.

[0059] One end of the third resistor R3 is connected to the control terminal of the second switching device Q2, and the other end of the third resistor R3 is connected to the first terminal of the first switching sub-circuit 100. One end of the fourth resistor R4 is connected to the control terminal of the second switching device Q2, and the other end of the fourth resistor R4 is connected to the second terminal of the second switching device Q2. The anode of the first Zener diode ZD1 is connected to the detection terminal in, and the cathode of the first Zener diode ZD1 is connected to the first terminal of the second switching device Q2. The second terminal of the second switching device Q2 is used to connect to the load R0.

[0060] The third resistor R3 acts as a voltage divider resistor to protect the second switching device Q2.

[0061] The fourth resistor R4 serves as a bias resistor to enhance the driving capability of the second switching device Q2.

[0062] The first Zener diode ZD1 is used to stabilize the voltage at the first terminal of the second switching device Q2.

[0063] The second switching device Q2 is connected to the first terminal of the first switching sub-circuit 100 through its control terminal. When the first switching sub-circuit 100 is turned on, it pulls down the level of the control terminal of the second switching device Q2. When the first switching sub-circuit 100 is turned off, the level of the control terminal of the second switching device Q2 is maintained. The second switching device Q2 can be turned on when its control terminal level is pulled down and turned off when its control terminal level is maintained, or it can be turned off when its control terminal level is pulled down and turned on when its control terminal level is maintained.

[0064] In some embodiments, the first switching device Q1 is an NPN transistor, and the second switching device Q2 is a PNP transistor. For the first switching device Q1 and the second switching device Q2, the first terminal of the first switching device Q1 and the second switching device Q2 represents the collector, the second terminal of the first switching device Q1 and the second switching device Q2 represents the emitter, and the control terminal of the first switching device Q1 and the second switching device Q2 represents the base.

[0065] In other embodiments, the first switching device Q1 is an N-type field-effect transistor (FET), and the second switching device Q2 is a P-type FET. For the first switching device Q1 and the second switching device Q2, the first terminal of the first switching device Q1 and the second switching device Q2 represents the drain, the second terminal of the first switching device Q1 and the second switching device Q2 represents the source, and the control terminal of the first switching device Q1 and the second switching device Q2 represents the gate.

[0066] In some embodiments, the third switching device Q3 is selected as an NPN transistor or an N-type field-effect transistor. When an NPN transistor is selected, the first terminal of the third switching device Q3 represents the collector, the second terminal of the third switching device Q3 represents the emitter, and the control terminal of the third switching device Q3 represents the base; when an N-type field-effect transistor is selected, the first terminal represents the drain, the second terminal represents the source, and the control terminal represents the gate.

[0067] Figure 3 This is a schematic diagram of the load detection circuit according to the third embodiment of the present invention.

[0068] Combination Figure 1 and Figure 3 In some embodiments, the load detection circuit further includes a third switch sub-circuit 400.

[0069] Specifically, the first terminal of the second switch sub-circuit 200 is connected to the control terminal of the third switch sub-circuit 400, the first terminal of the third switch sub-circuit 400 is connected to the DC voltage and control sub-circuit 300, and the second terminal of the third switch sub-circuit 400 is connected to the potential reference point.

[0070] In this embodiment, the second switch sub-circuit 200 transmits the load R0 access signal to the control sub-circuit 300 through the third switch sub-circuit 400.

[0071] The second switch sub-circuit 200, in the ON state, acquires the voltage signal of the load R0, uses the acquired voltage signal as the connection signal for the load R0, and sends it to the control terminal of the third switch sub-circuit 400, triggering a switch state change of the third switch sub-circuit 400. When the switch state of the third switch sub-circuit 400 changes, the control sub-circuit 300 monitors the level change at the port of the third switch sub-circuit 400. If the third switch sub-circuit 400 switches from OFF to ON, the level at the port of the control sub-circuit 300 is pulled low; conversely, if the third switch sub-circuit 400 switches from ON to OFF, the level at the port of the control sub-circuit 300 is raised. The control sub-circuit 300 determines whether to connect the load R0 based on the level change at this port.

[0072] More specifically, the third switch sub-circuit 400 includes a fifth resistor R5, a sixth resistor R6, a seventh resistor R7, a second diode D2, and a third switch device Q3.

[0073] The anode of the second diode D2 is connected to the first terminal of the second switch sub-circuit 200, and the cathode of the second diode D2 is connected to one end of the fifth resistor R5. The other end of the fifth resistor R5 is connected to the control terminal of the third switch device Q3. One end of the sixth resistor R6 is connected to the control terminal of the third switch device Q3, and the other end of the sixth resistor R6 is connected to the second terminal of the third switch device Q3 and the potential reference point. One end of the seventh resistor R7 is connected to the DC voltage, and the other end of the seventh resistor R7 is connected to the first terminal of the third switch device Q3 and the control sub-circuit 300.

[0074] The fifth resistor R5 and the seventh resistor R7 are used as voltage divider resistors to protect the third switching device Q3.

[0075] The sixth resistor, R6, serves as a bias resistor to enhance the driving capability of the third switching device, Q3.

[0076] The second diode, D2, serves as a rectifier.

[0077] The third switching device Q3 is cut off when the load detection circuit is in the ON state.

[0078] When the second switching sub-circuit 200 is in the ON state, it acquires the voltage signal of the load R0 as the input signal for the load R0. The second switching sub-circuit 200 sends the acquired voltage signal to the control terminal of the third switching device Q3, and the third switching device Q3 is turned on. Based on this, the port of the control sub-circuit 300 connected to the third switching device Q3 is connected to the voltage reference point, and the port level of the control sub-circuit 300 connected to the third switching device Q3 is pulled low. Based on this, the control sub-circuit 300 determines that the load R0 is connected, and then outputs a control signal to the first switching sub-circuit 100, causing the second switching sub-circuit 200 to be turned off, and the load detection circuit enters a sleep state.

[0079] The load detection circuit provided by the present invention triggers the second switch sub-circuit 200 to conduct through the first switch sub-circuit 100, so that the entire load detection circuit is in the on state. When the conducting second switch sub-circuit 200 detects the connection of load R0, it transmits the connection signal to the control sub-circuit 300. The control sub-circuit 300, which receives the connection signal, triggers the second switch sub-circuit 200 to turn off through the first switch sub-circuit 100, so that the entire load detection circuit is in the sleep state. The virtual voltage formed by the connection of load R0 is connected to the ground, thus eliminating the virtual voltage formed by the connection of load R0.

[0080] According to a second aspect of the present invention, an electronic device is proposed.

[0081] The electronic device includes the load detection circuit described above. The specific structure of the load detection circuit is as described in the above embodiments. Since the electronic device provided in this embodiment adopts all the technical solutions of all the above embodiments, it has at least all the beneficial effects brought about by the technical solutions of the above embodiments, which will not be described in detail here.

[0082] The electronic device provided by the present invention triggers the second switch sub-circuit to conduct through the first switch sub-circuit, so that the entire load detection circuit is in the open state. When the conducted second switch sub-circuit detects the connection of the load, it transmits the connection signal to the control sub-circuit. The control sub-circuit that receives the connection signal triggers the second switch sub-circuit to turn off through the first switch sub-circuit, so that the entire load detection circuit is in the sleep state. The virtual voltage formed by the connected load is connected to the ground, thus eliminating the virtual voltage formed by the connection of the load.

[0083] In this invention, unless otherwise expressly specified and limited, the terms "first," "second," "third," "fourth," etc. (if applicable) 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 used can be interchanged where appropriate so that the embodiments of this application 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 a 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.

[0084] In this invention, unless otherwise explicitly specified and limited, "at least one" means one or more, and "more" means two or more. "And / or" describes the relationship between related objects, indicating that three relationships can exist. For example, "A and / or B" can represent three cases: only A exists, only B exists, and both A and B exist simultaneously, where A and B can be singular or plural. The character " / " generally indicates that the preceding and following related objects are in an "or" relationship. "At least one of the following" or similar expressions refer to any combination of these items, including any combination of single or plural items. For example, at least one of a, b, or c can represent: a, b, c, "a and b", "a and c", "b and c", or "a and b and c", where a, b, and c can be single or multiple.

[0085] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0086] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A load detection circuit, characterized in that, It includes a first switch sub-circuit (100), a second switch sub-circuit (200), and a control sub-circuit (300); The control sub-circuit (300) is connected to the first switch sub-circuit (100), the first switch sub-circuit (100) is connected to the second switch sub-circuit (200), and the second switch sub-circuit (200) is used to connect the load (R0); one end of the load (R0) is connected to ground; The control sub-circuit (300) is used to control the switching state of the first switch sub-circuit (100), so that the switching state of the second switch sub-circuit (200) follows the switching state of the first switch sub-circuit (100) and when the second switch sub-circuit (200) receives the access signal of the load (R0), the first switch sub-circuit (100) controls the second switch sub-circuit (200) to be turned off. The load detection circuit has an on state and a sleep state. In the on state, the control sub-circuit (300) controls the first switch sub-circuit (100) to be turned on, so that the second switch sub-circuit (200) is turned on. In the sleep state, the control sub-circuit (300) controls the first switch sub-circuit (100) to be turned off, so that the second switch sub-circuit (200) is turned off, and the virtual voltage formed by the load (R0) is released through the ground. The load detection circuit further includes a third switch sub-circuit (400); the first end of the second switch sub-circuit (200) is connected to the control end of the third switch sub-circuit (400), the first end of the third switch sub-circuit (400) is connected to the DC voltage and the control sub-circuit (300), and the second end of the third switch sub-circuit (400) is connected to the potential reference point; The third switch sub-circuit (400) includes a fifth resistor (R5), a sixth resistor (R6), a seventh resistor (R7), a second diode (D2), and a third switch device (Q3). The anode of the second diode (D2) is connected to the first terminal of the second switch sub-circuit (200), the cathode of the second diode (D2) is connected to one end of the fifth resistor (R5), and the other end of the fifth resistor (R5) is connected to the control terminal of the third switch device (Q3). One end of the sixth resistor (R6) is connected to the control terminal of the third switching device (Q3), and the other end of the sixth resistor (R6) is connected to the second terminal of the third switching device (Q3) and the potential reference point; One end of the seventh resistor (R7) is connected to the DC voltage, and the other end of the seventh resistor (R7) is connected to the first terminal of the third switching device (Q3) and the control sub-circuit (300).

2. The load detection circuit according to claim 1, characterized in that, The control sub-circuit (300) is provided with a detection terminal (in), an on / off terminal (en), and a drive terminal (out). The drive terminal (out) is used to connect to the load (R0), and the control sub-circuit (300) outputs voltage to the load (R0) through the drive terminal (out). The on / off terminal (en) is connected to the control terminal of the first switch sub-circuit (100), the first terminal of the first switch sub-circuit (100) is connected to the control terminal of the second switch sub-circuit (200), the second terminal of the first switch sub-circuit (100) is connected to the potential reference point, the first terminal of the second switch sub-circuit (200) is connected to the detection terminal (in), and the second terminal of the second switch sub-circuit (200) is used to connect to the load (R0).

3. The load detection circuit according to claim 2, characterized in that, The first switch sub-circuit (100) includes a first resistor (R1), a second resistor (R2), a first diode (D1), and a first switching device (Q1). One end of the first resistor (R1) is connected to the control terminal of the first switching device (Q1), and the other end of the first resistor (R1) is connected to the on / off terminal (en). One end of the second resistor (R2) is connected to the control terminal of the first switching device (Q1), and the other end of the second resistor (R2) is connected to the second terminal of the first switching device (Q1) and the potential reference point; The anode of the first diode (D1) is connected to the control terminal of the second switch sub-circuit (200), and the cathode of the first diode (D1) is connected to the first terminal of the first switch sub-circuit (100).

4. The load detection circuit according to claim 2, characterized in that, The second switching sub-circuit (200) includes a third resistor (R3), a fourth resistor (R4), a first Zener diode (ZD1), and a second switching device (Q2); One end of the third resistor (R3) is connected to the control terminal of the second switching device (Q2), and the other end of the third resistor (R3) is connected to the first terminal of the first switching sub-circuit (100). One end of the fourth resistor (R4) is connected to the control terminal of the second switching device (Q2), and the other end of the fourth resistor (R4) is connected to the second terminal of the second switching device (Q2). The anode of the first Zener diode (ZD1) is connected to the detection terminal (in), and the cathode of the first Zener diode (ZD1) is connected to the first terminal of the second switching device (Q2). The second terminal of the second switching device (Q2) is used to connect the load (R0).

5. The load detection circuit according to claim 1, characterized in that, The third switching device (Q3) is an NPN transistor or an N-type field-effect transistor.

6. The load detection circuit according to claim 3, characterized in that, The first switching device (Q1) is an NPN transistor or an N-type field-effect transistor.

7. The load detection circuit according to claim 4, characterized in that, The second switching device (Q2) is a P-type field-effect transistor or a PNP-type transistor.

8. An electronic device, characterized in that, Includes the load detection circuit as described in any one of claims 1 to 7.

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