Self-adaptive wireless charging receiving system and control method thereof

Abstract

The invention relates to a self-adaptive wireless charging receiving system and a control method thereof, and the system comprises a receiving coil which is used for sensing an AC electromagnetic signal transmitted by a transmitting end, a first diode which is used for half-wave rectification to convert an AC signal into a DC pulse signal, a trigger control unit, and a switch voltage reduction and identification disturbance unit. The first end of the receiving coil is connected to the anode of the first diode, and the second end is grounded; the cathode of the first diode is connected to the first end of the first resistor, and the second end of the first resistor is connected to the first end of the second capacitor; the trigger control unit comprises a third chip for generating a switch control signal; the switch voltage reduction and identification disturbance unit comprises a first switch tube used for completing voltage reduction conversion in a switch mode. And the first switching tube is periodically switched on and switched off under the control of an output signal of the third chip U3. The receiving coil is used for switching voltage reduction, and on-off disturbance is used for replacing a special protocol to identify a receiving circuit and metal foreign matters.

Description

Technical Field

[0001] This invention relates to an adaptive wireless charging receiving system and its control method, belonging to the field of wireless charging. Background Technology

[0002] Currently, wireless charging receiver circuits are mainly used in various small portable devices, such as wireless charging watches, whose convenience and waterproof features have led to widespread market acceptance. However, the power requirements of the charging receiver vary at different stages of battery charging, necessitating the transmitter to adjust the output power in real time. Existing solutions typically employ the following methods: First, the receiver sends a response command to the transmitter to provide power adjustment information, simultaneously informing the transmitter that the current state is normal charging and not that the device is being mistakenly charged by a metal object (such as an iron spoon); second, in the absence of command communication, the receiver autonomously adjusts the receiving power through a linear buck converter. However, the linear buck converter has significant drawbacks: if the transmitting power is designed to be too high, the receiver's buck circuit will suffer significant power loss, leading to overheating or even damage to the device. To avoid this, the transmitting power is usually limited to a lower level, but this results in a decrease in overall transmission efficiency and a longer charging time. While using a switching buck converter instead of a linear buck converter can improve efficiency, it requires the introduction of a larger inductive component, which is not conducive to application in miniaturized devices.

[0003] Furthermore, to achieve universality and interoperability of wireless charging systems, existing technologies mostly adopt unified communication protocols, such as the widely used Qi protocol. However, such protocols usually require certification from relevant industry associations and necessitate the additional configuration of dedicated protocol chips and related circuits in both the transmitting and receiving ends. This not only increases system cost and size but also creates certain barriers to use due to protocol licensing and membership fee requirements.

[0004] It is evident that existing wireless charging solutions face three main problems: First, protocol-based solutions require additional dedicated hardware and protocol support, leading to increased costs and size. Second, protocol-free linear buck solutions suffer from severe overheating or can only operate at low power. Third, protocol-free switching buck solutions, due to the use of inductive components, have a relatively high failure rate, increasing product return rates and impacting user satisfaction and brand reputation. Furthermore, in protocol-free operating mode, the transmitter may fail to effectively detect metallic foreign objects, continuously heating them and posing a safety hazard. Summary of the Invention

[0005] This invention provides an adaptive wireless charging receiving system and its control method, aiming to solve at least one of the technical problems existing in the prior art. To this end, this invention proposes an adaptive wireless charging receiving system and its control method, which can improve charging efficiency and safety while reducing costs.

[0006] The technical solution of the present invention relates, in one aspect, to an adaptive wireless charging receiving system, comprising: A receiving coil L1 is used to sense the AC electromagnetic signal transmitted from the transmitting end, and a first diode D1 is used for half-wave rectification to convert the AC signal into a DC pulsating signal. The first end of the receiving coil L1 is connected to the anode of the first diode D1, and the second end of the receiving coil L1 is grounded to GND. The cathode of the first diode D1 is connected to the first end of the first resistor R1, and the second end of the first resistor R1 is connected to the first end of the second capacitor C2. A trigger control unit, the trigger control unit including a third chip U3 for generating and maintaining a switch control signal based on the potential change at the first terminal of the second capacitor C2; A switching buck converter and disturbance detection unit, wherein the switching buck converter and disturbance detection unit includes a first switching transistor Q1 for performing buck conversion in a switching manner; The first switch Q1 is turned on and off under the control of the output signal of the third chip U3 to switch the load of the receiving coil L1.

[0007] Furthermore, the switching buck and disturbance identification unit also includes a second switch Q2 and a third switch Q4 for forming a drive amplifier circuit to enhance the control capability of the first switch Q1.

[0008] Furthermore, it also includes a voltage regulator unit and a power path management unit, including a voltage regulator chip U1 as a low-dropout linear regulator; the input terminal of the voltage regulator chip U1 is connected to the cathode of the first diode D1, and the output terminal of the voltage regulator chip U1 is connected to the first terminal of the fifth capacitor C5 and the first terminal of the fourth capacitor C4 and outputs the system power supply VCC.

[0009] Furthermore, the voltage regulator unit and power path management unit also include a second chip U2 for power path management and reverse protection; the common cathode of the second chip U2 is connected to the input terminal of the voltage regulator chip U1 and the cathode node of the first diode D1, the first anode of the second chip U2 is connected to the system power supply VCC, and the second anode of the second chip U2 is connected to the positive terminal of the battery or the BAT pin of the charging management chip U4.

[0010] Furthermore, the second chip U2 is a common cathode packaged dual Schottky diode.

[0011] Furthermore, the discharge pin of the third chip U3 is connected to the second end of the third resistor R7, the second end of the third resistor R7 is connected to the first end of the eighth resistor R8, the second end of the eighth resistor R8 is connected to the first end of the third capacitor C3 and the threshold pin and trigger pin of the third chip U3; the output pin of the third chip U3 is connected to the first end of the fourth resistor R4.

[0012] Furthermore, the device also includes a charging management unit, which comprises a charging management chip U4 for single-cell lithium battery charging management, and a fifth resistor R5 and a Zener diode ZD1 for overvoltage protection. The battery positive terminal BAT of the charging management chip U4 is connected to the first terminal of the ninth resistor R9, and the second terminal of the ninth resistor R9 is connected to the first terminal of the tenth resistor R10 and the programming pin of the charging management chip U4. The first terminal of the fifth resistor R5 is connected to the battery negative terminal, and the second terminal of the fifth resistor R5 is connected to the cathode of the Zener diode ZD1, with the anode of the Zener diode ZD1 grounded.

[0013] Furthermore, the switching buck and disturbance identification unit also includes a fifth switching transistor Q5 as a first auxiliary switch and protection transistor. The gate of the fifth switching transistor Q5 is connected to the control signal source CTR and the first terminal of the first resistor R11 through a sixth resistor R6. The second terminal of the first resistor R11 is connected to the source of the first switching transistor Q1. The gate of the fifth switching transistor Q5 is connected to ground through a seventh resistor R3. The drain (D) of the fifth switching transistor Q5 is connected to the base of the third switching transistor Q4. The source (S) of the fifth switching transistor Q5 is directly connected to ground.

[0014] Another aspect of the technical solution of the present invention relates to a control method for an adaptive wireless charging receiving system, applied to the adaptive wireless charging receiving system of the above embodiments; the method includes the following steps: S100: The AC electromagnetic signal from the transmitting end is sensed by the receiving coil L1 and rectified to obtain a DC pulsating voltage signal. S200: Input the DC pulsating voltage signal to the voltage regulator chip U1 for voltage regulation and output a stable system operating voltage VCC; S300: The third chip U3 of the trigger control unit monitors the potential of the DC pulsating voltage signal; when the potential rises to a first preset threshold, the third chip U3 outputs a first-level switch control signal; when the potential drops to a second preset threshold, the third chip U3 outputs a second-level switch control signal and maintains it. S400. The switch control signal is transmitted to the control terminal of the first switch tube Q1 to control the first switch tube Q1 to turn on or off accordingly, so that the receiving circuit works in the controlled switch buck mode and generates a corresponding current change in the receiving coil L1 circuit. S500: The transmitting end detects the voltage change signal caused by the current disturbance in the transmitting end drive circuit, extracts the frequency, amplitude or timing characteristics of the voltage change signal, and compares the characteristics with a preset receiving circuit disturbance characteristic threshold for judgment. When the feature meets the preset threshold range, it is determined to be a normal receiving circuit, and the transmission power output is maintained or optimized; when the feature does not meet the preset threshold range or there is no obvious feature, it is determined to be a metallic foreign object or abnormal load, and protection operations such as reducing power or stopping transmission are performed.

[0015] Furthermore, it also includes the following steps: S600 manages battery charging through charging management chip U4 and controls the conduction state of fifth switch Q5 in response to external control signal CTR or protection signal TH. Then, it controls the forced shutdown of first switch Q1 through third switch Q4 to perform overcharge protection, overheat protection or manual shutdown functions. S700. An eleventh resistor R11 is connected in series between the source of the first switch Q1 and ground to sample the loop current and determine in real time whether the current exceeds the preset threshold based on the sampling result. If the current exceeds the limit, the fifth switch Q5 is controlled to perform shutdown protection.

[0016] The beneficial effects of this invention are as follows.

[0017] The adaptive wireless charging receiving system and its control method of this invention can enable the transmitter to work at full power while avoiding the problem of linear voltage drop and heat generation. It also uses switching disturbances instead of dedicated protocols to identify receiving circuits and metal foreign objects, thereby reducing costs while improving charging efficiency and safety.

[0018] This invention utilizes the receiving coil as a switching step-down element by switching the receiving circuit on and off, thus avoiding the overheating problem of traditional linear step-down circuits and allowing the transmitting circuit to fully utilize its transmission power. Simultaneously, the disturbance signal generated by this switching operation can be identified by the transmitting end to distinguish between a normal receiving circuit and metallic foreign objects. Status feedback can be achieved without relying on external communication protocols, thereby significantly improving the overall system energy efficiency and safety while reducing costs. Furthermore, with a correspondingly designed transmitting circuit, this invention provides a more optimized and reliable solution for wireless charging systems. Attached Figure Description

[0019] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which: Figure 1 This is a circuit schematic diagram of an adaptive wireless charging receiver system according to an embodiment of the present invention. Detailed Implementation

[0020] The following will provide a clear and complete description of the concept, specific structure, and technical effects of the present invention in conjunction with the embodiments and accompanying drawings, so as to fully understand the purpose, solution, and effects of the present invention. It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other.

[0021] It should be noted that, unless otherwise specified, when a feature is referred to as "fixed" or "connected" to another feature, it can be directly fixed or connected to the other feature, or indirectly fixed or connected to the other feature. Furthermore, the descriptions of "upper," "lower," "left," "right," "top," and "bottom" used in this invention are only relative to the relative positional relationships of the various components of the invention in the accompanying drawings.

[0022] Furthermore, unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. The terminology used in this specification is for the purpose of describing particular embodiments only and not for limiting the invention. The term "and / or" as used herein includes any combination of one or more of the associated listed items.

[0023] It should be understood that although the terms first, second, third, etc., may be used in this disclosure to describe various elements, these elements should not be limited to these terms. These terms are only used to distinguish elements of the same type from one another. For example, without departing from the scope of this disclosure, a first element may also be referred to as a second element, and similarly, a second element may also be referred to as a first element.

[0024] See Figure 1 The adaptive wireless charging receiving system of the present invention includes: The system includes a receiving coil L1 for sensing AC electromagnetic signals transmitted from the transmitter, a first diode D1 for half-wave rectification to convert the AC signal into a DC pulsating signal, a trigger control unit, and a switching buck and disturbance identification unit. The first end of the receiving coil L1 is connected to the anode of the first diode D1, and the second end of the receiving coil L1 is grounded to GND. The cathode of the first diode D1 is connected to the first end of the first resistor R1, and the second end of the first resistor R1 is connected to the first end of the second capacitor C2. The trigger control unit includes a third chip U3 for generating a switching control signal. The switching buck and disturbance identification unit includes a first switching transistor Q1 for performing buck conversion in a switching manner. The first switching transistor Q1 is turned on and off under the control of the output signal of the third chip U3 to switch the load of the receiving coil L1.

[0025] This invention, through the coordinated operation of the receiving coil and the switching transistor, achieves efficient switching voltage reduction, avoids heat generation, and improves overall energy efficiency. Simultaneously, it utilizes load disturbances generated by on / off operations to reliably identify the state of the receiving circuit, providing a highly efficient, safe, and cost-optimized wireless charging solution. It should be noted that the receiving circuit of this invention turns on or off according to the subsequent charging state, eliminating the need for large-dropout linear voltage reduction switching, thus significantly improving efficiency. Furthermore, the disturbances in the receiving circuit provide a protocol-independent foreign object detection capability. In applications, auxiliary disturbances can be added—that is, additional disturbances—to ensure the timeliness of the disturbances and prevent weak disturbances caused by low power requirements in subsequent charging circuits.

[0026] Specifically, by controlling the on / off state of the first switch Q1 and the second switch Q2, the receiving coil operates in a switching buck mode, thus avoiding the overheating problem of linear buck mode and allowing the transmitting circuit to fully utilize its transmission power. Simultaneously, the current disturbance generated in the coil circuit by this on / off operation can be detected and identified by the transmitting end, thereby distinguishing between a normal receiving circuit and metallic foreign objects, achieving status feedback without relying on external communication protocols. This invention significantly improves charging efficiency and safety while reducing system cost and complexity, providing a more optimized solution for wireless charging systems.

[0027] When the switching transistors (Q1, Q2) at the receiving end are switched on and off, the equivalent load of the coil circuit changes. At the instant the transistors are turned on, the coil circuit impedance decreases, causing the energy coupled from the transmitter to the receiver to be rapidly absorbed, resulting in a corresponding change in the impedance reflected back to the transmitter. When the transistors are turned off, the circuit impedance recovers, and energy absorption decreases. This load change creates a detectable current or voltage disturbance signal in the transmitter's drive circuit.

[0028] The transmitting end can determine whether the receiving end is performing regular switching operations by detecting specific frequency, amplitude, or timing characteristics of the disturbance signal. A normal receiving circuit switches according to a predetermined pattern, generating disturbances with specific characteristics; however, metallic foreign objects, lacking active switching capabilities, typically exhibit random or irregular load changes and do not produce such characteristic signals. Therefore, the transmitting end does not need to rely on complex communication protocols; it can effectively distinguish between normal receiving circuits and metallic foreign objects simply by monitoring load disturbances, and adjust or maintain the transmission state accordingly. This achieves foreign object identification while eliminating the need for dedicated protocol chips and related circuitry, reducing system cost and size.

[0029] In some embodiments of the present invention, the receiving and rectifying unit of the present invention includes a receiving coil L1 for sensing AC electromagnetic signals transmitted from the transmitting end and a first diode D1 for half-wave rectification to convert the AC signal into a DC pulsating signal.

[0030] See Figure 1 The first terminal of the receiving coil L1 is connected to the anode of the first diode D1, and the second terminal of the receiving coil L1 is grounded (GND). The cathode of the first diode D1 is connected to the first terminal of the first resistor R1, and the second terminal of the first resistor R1 is connected to the first terminal of the second capacitor C2, the second terminal of the first capacitor C2 being grounded. Specifically, the receiving coil L1 is used to sense the AC electromagnetic signal transmitted from the transmitting end, and the first diode D1 performs half-wave rectification, converting the AC signal into a DC pulsating signal. The first capacitor C2 and the first resistor R1 form a filter network to smooth the rectified voltage and provide a stable DC input (IN) for subsequent circuits.

[0031] In some embodiments of the present invention, the voltage regulation power supply unit and power path management unit of the present invention include a voltage regulator chip U1 as a low-dropout linear regulator. See also Figure 1 The input terminal (pin 1) of the voltage regulator chip U1 is connected to the cathode of the first diode D1. The ground terminal (pin 2) of the voltage regulator chip U1 is grounded. The output terminal (pin 3) of the voltage regulator chip U1 is connected to the first terminal of the fifth capacitor C5 and the first terminal of the fourth capacitor C4, outputting the system power supply VCC. The second terminal of the fifth capacitor C5 and the second terminal of the fourth capacitor C4 are grounded. The anode of the second diode D2 is connected to the input terminal of the voltage regulator chip U1, and the cathode of the second diode D2 is connected to the first terminal of the second resistor R2, the second terminal of the second resistor R2 is grounded. Specifically, the voltage regulator chip U1 is a low-dropout linear regulator that stabilizes the input voltage at +5V, providing power for subsequent control and charging circuits. The second diode D2 and the second resistor R2 constitute an input overvoltage protection circuit to prevent damage to the voltage regulator chip U1 due to excessively high input voltage. The fourth capacitor C4 and the fifth capacitor C5 are used for output filtering to improve power supply stability.

[0032] In some specific embodiments of the present invention, the voltage regulator unit and power path management unit of the present invention further include a second chip U2 for power path management and reverse protection, see [link to relevant documentation]. Figure 1 The second chip U2 is a common-cathode packaged diode. The common cathode (pin 3) of the second chip U2 is connected to the input terminal (pin 1) of the voltage regulator chip U1 and the cathode node of the first diode D1. The first anode (pin 1) of the second chip U2 is connected to the system power supply VCC, and the second anode (pin 2) of the second chip U2 is connected to the positive terminal of the battery (BT+) or the BAT pin network of the charging management chip U4. Furthermore, the second chip U2 of the present invention can be a dual Schottky diode. Utilizing the low forward voltage drop and fast switching characteristics of the dual Schottky diode, voltage loss and switching delay in this path can be reduced, thereby improving overall efficiency.

[0033] Specifically, when the voltage at the receiving coil L1 (IN terminal) is present, current flows through the voltage regulator chip U1 to provide VCC to the system, and simultaneously charges the battery through the second anode of the second chip U2. If the power supply to the receiving coil L1 is disconnected, the battery voltage can continue to supply power to subsequent control circuits (such as the third chip U3, charging management chip U4, etc.) through the first anode of the second chip U2 (connected to VCC), preventing the system from experiencing a momentary power outage and ensuring that the battery does not discharge in reverse to the receiving coil terminal.

[0034] It is understood that the voltage regulator chip U1 of this invention stabilizes the input voltage at +5V to power the system. The second diode D2 and the second resistor R2 constitute input overvoltage protection. The second chip U2 is the core dual power path management device, realizing automatic and seamless switching and isolation between the receiving coil power supply and the battery power supply, ensuring that the system is seamlessly powered by the battery when wireless charging is interrupted, while preventing battery current backflow, improving the reliability and continuity of the system. The fourth capacitor C4 and the fifth capacitor C5 are used for output filtering.

[0035] In some embodiments of the present invention, the trigger control unit of the present invention includes a third chip U3 for generating switch control signals, see [link to relevant documentation]. Figure 1 The power supply pin (pin 8) of the third chip U3 is connected to VCC, and the ground pin (pin 1) of the third chip U3 is grounded. The first end of the third resistor R7 is connected to VCC, and the second end of the third resistor R7 is connected to the first end of the eighth resistor R8 and the discharge pin (pin 7) of the third chip U3. The second end of the eighth resistor R8 is connected to the first end of the third capacitor C3 and the threshold pin (pin 6) and trigger pin (pin 2) of the third chip U3. The output pin (pin 3) of the third chip U3 is connected to the first end of the fourth resistor R4, and the reset pin (pin 4) and control pin (pin 5) of the third chip U3 are connected to VCC and grounded through a capacitor, respectively (specific connections are not shown in the figure).

[0036] Specifically, the third chip U3 has its input connected to the first terminal of the second capacitor C2. The third chip U3 utilizes its internal voltage comparator and trigger latch mechanism to operate based on the potential at the first terminal of the second capacitor C2, which changes with the received energy. When this potential rises to a high threshold value (e.g., 2 / 3 VCC) set internally, its output flips to a low level; when this potential drops to a low threshold value (e.g., 1 / 3 VCC) set internally, its output flips to a high level and remains high, thereby triggering the control unit to output a switching signal controlled by the input potential. The first switching transistor Q1, under the control of the output signal from the third chip U3, is turned on or off, thereby switching the load state of the receiving coil L1, achieving switching voltage reduction, and generating a specific current disturbance for identification.

[0037] In some embodiments of the present invention, the charging management unit includes a charging management chip U4 for single-cell lithium battery charging management, and a fifth resistor R5 and a Zener diode ZD1 for overvoltage protection. See also Figure 1 The power supply pin (pin 4) of the charging management chip U4 is connected to VCC, and the ground pin (pin 2) of the charging management chip U4 is grounded. The battery positive terminal (BT+) BAT (pin 3) of the charging management chip U4 is connected to the first end of the ninth resistor R9, the second end of the ninth resistor R9 is connected to the first end of the tenth resistor R10 and the programming pin PROG (pin 5) of the charging management chip U4, and the second end of the tenth resistor R10 is grounded. The charging status indicator pin CHRG (pin 1) of the charging management chip U4 is grounded through the first capacitor C1. The first end of the fifth resistor R5 is connected to the battery negative terminal (BT-), and the second end of the fifth resistor R5 is connected to the cathode of the Zener diode ZD1, and the anode of the Zener diode ZD1 is grounded. Specifically, the charging management chip U4 is a single-cell lithium battery charging management chip, and the charging current is set through the ninth resistor R9 and the tenth resistor R10. The fifth resistor R5 and the Zener diode ZD1 form a battery input overvoltage protection circuit to prevent the battery from being overcharged.

[0038] In some embodiments of the present invention, the switching buck and disturbance identification unit of the present invention includes a first switching transistor Q1 for performing buck conversion in a switching manner, and a second switching transistor Q2 and a third switching transistor Q4 for forming a drive amplifier circuit to enhance the control capability of the first switching transistor Q1; wherein, the first switching transistor Q1 is turned on and off under the control of the output signal of the third chip U3 to perform load switching of the receiving coil L1.

[0039] See Figure 1 The gate (G) of the first switching transistor Q1 is connected to the second terminal of the fourth resistor R4. The drain (D) of the first switching transistor Q1 is connected to the cathode of the first diode D1 (i.e., the rectified output node). The source (S) of the first switching transistor Q1 is connected to the first terminal of the eleventh resistor R11, and the second terminal of the eleventh resistor R11 is grounded. The base of the second switching transistor Q2 is connected to the control signal through the sixth resistor R6. The emitter of the second switching transistor Q2 is grounded, and the collector of the second switching transistor Q2 is connected to the base of the third switching transistor Q4. The emitter of the third switching transistor Q4 is connected to VCC, and the collector of the third switching transistor Q4 is connected to the gate drive circuit of the first switching transistor Q1. The seventh resistor R3 is connected between the base of the second switching transistor Q2 and ground.

[0040] Specifically, the first switch Q1 is turned on and off under the control of the output signal of the third chip U3, realizing the load switching of the receiving coil L1, thereby completing the step-down conversion in a switching manner and avoiding the heat generation problem of linear regulation. The second switch Q2 and the third switch Q4 constitute a drive amplifier circuit to enhance the control capability of the first switch Q1. When Q1 switches, the current in the receiving coil is disturbed. This disturbance is detected by the transmitter through magnetic field coupling, thereby replacing the traditional communication protocol and realizing the identification and foreign object differentiation of the receiving circuit.

[0041] In some specific embodiments of the present invention, the switching step-down and disturbance identification unit of the present invention further includes a fifth switching transistor Q5, which serves as both an auxiliary switch and a protection transistor. See [link to relevant documentation]. Figure 1 The gate (G) of the fifth switch Q5 is connected to the control signal source CTR and the first terminal of the first resistor R11 through the sixth resistor R6. The second terminal of the first resistor R11 is connected to the source of the first switch Q1. The gate (G) of the fifth switch Q5 is also connected to ground (GND) through the seventh resistor R3. The drain (D) of the fifth switch Q5 is connected to the base of the third switch Q4. The source (S) of the fifth switch Q5 is directly connected to ground (GND).

[0042] Specifically, the fifth switch Q5, together with the second switch Q2 and the third switch Q4, forms a multi-stage drive circuit, improving the control speed and driving capability of the gate of the first switch Q1, ensuring its rapid and complete switching, thereby improving the switching buck efficiency and generating a clear disturbance identification signal. Simultaneously, the fifth switch Q5 responds to signals from the trigger control unit (third chip U3) or other control nodes (such as CTR, TH) to implement more complex switching timing logic, such as shutting down the main power circuit under specific conditions to provide overcurrent or overheat protection. Furthermore, the fifth switch Q5 is placed in the feedback path to adjust the strength or on / off state of the source current sampling signal of the first switch Q1 (from the first resistor R11), achieving current limiting control or enable control.

[0043] It should be noted that this invention includes an on / off receiving circuit. The first switching transistor Q1 is turned on and off by a trigger control unit, enabling the receiving circuit to operate in a switching manner. Simultaneously, the receiving coil L1 is used for switching voltage reduction. The load state of the receiving coil L1 is directly controlled by the first switching transistor Q1, achieving efficient voltage reduction conversion and avoiding continuous conduction losses in linear circuits. Furthermore, the switching voltage reduction method significantly reduces power loss and effectively reduces circuit heat generation. The transmitting circuit of this invention utilizes its full transmitting capability. Its receiving-side load is dynamically matched, ensuring the transmitting circuit is always in an optimal power transmission state. Additionally, current disturbances in the receiving coil create specific magnetic field changes. The transmitting end detects these changes to identify the receiving circuit, eliminating metallic foreign objects. Disturbance identification replaces protocol identification, thus eliminating the need for complex communication chips and protocols. This simplifies the circuit structure and effectively improves overall cost reduction and efficiency.

[0044] See Figure 1 The control method of the adaptive wireless charging receiving system of the present invention is applied to the adaptive wireless charging receiving system of the present invention embodiment, and the method includes at least the following steps: S100: The AC electromagnetic signal from the transmitting end is sensed by the receiving coil L1 and rectified to obtain a DC pulsating voltage signal. S200: Input the DC pulsating voltage signal to the voltage regulator chip U1 for voltage regulation and output a stable system operating voltage VCC; S300: The potential of the DC pulsating voltage signal is monitored by the third chip (U3) of the trigger control unit; when the potential rises to a first preset threshold, the third chip (U3) outputs a first-level switch control signal; when the potential drops to a second preset threshold, the third chip (U3) outputs a second-level switch control signal and maintains it. S400. The switch control signal is transmitted to the control terminal of the first switch (Q1) to control the first switch (Q1) to be turned on or off accordingly, so that the receiving circuit works in the controlled switch buck mode and generates a corresponding current change in the receiving coil (L1) circuit. S500: The transmitting end detects the voltage change signal caused by the current disturbance in the transmitting end drive circuit, extracts the frequency, amplitude or timing characteristics of the voltage change signal, and compares the characteristics with a preset receiving circuit disturbance characteristic threshold for judgment. When the feature meets the preset threshold range, it is determined to be a normal receiving circuit, and the transmission power output is maintained or optimized; when the feature does not meet the preset threshold range or there is no obvious feature, it is determined to be a metallic foreign object or abnormal load, and protection operations such as reducing power or stopping transmission are performed.

[0045] Furthermore, the control method of the adaptive wireless charging receiving system of the present invention further includes the following steps: S600 manages battery charging through charging management chip U4 and controls the conduction state of fifth switch Q5 in response to external control signal CTR or protection signal TH. Then, it controls the forced shutdown of first switch Q1 through third switch Q4 to perform overcharge protection, overheat protection or manual shutdown functions. S700. An eleventh resistor R11 is connected in series between the source of the first switch Q1 and ground to sample the loop current and determine in real time whether the current exceeds the preset threshold based on the sampling result. If the current exceeds the limit, the fifth switch Q5 is controlled to perform shutdown protection.

[0046] This invention significantly improves charging efficiency and safety while reducing system cost and complexity, providing a more optimized solution for wireless charging systems. By controlling the on / off state of the first and second switching transistors, the receiving coil operates in a switching buck mode, thus avoiding the overheating problem of linear buck methods and allowing the transmitting circuit to fully utilize its transmission power. Simultaneously, the current disturbance generated in the coil circuit by this on / off operation can be detected and identified by the transmitting end, thereby distinguishing between a normal receiving circuit and metallic foreign objects, achieving status feedback without relying on external communication protocols.

[0047] Specifically, in this invention, the first switch Q1 and the second switch Q2 are connected in parallel between the output terminal of the receiving coil L1 and ground. When the control signal causes Q1 and Q2 to be turned on alternately or synchronously, the induced current in the receiving coil L1 can be quickly discharged to ground through the switch, thereby pulling down the voltage across the receiving coil L1. When the switch is turned off, the voltage across the coil is restored. By adjusting the duty cycle of the switch, the average voltage obtained by the rectifier and filter circuit at the rear of the coil can be effectively adjusted, thereby realizing the switching voltage reduction function based on the coil itself.

[0048] Compared to traditional linear buck converters, this method uses a switching transistor that operates in a low-resistance state when on and a high-resistance state when off. Its power consumption is significantly lower than that of linear regulators that always operate in the linear region, thus fundamentally avoiding the heat generation problem caused by excessive power consumption. Furthermore, due to its high efficiency, this buck converter allows the transmitter to operate continuously at higher power without needing to deliberately reduce transmission power to limit heat generation, thereby fully utilizing the power transmission capability of the transmitting circuit.

[0049] The above description is merely a preferred embodiment of the present invention. The present invention is not limited to the above-described embodiments. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of this disclosure, as long as they achieve the same technical effects, should be included within the scope of protection of this disclosure and fall under the protection scope of the present invention. Within the protection scope of the present invention, the technical solutions and / or implementation methods can have various modifications and variations.

Claims

1. An adaptive wireless charging receiver system, characterized in that, include: A receiving coil L1 is used to sense the AC electromagnetic signal transmitted from the transmitting end, and a first diode D1 is used for half-wave rectification to convert the AC signal into a DC pulsating signal. The first end of the receiving coil L1 is connected to the anode of the first diode D1, and the second end of the receiving coil L1 is grounded to GND. The cathode of the first diode D1 is connected to the first end of the first resistor R1, and the second end of the first resistor R1 is connected to the first end of the second capacitor C2. A trigger control unit, the trigger control unit including a third chip U3 for generating and maintaining a switch control signal based on the potential change at the first terminal of the second capacitor C2; A switching buck converter and disturbance detection unit, wherein the switching buck converter and disturbance detection unit includes a first switching transistor Q1 for performing buck conversion in a switching manner; The first switch Q1 is turned on and off under the control of the output signal of the third chip U3 to switch the load of the receiving coil L1.

2. The adaptive wireless charging receiving system according to claim 1, characterized in that, The switching buck and disturbance identification unit also includes a second switch Q2 and a third switch Q4 for forming a drive amplifier circuit to enhance the control capability of the first switch Q1.

3. The adaptive wireless charging receiving system according to claim 1, characterized in that, It also includes a voltage regulator unit and a power path management unit, including a voltage regulator chip U1 as a low dropout linear regulator; the input terminal of the voltage regulator chip U1 is connected to the cathode of the first diode D1, and the output terminal of the voltage regulator chip U1 is connected to the first terminal of the fifth capacitor C5 and the first terminal of the fourth capacitor C4 and outputs the system power supply VCC.

4. The adaptive wireless charging receiving system according to claim 1, characterized in that, The voltage regulator unit and power path management unit also include a second chip U2 for power path management and reverse protection; the common cathode of the second chip U2 is connected to the input terminal of the voltage regulator chip U1 and the cathode node of the first diode D1, the first anode of the second chip U2 is connected to the system power supply VCC, and the second anode of the second chip U2 is connected to the positive terminal of the battery or the BAT pin of the charging management chip U4.

5. The adaptive wireless charging receiving system according to claim 4, characterized in that, The second chip U2 is a common cathode packaged dual Schottky diode.

6. The adaptive wireless charging receiving system according to claim 1, characterized in that, The discharge pin of the third chip U3 is connected to the second end of the third resistor R7, the second end of the third resistor R7 is connected to the first end of the eighth resistor R8, the second end of the eighth resistor R8 is connected to the first end of the third capacitor C3 and the threshold pin and trigger pin of the third chip U3; the output pin of the third chip U3 is connected to the first end of the fourth resistor R4.

7. The adaptive wireless charging receiving system according to claim 1, characterized in that, The device also includes a charging management unit, which comprises a charging management chip U4 for single-cell lithium battery charging management, and a fifth resistor R5 and a Zener diode ZD1 for overvoltage protection. The battery positive terminal BAT of the charging management chip U4 is connected to the first terminal of the ninth resistor R9, and the second terminal of the ninth resistor R9 is connected to the first terminal of the tenth resistor R10 and the programming pin of the charging management chip U4. The first terminal of the fifth resistor R5 is connected to the battery negative terminal, and the second terminal of the fifth resistor R5 is connected to the cathode of the Zener diode ZD1, and the anode of the Zener diode ZD1 is grounded.

8. The adaptive wireless charging receiving system according to claim 7, characterized in that, The switching step-down and disturbance identification unit also includes a fifth switching transistor Q5 as a first auxiliary switch and protection transistor. The gate of the fifth switching transistor Q5 is connected to the control signal source CTR and the first terminal of the first resistor R11 through a sixth resistor R6. The second terminal of the first resistor R11 is connected to the source of the first switching transistor Q1. The gate of the fifth switching transistor Q5 is connected to ground through a seventh resistor R3. The drain (D) of the fifth switching transistor Q5 is connected to the base of the third switching transistor Q4. The source (S) of the fifth switching transistor Q5 is directly connected to ground.

9. A control method for an adaptive wireless charging receiving system, applied to the control system of the adaptive wireless charging receiving system according to any one of claims 1 to 8; the method includes the following steps: S100: The AC electromagnetic signal from the transmitting end is sensed by the receiving coil L1 and rectified to obtain a DC pulsating voltage signal. S200: Input the DC pulsating voltage signal to the voltage regulator chip U1 for voltage regulation and output a stable system operating voltage VCC; S300: The third chip U3 of the trigger control unit monitors the potential of the DC pulsating voltage signal; when the potential rises to a first preset threshold, the third chip U3 outputs a first-level switching control signal. When the potential drops to the second preset threshold, the third chip U3 outputs a second-level switching control signal and maintains it. S400. The switch control signal is transmitted to the control terminal of the first switch tube Q1 to control the first switch tube Q1 to turn on or off accordingly, so that the receiving circuit works in the controlled switch buck mode and generates a corresponding current change in the receiving coil L1 circuit. S500: The transmitting end detects the voltage change signal caused by the current disturbance in the transmitting end drive circuit, extracts the frequency, amplitude or timing characteristics of the voltage change signal, and compares the characteristics with a preset receiving circuit disturbance characteristic threshold for judgment. When the feature meets the preset threshold range, it is determined to be a normal receiving circuit, and the transmission power output is maintained or optimized; when the feature does not meet the preset threshold range or there is no obvious feature, it is determined to be a metallic foreign object or abnormal load, and protection operations such as reducing power or stopping transmission are performed.

10. The method according to claim 9, characterized in that, S600 manages battery charging through charging management chip U4 and controls the conduction state of fifth switch Q5 in response to external control signal CTR or protection signal TH. Then, it controls the forced shutdown of first switch Q1 through third switch Q4 to perform overcharge protection, overheat protection or manual shutdown functions. S700. An eleventh resistor R11 is connected in series between the source of the first switch Q1 and ground to sample the loop current and determine in real time whether the current exceeds the preset threshold based on the sampling result. If the current exceeds the limit, the fifth switch Q5 is controlled to perform shutdown protection.

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