Input detection control circuit for direct-current power supply and intelligent equipment

Abstract

The invention provides an input detection control circuit for a direct current power supply and intelligent equipment, and the circuit comprises a voltage clamping module which is used for limiting the input voltage of a direct current power supply injection front-end circuit; the current sampling module is electrically connected with the voltage clamping module and is used for monitoring the input current of the direct-current power supply injection front-end circuit; the voltage switch module is electrically connected with the current sampling module and is used for controlling the voltage output of the front-end circuit according to the output voltage of the current sampling module and the reference voltage; the master control and load circuit is electrically connected with the voltage switch module; and the auxiliary control unit is electrically connected with the main control and load circuit, the current sampling module and the voltage switch module respectively, and is used for adjusting the reference voltage according to the load in the main control and load circuit. The circuit solves the problem that in the prior art, a direct-current input controller circuit lacks detection on input voltage and load current, and the circuit is prone to being damaged due to abnormal load.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of power electronics, and in particular to an input detection control circuit for a direct current power supply and a smart device. BACKGROUND

[0002] In the prior art, for the controller hardware of a direct current power supply input, an external direct current power supply is usually connected to an internal circuit in a direct connection manner. Although the above circuit is easy to implement, it has obvious limitations in actual application.

[0003] It can be understood that the input voltage fluctuation of an external direct current power supply often exceeds the design range of the controller hardware. In particular, in the fields of industrial control, automation systems and embedded communication, the instability and suddenness of the power supply are very common. The suddenness of the input may cause damage to the front-end circuit, and even affect the normal operation of the entire system. On the other hand, the load of the circuit device in the above fields also often changes, which may also cause current overload in the circuit and damage.

[0004] It can be seen that the direct current input controller hardware in the prior art lacks voltage and current self-checking and deployment, and lacks necessary protection measures, and is easy to be damaged due to input abnormalities and load abnormalities. SUMMARY

[0005] The main purpose of the present application is to provide an input detection control circuit for a direct current power supply and a smart device, so as to at least solve the problem that the controller circuit of the direct current input in the prior art lacks detection of the input voltage and the load current, and is easy to be damaged due to load abnormalities.

[0006] In order to achieve the above purpose, according to one aspect of the present application, an input detection control circuit for a direct current power supply is provided, comprising: a voltage clamping module for limiting the input voltage of a direct current power supply injected into a front-end circuit; a current sampling module electrically connected with the voltage clamping module, for monitoring the input current of the direct current power supply injected into the front-end circuit; a voltage switch module electrically connected with the current sampling module, for controlling the voltage output of the front-end circuit according to the output voltage of the current sampling module and a reference voltage; a main control and load circuit electrically connected with the voltage switch module; an auxiliary control unit electrically connected with the main control and load circuit, the current sampling module and the voltage switch module respectively, for adjusting the reference voltage according to the load in the main control and load circuit.

[0007] Optionally, the voltage clamping module comprises a voltage dividing resistor group connected to the gate of the first MOS tube for adjusting the input voltage of the first MOS tube; the source of the first MOS tube is connected to the input end of the DC power supply, and the drain of the first MOS tube is connected to the input end of the current sampling module.

[0008] Optionally, the current sampling module comprises a sampling resistor connected in series between the first MOS tube and the second MOS tube; a differential amplifier, the input end of which is connected to both ends of the sampling resistor, and the output end of which is connected to the input end of the voltage switch module and the input end of the auxiliary control unit.

[0009] Optionally, the voltage switch module comprises a comparator, the same direction end of which is connected to the output end of the differential amplifier, and the reverse end of which is connected to the output end of the auxiliary control unit for receiving the reference voltage; the second MOS tube, the source of which is connected to the drain of the first MOS tube, the drain of which is connected to the power input end of the master and load circuit, and the gate of which is connected to the output end of the comparator.

[0010] Optionally, the auxiliary control unit comprises a microcontroller, an ADC and a DAC, the microcontroller receives the current signal output by the current sampling module and the load demand signal output by the master and load circuit through the ADC, and outputs the reference voltage to the voltage switch module through the DAC.

[0011] Optionally, the auxiliary control unit further comprises a communication module for realizing the communication between the auxiliary control unit and the master and load circuit.

[0012] Optionally, the sampling resistor is a sliding rheostat.

[0013] Optionally, the driving circuit of the first MOS tube and the second MOS tube comprises a buffer stage for smoothing the input voltage of the first MOS tube and the second MOS tube.

[0014] Optionally, the voltage dividing resistor group comprises a first resistor and a second resistor connected in series, and a tap between the first resistor and the second resistor is connected to the gate of the first MOS tube.

[0015] In another aspect of the present application, an intelligent device is provided, which comprises any one of the input detection control circuits for DC power supply.

[0016] By applying the technical solution of the present application, the circuit solution of the present application effectively prevents circuit damage caused by abnormal input voltage or overcurrent of load current through the synergistic effect of voltage clamping, current sampling and voltage switching, and improves the stability and safety of the system. The introduction of the auxiliary control unit realizes dynamic adjustment of the reference voltage, enhances the adaptability of the circuit to different loads, and makes the circuit solution have significant advantages in application scenarios such as industrial control, embedded systems and automation equipment, which can effectively improve the operation efficiency and reliability of the equipment, and solve the problem that the existing controller circuit with direct current input lacks detection of input voltage and load current, and is easy to damage the circuit due to abnormal load. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 A structural schematic diagram of an input detection control circuit for a direct current power supply is shown according to an embodiment of the present application;

[0018] Figure 2 A circuit diagram of an input detection control circuit for a direct current power supply is shown according to an embodiment of the present application. DETAILED DESCRIPTION

[0019] It should be noted that the embodiments and features in the present application can be combined with each other without conflict. The technical solutions in the embodiments of the present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0020] In order 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 described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present application, not all. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor should be within the scope of protection of the present application.

[0021] It should be noted that the terms "first", "second" and the like in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and do not necessarily describe a specific order or sequence. It should be understood that the data thus used can be interchanged under appropriate circumstances, so that the embodiments of the present application described herein can be implemented. In addition, the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusion, for example, a process, method, system, product or device including a series of steps or units does not necessarily limit to those steps or units clearly listed, but can include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0022] As introduced in the background, the prior art DC input controller hardware lacks voltage, current self-checking and adjustment, lacks necessary protection measures, and is prone to circuit damage due to input abnormalities and load abnormalities. To solve the problem of lack of detection of input voltage and load current in the prior art DC input controller circuit, which is prone to damage to the circuit due to load abnormalities, embodiments of the present application provide an input detection control circuit for a DC power supply and a smart device.

[0023] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application.

[0024] In an embodiment of the present application as shown in Figure 1 The input detection control circuit for a DC power supply comprises:

[0025] A voltage clamping module 20 is configured to limit the input voltage of the DC power supply to the front-end circuit.

[0026] It can be understood that the voltage clamping module 20 is directly connected to the power supply 10 (DC power supply). The voltage clamping module limits the input voltage of the DC power supply to the front-end circuit, so as to ensure that the input voltage is within a safe range and avoid damage to subsequent circuits due to excessively high voltage.

[0027] A current sampling module 30 is electrically connected to the voltage clamping module and is configured to monitor the input current of the DC power supply to the front-end circuit.

[0028] A voltage switching module 40 is electrically connected to the current sampling module and is configured to control the voltage output of the front-end circuit according to the output voltage of the current sampling module and a reference voltage.

[0029] Specifically, the current sampling module 30 and the voltage switching module 40 are linked together. The current sampling module 30 monitors the input current of the DC power supply in real time. Once it is detected that the current exceeds a preset safety threshold, the voltage switching module 40 immediately responds and controls the voltage output of the front-end circuit according to the output voltage of the sampling module and the reference voltage, thereby cutting off the voltage supply and protecting the circuit from damage caused by overcurrent.

[0030] A main control and load circuit 50 is electrically connected to the voltage switching module.

[0031] An auxiliary control unit 60 is electrically connected to the main control and load circuit, the current sampling module, and the voltage switching module, respectively, and is configured to adjust the reference voltage according to the load in the main control and load circuit.

[0032] Specifically, the auxiliary control unit dynamically adjusts the reference voltage according to the load demand in the master control and load circuit (the master control circuit and the corresponding load), realizes accurate control of the voltage switch module, ensures that the circuit can work stably under different load conditions, and effectively avoids damage to the circuit caused by abnormal load.

[0033] Through the above embodiment, the direct current power supply input detection control circuit includes a voltage clamping module, a current sampling module, a voltage switch module, and an auxiliary control unit. Through multi-stage detection and control, the stability and safety of the circuit are significantly improved, and the problem of circuit damage caused by abnormal input voltage or abnormal load of the direct current input controller hardware is solved.

[0034] In an embodiment of the present application, as shown in Figure 2 The voltage clamping module 20 includes:

[0035] The voltage clamping module 20 includes:

[0036] The source of the first MOS tube is connected to the input end of the direct current power supply, and the drain of the first MOS tube is connected to the input end of the current sampling module.

[0037] As shown in Figure 2 The voltage clamping module 20 includes a voltage divider resistor group (i.e. R1, R2) and a first MOS tube Q1.

[0038] The voltage clamping module 20 includes a voltage divider resistor group (i.e. R1, R2) and a first MOS tube Q1.

[0039] The above design realizes effective monitoring of the input voltage. Once it is detected that the input voltage exceeds the preset range, the first MOS tube Q1 will automatically close, preventing voltage from being transmitted to the subsequent circuit, thereby avoiding damage to the circuit caused by abnormal voltage. In addition, through the accurate configuration of the voltage divider resistor group, it can be ensured that the first MOS tube Q1 opens or closes in time according to the actual required voltage, thereby providing a guarantee for the safe operation of the system.

[0040] In an embodiment of the present application, as shown in Figure 2 The current sampling module 30 includes:

[0041] The current sampling module 30 includes:

[0042] A differential amplifier, an input end of the differential amplifier is connected to both ends of the sampling resistor, and an output end of the differential amplifier is connected to an input end of the voltage switch module and an input end of the auxiliary control unit.

[0043] It can be understood that, as Figure 2 shown, the current sampling module 30 block includes a sampling resistor R3 and a differential amplifier U1.

[0044] The sampling resistor R3 is connected in series between the first MOS tube Q1 and the second MOS tube Q2, and is used to detect the current passing through the first MOS tube Q1. The input end of the differential amplifier U1 is connected to both ends of the sampling resistor R3, which can convert the voltage on the sampling resistor R3 into an amplified differential signal. The output end of the differential amplifier U1 is connected to the input end of the voltage switch module 40 and the input end of the auxiliary control unit 60, which is used to transmit the detected current information to the two modules. When the current passes through, the sampling resistor R3 will generate a voltage drop proportional to it, and this voltage signal is sent to the differential amplifier U1 for amplification processing, and then input to the voltage switch module 40 for judgment.

[0045] The above design can realize real-time monitoring of the input current, and when the current exceeds the preset threshold, the auxiliary control unit 60 can timely adjust the reference voltage of the comparator, so as to control the conduction state of the second MOS tube Q2, effectively preventing the circuit from being damaged due to current overload. Through the synergistic effect of the voltage switch module 40 and the auxiliary control unit 60, the stability and safety of the circuit system when facing abnormal input voltage or load change are ensured. Of course, in other embodiments, the configuration of the sampling resistor R3 and the differential amplifier U1 can also be adjusted appropriately to adapt to different current detection needs and circuit design requirements.

[0046] In an embodiment of the present application, as Figure 2 shown, the voltage switch module 40 includes:

[0047] A comparator, a same direction end of the comparator is connected to an output end of the differential amplifier, and an opposite direction end of the comparator is connected to an output end of the auxiliary control unit, which is used to receive the reference voltage;

[0048] The second MOS tube, a source of the second MOS tube is connected to a drain of the first MOS tube, a drain of the second MOS tube is connected to a power input end of the main control and load circuit, and a gate of the second MOS tube is connected to an output end of the comparator.

[0049] It can be understood that, as Figure 2As shown, the voltage switch module 40 includes a comparator U2 and a second MOS tube Q2. The same direction end of the comparator U2 is connected to the output end of the differential amplifier U1 for receiving the current sampling signal; and the opposite direction end is connected to the output end of the auxiliary control unit 60 for receiving the reference voltage. The source of the second MOS tube Q2 is connected to the drain of the first MOS tube Q1, the drain is connected to the power input end of the master control and load circuit 50, and the gate is connected to the output end of the comparator U2. Through the comparator U2, the sampling current and the reference voltage are compared in real time. When the sampling current exceeds the set reference voltage, the comparator outputs a high level, the second MOS tube Q2 is closed, the power input is cut off, and thus the overcurrent protection of the rear-end circuit is realized. In the normal working state, the comparator U2 outputs a low level, the second MOS tube Q2 is turned on, and the normal power supply to the master control and load circuit 50 is ensured.

[0050] The above design ensures the fast response of the circuit in the overcurrent condition, effectively avoiding the hardware damage caused by overcurrent. At the same time, the auxiliary control unit 60 can dynamically adjust the reference voltage, so that the circuit can adapt to the current change under different load requirements, and the stability and reliability of the system are ensured.

[0051] In other embodiments not shown, the voltage switch module 40 can also achieve the same function through other types of switching devices and control strategies, for example, using a transistor or a relay as a switch, and through a software algorithm to control the linkage of current sampling and voltage switching, so as to achieve the purpose of protecting the circuit and adapting to the load change.

[0052] In an embodiment of the present application, the auxiliary control unit 60 includes a microcontroller, an ADC and a DAC. The microcontroller receives the current signal output by the current sampling module 30 and the load demand signal output by the master control and load circuit 50 through the ADC, and outputs the reference voltage to the voltage switch module 40 through the DAC.

[0053] The auxiliary control unit includes a microcontroller, an ADC and a DAC. The microcontroller receives the current signal from the current sampling module R3 and U1 and the load demand signal output by the master control and load circuit 50 through the ADC, and outputs the corresponding reference voltage to the voltage switch module 40 through the DAC.

[0054] The above design enables real-time conversion and processing of current signals. An ADC converts analog current samples into digital signals, facilitating precise analysis and judgment by the microcontroller. This allows for adjustment of the reference voltage to control the conduction state of the voltage switching module 40. Consequently, it not only monitors whether the input current exceeds a preset threshold in real time but also dynamically adjusts the voltage supply according to the actual load requirements, ensuring a safe and stable operating environment under any circumstances and effectively preventing circuit damage caused by overcurrent or voltage anomalies. Throughout the control process, this closed-loop feedback mechanism significantly improves the system's reliability and adaptability, making it particularly suitable for industrial control scenarios requiring frequent adjustments to load conditions.

[0055] Specifically, the auxiliary control unit 60 functions to adjust and optimize the operating parameters of the current sampling module 30 and comparator U2 in real time, ensuring accurate response to various load conditions. It collects data from the differential amplifier U1, analyzes the current status, and dynamically adjusts the comparator's reference voltage according to instructions from the main control circuit to adapt to changes in current demand from different loads. This mechanism not only enhances the system's adaptability but also ensures appropriate circuit protection under various operating environments, avoiding overcurrent risks caused by sudden load changes. The technical solution in this embodiment demonstrates a high degree of emphasis on circuit safety and a refined management strategy for input voltage and current, making it suitable for various industrial control, automation systems, and embedded communication devices requiring stable DC power input.

[0056] In alternative embodiments not shown, the auxiliary control unit may also be configured in different ways, such as directly using an analog signal processing chip to replace the microcontroller in conjunction with the ADC, or realizing remote monitoring and adjustment through a network communication module. These solutions are all aimed at optimizing the detection and control accuracy of voltage and current to adapt to more diverse application needs.

[0057] Understandably, the auxiliary control unit 60 integrates a DAC, which is responsible for converting the reference voltage into an analog signal and outputting it to the voltage switching module. This technical feature enables precise control of the voltage switching module, ensuring that the input voltage only passes when preset conditions are met, thus protecting the subsequent circuitry from abnormal voltage surges. The use of a DAC not only improves the flexibility of voltage control but also ensures the efficiency and stability of signal conversion, allowing the circuit system to dynamically adjust the voltage input according to actual needs and effectively cope with load changes under various operating conditions.

[0058] The above design is particularly suitable for industrial control, embedded systems and automation equipment applications that require precise voltage control and current detection. By optimizing the control logic of the front-end circuit, the reliability and safety of the system are significantly improved.

[0059] In other embodiments not shown, the auxiliary control unit can also optimize the circuit system through different control strategies. For example, it can use software algorithms to adjust the output of the DAC in real time to respond to more complex working environments, thereby further enhancing the adaptability and performance of the circuit.

[0060] In one embodiment of this application, the auxiliary control unit further includes:

[0061] The communication module is used to enable communication between the auxiliary control unit and the main control and load circuits.

[0062] The auxiliary control unit 60 integrates a communication module for communication between itself and the main control and load circuits 50. This design ensures that the system can dynamically adjust circuit parameters according to real-time load demands. Specifically, the communication module enables the auxiliary control unit 60 to acquire the current sampling value of the differential amplifier U1 and the reference voltage value of the comparator U2. Through communication with the main control circuit, it confirms the actual load demand and then adjusts the voltage reference value of the comparator in real time to achieve precise current regulation. This configuration allows the circuit system to respond quickly to different loads and load changes, ensuring that the voltage and current supply remains stable within a safe and efficient operating range.

[0063] In alternative embodiments not described, the communication module can be implemented in other ways, such as using wired or wireless communication protocols, to adapt to different application scenarios and requirements, further enhancing the system's flexibility and applicability. Through the coordinated control of the communication module, the entire circuit system can achieve more precise current control, ensuring safe operation and performance optimization under various operating conditions, effectively avoiding hardware damage caused by overcurrent or voltage abnormalities, and improving the system's stability and reliability.

[0064] In one embodiment of this application, the sampling resistor is a sliding rheostat.

[0065] It is understandable that the sampling resistor R3 is in the form of a sliding rheostat.

[0066] The above design allows for flexible adjustment of the input current detection range, enhancing the adaptability of the circuit system. By adjusting the resistance of the sliding rheostat, the output signal of the differential amplifier U1 can be changed, thereby affecting the trigger threshold of the comparator U2. When the input current exceeds the set threshold, the comparator U2 will output a high-level signal, causing the second MOSFET Q2 to turn off, cutting off the voltage supply to the subsequent circuit and effectively preventing circuit damage caused by current overload. Using a sliding rheostat as the sampling resistor not only simplifies the circuit design but also provides real-time monitoring and control capabilities, enabling the circuit to respond quickly to different load demands or changes in operating conditions, ensuring the safe operation of the system. In addition, the auxiliary control unit 60 can cooperate with the sliding rheostat to automatically adjust its resistance value based on feedback information from the main control circuit, realizing the dynamic setting of the overcurrent protection point. This structure enhances the accuracy and real-time performance of the circuit's overcurrent protection without requiring additional complex control logic.

[0067] In other embodiments not shown, the sampling resistor may also be a precision resistor with temperature compensation or other types of adjustable resistors to adapt to more diverse environmental conditions and further improve the reliability and stability of the circuit.

[0068] In one embodiment of this application, the driving circuit of the first MOSFET Q1 and the second MOSFET Q2 includes a buffer stage, which is used to smooth the input voltage of the first MOSFET Q1 and the second MOSFET Q2.

[0069] Understandably, the drive circuits for the first MOSFET Q1 and the second MOSFET Q2 include a buffer stage. This buffer stage smooths the input voltage of the MOSFETs, ensuring that they are not affected by instantaneous voltage fluctuations during switching, thereby improving the stability and reliability of the circuit. By introducing the buffer stage, the entire circuit system can more effectively cope with rapid changes in power supply voltage, avoiding switching delays or malfunctions of the MOSFETs caused by voltage surges, thus ensuring the safety and efficiency of the circuit during DC power input. The implementation of the buffer stage enables dynamic voltage regulation, ensuring that the MOSFETs maintain optimal switching performance under various operating conditions, reducing stress on other components in the circuit, and extending the lifespan of the entire system.

[0070] In other embodiments not shown, the buffer stage can also be implemented through different circuit designs, such as using capacitors, inductors, or additional voltage regulators, to adapt to different application requirements and improve the adaptability and flexibility of the circuit.

[0071] In one embodiment of this application, such as Figure 2As shown, the voltage divider resistor group includes a first resistor and a second resistor. The first resistor and the second resistor are connected in series, and the tap between the first resistor and the second resistor is connected to the gate of the first MOS transistor.

[0072] As can be understood, the voltage divider resistor group includes a first resistor R1 and a second resistor R2, which are connected in series. The tap formed between R1 and R2 is directly connected to the gate of the first MOSFET Q1. This configuration enables precise detection and control of the input voltage. Specifically, through the voltage divider effect of R1 and R2, a threshold voltage can be set. When the input voltage reaches this threshold, the gate voltage of Q1 rises to its turn-on voltage, causing Q1 to conduct and allowing voltage to enter subsequent circuits. Conversely, if the input voltage is too low or too high, failing to meet the preset conditions, Q1 remains in the off state, effectively isolating the voltage and preventing damage to subsequent circuits.

[0073] The above design not only simplifies the circuit structure for voltage detection and protection, but also enhances the circuit's protection capabilities and stability through the fast response characteristics of the MOSFET, ensuring safe operation of the system even under abnormal input voltage conditions. This system demonstrates significant advantages in protecting sensitive electronic components and preventing circuit failures caused by voltage fluctuations, making it particularly suitable for industrial control, automation equipment, and communication systems requiring precise voltage control and protection.

[0074] In addition to using fixed values ​​of R1 and R2 for voltage division, in other embodiments not shown, adjustable resistors or digitally programmable resistors can be used instead of voltage divider resistors to adapt to more complex and variable voltage monitoring requirements and improve the system's adaptability and control accuracy.

[0075] In another embodiment of this application, a smart device is also provided, wherein the smart device applies the above-mentioned input detection and control circuit for DC power supply to ensure the operational stability of the smart device.

[0076] In practice, the aforementioned smart devices include, but are not limited to, washing machines, televisions, and air conditioners.

[0077] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0078] It should also be noted that the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0079] As can be seen from the above description, the embodiments of this application achieve the following technical effects:

[0080] This application discloses an input detection and control circuit for DC power supplies. The circuit scheme effectively prevents circuit damage caused by abnormal input voltage or overcurrent load through the synergistic effect of voltage clamping, current sampling, and voltage switching, thus improving system stability and safety. The introduction of an auxiliary control unit enables dynamic adjustment of the reference voltage, enhancing the circuit's adaptability to different loads. This circuit scheme offers significant advantages in applications such as industrial control, embedded systems, and automation equipment, effectively improving equipment operating efficiency and reliability. It also solves the problem in existing DC input controller circuits that lack input voltage and load current detection, making them susceptible to circuit damage due to abnormal loads.

[0081] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. An input detection and control circuit for a DC power supply, characterized in that, include: Voltage clamping module, used to limit the input voltage of DC power supply injected into the front-end circuit; A current sampling module, electrically connected to the voltage clamping module, is used to monitor the input current injected into the front-end circuit by the DC power supply; A voltage switching module, electrically connected to the current sampling module, is used to control the voltage output of the front-end circuit based on the output voltage of the current sampling module and the reference voltage. The main control and load circuits are electrically connected to the voltage switch module. An auxiliary control unit is electrically connected to the main control and load circuit, the current sampling module, and the voltage switching module, respectively, and is used to adjust the reference voltage according to the load in the main control and load circuit.

2. The circuit according to claim 1, characterized in that, The voltage clamping module includes: A voltage divider resistor group is connected to the gate of the first MOSFET and is used to adjust the input voltage of the first MOSFET. The source of the first MOSFET is connected to the input terminal of the DC power supply, and the drain of the first MOSFET is connected to the input terminal of the current sampling module.

3. The circuit according to claim 1, characterized in that, The current sampling module includes: A sampling resistor, wherein the sampling resistor is connected in series between the first MOSFET and the second MOSFET; A differential amplifier, the input of which is connected to both ends of the sampling resistor, and the output of which is connected to the input of the voltage switching module and the input of the auxiliary control unit.

4. The circuit according to claim 3, characterized in that, The voltage switching module includes: A comparator, the non-inverting terminal of which is connected to the output terminal of the differential amplifier, and the inverting terminal of which is connected to the output terminal of the auxiliary control unit, is used to receive the reference voltage; The second MOSFET has its source connected to the drain of the first MOSFET, its drain connected to the power input of the main control and load circuit, and its gate connected to the output of the comparator.

5. The circuit according to claim 1, characterized in that, The auxiliary control unit includes a microcontroller, an ADC, and a DAC. The microcontroller receives the current signal output by the current sampling module and the load demand signal output by the main control and load circuits through the ADC, and outputs the reference voltage to the voltage switching module through the DAC.

6. The circuit according to claim 5, characterized in that, The auxiliary control unit also includes: A communication module is used to enable communication between the auxiliary control unit and the main control and load circuits.

7. The circuit according to claim 3, characterized in that, The sampling resistor is a sliding rheostat.

8. The circuit according to claim 3, characterized in that, The driving circuits for the first MOSFET and the second MOSFET include a buffer stage, which is used to smooth the input voltage of the first MOSFET and the second MOSFET.

9. The circuit according to claim 2, characterized in that, The voltage divider resistor group includes a first resistor and a second resistor, the first resistor and the second resistor are connected in series, and the tap between the first resistor and the second resistor is connected to the gate of the first MOS transistor.

10. A smart device, characterized in that, Includes the input detection and control circuit for a DC power supply as described in any one of claims 1 to 9.

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