Wireless charging circuit

Abstract

The utility model belongs to the field of wireless charging, and particularly relates to a wireless charging circuit, which comprises a microcontroller, a wireless transmitting power control driving module and a wireless charging power detection module, the wireless transmitting power control driving module adopts PWM signals generated by the microcontroller to control the two bridge type driving circuits so as to achieve accurate charging and discharging control of an external transmitting coil, and the wireless charging power detection module is connected with the wireless transmitting power control driving module and the microcontroller. The circuit is simple in design and suitable for production and use in most factories. And meanwhile, a single-chip microcomputer self-programming mode is adopted for driving, so that the cost is relatively low, the design is relatively flexible, and some wireless charging places with special requirements can be met.

Description

TECHNICAL FIELD

[0001] The utility model belongs to wireless charging field, especially a wireless charging circuit. BACKGROUND

[0002] The current wireless charging is all adopted special chip to realize wireless equipment charging, generally charging equipment is standard mobile phone equipment, carries out according to standard charging agreement, and is all Huawei, apple, Xiaomi mobile phone charging.But for non-mobile phone equipment or user needs wireless charging and some custom content, standard wireless charging chip is a little bit not satisfied.

[0003] Chinese patent CN203135540U discloses a kind of wireless charging device, including radio frequency charging receiver, battery management chip, battery, data charging connector and mobile phone data charging connector, wherein battery is connected with battery management chip, battery management chip is connected with mobile phone charging connector by mobile phone data charging connector, radio frequency charging receiver is connected with battery management chip;Battery charge-discharge management chip is connected with external circuit by data charging connector, radio frequency charging receiver and the data charging connector of external circuit connection are in parallel.Radio frequency charging receiver is composed of diode and film coil, diode and film coil are in parallel.

[0004] The patent is only applicable to the wireless charging of mobile phone, and cannot be applied to non-mobile phone equipment or wireless charging equipment needing self-customization. UTILITY MODEL CONTENT

[0005] The utility model aims at overcoming the insufficient of prior art, provide a kind of wireless charging circuit, using common microcontroller (single-chip microcomputer) and self-made charging circuit to charge, can be according to oneself needs to carry out agreement customization and charging power control, greatly satisfy the flexible requirement of non-mobile phone charging equipment.

[0006] The technical scheme for solving the technical problems of the utility model is as follows:

[0007] The utility model provides a wireless charging circuit, include: microcontroller, wireless transmission power control drive module, wireless charging power detection module, wireless transmission power control drive module connects microcontroller, wherein, wireless transmission power control drive module includes: electric capacity C5, electric capacity C6, electric capacity C7, electric capacity C8, electric capacity C10, electric capacity C11, electric capacity C12, electric capacity C14, electric capacity C15, electric capacity C16, resistance R6, resistance R7, resistance R9, resistance R10, driver D2, driver D4, the 1 pin of driver D2 receives the PWM1 signal from microcontroller, and connects resistance R6 one end, the other end of resistance R6 connects electric capacity C6 and ground, the 2 pin of driver D2 connects power input end VHV, and connects the other end of electric capacity C6, electric capacity C7, electric capacity C8, electric capacity C11, the 2 pin of driver D4, the other end of electric capacity C8 connects power ground P GND, the 3 pin of driver D2 connects the other end of electric capacity C7, the 4 pin of driver D4 respectively, the 6 pin of driver D2 connects the 4 pin of driver D2, the other end of electric capacity C11, the 3 pin of driver D4, resistance R7, XP1 end respectively, the other end of resistance R7 connects power ground P GND through electric capacity C5, the 5 pin of driver D2 connects power ground P GND, the 1 pin of driver D4 receives the PWM2 signal from microcontroller, and connects resistance R9 one end, the other end of resistance R9 is grounded, the 6 pin of driver D4 connects resistance R10, electric capacity C10, electric capacity C12, electric capacity C14, electric capacity C16 respectively, the other end of resistance R10 connects electric capacity C15, the other end of electric capacity C15 is grounded, the other end of electric capacity C10, electric capacity C12, electric capacity C14, electric capacity C16 connects input voltage V COMM, XP2 end, the 5 pin of driver D4 connects power ground P GND, wireless charging power detection module connects wireless transmission power control drive module and microcontroller.

[0008] Further, the wireless charging power detection module comprises a first circuit and a second circuit; the first circuit comprises a resistor R3, a resistor R4 and a capacitor C1, one end of the resistor R3 is connected to a current detection input end I DC of the microcontroller and connected to the capacitor C1, the other end of the resistor R3 is connected to a power ground P GND and the resistor R4, the other end of the capacitor C1 is connected to the other end of the resistor R4 and grounded; the second circuit comprises a diode V1, a resistor R12, a resistor R13, a resistor R14, a capacitor C13, a capacitor C17 and a capacitor C18, the positive electrode of the diode V1 is connected to an input voltage V COMM, the negative electrode of the diode V1 is connected to the resistor R12, the other end of the resistor R12 is connected to the resistor R14, the capacitor C13 and the capacitor C18 respectively, the other end of the capacitor C13 is connected to the resistor R13, the other end of the resistor R13 is connected to an analog input end CIN of the microcontroller and connected to the capacitor C17, the other ends of the resistor R14, the capacitor C18 and the capacitor C17 are all connected and grounded.

[0009] Further, the microcontroller comprises a USB interface, a control chip D3 and a power management circuit; the USB interface comprises an interface connector XS1, the No. 5 interface of the interface connector XS1 is grounded, the No. 4 interface of the interface connector XS1 is connected to the resistor R2 and then grounded, the No. 1 interface of the interface connector XS1 is connected to a supply voltage V HV of the USB interface; the control chip D3 is used to realize the functions of LED indication and PWM output; the power management circuit comprises a voltage stabilizer D1, a capacitor C3, a capacitor C4, a resistor R1 and a resistor R5, the No. 2 pin of the voltage stabilizer D1 and the capacitor C3 are both connected to the supply voltage V HV of the USB interface, the No. 3 pin of the voltage stabilizer D1 is connected to the capacitor C4 and a 5V voltage, the No. 1 pin of the voltage stabilizer D1 is connected to the other end of the capacitor C3, the other end of the capacitor C4 and grounded respectively; one end of the resistor R1 is connected to the supply voltage V HV of the USB interface, the input voltage VIN of the voltage stabilizer D1 is connected to the other end of the resistor R1, one end of a capacitor C2 and one end of a resistor R5, the other end of the capacitor C2 is connected to the other end of the resistor R5 and grounded.

[0010] Further, the models of the driver D2 and the driver D4 of the wireless transmission power control driving module are both AD70235.

[0011] Further, the model of the diode V1 of the wireless charging power detection module is 4148WS.

[0012] Further, the model of the voltage stabilizer D1 is LP3993-50.

[0013] Further, the model of the voltage stabilizer D1 of the USB interface is LP3993-50.

[0014] Further, the microcontroller has PWM and AD.

[0015] The utility model discloses the advantages and positive effects are:

[0016] The utility model discloses a kind of 8-bit processors with PWM and AD for application function design, the chip cost is low, reliability is high, while two MOS bridges drive circuit consisting of are designed, can effectively drive outside coil to carry out power control charging.Electric current detection circuit corresponding additionally, carry out current inspection of point waveform, internal conversion success power controls power, while charging equipment, take away have corresponding detection function;The circuit design is simple, suitable for most factory production and use.Microcontroller (single-chip microcontroller) is driven by programming mode simultaneously, cost is relatively low, design is more flexible, can satisfy some special requirements of wireless charging place. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 It is the circuit diagram of the utility model wireless charging circuit;

[0018] Figure 2 It is the circuit diagram of the utility model microcontroller;

[0019] Figure 3 It is the circuit diagram of the utility model wireless transmission power control drive module;

[0020] Figure 4 It is the circuit diagram of the utility model wireless charging power detection module;

[0021] Figure 5 It is the communication waveform diagram of the utility model wireless charging circuit. DETAILED DESCRIPTION

[0022] It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other without conflict.The utility model will be described in detail below with reference to the drawings and in combination with embodiments.

[0023] It should be noted that, unless otherwise specified, all technical and scientific terms used in the present application have the same meaning as generally understood by those skilled in the art to which the present application belongs.

[0024] As Figures 1-5 shown, the utility model provides a kind of wireless charging circuit, comprising: microcontroller, wireless transmission power control drive module, wireless charging power detection module.

[0025] As Figure 2 shown, it is the circuit design of microcontroller, including USB interface, power management, LED indication and PWM output etc.Function.In addition, the microcontroller has PWM and AD.

[0026] The USB interface includes an interface connector XS1 for connecting external USB devices or hosts, the No. 5 interface of the interface connector XS1 is grounded, CC1 is a configuration channel pin of the USB Type-C interface, used for detecting the insertion direction and performing power management, and is grounded after being connected with the resistor R2. R2 (5.1KΩ) is a pull-up resistor used to realize the standard pull-up function in the USB Type-C connector, helping to identify the connection state. VHV is the power supply voltage of the USB interface.

[0027] The control chip D3 of the microcontroller is the core of the circuit, responsible for processing input and output signals and controlling other components. PA0-PA7: These pins are used for general input and output. PB3-PB5: These pins are used for PWM output or other functions. PC3-PC5: These pins may be used for LED control or other functions. VDD, VSS: Power supply and ground respectively.

[0028] NRST: Reset pin. VBAT: Backup battery input for RTC or other low-power functions.

[0029] PA13 (SWDIO), PA14 (SWCLK): These pins are used for debugging and programming.

[0030] D1 (LP3993-50) in the power management circuit: a low-dropout linear regulator that stabilizes the input voltage (VHV) to 5V. C3 (104), C4 (105): These are bypass capacitors used to filter power supply noise and ensure stable regulator output. R1 (100KΩ), R5 (5.1KΩ): These resistors are used for voltage division or current limiting. VIN: This is the input voltage of the regulator.

[0031] LED_R in the LED indication part: This is a red LED controlled through the PC5 pin. R8 (300Ω): This is the current limiting resistor for the LED, protecting the LED from being damaged by excessive current.

[0032] PWM1, PWM2: These are PWM signals output through the PB3 and PB4 pins, used to control two bridge drive circuits.

[0033] C9 (104): A decoupling capacitor used to filter power supply noise and ensure stable operation of the microcontroller.

[0034] Specifically, the power management circuit includes voltage regulator D1, capacitor C3, capacitor C4, resistor R1, resistor R5, pin 2 of voltage regulator D1, and capacitor C3 are connected to the supply voltage VHV of the USB interface, pin 3 of voltage regulator D1 is connected to capacitor C4 and 5V voltage, pin 1 of voltage regulator D1 is connected to the other end of capacitor C3 and the other end of capacitor C4 and grounded; one end of resistor R1 is connected to the supply voltage VHV of the USB interface, the input voltage VIN of voltage regulator D1 is connected to the other end of resistor R1, one end of capacitor C2, and one end of resistor R5, the other end of capacitor C2 is connected to the other end of resistor R5 and grounded.

[0035] The board supply range is 6-9VDC input, and LDO is used to supply 5V to the microcontroller (single-chip microcomputer), and an external supply voltage detection part is added to determine whether to charge according to the external voltage.

[0036] As shown in Figure 3 , it is a wireless transmission power control drive module connected to the microcontroller. This module uses the PWM signal generated by the microcontroller (single-chip microcomputer) to control two bridge drive circuits, thereby achieving precise charge and discharge control of the external transmitting coil.

[0037] The microcontroller (single-chip microcomputer) in the figure generates PWM signals, which are output through specific pins (such as PB3 and PB4 in the figure) to control the switching state of the bridge drive circuit.

[0038] The PWM signals are pulled up to VHV through resistors (such as R6 and R9) to ensure signal stability. These signals are filtered through filter capacitors (such as C6, C7, C8, and C11) to remove high-frequency noise and ensure signal purity.

[0039] Two AD70235 bridge drivers (D2 and D4) are used in the circuit, each responsible for controlling one bridge arm, thereby achieving forward and reverse driving of the external transmitting coil.

[0040] The input of the driver receives the PWM signal from the microcontroller (single-chip microcomputer), and the output is connected to the external transmitting coil.

[0041] The external transmitting coil is connected between XP1 and XP2, and the energy is transmitted wirelessly through the charge and discharge control of the bridge drive.

[0042] The microcontroller (single-chip microcomputer) adjusts the duty cycle of the PWM signal according to the requirements of the wireless charging system, thereby controlling the conduction time of the bridge drive and achieving the conversion of the wireless charging power. By precisely controlling the PWM signal, precise adjustment of the wireless charging power can be achieved, improving the energy transmission efficiency.

[0043] The filter capacitors at the output (e.g. C5, C10-C16) are used to smooth the output voltage, reduce ripple, and ensure stability of energy transfer.

[0044] The resistors in series at the output (e.g. R7 and R10) are used for current sensing or current limiting, protecting the circuit and load from overcurrent damage.

[0045] This circuit design is intended for transmit power control in a wireless charging system, with the PWM signals generated by the microcontroller (MCU) controlling the bridge driver circuit to achieve precise charging and discharging control of the external transmit coil. The circuit includes filter capacitors and resistors that may be used for current sensing to ensure the stability of the circuit and smooth control of the load. This design is suitable for applications that require precise control of wireless charging power.

[0046] The power input is labeled VHV, providing a high voltage power supply. Two 22 microfarad / 16 volt capacitors (C6 and C8) are connected in parallel between the power input and the power ground (P_GND) for power filtering.

[0047] The PWM1 and PWM2 signals are pulled up to VHV through 10KΩ resistors (R6 and R9) and connected to the S1 and S2 pins of the AD70235 driver.

[0048] Two AD70235 drivers (D2 and D4) are used, each responsible for controlling one bridge leg. The G1 and G2 pins of the AD70235 are connected to VHV and P_GND respectively to power it. The D1 and D2 pins of the driver are connected to XP1 and XP2 for output.

[0049] XP1 and XP2 are connected to P_GND through capacitor C5 (103) for output filtering. Two 2Ω resistors (R7 and R10) are connected in series at the output.

[0050] Four NPO-104-100V capacitors (C10 to C16) are connected in parallel between XP1 and XP2 and P_GND for further smoothing of the output voltage.

[0051] A 473Ω resistor (C7) and 103 capacitor (C15) are also connected in parallel between the D1 and D2 pins of D2 and P_GND for current limiting and filtering.

[0052] Specifically, the wireless transmission power control driving module comprises: a capacitor C5, a capacitor C6, a capacitor C7, a capacitor C8, a capacitor C10, a capacitor C11, a capacitor C12, a capacitor C14, a capacitor C15, a capacitor C16, a resistor R6, a resistor R7, a resistor R9, a resistor R10, a driver D2, a driver D4, a No.1 pin of the driver D2 receives a PWM1 signal from a microcontroller and is connected to one end of the resistor R6, the other end of the resistor R6 is connected to the capacitor C6 and grounded, a No.2 pin of the driver D2 is connected to a power input end VHV and connected to the other end of the capacitor C6, the capacitor C7, the capacitor C8, the capacitor C11 and a No.2 pin of the driver D4, the other end of the capacitor C8 is connected to a power ground P_GND, a No.3 pin of the driver D2 is connected to the other end of the capacitor C7 and a No.4 pin of the driver D4 respectively, a No.6 pin of the driver D2 is connected to a No.4 pin of the driver D2, the other end of the capacitor C11, a No.3 pin of the driver D4, the resistor R7 and an XP1 end respectively, the other end of the resistor R7 is connected to the power ground P_GND through the capacitor C5, a No.5 pin of the driver D2 is connected to the power ground P_GND, a No.1 pin of the driver D4 receives a PWM2 signal from the microcontroller and is connected to one end of the resistor R9, the other end of the resistor R9 is grounded, a No.6 pin of the driver D4 is connected to the resistor R10, the capacitor C10, the capacitor C12, the capacitor C14 and the capacitor C16 respectively, the other end of the resistor R10 is connected to the capacitor C15, the other end of the capacitor C15 is grounded, the other ends of the capacitor C10, the capacitor C12, the capacitor C14 and the capacitor C16 are connected to an input voltage V-COMM and an XP2 end, and a No.5 pin of the driver D4 is connected to the power ground P_GND.

[0053] The wireless transmission power control driving module controls two bridge driving circuits by using PWM signals of a microcontroller (a single-chip microcomputer), converts power, charges and discharges an external transmitting coil through the bridge driving circuit, and realizes wireless charging power conversion.

[0054] As shown in Figure 4 The wireless charging power detection module can be connected with the wireless transmission power control driving module and a microcontroller, and accurately measures the size of a charging current by using a detection resistor to detect the current to the ground through a low-end detection method.

[0055] The wireless charging power detection circuit comprises:

[0056] A detection resistor (R4 in the figure, marked as RO20) is used to detect the current flowing through the resistor.

[0057] The detection resistor is connected to a current detection input end (I_DC) and the ground (GND) respectively.

[0058] By measuring the voltage drop across the detection resistor, the current flowing through the resistor can be calculated.

[0059] Current detection circuit:

[0060] A 1KΩ resistor (R3) and a capacitor C1 (104) are included to filter out high-frequency noise in the current detection signal.

[0061] The current detection input (I_DC) is connected to the current detection input of the microcontroller (MCU) through a 1KΩ resistor.

[0062] Filtering circuit:

[0063] A capacitor C13 (103) and a 150KΩ resistor (R13) are included to filter out high-frequency noise on the power line.

[0064] A 6.8nF capacitor (C17) is used for further filtering to ensure the stability of the microcontroller's (MCU) analog input (CIN).

[0065] Voltage dividing circuit:

[0066] A 2KΩ resistor (R12) and a 33KΩ resistor (R14) are included to divide the input voltage (V-COMM).

[0067] The divided voltage is filtered by capacitor C18 (103) to provide a stable reference voltage.

[0068] The microcontroller (MCU) reads the filtered voltage signal through its analog input (CIN) to calculate the charging current.

[0069] The wireless charging power detection module is connected to the microcontroller (MCU) through its current detection input (I_DC). The microcontroller (MCU) reads the filtered voltage signal through the analog input (CIN) to calculate the charging current. By adjusting the resistance value and capacitor parameters, the accuracy and response speed of current detection can be optimized.

[0070] Specifically, the wireless charging power detection module comprises a first circuit and a second circuit. The first circuit comprises a resistor R3, a resistor R4 and a capacitor C1. One end of the resistor R3 is connected to a current detection input end of a microcontroller and connected to the capacitor C1. The other end of the resistor R3 is connected to a power ground P_GND and the resistor R4. The other end of the capacitor C1 is connected to the other end of the resistor R4 and grounded. The second circuit comprises a diode V1, a resistor R12, a resistor R13, a resistor R14, a capacitor C13, a capacitor C17 and a capacitor C18. The positive electrode of the diode V1 is connected to an input voltage V-COMM. The negative electrode of the diode V1 is connected to the resistor R12. The other end of the resistor R12 is connected to the resistor R14, the capacitor C13 and the capacitor C18 respectively. The other end of the capacitor C13 is connected to the resistor R13. The other end of the resistor R13 is connected to the capacitor C17 through an analog input end CIN of the microcontroller. The other ends of the resistor R14, the capacitor C18 and the capacitor C17 are all connected and grounded. The diode V1 of the wireless charging power detection module is model 4148WS.

[0071] The first circuit is a current detection part, and the second circuit is used for realizing external charging device disengagement detection.

[0072] As Figure 5 shown, it is a communication waveform diagram of the wireless charging circuit.

[0073] The communication and data transmission timing diagram in the wireless charging system is divided into two parts. The synchronization pulse, data sending and receiving process between devices are described in detail. The following is the interpretation of the contents in the figure:

[0074] Part 1: synchronization and data sending timing

[0075] Synchronization pulse:

[0076] Two synchronization pulses are shown in the figure, each with a pulse width of 22 milliseconds (ms), used for synchronization between devices.

[0077] Data packet:

[0078] The data is divided into 32 groups, each containing 8 addresses (or data packets).

[0079] From the first pulse, the data of devices 2 to 8 is sent in turn.

[0080] Pulse interval:

[0081] The interval between each pulse is 32 milliseconds (ms) ± 10 microseconds (us).

[0082] Data sending:

[0083] Data is sent in 2 bits, and data for each device is sent sequentially.

[0084] The transmitted data includes the status or control information of the device.

[0085] P0,1bit parity check:

[0086] After data transmission, parity bit (P0,1bit) detection is performed to ensure the accuracy of data transmission.

[0087] Part II: Data reception and processing timing

[0088] Command transmission:

[0089] The master device sends a 4-bit command (C0~C3) to instruct the device to perform a specific operation.

[0090] Data reception:

[0091] After receiving the command, the device prepares to send data.

[0092] There is a 14 microsecond (us) delay before data transmission, and then data transmission begins.

[0093] Data format:

[0094] Data is sent in groups of 6066 bits, with a 100 microsecond (us) high-level interval between each group of data.

[0095] If the transmitted data is 0, it remains high for 100 microseconds; if it is 1, it remains low for 100 microseconds.

[0096] Data reception and processing:

[0097] After receiving the data, the master device processes and synchronizes it.

[0098] The synchronization time includes a 32 millisecond (ms) pulse interval and a 100 microsecond (us) data processing time.

[0099] Voltage range:

[0100] The voltage range is marked in the figure, from -7.5V to +6V, indicating the voltage variation range of the signal.

[0101] These two parts describe in detail the communication timing between devices in the wireless charging system, including synchronization pulses, data grouping, data transmission and reception, and parity checking processes. This timing control ensures the accuracy and synchronization of data transmission, which is crucial for implementing an efficient and reliable wireless charging system.

[0102] The circuit fully considers the reliability, versatility, fast response, hardware protection and power control of loop hardware, and the software part is provided with the selected waveform satisfying the charging waveform requirement and providing effective power supply time for the equipment.

[0103] The utility model discloses a kind of 8-bit processors with PWM and AD for the design of application function, the chip low cost, high reliability, while designed two MOSs consisting Bridge drive circuit, can effectively drive outside coil to carry out power control charging to equipment.In addition there is corresponding charging current detection circuit, the current of point waveform is checked, internal conversion success power controls, simultaneously for the equipment charging, take away have corresponding detection function;The circuit design is simple, cost is very low, suitable for the production and use of most factory.Microcontroller (single-chip microcomputer) is driven by programming mode simultaneously, cost is relatively low, design is more flexible, can satisfy some special requirements of wireless charging place.

[0104] The above only for the preferred embodiment of the utility model, and does not limit the utility model, for the skilled person in the art, the utility model can have various changes and changes. Any modification, equivalent replacement, improvement etc. within the spirit and principle of the utility model should be included in the protection scope of the utility model.

Claims

1. A wireless charging circuit, characterized in that, include: microcontroller; A wireless transmission power control driver module is connected to a microcontroller. The module includes: capacitors C5, C6, C7, C8, C10, C11, C12, C14, C15, and C16; resistors R6, R7, R9, and R10; driver D2; and driver D4. Pin 1 of driver D2 receives a PWM1 signal from the microcontroller and is connected to one end of resistor R6. The other end of resistor R6 is connected to capacitor C6 and grounded. Pin 2 of driver D2 is connected to the power input terminal VHV and is also connected to the other end of capacitor C6, capacitors C7, C8, and C11, and pin 2 of driver D4. The other end of capacitor C8 is connected to power ground P_GND. Pin 3 of driver D2 is connected to the other end of capacitor C7... Pin 4 of driver D4 and pin 6 of driver D2 are connected to pin 4 of driver D2, the other end of capacitor C11, pin 3 of driver D4, resistor R7, and the XP1 terminal, respectively. The other end of resistor R7 is connected to power ground P_GND through capacitor C5. Pin 5 of driver D2 is connected to power ground P_GND. Pin 1 of driver D4 receives the PWM2 signal from the microcontroller and is connected to one end of resistor R9. The other end of resistor R9 is grounded. Pin 6 of driver D4 is connected to resistor R10, capacitor C10, capacitor C12, capacitor C14, and capacitor C16, respectively. The other end of resistor R10 is connected to capacitor C15. The other end of capacitor C15 is grounded. The other ends of capacitors C10, C12, C14, and C16 are connected to the input voltage V-COMM and the XP2 terminal, respectively. Pin 5 of driver D4 is connected to power ground P_GND. A wireless charging power detection module, which is connected to a wireless transmission power control and drive module and a microcontroller.

2. The wireless charging circuit according to claim 1, characterized in that, The wireless charging power detection module includes: a first circuit and a second circuit; The first circuit includes: resistor R3, resistor R4, and capacitor C1. One end of resistor R3 is connected to the current detection input terminal I_DC of the microcontroller and is connected to capacitor C1. The other end of resistor R3 is connected to power ground P_GND and resistor R4. The other end of capacitor C1 is connected to the other end of resistor R4 and grounded. The second circuit includes: diode V1, resistors R12, R13, and R14, capacitors C13, C17, and C18. The positive terminal of diode V1 is connected to the input voltage V-COMM, and the negative terminal of diode V1 is connected to resistor R12. The other end of resistor R12 is connected to resistor R14, capacitor C13, and capacitor C18 respectively. The other end of capacitor C13 is connected to resistor R13. The analog input terminal CIN of the microcontroller is connected to the other end of resistor R13 and then to capacitor C17. The other ends of resistor R14, capacitor C18, and capacitor C17 are all connected to and grounded.

3. The wireless charging circuit according to claim 2, characterized in that, The microcontroller includes a USB interface, a control chip D3, and a power management circuit. The USB interface includes interface connector XS1. Interface connector XS1 pin 5 is grounded, interface connector XS1 pin 4 is connected to resistor R2 and then grounded, and interface connector XS1 pin 1 is connected to the power supply voltage VHV of the USB interface. The control chip D3 is used to implement the functions of LED indication and PWM output; The power management circuit includes a voltage regulator D1, capacitors C3 and C4, resistors R1 and R5. Pin 2 of voltage regulator D1 and capacitor C3 are both connected to the power supply voltage VHV of the USB interface. Pin 3 of voltage regulator D1 is connected to capacitor C4 and connected to a 5V voltage. Pin 1 of voltage regulator D1 is connected to the other end of capacitor C3 and the other end of capacitor C4 and grounded. One end of resistor R1 is connected to the power supply voltage VHV of the USB interface. The input voltage VIN of voltage regulator D1 is connected to the other end of resistor R1, one end of capacitor C2, and one end of resistor R5. The other end of capacitor C2 is connected to the other end of resistor R5 and grounded.

4. The wireless charging circuit according to claim 3, characterized in that, The driver D2 and driver D4 of the wireless transmission power control drive module are both model AD70235.

5. The wireless charging circuit according to claim 4, characterized in that, The diode V1 in the wireless charging power detection module is model 4148WS.

6. The wireless charging circuit according to claim 5, characterized in that, The voltage regulator D1 is model LP3993-50.

7. The wireless charging circuit according to claim 6, characterized in that, The microcontroller has PWM and AD.

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