Wireless charging mobile power supply and control method thereof

Abstract

The invention relates to the technical field of wireless charging, and relates to a wireless charging mobile power supply and a control method thereof, and the wireless charging mobile power supply comprises a magnetic attraction assembly, a battery module, a switch module, a power supply management module, a wireless charging control module, a wireless charging coil and a tunnel magnetoresistive sensor. The magnetic attraction assembly is arranged on the peripheral side of the wireless charging coil, and a magnetic attraction surface is formed on the magnetic attraction assembly; the input end of the switch module is connected with the voltage output end of the battery module, and the output end is connected with the voltage input end of the wireless charging module; the tunnel magnetoresistive sensor is arranged on the back side of the magnetic suction surface, the magnetic field sensitive direction of the tunnel magnetoresistive sensor is parallel to the magnetic suction surface, and the tunnel magnetoresistive sensor is used for detecting the magnetic field intensity generated by the magnetic suction assembly, outputting a first level signal when the magnetic field intensity is higher than a first preset threshold value and outputting a second level signal when the magnetic field intensity is lower than a second preset threshold value; the power management module is used for controlling the switch module to be turned on or turned off according to the first level signal or the second level signal. According to the method, operation convenience and hardware type selection diversity can be considered, and the method is suitable for special structural design.

Description

Technical Field

[0001] This invention relates to the field of wireless charging technology, and in particular to a wireless charging power bank and its control method. Background Technology

[0002] Wireless charging power banks have a wide range of applications. They typically activate wireless charging via a wake-up function to achieve low power consumption, and use magnetic attraction to automatically align the wireless charging coil with the electronic device.

[0003] There are several ways to wake up and activate wireless charging in a wireless charging power bank: The first is to place the electronic device on the power bank, and the capacitive touch sensor automatically senses and wakes the power supply to power the wireless charging module, thus activating wireless charging. However, this method requires the touch-sensitive surface of the casing to be coplanar with the wireless charging coil of the module, making it unsuitable for structures where the wireless charging coil protrudes outwards from the power bank's casing. The second method is to wake up and activate wireless charging through Q-value (quality factor) detection, but this method places high demands on the control chip and other hardware, limiting hardware selection. The third method involves setting up an operation button, allowing the user to wake up and activate wireless charging by pressing the button, but this requires additional user action.

[0004] Therefore, the existing wireless charging wake-up activation method of wireless charging power banks cannot simultaneously meet the needs of the special structural design of the wireless charging coil protruding outward from the casing of the wireless charging power bank, the diversity of hardware selection, and the user's need for convenient operation. Summary of the Invention

[0005] This invention provides a wireless charging power bank and its control method to solve the problem that existing wireless charging power banks' wake-up-to-start wireless charging methods cannot simultaneously meet the needs of the special structural design of the wireless charging coil protruding outward from the power bank's casing, the diversity of hardware selection, and the user's operational convenience.

[0006] This invention discloses a wireless charging power bank, including a magnetic suction component, a battery module, a switch module, a power management module, a wireless charging control module, a wireless charging coil, and a tunnel magnetoresistive sensor; The magnetic attraction component is arranged on the outer periphery of the wireless charging coil and forms a magnetic attraction surface for magnetic attraction with external electronic devices; The input terminal of the switch module is connected to the voltage output terminal of the battery module, its output terminal is connected to the voltage input terminal of the wireless charging module, and its control terminal is connected to the power management module. The tunnel magnetoresistive sensor is disposed on the back side of the magnetic attraction surface and its magnetic field sensing direction is parallel to the magnetic attraction surface; the tunnel magnetoresistive sensor is used to detect the magnetic field strength generated by the magnetic attraction component, and outputs a first level signal when the magnetic field strength is higher than a first preset threshold, and outputs a second level signal when the magnetic field strength is lower than a second preset threshold, and transmits the first level signal and the second level signal to the power management module. The power management module is used to control the switching module to be turned on or off according to the first level signal or the second level signal, so as to connect or disconnect the power supply circuit between the wireless charging control module and the battery module.

[0007] Optionally, the range of the first preset threshold is 10Gs to 25Gs, and the range of the second preset threshold is -25Gs to -10Gs.

[0008] Optionally, the wireless charging power bank further includes a circuit board, on which the switch module, power management module, wireless charging control module, and tunnel magnetoresistive sensor are all mounted; the magnetic attraction component includes multiple magnets, which are distributed circumferentially around the outer periphery of the wireless charging coil; wherein, a clearance opening is formed between two magnets located at the beginning and end of the circumferential distribution, and the orthographic projection area of ​​the clearance opening on the circuit board corresponds to the position of the tunnel magnetoresistive sensor; both ends of the wireless charging coil pass through the clearance opening and are connected to the circuit board.

[0009] Optionally, the switching module includes a first resistor, a second resistor, a first NPN transistor, a first PMOS transistor, and a second PMOS transistor; the base of the first NPN transistor is connected to the power management module through the first resistor, its collector is connected to the gate of the first PMOS transistor and the gate of the second PMOS transistor, and is connected to the source of the first PMOS transistor and the source of the second PMOS transistor through the second resistor, and its emitter is grounded; the drain of the first PMOS transistor is connected to the voltage output terminal of the battery module; the drain of the second PMOS transistor is connected to the voltage input terminal of the wireless charging control module.

[0010] Optionally, the wireless charging control module includes a buck-boost unit, a wireless charging control chip, and a resonant unit; the voltage input terminal of the buck-boost unit is connected to the output terminal of the switching module, its voltage output terminal is connected to the power input terminal of the wireless charging control chip, and its feedback terminal is connected to the wireless charging control chip; the resonant unit is connected to one end of the wireless charging coil; the first switching node terminal of the wireless charging control chip is connected to the resonant unit, its second switching node terminal is connected to the other end of the wireless charging coil, and its communication terminal is connected to the power management module.

[0011] Optionally, the resonant unit includes a first resonant subunit, a first NMOS transistor, a second NMOS transistor, a second resonant subunit, and a third resonant subunit; the first switching node of the wireless charging control chip is connected to one end of the first resonant subunit, the source of the first NMOS transistor, and the source of the second NMOS transistor; its first drive output terminal is connected to the gate of the first NMOS transistor, and its second drive output terminal is connected to the gate of the second NMOS transistor; the drain of the first NMOS transistor is connected to one end of the second resonant subunit, and the other end of the second resonant subunit is connected to one end of the wireless charging coil; the drain of the second NMOS transistor is connected to one end of the second resonant subunit, and the other end of the second resonant subunit is connected to one end of the wireless charging coil.

[0012] Optionally, the first resonant subunit includes a first resonant capacitor; one end of the first resonant capacitor is connected to the first switching node terminal of the wireless charging control chip, and the other end is connected to one end of the wireless charging coil; The second resonant subunit includes a second resonant capacitor, a third resonant capacitor, a fourth resonant capacitor, and a fifth resonant capacitor. The second, third, fourth, and fifth resonant capacitors are connected in parallel, with one end connected to the drain of the first NMOS transistor and the other end connected to one end of the wireless charging coil. The third resonant subunit includes a sixth resonant capacitor, one end of which is connected to the drain of the second NMOS transistor, and the other end is connected to one end of the wireless charging coil.

[0013] Optionally, the resonant unit further includes a third NMOS transistor, a driving subunit, and a third resonant subunit; The third resonant subunit includes a seventh resonant capacitor, one end of which is connected to the drain of the third NMOS transistor, and the other end is connected to one end of the wireless charging coil. The driving subunit includes a second NPN transistor, a PNP transistor, a third resistor, a fourth resistor, a fifth resistor, a sixth resistor, a seventh resistor, a diode, and a Zener diode. The base of the second NPN transistor is connected to the third drive output terminal of the wireless charging control chip through the third resistor, its emitter is grounded, and its collector is connected to the base of the PNP transistor through the fifth resistor. The fourth resistor is connected in parallel between the base and emitter of the second NPN transistor. The sixth resistor is connected in parallel between the base and emitter of the PNP transistor. The emitter of the PNP transistor is also connected to the analog power input terminal of the wireless charging control chip, and its collector is connected to the anode of the diode. The cathode of the diode is connected to the gate of the third NMOS transistor and the cathode of the Zener diode through the seventh resistor. The anode of the Zener diode is connected to the source of the third NMOS transistor.

[0014] Optionally, the resonant unit further includes a first capacitor, a second capacitor, a third capacitor, an eighth resistor, a ninth resistor, and a tenth resistor; the first capacitor and the eighth resistor are connected in parallel and then connected between the gate and source of the first NMOS transistor; the second capacitor and the ninth resistor are connected in parallel and then connected between the gate and source of the second NMOS transistor; the third capacitor and the tenth resistor are connected in parallel and then connected between the gate and source of the third NMOS transistor.

[0015] This invention also discloses a control method for a wireless charging power bank, characterized in that it is applied to a wireless charging power bank as described in any of the above claims, and the control method for the wireless charging power bank includes: The tunnel magnetoresistive sensor detects the magnetic field strength generated by the magnetic attraction component, and outputs a first level signal when the magnetic field strength is higher than a first preset threshold, and outputs a second level signal when the magnetic field strength is lower than a second preset threshold. Based on the first or second level signal, the switch module is controlled to be turned on or off, thereby connecting or disconnecting the power supply circuit between the wireless charging control module and the battery module.

[0016] The beneficial effects of the wireless charging power bank and its control method provided in this invention are as follows: By arranging a magnetic attraction component on the outer periphery of the wireless charging coil and placing a tunnel magnetoresistive sensor on the back side of the magnetic attraction surface of the magnetic attraction component with its magnetic field sensitive direction parallel to the magnetic attraction surface, the tunnel magnetoresistive sensor detects the change in the magnetic field strength of the magnetic attraction component. When the magnetic field strength is higher than a first preset threshold and lower than a second preset threshold, the corresponding level signal is output. The power management module automatically controls the switch module to turn on or off according to the corresponding level signal, so as to connect or disconnect the power supply circuit between the wireless charging control module and the battery module. This enables the wireless charging function to be activated when the electronic device is placed, achieving low-power standby. No additional mechanical switch is required, making it convenient for users to operate. It also has low requirements for hardware selection, improving the diversity of hardware selection, and is suitable for the special structural design where the wireless charging coil protrudes outward from the shell of the wireless charging power bank. Attached Figure Description

[0017] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. In the accompanying drawings: Figure 1 This is a structural block diagram of a wireless charging power bank according to an embodiment of the present invention; Figure 2 This is a partial circuit diagram of the power management module according to an embodiment of the present invention; Figure 3 This is a circuit diagram of the tunnel magnetoresistive sensor according to an embodiment of the present invention; Figure 4 This is a circuit diagram showing the connection between the boost / buck unit and the switching module in an embodiment of the present invention; Figure 5 This is a circuit diagram of the wireless charging control chip according to an embodiment of the present invention; Figure 6 This is a circuit diagram showing the connection between the resonant unit and the wireless charging coil in an embodiment of the present invention; Figure 7 This is a three-dimensional structural diagram of a wireless charging power bank according to an embodiment of the present invention; Figure 8 This is a partial internal structure diagram of the wireless charging power bank according to an embodiment of the present invention; Figure 9 yes Figure 8 A magnified view of part A in the middle; Figure 10 This is a flowchart illustrating the control method of a wireless charging power bank according to an embodiment of the present invention.

[0018] The labels for the attached figures are as follows: 10. Magnetic suction assembly; 11. Magnet; 10a. Clearance opening; 20. Battery module; 30. Switch module; 40. Power management module; 50. Wireless charging control module; 51. Buck-boost unit; 52. Wireless charging control chip; 53. Resonant unit; 60. Wireless charging coil; 70. Tunnel magnetoresistive sensor; 80. Circuit board; R1, first resistor; R2, second resistor; Q1, first NPN transistor; Q2, first PMOS transistor; Q3, second PMOS transistor; Q4, first NMOS transistor; Q5, second NMOS transistor; C1, first resonant capacitor; C2, second resonant capacitor; C3, third resonant capacitor; C4, fourth resonant capacitor; C5, fifth resonant capacitor; C6, sixth resonant capacitor; C7, seventh resonant capacitor; Q6, third NMOS transistor; Q7, second NPN transistor; Q8, PNP transistor; R3, third resistor; R4, fourth resistor; R5, fifth resistor; R6, sixth resistor; D1, diode; D2, Zener diode; C8, first capacitor; C9, second capacitor; C10, third capacitor; R7, seventh resistor; R8, eighth resistor; R9, ninth resistor; R10, tenth resistor; U1, buck-boost converter chip; L1, inductor. Detailed Implementation

[0019] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. The preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0020] This invention provides a wireless charging power bank, such as... Figure 1 , Figures 7 to 9 As shown, the wireless charging power bank includes a magnetic attachment component 10, a battery module 20, a switch module 30, a power management module 40, a wireless charging control module 50, a wireless charging coil 60, and a tunnel magnetoresistive sensor 70.

[0021] The magnetic attachment component 10 is disposed on the outer periphery of the wireless charging coil 60 and has a magnetic surface for magnetic attraction with external electronic devices. When the electronic device approaches the wireless charging coil 60, the electronic device magnetically engages with the magnetic surface of the magnetic attachment component 10. Magnetic engagement with the electronic device can be achieved by directly engaging with the magnetic attachment component built into the electronic device, or by using a magnetic attachment component installed on the electronic device, such as an attached magnetic attachment component, to achieve mutual magnetic attraction.

[0022] The input terminal of the switch module 30 is connected to the voltage output terminal of the battery module 20, its output terminal is connected to the voltage input terminal of the wireless charging module, and its control terminal is connected to the power management module 40.

[0023] A tunnel magnetoresistive sensor 70 is disposed on the back side of the magnetic attraction surface, with its magnetic field sensing direction parallel to the magnetic attraction surface. The tunnel magnetoresistive sensor 70 detects the magnetic field strength generated by the magnetic attraction assembly 10, outputting a first-level signal when the magnetic field strength is higher than a first preset threshold, and outputting a second-level signal when the magnetic field strength is lower than a second preset threshold. Both the first-level and second-level signals are transmitted to the power management module 40. The circuit diagram of the tunnel magnetoresistive sensor 70 is shown in the figure, and its output terminal VOUT is connected to the power management module 40.

[0024] The power management module 40 is used to control the switching module 30 to turn on or off according to the first level signal or the second level signal, so as to connect or disconnect the power supply circuit between the wireless charging control module 50 and the battery module 20.

[0025] This embodiment of the application arranges a magnetic attraction component 10 on the outer periphery of the wireless charging coil 60, and places a tunnel magnetoresistive sensor 70 on the back side of the magnetic attraction surface of the magnetic attraction component 10 with its magnetic field sensing direction parallel to the magnetic attraction surface. The tunnel magnetoresistive sensor 70 detects changes in the magnetic field strength of the magnetic attraction component 10, and outputs corresponding level signals when the magnetic field strength is higher than a first preset threshold and lower than a second preset threshold. The power management module 40 automatically controls the switch module 30 to turn on or off according to the corresponding level signal, so as to connect or disconnect the power supply circuit between the wireless charging control module 50 and the battery module 20. This realizes the function of waking up and starting wireless charging when placing electronic devices, without the need for additional mechanical switches, making it convenient for users to operate, with low requirements for hardware selection, improving the diversity of hardware selection, and also adapting to the special structural design of the wireless charging coil 60 protruding outward from the shell of the wireless charging power bank.

[0026] In a specific embodiment, the first preset threshold is the magnetic field operating point of the tunnel magnetoresistive sensor 70, and the second preset threshold is the magnetic field release point of the tunnel magnetoresistive sensor 70. The difference between the two is the hysteresis value of the tunnel magnetoresistive sensor 70, which determines the difference in magnetic field strength of the magnetic attraction component 10 before and after the electronic device approaches, ensuring that wireless charging is activated when wireless charging is needed, thereby achieving low power consumption. In a specific embodiment, when the magnetic field strength detected by the tunnel magnetoresistive sensor 70 exceeds a first preset threshold, the tunnel magnetoresistive sensor 70 outputs a first level signal, which is a low-level signal, and transmits the low-level signal to the power management module 40. The power management module 40 controls the disconnect switch module 30, thereby cutting off the power supply circuit between the wireless charging control module 50 and the battery module 20, so that the wireless charging power bank enters a low-power standby state. When the magnetic field strength detected by the tunnel magnetoresistive sensor 70 is lower than a second preset threshold, the tunnel magnetoresistive sensor 70 outputs a second level signal, which is a high-level signal, and transmits the high-level signal to the power management module 40. The power management module 40 controls the turn-on switch module 30, thereby turning on the power supply circuit between the wireless charging control module 50 and the battery module 20, waking up and starting wireless charging, and realizing the function of wireless charging that can be turned on immediately upon placement. When the electronic device is not placed on the wireless charging coil 60, the tunnel magnetoresistive sensor 70 detects that the magnetic field strength generated by the magnetic attraction component 10 is high. When the electronic device is placed on the wireless charging coil 60, the electronic device and the magnetic attraction component 10 attract each other, thereby weakening the magnetic field strength between the N pole and the S pole of the magnetic attraction component 10. Therefore, the tunnel magnetoresistive sensor 70 detects that the magnetic field strength of the magnetic attraction component 10 will decrease.

[0027] Optionally, the first preset threshold ranges from 10Gs to 25Gs, and the second preset threshold ranges from -25Gs to -10Gs, which can accurately distinguish between effective magnetic attraction events and interference signals, thereby improving the reliability of wireless charging wake-up.

[0028] Battery module 20 is responsible for storing and releasing energy; power management module 40 is responsible for power management, collecting information such as voltage and current of battery module 20, controlling the charging and discharging voltage of battery module 20, controlling the on and off of switch module 30, acquiring voltage and current data of battery module 20, calculating battery capacity, and sending battery voltage, current, and capacity information to the display module for display when a display module is set, as well as performing external device insertion detection; when a display module is set, the display module is responsible for displaying voltage, current, and capacity information. Wireless charging coil 60 is responsible for realizing wireless power transmission.

[0029] like Figure 1 , Figures 7 to 9As shown, in an optional embodiment of this application, the wireless charging power bank further includes a circuit board 80, on which a switch module 30, a power management module 40, a wireless charging control module 50, and a tunnel magnetoresistive sensor 70 are all disposed; the magnetic attraction component 10 includes a plurality of magnets 11, which are distributed circumferentially around the outer periphery of the wireless charging coil 60; wherein, a clearance opening 10a is formed between two magnets 11 located at the beginning and end of the circumferential distribution, and the orthographic projection area of ​​the clearance opening 10a on the circuit board 80 corresponds to the position of the tunnel magnetoresistive sensor 70; the two ends of the wireless charging coil 60 pass through the clearance opening 10a and are connected to the circuit board 80.

[0030] Specifically, multiple magnets 11 are distributed circumferentially along the wireless charging coil 60, which not only forms a uniform magnetic field to ensure the stability of the electronic device's adsorption, but also creates clearance openings 10a through the gaps between the first and last magnets 11, providing space for the wiring of the wireless charging coil 60. The orthogonal projection area of ​​the clearance openings 10a on the circuit board 80 corresponds to the position of the tunnel magnetoresistive sensor 70, placing the tunnel magnetoresistive sensor 70 in the gap region of the magnetic field of the magnets 11, preserving the effective magnetic field range generated by the magnetic attraction component 10, and further improving the accuracy of the tunnel magnetoresistive sensor 70 in identifying the adsorption / removal state of the electronic device.

[0031] like Figures 1 to 5 As shown, in an optional embodiment of this application, the switching module 30 includes a first resistor R1, a second resistor R2, a first NPN transistor Q1, a first PMOS transistor Q2, and a second PMOS transistor Q3; the base of the first NPN transistor Q1 is connected to the power management module 40 through the first resistor R1, its collector is connected to the gate of the first PMOS transistor Q2 and the gate of the second PMOS transistor Q3, and is connected to the source of the first PMOS transistor Q2 and the source of the second PMOS transistor Q3 through the second resistor R2, and its emitter is grounded; the drain of the first PMOS transistor Q2 is connected to the voltage output terminal of the battery module 20; the drain of the second PMOS transistor Q3 is connected to the voltage input terminal of the wireless charging control module 50.

[0032] Specifically, when the power management module 40 outputs a high-level signal, it flows into the first NPN transistor Q1 through the first resistor R1. The first NPN transistor Q1 conducts, pulling the gates of the first PMOS transistors Q2 and Q3 low to ground. This turns on the first PMOS transistors Q2 and Q3, thus connecting the power supply circuit between the voltage output terminal of the battery module 20 and the voltage input terminal of the wireless charging control module 50. The wireless charging control module 50 receives power and starts wireless charging. When the power management module 40 outputs a high-level signal, it flows into the first NPN transistor Q1 through the first resistor R1. The first NPN transistor Q1 is turned off, and the first PMOS transistors Q2 and Q3 are also turned off. The power supply circuit between the voltage output terminal of the battery module 20 and the voltage input terminal of the wireless charging control module 50 is disconnected, and the wireless charging control module 50 cannot receive power, maintaining a standby state with no output. The first resistor R1 acts as a current limiter. When the first NPN transistor Q1 is turned off, the second resistor R2 pulls up the gate level of the first PMOS transistor Q2 and the second PMOS transistor Q3, keeping the first PMOS transistor Q2 and the second PMOS transistor Q3 off and preventing false triggering of conduction.

[0033] In the circuit of the aforementioned switching module 30, the static current is very low when the first PMOS transistor Q2 and the second PMOS transistor Q3 are turned off, and the first NPN transistor Q1 consumes only a small current when it is turned on, resulting in low standby power consumption of the wireless charging power bank.

[0034] like Figures 1 to 6 As shown, in an optional embodiment of this application, the wireless charging control module 50 includes a buck-boost unit 51, a wireless charging control chip 52, and a resonant unit 53; the voltage input terminal of the buck-boost unit 51 is connected to the output terminal of the switching module 30, its voltage output terminal is connected to the power input terminal of the wireless charging control chip 52, and its feedback terminal is connected to the wireless charging control chip 52; the resonant unit 53 is connected to one end of the wireless charging coil 60; the first switching node terminal of the wireless charging control chip 52 is connected to the resonant unit 53, its second switching node terminal is connected to the other end of the wireless charging coil 60, and its communication terminal is connected to the power management module 40.

[0035] Specifically, the buck-boost unit 51 adjusts the output voltage based on feedback from the wireless charging control chip 52, enabling the wireless charging control to regulate the resonant unit 53 in conjunction with the wireless charging coil 60 to output the required charging power, and to adapt to voltage fluctuations in the battery module 20, ensuring stable power supply. The resonant unit 53 and the wireless charging coil 60 form an LC resonant circuit. The wireless charging control chip 52 controls and adjusts the operating frequency of the LC resonant circuit to achieve adjusted charging power output, and is responsible for wireless charging power transmission management, communication protocol processing, and FOD (Foreign Object Detection) processing.

[0036] like Figure 5 and Figure 6 As shown, in an optional embodiment of this application, the resonant unit 53 includes a first resonant subunit, a first NMOS transistor Q4, a second NMOS transistor Q5, a second resonant subunit, and a third resonant subunit; the first switching node terminal of the wireless charging control chip 52 is connected to one end of the first resonant subunit, the source of the first NMOS transistor Q4, and the source of the second NMOS transistor Q5, its first drive output terminal is connected to the gate of the first NMOS transistor Q4, and its second drive output terminal is connected to the gate of the second NMOS transistor Q5; the drain of the first NMOS transistor Q4 is connected to one end of the second resonant subunit, and the other end of the second resonant subunit is connected to one end of the wireless charging coil 60; the drain of the second NMOS transistor Q5 is connected to one end of the second resonant subunit, and the other end of the second resonant subunit is connected to one end of the wireless charging coil 60.

[0037] Specifically, the first NMOS transistor Q4 and the second NMOS transistor Q5 are controlled by the first and second drive output terminals of the wireless charging control chip 52, respectively, and can be turned on or off, thereby selecting to connect to the second resonant subunit and / or the third resonant subunit in combination with the first resonant subunit to output different resonant frequencies. Through the switching control of the first NMOS transistor Q4 and the second NMOS transistor Q5, the parameters of the resonant circuit can be quickly switched, enabling the wireless charging coil 60 to operate in the target frequency band, adapting to the wireless charging frequency requirements of different electronic devices, and improving the charging experience.

[0038] like Figure 5 and Figure 6 As shown, in an optional embodiment of this application, the first resonant subunit includes a first resonant capacitor C1; one end of the first resonant capacitor C1 is connected to the first switching node terminal of the wireless charging control chip 52, and the other end is connected to one end of the wireless charging coil 60; the second resonant subunit includes a second resonant capacitor C2, a third resonant capacitor C3, a fourth resonant capacitor C4, and a fifth resonant capacitor C5, which are connected in parallel, and one end of the parallel connection is connected to the drain of the first NMOS transistor Q4, and the other end is connected to one end of the wireless charging coil 60; the third resonant subunit includes a sixth resonant capacitor C6, one end of which is connected to the drain of the second NMOS transistor Q5, and the other end is connected to one end of the wireless charging coil 60.

[0039] Specifically, the first resonant subunit uses a first resonant capacitor C1, matched to a preset resonant frequency. The second resonant subunit uses a second resonant capacitor C2, a third resonant capacitor C3, a fourth resonant capacitor C4, and a fifth resonant capacitor C5 connected in parallel. The total capacitance after parallel connection is greater than that of a single capacitor, corresponding to a lower resonant frequency, which is suitable for high-current, low-power trickle charging scenarios. At the same time, the parallel connection of multiple capacitors can improve the voltage withstand value and current carrying capacity of the capacitors, avoiding capacitor overheating and damage under high power. The third resonant subunit uses a sixth resonant capacitor C6, which can be combined with the first resonant subunit to match another preset resonant frequency, realizing matching different resonant frequencies and meeting the wireless charging frequency band requirements of different electronic devices.

[0040] Therefore, by controlling the on / off state of the first NMOS transistor Q4 and the second NMOS transistor Q5, the wireless charging control chip 52 can combine the first resonant capacitor C1, the second resonant capacitor C2, the third resonant capacitor C3, the fourth resonant capacitor C4, the fifth resonant capacitor C5, and the sixth resonant capacitor C6 to meet different charging power requirements. For example, when the switching module 30 is turned on, the buck-boost unit 51 supplies power to the wireless charging control chip 52, and the wireless charging control chip 52 controls the first NMOS transistor Q4 to turn on and the second NMOS transistor Q5 to turn off, controlling the first resonant capacitor C1, the second resonant capacitor C2, the third resonant capacitor C3, the fourth resonant capacitor C4, the fifth resonant capacitor C5, and the sixth resonant capacitor C6 to meet different charging power requirements. Resonant capacitors C4 and C5 operate, emitting a coupled magnetic field through the wireless charging coil 60. When the electronic device is detected to support Android wireless charging (BPP and EPP protocols) or only support the Qi wireless charging protocol, the first resonant capacitor C1, the second resonant capacitor C2, the third resonant capacitor C3, the fourth resonant capacitor C4, and the fifth resonant capacitor C5 remain operational. If the electronic device supports Qi2 charging protocol and MagSafe charging, the first NMOS transistor Q4 is turned off, the second NMOS transistor Q5 is turned on, and the first resonant capacitor C1 and the sixth resonant capacitor C6 are controlled to operate, thereby meeting the needs of different charging power.

[0041] like Figure 5 and Figure 6As shown, in an optional embodiment of this application, the resonant unit 53 further includes a third NMOS transistor Q6, a driving subunit, and a third resonant subunit; the third resonant subunit includes a seventh resonant capacitor C7, one end of which is connected to the drain of the third NMOS transistor Q6, and the other end is connected to one end of the wireless charging coil 60; the driving subunit includes a second NPN transistor Q7, a PNP transistor Q8, a third resistor R3, a fourth resistor R4, a fifth resistor R5, a sixth resistor R6, a seventh resistor R7, a diode D1, and a Zener diode D2; the base of the second NPN transistor Q7 is connected to the wireless charging control chip through the third resistor R3. The third drive output terminal of chip 52 has its emitter grounded, and its collector is connected to the base of the PMP transistor through the fifth resistor R5; the fourth resistor R4 is connected in parallel between the base and emitter of the second NPN transistor Q7; the sixth resistor R6 is connected in parallel between the base and emitter of the PNP transistor Q8; the emitter of the PNP transistor Q8 is also connected to the analog power input terminal of the wireless charging control chip 52, and its collector is connected to the anode of diode D1; the cathode of diode D1 is connected to the gate of the third NMOS transistor Q6 and the cathode of Zener diode D2 through the seventh resistor R7; the anode of Zener diode D2 is connected to the source of the third NMOS transistor Q6.

[0042] Specifically, the third resonant capacitor C3 is selectively connected to the resonant circuit through the conduction or cutoff of the third NMOS transistor Q6. Combined with the first and second resonant units, it forms more resonant frequency combinations, allowing for matching of more special power levels and meeting the wireless charging protocol requirements of different electronic devices. Regarding the driving of the third NMOS transistor Q6, since the driving capabilities of different drive output terminals within the wireless charging control chip 52 are different, the driving capability of its third drive output terminal is insufficient to drive the third NMOS transistor Q6. By setting the second NPN transistor Q7, PNP transistor Q8, third resistor R3, fourth resistor R4, fifth resistor R5, sixth resistor R6, diode D1, and Zener diode D2, the third drive output terminal of the wireless charging control chip 52 is pulled up through the second NPN transistor Q7 and PNP transistor Q8, ensuring that it can drive the third NMOS transistor Q6 and guaranteeing that the third resonant capacitor C3 can be connected and used. The third resistor R3 serves as a current limiter to prevent excessive current from damaging the second NPN transistor Q7. The fourth resistor, R4, acts as a pull-down resistor, pulling the base of the second NPN transistor Q7 low when the wireless charging control chip 52 has no output, preventing Q7 from being mis-turned on. The fifth resistor, R5, acts as a current limiter, preventing excessive current from damaging the PNP transistor Q8. The sixth resistor, R6, is a pull-up resistor, pulling the base of the PNP transistor Q8 up when the second NPN transistor Q7 is off, preventing Q8 from being mis-turned on. The seventh resistor, R7, also acts as a current limiter, preventing excessive current from damaging the third NMOS transistor Q6. The Zener diode, D2, acts as a voltage regulator.

[0043] like Figure 5 and Figure 6 As shown, in an optional embodiment of this application, the resonant unit 53 further includes a first capacitor C8, a second capacitor C9, a third capacitor C10, an eighth resistor R8, a ninth resistor R9, and a tenth resistor R10; the first capacitor C8 and the eighth resistor R8 are connected in parallel, and after being connected in parallel, they are connected between the gate and source of the first NMOS transistor Q4; the second capacitor C9 and the ninth resistor R9 are connected in parallel, and after being connected in parallel, they are connected between the gate and source of the second NMOS transistor Q5; the third capacitor C10 and the tenth resistor R10 are connected in parallel, and after being connected in parallel, they are connected between the gate and source of the third NMOS transistor Q6.

[0044] Specifically, the first capacitor C8 and the eighth resistor R8 are connected in parallel to provide a controllable charging and discharging path for the gate charge of the first NMOS transistor Q4, enabling slow on- and slow discharge of the first MOS transistor and preventing instantaneous turn-on or turn-off of the first NMOS transistor Q4, thus protecting Q4. Similarly, the second capacitor C9 and the ninth resistor R9 are connected in parallel to provide a controllable charging and discharging path for the gate charge of the second NMOS transistor Q5, enabling slow on- and slow discharge of the second MOS transistor and preventing instantaneous turn-on or turn-off of the second NMOS transistor Q5, thus protecting Q5. The third capacitor C10 and the tenth resistor R10 are connected in parallel to provide a controllable charging and discharging path for the gate charge of the third NMOS transistor Q6, enabling slow on- and slow discharge of the third MOS transistor and preventing instantaneous turn-on or turn-off of the third NMOS transistor Q6, thus protecting Q6.

[0045] like Figures 4 to 6 As shown, in an optional embodiment of this application, the buck-boost unit 51 includes a buck-boost chip U1 and an inductor L1. The voltage input terminal of the buck-boost chip U1 is connected to the output terminal of the switching module 30, and the voltage output terminal of the buck-boost chip U1 is connected to the power input terminal of the wireless charging control chip 52. Its drive terminal and feedback terminal are connected to the wireless charging control chip 52. One end of the inductor L1 is connected to the first switching node terminal of the buck-boost chip U1, and the other end is connected to the second switching node terminal of the buck-boost chip U1.

[0046] Specifically, the buck-boost chip U1 integrates the switching transistors and control logic functions of a traditional buck-boost circuit. Under the drive and control of the wireless charging control chip 52, it works with inductor L1 to achieve buck-boost conversion, transforming the output voltage of the battery module 20 into a suitable voltage for transmission to the wireless charging control chip 52. The buck-boost chip U1 has a high degree of integration, reducing the overall number of components required, simplifying PCB routing, and lowering the difficulty of production assembly and troubleshooting.

[0047] refer to Figures 1 to 10This application also provides a control method for a wireless charging power bank, applied to the aforementioned wireless charging power bank. The control method for the wireless charging power bank includes: S110. The magnetic field strength generated by the magnetic attraction component 10 is detected by the tunnel magnetoresistive sensor 70, and a first level signal is output when the magnetic field strength is higher than a first preset threshold, and a second level signal is output when the magnetic field strength is lower than a second preset threshold. S120. Based on the first level signal or the second level signal, control the switch module 30 to turn on or off, so as to connect or disconnect the power supply circuit between the wireless charging control module 50 and the battery module 20.

[0048] This embodiment of the application arranges a magnetic attraction component 10 on the outer periphery of the wireless charging coil 60, and places a tunnel magnetoresistive sensor 70 on the back side of the magnetic attraction surface of the magnetic attraction component 10 with its magnetic field sensing direction parallel to the magnetic attraction surface. The tunnel magnetoresistive sensor 70 detects changes in the magnetic field strength of the magnetic attraction component 10, and outputs corresponding level signals when the magnetic field strength is higher than a first preset threshold and lower than a second preset threshold. Then, based on the corresponding level signals, it automatically controls the switch module 30 to turn on or off, so as to connect or disconnect the power supply circuit between the wireless charging control module 50 and the battery module 20. This realizes the function of waking up and starting wireless charging when placing an electronic device, without the need for an additional mechanical switch. It is convenient for users to operate, has low requirements for hardware selection, improves the diversity of hardware selection, and can also be used for the special structural design of the wireless charging coil 60 protruding outward from the shell of the wireless charging power bank.

[0049] The structure and beneficial effects of the wireless charging power bank used in the control method of the wireless charging power bank have been described in detail in the foregoing embodiments, and will not be repeated here.

[0050] It should be understood that the above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit them. Those skilled in the art can modify the technical solutions described in the above embodiments, or make equivalent substitutions for some of the technical features; and all such modifications and substitutions should fall within the protection scope of the appended claims of the present invention.

Claims

1. A wireless charging power bank, characterized in that, It includes a magnetic charging component, a battery module, a switch module, a power management module, a wireless charging control module, a wireless charging coil, and a tunnel magnetoresistive sensor; The magnetic attraction component is arranged on the outer periphery of the wireless charging coil and forms a magnetic attraction surface for magnetic attraction with external electronic devices; The input terminal of the switch module is connected to the voltage output terminal of the battery module, its output terminal is connected to the voltage input terminal of the wireless charging module, and its control terminal is connected to the power management module. The tunnel magnetoresistive sensor is disposed on the back side of the magnetic attraction surface and its magnetic field sensing direction is parallel to the magnetic attraction surface; the tunnel magnetoresistive sensor is used to detect the magnetic field strength generated by the magnetic attraction component, and outputs a first level signal when the magnetic field strength is higher than a first preset threshold, and outputs a second level signal when the magnetic field strength is lower than a second preset threshold, and transmits the first level signal and the second level signal to the power management module. The power management module is used to control the switching module to be turned on or off according to the first level signal or the second level signal, so as to connect or disconnect the power supply circuit between the wireless charging control module and the battery module.

2. The wireless charging power bank according to claim 1, characterized in that, The first preset threshold ranges from 10Gs to 25Gs, and the second preset threshold ranges from -25Gs to -10Gs.

3. The wireless charging power bank according to claim 1, characterized in that, The wireless charging power bank also includes a circuit board, on which the switch module, power management module, wireless charging control module, and tunnel magnetoresistive sensor are all mounted. The magnetic attraction assembly includes multiple magnets, which are distributed circumferentially around the outer periphery of the wireless charging coil. A clearance opening is formed between two magnets located at the beginning and end of the circumferential distribution, and the orthographic projection area of ​​the clearance opening on the circuit board corresponds to the position of the tunnel magnetoresistive sensor. Both ends of the wireless charging coil pass through the clearance opening and are connected to the circuit board.

4. The wireless charging power bank according to any one of claims 1-3, characterized in that, The switching module includes a first resistor, a second resistor, a first NPN transistor, a first PMOS transistor, and a second PMOS transistor. The base of the first NPN transistor is connected to the power management module through the first resistor, its collector is connected to the gate of the first PMOS transistor and the gate of the second PMOS transistor, and is connected to the source of the first PMOS transistor and the source of the second PMOS transistor through the second resistor. Its emitter is grounded. The drain of the first PMOS transistor is connected to the voltage output terminal of the battery module. The drain of the second PMOS transistor is connected to the voltage input terminal of the wireless charging control module.

5. The wireless charging power bank according to any one of claims 1-3, characterized in that, The wireless charging control module includes a buck-boost unit, a wireless charging control chip, and a resonant unit. The voltage input terminal of the buck-boost unit is connected to the output terminal of the switching module, its voltage output terminal is connected to the power input terminal of the wireless charging control chip, and its feedback terminal is connected to the wireless charging control chip. The resonant unit is connected to one end of the wireless charging coil. The first switching node terminal of the wireless charging control chip is connected to the resonant unit, its second switching node terminal is connected to the other end of the wireless charging coil, and its communication terminal is connected to the power management module.

6. The wireless charging power bank according to claim 5, characterized in that, The resonant unit includes a first resonant subunit, a first NMOS transistor, a second NMOS transistor, a second resonant subunit, and a third resonant subunit. The first switching node of the wireless charging control chip is connected to one end of the first resonant subunit, the source of the first NMOS transistor, and the source of the second NMOS transistor. Its first drive output terminal is connected to the gate of the first NMOS transistor, and its second drive output terminal is connected to the gate of the second NMOS transistor. The drain of the first NMOS transistor is connected to one end of the second resonant subunit, and the other end of the second resonant subunit is connected to one end of the wireless charging coil. The drain of the second NMOS transistor is connected to one end of the second resonant subunit, and the other end of the second resonant subunit is connected to one end of the wireless charging coil.

7. The wireless charging power bank according to claim 6, characterized in that, The first resonant subunit includes a first resonant capacitor; one end of the first resonant capacitor is connected to the first switching node terminal of the wireless charging control chip, and the other end is connected to one end of the wireless charging coil; The second resonant subunit includes a second resonant capacitor, a third resonant capacitor, a fourth resonant capacitor, and a fifth resonant capacitor. The second, third, fourth, and fifth resonant capacitors are connected in parallel, with one end connected to the drain of the first NMOS transistor and the other end connected to one end of the wireless charging coil. The third resonant subunit includes a sixth resonant capacitor, one end of which is connected to the drain of the second NMOS transistor, and the other end is connected to one end of the wireless charging coil.

8. The wireless charging power bank according to claim 6, characterized in that, The resonant unit also includes a third NMOS transistor, a driving subunit, and a third resonant subunit; The third resonant subunit includes a seventh resonant capacitor, one end of which is connected to the drain of the third NMOS transistor, and the other end is connected to one end of the wireless charging coil. The driving subunit includes a second NPN transistor, a PNP transistor, a third resistor, a fourth resistor, a fifth resistor, a sixth resistor, a seventh resistor, a diode, and a Zener diode. The base of the second NPN transistor is connected to the third drive output terminal of the wireless charging control chip through the third resistor, its emitter is grounded, and its collector is connected to the base of the PNP transistor through the fifth resistor. The fourth resistor is connected in parallel between the base and emitter of the second NPN transistor. The sixth resistor is connected in parallel between the base and emitter of the PNP transistor. The emitter of the PNP transistor is also connected to the analog power input terminal of the wireless charging control chip, and its collector is connected to the anode of the diode. The cathode of the diode is connected to the gate of the third NMOS transistor and the cathode of the Zener diode through the seventh resistor. The anode of the Zener diode is connected to the source of the third NMOS transistor.

9. The wireless charging power bank according to claim 8, characterized in that, The resonant unit further includes a first capacitor, a second capacitor, a third capacitor, an eighth resistor, a ninth resistor, and a tenth resistor; the first capacitor and the eighth resistor are connected in parallel and then connected between the gate and source of the first NMOS transistor; the second capacitor and the ninth resistor are connected in parallel and then connected between the gate and source of the second NMOS transistor; the third capacitor and the tenth resistor are connected in parallel and then connected between the gate and source of the third NMOS transistor.

10. A control method for a wireless charging power bank, characterized in that, The control method for the wireless charging power bank, applied in any one of claims 1-9, includes: The tunnel magnetoresistive sensor detects the magnetic field strength generated by the magnetic attraction component, and outputs a first level signal when the magnetic field strength is higher than a first preset threshold, and outputs a second level signal when the magnetic field strength is lower than a second preset threshold. Based on the first or second level signal, the switch module is controlled to be turned on or off, thereby connecting or disconnecting the power supply circuit between the wireless charging control module and the battery module.

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