Wireless charging method, system and equipment

Abstract

The invention relates to the technical field of wireless charging, in particular to a wireless charging method, system and device. A wireless charging device comprises a transmitting module which comprises a planar spiral transmitting coil, a magnetic isolation sheet and an annular magnetic ring, and the magnetic isolation sheet and the magnetic ring jointly define a magnetic flux cavity with an opening in one side; the receiving module is embedded into the barrel wall of the to-be-charged equipment and comprises a spiral receiving coil tightly attached to the barrel wall; the charging box is provided with a circular ring positioning groove concentric with the transmitting coil, and the positioning groove is used for non-directionally accommodating equipment to be charged; when the to-be-charged device is placed in the positioning groove, the transmitting coil and the receiving coil are axially sleeved and share the same center line, the magnetic flux cavity seals external magnetic fields of the two coils to improve the coupling efficiency, and the air cooling unit arranged in the charging box discharges heat of the coils along an annular path. According to the invention, an efficient wireless charging scheme without directionality and distance influence is designed, the charging experience of a user is improved, and charging energy supplementation is performed on the to-be-charged equipment efficiently.

Description

Technical Field

[0001] This invention relates to the field of wireless charging technology, and in particular to a wireless charging method, system and device. Background Technology

[0002] Current wireless charging technology faces significant technical bottlenecks in its adaptation to small wearable devices (such as ring-shaped products). First, coil alignment is critical. Existing solutions mostly rely on planar coupling structures, requiring precise alignment of the transmitting and receiving coils. Even slight misalignment drastically reduces coupling efficiency, failing to meet the needs of freely placed devices like rings. Second, directionality is a significant limitation. The receiving coil is typically fixed to a single plane on the device; rotation of the device can easily disrupt magnetic field coupling, making it difficult to achieve the omnidirectional charging required for ring-shaped devices.

[0003] Furthermore, heat dissipation and efficiency are mutually restrictive. Traditional coils employ a tightly wound design, resulting in limited heat dissipation area. During charging, heat buildup can necessitate power reduction, further decreasing charging efficiency. Finally, the design suffers from poor adaptability to small devices. Existing solutions do not incorporate coil design into the cylindrical structure of toroidal devices, requiring the receiving coil to occupy additional internal space. Moreover, magnetic field leakage is a significant issue, leading to energy waste and potential electromagnetic interference, thus failing to meet the efficient and safe charging needs of miniature devices such as rings. Summary of the Invention

[0004] Therefore, it is necessary to provide a wireless charging method, system, and device to solve at least one of the aforementioned technical problems.

[0005] To achieve the above objectives, a wireless charging device includes: The transmitting module includes a planar helical transmitting coil, a magnetic shielding sheet, and a ring magnetic ring. The magnetic shielding sheet and the magnetic ring together define a magnetic flux cavity with an opening on one side. A receiving module, embedded in the wall of the device to be charged, includes a spiral receiving coil that is tightly attached to the wall of the device; The charging box has an annular positioning groove concentric with the transmitting coil, which is used to omnidirectionally accommodate the device to be charged. When the device to be charged is placed in the positioning slot, the transmitting coil and the receiving coil are axially coupled and share the same center line. The magnetic flux cavity seals the external magnetic field of the two coils to improve the coupling efficiency, and the built-in air-cooling unit of the charging box dissipates the heat of the coils along the ring path.

[0006] Optionally, the present invention also provides a wireless charging method, comprising the following steps: Step S1: Place the device to be charged into the positioning slot at any rotation angle so that the transmitting coil and the receiving coil are axially engaged; Step S2: Output a high-frequency alternating magnetic field to the transmitting coil and simultaneously collect the current value of the transmitting coil. If the current value exceeds the preset current range, adjust the duty cycle of the driving signal to control the current value within the preset current range. Step S3: Acquire the voltage signal output by the receiving coil after rectification, and calculate the change in voltage signal between two consecutive times; if the change exceeds the preset amplitude, pause the drive signal and resume drive after a fixed interval. Step S4: When the voltage signal reaches the full charge voltage of the battery and the corresponding output current is lower than the trickle threshold, switch the drive signal to intermittent pulse mode until charging is finished.

[0007] Optionally, the present invention also provides a wireless charging system for performing the wireless charging method described above, the wireless charging system comprising: The coil fitting and positioning module is used to place the device to be charged into the positioning slot at any rotation angle, so that the transmitting coil and the receiving coil are axially fitted together. The current value adjustment module is used to output a high-frequency alternating magnetic field to the transmitting coil and simultaneously collect the current value of the transmitting coil. If the current value exceeds the preset current range, the duty cycle of the drive signal is adjusted to control the current value within the preset current range. The voltage determination and control module is used to acquire the voltage signal output by the receiving coil after rectification, calculate the change in voltage signal between two consecutive signals; if the change exceeds the preset amplitude, the drive signal is paused and the drive is resumed after a fixed interval. The full charge state pulse switching module is used to switch the drive signal to intermittent pulse mode when the voltage signal reaches the battery full charge voltage and the corresponding output current is lower than the trickle threshold, until the charging is completed.

[0008] The beneficial effects of the present invention are as follows: I. Design a high-efficiency wireless charging solution that is unaffected by direction and distance, which can improve the user's charging experience. Simply place the device to be charged into the charging case, and it can be charged efficiently. This eliminates the need for users to worry about aligning the charging coil as with other wireless charging products. Furthermore, this solution makes full use of the ring structure, integrating the wireless charging coil with the ring, thereby achieving better electromagnetic field coupling without the need for alignment.

[0009] Second, by using a ring structure to design the coil, the coil is non-directional; strict coil alignment is not required, and full electromagnetic field coupling of the coil is achieved simply by inserting the ring into a designated position, which improves charging efficiency; at the same time, the charging heat dissipation area is larger, the heat generation is lower, it is more energy-efficient, and the user experience is better due to the low placement requirements. Attached Figure Description

[0010] Figure 1A flowchart illustrating the steps of a wireless charging method; Figure 2 This is a schematic diagram of a wireless charging structure. Figure 3 A schematic diagram of a wireless charging receiver coil for wireless charging; Figure 4 A schematic diagram showing the direction of the magnetic field for wireless charging. The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0011] The technical method of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0012] Furthermore, the accompanying drawings are merely illustrative of the invention and are not necessarily drawn to scale. The same reference numerals in the drawings denote the same or similar parts, and therefore repeated descriptions of them will be omitted. Some block diagrams shown in the drawings are functional entities and do not necessarily correspond to physically or logically independent entities. These functional entities can be implemented in software, in one or more hardware modules or integrated circuits, or in different network and / or processor methods and / or microcontroller methods.

[0013] It should be understood that although the terms "first," "second," etc., may be used herein to describe various units, these units should not be limited by these terms. These terms are used merely to distinguish one unit from another. For example, without departing from the scope of the exemplary embodiments, a first unit may be referred to as a second unit, and similarly, a second unit may be referred to as a first unit. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0014] To achieve the above objectives, please refer to Figures 1 to 4 A wireless charging method, the method comprising the following steps: Preferably, in step S1: the device to be charged is placed into the positioning slot at any rotation angle, so that the transmitting coil and the receiving coil are axially engaged; In one embodiment, the device to be charged is placed in the annular positioning groove of the charging box. A spiral receiving coil is embedded in the cylindrical wall of the device to be charged. The spiral surface of the spiral receiving coil is in close contact with the cylindrical wall of the device to be charged, and its spiral axis is consistent with the normal direction of the device to be charged. During the placement process, the device to be charged can maintain any rotation angle without adjusting its rotation direction.

[0015] For example, please refer to Figure 2 The circular positioning groove of the charging box is concentrically set with the planar spiral transmitting coil built into the charging box. The structural design of the positioning groove meets the space constraints of the device to be charged. It can be designed as a sunken structure or a raised structure. The inner diameter of the positioning groove is adapted to the outer diameter of the device to be charged, and the outer diameter of the positioning groove is matched with the outer diameter of the planar spiral transmitting coil.

[0016] In another embodiment, after the device to be charged is fully placed in the positioning slot, the planar spiral transmitting coil and the spiral receiving coil embedded in the device to be charged form an axially fitted structure. If the diameter of the planar spiral transmitting coil is larger than the diameter of the spiral receiving coil, the planar spiral transmitting coil is fitted on the outside of the spiral receiving coil; if the diameter of the planar spiral transmitting coil is smaller than the diameter of the spiral receiving coil, the planar spiral transmitting coil is fitted on the inside of the spiral receiving coil, and the planar spiral transmitting coil and the spiral receiving coil share the same center line. In this state, no additional alignment operation is required to achieve the initial coupling of the two coils.

[0017] It should be noted that the design of the circular positioning groove does not require the receiving device to be directional; it only needs to provide enough space for the device to be charged to be placed. This ensures that the device to be charged can be stably positioned so that the two coils are axially aligned after it is placed, further simplifying the placement of the device to be charged.

[0018] Preferably, in step S2: output a high-frequency alternating magnetic field to the transmitting coil and simultaneously collect the current value of the transmitting coil. If the current value exceeds the preset current range, adjust the duty cycle of the driving signal to control the current value within the preset current range. Optionally, the charging box contains a drive circuit and an inverter circuit. Specifically, in step S2, the high-frequency alternating magnetic field is output to the transmitting coil as follows: The charging box's built-in power supply is activated, inputting a DC voltage into the drive circuit of the transmitting coil. This DC voltage is then converted into an alternating voltage via an inverter circuit. The output frequency of the alternating signal is set according to the inherent resonant frequency of the transmitting coil, so that the alternating voltage drives the planar spiral transmitting coil to generate a high-frequency alternating magnetic field; By setting a magnetic field detection point inside the annular magnetic ring, the intensity value of the alternating magnetic field is collected. If the intensity value is lower than the preset threshold, the output power of the drive circuit is increased. Maintaining a high-frequency alternating magnetic field output, while confining the magnetic field within the coupling region of the transmitting coil and the receiving coil through the magnetic flux cavity formed by the magnetic shielding sheet and the annular magnetic ring.

[0019] In one embodiment, when outputting a high-frequency alternating magnetic field to the transmitting coil, the built-in power supply of the charging box is activated, and a DC voltage is input to the driving circuit of the transmitting coil. This DC voltage is converted into an alternating voltage by the inverter circuit inside the charging box.

[0020] In another embodiment, the inherent resonant frequency of the planar spiral transmitting coil is obtained through the internal components of the charging box, and the alternating signal output frequency is set according to this frequency, so that the alternating voltage drives the planar spiral transmitting coil to generate a high-frequency alternating magnetic field.

[0021] It should be noted that a magnetic field detection point is set inside the annular magnetic ring to collect the alternating magnetic field strength value. If the strength value is lower than the preset threshold, the output power is increased through the power adjustment component of the drive circuit. This maintains the high-frequency alternating magnetic field output, while the magnetic shielding sheet and the annular magnetic ring form a magnetic flux cavity, confining the external magnetic fields of the transmitting coil and receiving coil within the coupling region.

[0022] For example, the charging case has a built-in power supply that outputs 12V DC voltage, which is converted into 8V effective value alternating voltage by an inverter circuit; the planar spiral transmitting coil has a natural resonant frequency of 100kHz, and the alternating signal output frequency is set to 100kHz; three magnetic field detection points are evenly arranged on the inner side of the annular magnetic ring, and the intensity is collected by a Hall sensor. The preset threshold is 50mT. When the value is lower than the threshold, the drive circuit increases the PWM duty cycle and increases the output power from 5W in increments of 1W; the magnetic shielding sheet is made of 1mm thick ferrite material and fits the bottom surface of the transmitting coil; the annular magnetic ring is a manganese-zinc ferrite magnetic ring with an inner diameter of 20mm, an outer diameter of 30mm, and a height of 5mm, which surrounds the outer side of the transmitting coil.

[0023] It should be noted that the magnetic shielding sheet and the ring magnetic ring are connected with insulating and high-temperature resistant adhesive, and the conversion efficiency of the inverter circuit is not less than 85% when the input is 12V and the output is 8V.

[0024] In another embodiment, the charging box has a built-in power supply that outputs a 15V DC voltage, which is converted to a 10V effective value alternating voltage by an inverter circuit; the planar spiral transmitting coil has a natural resonant frequency of 95kHz, and the alternating signal output frequency is set to 95kHz; four magnetic field detection points are provided on the inner side of the annular magnetic ring, with an adjacent interval of 90°, and a preset threshold of 45mT. When the threshold is lower than the threshold, the drive circuit increases the power supply voltage by a 0.5V gradient; the magnetic shielding sheet is 1.2mm thick, and the annular magnetic ring has an inner diameter of 18mm, an outer diameter of 28mm, and a height of 4mm.

[0025] Optionally, the synchronous acquisition of the current value of the transmitting coil in step S2 includes: Simultaneously, current signals are collected at three positions: the beginning, middle, and end of the planar spiral transmitting coil. The arithmetic mean of the current signals at the three positions is used as the basis for judgment. If the average value is higher than the upper limit of the preset current range, the adjustment range is determined by increasing the duty cycle adjustment amount by 1% for every 1% increase in the rated current of the transmitting coil based on the difference between the average value and the upper limit. If the average value is lower than the preset current range lower limit, the adjustment range is determined by increasing the duty cycle adjustment by 1% of the rated current of the transmitting coil for every 1% increase in the difference between the average value and the lower limit. After adjustment, the current signal is re-acquired for verification.

[0026] In one embodiment, when outputting a high-frequency alternating magnetic field to the planar helical transmitting coil, current acquisition and adjustment operations are performed simultaneously. A 0.05Ω current sampling resistor with a precision class of 0.1 is welded and fixed at the starting, middle, and ending points of the planar helical transmitting coil, respectively. The current signal at the corresponding position is converted into a voltage signal through these three sampling resistors. It should be noted that the three voltage signals are respectively connected to the signal amplification circuit inside the charging box. The amplification factor of the signal amplification circuit is set to 20 times. After amplifying the voltage signals, they are transmitted to the ADC acquisition circuit with 12-bit resolution and a sampling frequency of 1kHz. The ADC acquisition circuit synchronously acquires the three amplified voltage signals and converts them into specific current values. The three current values ​​are then transmitted to the signal processing circuit, which calculates the arithmetic mean of the three current values ​​and uses this average value as the basis for current judgment.

[0027] In another embodiment, the rated current of the planar spiral transmitting coil is set to 1.5A, and the preset current range is 0.8A-1.2A. If the average current calculated by the signal processing circuit is higher than the upper limit of the preset range of 1.2A, the difference between the average value and 1.2A is first calculated. The adjustment range is determined by increasing the duty cycle adjustment by 0.5% for every 0.015A increase in the difference (i.e., 1% of the rated current of the transmitting coil of 1.5A). Subsequently, the signal processing circuit sends an adjustment command to the PWM controller of the drive circuit, and the PWM controller reduces the duty cycle of the drive signal according to the determined adjustment range. If the average current is lower than the preset lower limit of 0.8A, calculate the difference between the average value and 0.8A, and determine the adjustment range by increasing the duty cycle adjustment by 0.5% for every 0.015A increase in the difference. The PWM controller then increases the duty cycle of the drive signal according to this adjustment range.

[0028] After adjustment, at 200ms intervals, the current signal is re-acquired through the three current sampling resistors, signal amplification circuit and ADC acquisition circuit mentioned above. The signal processing circuit calculates the new average current value and verifies whether it is within the preset current range of 0.8A-1.2A.

[0029] In another embodiment, the rated current of the planar spiral transmitting coil is set to 2A, the preset current range is 1A-1.5A, the resistance of the current sampling resistor connected in series at the three positions is 0.04Ω, the amplification factor of the signal amplification circuit is 25 times, and the sampling frequency of the ADC acquisition circuit is 1.2kHz. When the average current exceeds the preset range, the amplitude is determined by increasing the duty cycle adjustment by 0.4% for every 0.02A increase in the difference (i.e., 1% of the rated current of 2A). After adjustment, the current signal is re-acquired and verified after an interval of 150ms.

[0030] It should be noted that the welding position of the current sampling resistor should avoid the coupling area between the planar spiral transmitting coil and the ring magnetic ring to avoid affecting the magnetic field distribution; a 100kΩ resistor should be connected in series at the input end of the signal amplification circuit and a 10Ω resistor should be connected in parallel at the output end to ensure stable voltage signal transmission.

[0031] Optionally, adjusting the duty cycle of the drive signal in step S2 is specifically as follows: By using the magnetic field direction detection element at the opening of the magnetic flux cavity of the transmitting module, it is confirmed that the orientation of the opening on one side of the magnetic flux cavity is consistent with the direction of the receiving coil. If the opening is misaligned, the position adjustment structure of the transmitting module is used to fine-tune the transmitting module so that the opening is directly facing the receiving coil. The adjustment level is then determined based on the deviation between the current value and the preset range. The duty cycle is gradually adjusted according to the magnitude corresponding to the adjustment level. After each adjustment, the high-frequency alternating magnetic field output is maintained and the current value is collected.

[0032] In one embodiment, when adjusting the duty cycle of the drive signal, three linear Hall sensors are first uniformly installed along the circumference at the opening of the magnetic flux cavity of the transmitting module. The distance between the sensors and the edge of the opening is 3mm and the adjacent spacing is 120°. The magnetic field direction data at the opening is collected by the sensors and transmitted to the signal processing circuit. After the circuit calculates the average magnetic field direction, it compares it with the preset reference direction of the receiving coil to confirm whether the opening orientation is consistent.

[0033] Please see Figure 4 It should be noted that the allowable offset angle between the opening and the direction of the receiving coil is set to ±5°. If the offset exceeds ±5°, the position adjustment structure of the transmitting module is activated. This structure contains two miniature stepper motors with a step angle of 0.9° and an arc-shaped guide rail. The motor drives the transmitting module to move 0.9° along the guide rail each time. After pausing for 200ms, the magnetic field direction data is collected again until the offset angle is ≤ ±5°, ensuring that the opening is directly facing the receiving coil.

[0034] In another embodiment, after the opening is aligned, the current value is acquired by a 0.05Ω / 0.1-level current sampling resistor connected in series at the start of the transmitting coil. This value is then processed by a 20x amplification circuit and converted by a 12-bit ADC to obtain the specific value. The preset current range of the transmitting coil is set to 0.8A-1.2A, and adjustment levels are divided according to deviation: 0-0.1A is level one (amplitude 0.5%), 0.1A-0.2A is level two (amplitude 1%), and >0.2A is level three (amplitude 1.5%).

[0035] In another embodiment, the PWM controller adjusts the duty cycle according to the corresponding amplitude. After each adjustment, the high-frequency alternating magnetic field output is maintained for 300ms. Then, the current value is re-acquired through the above-mentioned sampling resistor, amplification circuit and ADC. If the current value does not reach the preset range, the deviation detection, level classification and adjustment are repeated until the current value is within 0.8A-1.2A.

[0036] In another embodiment, four Hall sensors (spaced 90° apart) are installed at the opening of the flux cavity, allowing an offset of ±3°, and the step angle of the adjustment structure motor is 0.45°; the transmitting coil has a preset current of 1A-1.5A, a sampling resistor of 0.04Ω, and an amplification of 25 times. A deviation of 0-0.15A is classified as Level 1 (0.4%), 0.15A-0.3A as Level 2 (0.8%), and >0.3A as Level 3 (1.2%). After adjustment, the output is maintained for 250ms before verifying the current.

[0037] It should be noted that the Hall sensor is powered by 5V and has a sampling frequency of 1kHz; the radius of curvature of the arc-shaped guide rail matches the motion trajectory of the transmitting module to ensure that the concentricity of the coil remains unchanged during fine-tuning.

[0038] Optionally, controlling the current value within a preset current range in step S2 includes: The position detection element inside the circular positioning groove of the charging box determines the coincidence status between the center of the device to be charged and the center of the positioning groove. If the two overlap completely, the duty cycle is changed at intervals of 1 / 20 of the drive signal period. If there is a deviation in the overlapping state of the two, the duty cycle is changed at intervals of 1 / 10 of the driving signal period; The current value is collected after each adjustment until the current value is controlled within the preset current range.

[0039] In one embodiment, when the current value is controlled within a preset range, four infrared ranging sensors are evenly installed along the circumference of the inner sidewall of the circular positioning groove of the charging box. The distance between the sensors and the center of the positioning groove is 15mm, and the adjacent sensors are spaced 90° apart. The sensor measurement range is 5mm-20mm, the accuracy is ±0.1mm, and the power supply is 3.3V. The distance values ​​between the outer surface of the device to be charged and the sensors are collected by the sensors and transmitted to the signal processing circuit. The circuit calculates the variance of the four distance values. If the variance is 0, it is determined that the center of the device is completely aligned with the center of the positioning groove; if the variance is greater than 0, it is determined that there is an offset.

[0040] In another embodiment, the period of the planar spiral transmitting coil drive signal is set to 200μs, and the preset current range is 0.8A-1.2A. When the signals are fully aligned, the PWM controller adjusts the duty cycle at 10μs (1 / 20 of the period) intervals with an amplitude of 0.5%; when there is a deviation, it adjusts at 20μs (1 / 10 of the period) intervals with an amplitude of 1%. After each adjustment, the current signal is acquired through a 0.05Ω / 0.1-level current sampling resistor connected in series at the start of the transmitting coil. This signal is then processed by a 20x amplification circuit and converted into a current value by a 12-bit resolution 1kHz sampling frequency ADC. The current value is transmitted to the circuit for comparison with the preset range. If the value does not meet the standard, the position detection and adjustment are repeated until the current value is within the 0.8A-1.2A range.

[0041] It should be noted that the positioning slot is equipped with three infrared ranging sensors (120° apart, 12mm from the center), with a drive signal period of 150μs and a preset current of 1A-1.5A. When perfectly aligned, adjustments are made at 7.5μs intervals with a 0.4% amplitude; when offset, adjustments are made at 15μs intervals with a 0.8% amplitude. The current sampling resistor is 0.04Ω, the amplifier circuit amplifies the current by 25 times, and the ADC sampling frequency is 1.2kHz. After adjustment, the current values ​​are collected and compared until the target is met.

[0042] Preferably, step S3: acquire the voltage signal output by the receiving coil after rectification, and calculate the change in voltage signal between two adjacent signals; if the change exceeds the preset amplitude, pause the drive signal and resume drive after a fixed interval. Optionally, in step S3, the voltage signal output from the rectified receiving coil is acquired, and the change in voltage signal between two consecutive steps is calculated, including: Two voltage sampling points are set at the output of the receiving coil rectifier circuit, corresponding to the positive and negative terminals of the rectified output respectively. The sampling points are electrically connected to the spiral end of the receiving coil. At preset time intervals, the output voltage value of the receiving coil after rectification is continuously acquired through the acquisition point to obtain the first voltage signal and the second voltage signal; The change in voltage between two consecutive voltage signals is obtained by subtracting the value of the first voltage signal from the value of the second voltage signal, and the relative position of the transmitting coil and the receiving coil during the two acquisitions is recorded.

[0043] Please see Figure 3 In one embodiment, when acquiring the voltage signal output by the receiving coil after rectification and calculating the change in voltage signal between two adjacent times, two voltage acquisition points are determined at the output end of the rectifier circuit of the receiving coil. One acquisition point is connected to the positive terminal of the rectifier output, and the other acquisition point is connected to the negative terminal of the rectifier output. Both acquisition points are electrically connected to the spiral end of the receiving coil through wires. The wires are enameled copper wires with a cross-sectional area of ​​0.1 mm². The connection position is fixed by soldering and wrapped with insulating tape.

[0044] It should be noted that the preset time interval for voltage acquisition is 500ms. Voltage sensors installed at two voltage acquisition points continuously acquire the output voltage value after rectification by the receiving coil. The voltage sensors are DC voltage sensors with an accuracy class of 0.2 and a measurement range of 0-5V. Their output signals are processed by a signal amplification circuit with a 10x amplification factor before being transmitted to an ADC acquisition circuit with 12-bit resolution and a sampling frequency of 2kHz. The ADC acquisition circuit acquires the first output voltage value at the first 500ms interval, recorded as the first voltage signal; and acquires the second output voltage value at the second 500ms interval, recorded as the second voltage signal.

[0045] In another embodiment, the change in voltage signal between two adjacent signals is obtained by subtracting the first voltage signal value from the second voltage signal value obtained by the ADC acquisition circuit, and the change is retained to two decimal places. Simultaneously, four infrared ranging sensors (15mm from the center of the positioning groove and spaced 90° apart) installed on the inner sidewall of the charging box's circular positioning groove collect the position data of the device to be charged. The signal processing circuit determines the relative position state of the transmitting coil and receiving coil (complete overlap or offset) based on the position data, and synchronously records this relative position state and the calculated voltage signal change to the storage unit. The storage interval of the storage unit is consistent with the voltage acquisition time interval, both being 500ms.

[0046] In another embodiment, the voltage acquisition point at the output of the rectifier circuit of the receiving coil is connected to the spiral end of the receiving coil via a gold-plated contact with a diameter of 1 mm and a thickness of 0.2 mm. The preset time interval for voltage acquisition is set to 300 ms. The voltage sensor has an accuracy class of 0.1 and a measurement range of 0-3.3 V. The signal amplification circuit has an amplification factor of 8 times. The ADC acquisition circuit has a resolution of 16 bits and a sampling frequency of 3 kHz. The relative position of the transmitting coil and the receiving coil is determined by three infrared ranging sensors (120° apart and 12 mm from the center). The position data and voltage change are stored synchronously in the storage unit at a storage interval of 300 ms.

[0047] It should be noted that the power supply voltage of the voltage sensor is set to 5V, and the linearity error of the acquired signal is controlled within ±0.5%; the measurement accuracy of the infrared ranging sensor is set to ±0.1mm to ensure the accuracy of the relative position determination.

[0048] Optionally, if the change exceeds a preset amplitude in step S3, the drive signal is paused and the drive is resumed after a fixed interval. Specifically: The change is compared with the preset amplitude. If the change exceeds the preset amplitude, a stop command is sent to the drive circuit of the transmitting coil to interrupt the high-frequency alternating magnetic field output and pause the drive signal. The charging case's built-in timing mechanism is activated, and the timing begins for a preset fixed duration, maintaining the relative positions of the transmitting and receiving coils unchanged during the timing period; After the timing ends, a start command is sent to the drive circuit of the transmitting coil to restore the high-frequency alternating magnetic field output and the drive signal is output again.

[0049] In one embodiment, when the change in the processed voltage signal exceeds a preset amplitude, the calculated changes in two consecutive voltage signals are first compared with the preset amplitude of 0.3V. If the change is greater than 0.3V, the signal processing circuit outputs a 3.3V high-level stop command to the transmitting coil drive circuit. The MOSFET (model IRF3205) in the drive circuit cuts off within 100ns after receiving the command, the planar spiral transmitting coil stops outputting the high-frequency alternating magnetic field, and the drive signal is paused.

[0050] It should be noted that the built-in RC timer of the charging case starts timing. This RC timer consists of a 10μF electrolytic capacitor and a 200kΩ metal film resistor, with a preset fixed duration of 2 seconds. The timing signal is output through a timing chip powered by 5V.

[0051] In another embodiment, during the timing period, four infrared ranging sensors (model GP2Y0A21YK) spaced 90° apart and 15mm from the center on the inner sidewall of the charging box's circular positioning groove collect distance data of the device to be charged in real time. If the data variance exceeds 0.01mm², the position is determined to be off, and the positioning locking mechanism is immediately triggered. Two miniature stepper motors (model 28BYJ-48) with a step angle of 0.9° drive the transmitting module to move along the arc-shaped guide rail. After each 0.9° movement, the module pauses for 200ms to re-collect distance data until the variance is ≤0.01mm², ensuring that the relative positions of the transmitting coil and the receiving coil remain unchanged.

[0052] In another embodiment, when the RC timer reaches 2s, the timing chip outputs a low-level trigger signal. After receiving the signal, the signal processing circuit outputs a 0V low-level start command to the drive circuit, the MOS transistor resumes conduction, and the planar spiral transmitting coil resumes outputting a high-frequency alternating magnetic field at the 30% duty cycle before the pause. At the same time, a 0.05Ω / 0.1-level current sampling resistor connected in series at the start of the transmitting coil collects the current signal. The signal is processed by a 20x amplification circuit (composed of an OPA2340 operational amplifier) ​​and converted into a current value by a 12-bit ADC (model ADS1115). If the current value is lower than the preset range of 0.8A, the PWM controller increases the duty cycle by 0.5% per cycle. After each adjustment, the current value is re-collected after 300ms until the duty cycle is restored to the parameters before the pause.

[0053] In another embodiment, the voltage signal change is preset to 0.2V, the charging box's built-in timing structure uses a 1MHz crystal oscillator (model HC-49S) with a fixed duration of 1.5s; position monitoring uses three infrared ranging sensors spaced 120° apart and 12mm from the center, and when the position deviates, it is locked by a miniature stepper motor (model 16HS2408) with a step angle of 0.45°; when the drive signal is restored, it first outputs at 90% of the duty cycle before the pause, and collects the current value through a 0.04Ω sampling resistor, a 25x amplification circuit and an ADC, and adjusts the duty cycle at an amplitude of 0.4% / time until the current value is within the preset range of 1A-1.5A.

[0054] It should be noted that the infrared ranging sensor is powered by 3.3V, has a measurement accuracy of ±0.1mm, and a sampling frequency of 1kHz; the turn-on / turn-off delay time of the MOSFET is controlled within 100ns to avoid inrush current when the magnetic field output is interrupted and restored.

[0055] Preferably, in step S4: when the voltage signal reaches the full charge voltage of the battery and the corresponding output current is lower than the trickle threshold, the drive signal is switched to intermittent pulse mode until charging is finished.

[0056] Optionally, in step S4, switching the drive signal to intermittent pulse mode specifically involves: When the voltage signal reaches the full charge voltage of the battery and the corresponding output current is lower than the trickle threshold, the preset position detection structure in the circular positioning groove of the charging box confirms whether the transmitting coil and the receiving coil are axially nested and share the same center line. If the two axes are completely aligned, the drive signal is directly switched to intermittent pulse mode; If there is a misalignment between the two axes, the device to be charged is pushed by the elastic guide provided on the inner wall of the charging box's circular positioning groove, so that the device to be charged moves radially along the positioning groove until the axes of the transmitting coil and the receiving coil coincide, and then the drive signal switching operation is performed.

[0057] In one embodiment, when switching the drive signal mode in step S4, the voltage signal is first acquired through a 0.2-level, 0-5V voltage sensor at the output of the receiving coil rectifier circuit, and the output current is acquired through a 0.05Ω / 0.1-level current sampling resistor connected in series in the receiving coil circuit. The battery full charge voltage is set to 4.2V and the trickle charge threshold to 50mA. When the voltage reaches 4.2V and the current is below 50mA, the position detection structure within the charging box's circular positioning groove—three laser displacement sensors (accuracy ±0.01mm, sampling 500Hz) spaced 120° apart and 18mm from the center—is activated to measure the radial distance difference between the transmitting coil and the receiving coil. The signal processing circuit determines that if all three distance differences are 0, the axes are completely aligned; if any difference is greater than 0, there is an offset.

[0058] It should be noted that when the axes are completely aligned, a mode switching command is sent to the drive circuit. The PWM controller switches the drive signal to intermittent pulse mode, with a pulse period of 1 second, a width of 200 ms, and an amplitude consistent with the previous mode. When the axes deviate, the three arc-shaped silicone elastic guides (elastic coefficient 5 N / mm, initial compression 2 mm, maximum extension 5 mm) on the inner wall of the positioning groove are activated. Based on the distance difference, the device to be charged is pushed to move radially. After each push, a 100 ms pause is performed to remeasure until the distance difference is zero, and then the drive signal is switched again.

[0059] In another embodiment, the battery has a full charge voltage of 3.7V and a trickle threshold of 30mA. Position detection uses four laser displacement sensors spaced 90° apart and 15mm from the center. The elastic guide is made of rubber (elastic coefficient 4N / mm, initial compression 1.5mm). The intermittent pulse period is 1.5s and the width is 300ms. Before switching, the current is confirmed to be below 30mA again by a 0.04Ω sampling resistor and a 25x amplification circuit.

[0060] It should be noted that after mode switching, the voltage is collected every 5 seconds by a voltage sensor to ensure that it is stable at the full charge voltage; excessive force should be avoided when pushing the elastic guide to prevent damage to the equipment.

[0061] Of particular importance is that, in step S4, switching the drive signal to intermittent pulse mode specifically involves: Before switching, magnetic field distribution data of the coupling area between the two coils is collected by a magnetic field detection element placed between the transmitting coil and the receiving coil. If the magnetic field distribution data shows that the magnetic field uniformly covers the coupling area, the pulse output duration and pause duration of the intermittent pulse mode are set to be in the same proportion; If the magnetic field distribution data shows that there are local magnetic field concentration areas, shorten the single pulse output duration of the intermittent pulse mode and extend the pause duration so that the heat in the local magnetic field concentration area is dispersed through the coil's own structure before switching the drive signal to the intermittent pulse mode.

[0062] In one embodiment, before switching the drive signal in step S4, six high-sensitivity Hall sensors are uniformly installed along the circumference of the coupling area between the transmitting and receiving coils. The sensors are 10 mm from the center of the coupling area and spaced 60° apart. The detection surface is perpendicular to the magnetic field direction. Magnetic field strength data is collected at a frequency of 2 kHz and transmitted to the signal processing circuit. The circuit calculates the variance of the six data points. If the variance is ≤0.5 mT², the magnetic field uniformly covers the coupling area; if the variance is >0.5 mT², a local magnetic field concentration area exists.

[0063] In another embodiment, when the magnetic field is uniform, the PWM controller sets the pulse output duration and pause duration of the intermittent pulse mode to 500ms (1:1 ratio), with a pulse amplitude of 12V, and directly switches the drive signal. When there is local magnetic field concentration, the single pulse output duration is shortened to 300ms and the pause duration is extended to 700ms. A 2-second wait is allowed for heat to dissipate through the ring structure. During this period, a temperature sensor with a measurement range of -20℃ to 125℃ and an accuracy of ±0.5℃ is used to collect the coil surface temperature. Once the temperature is confirmed to have dropped below 45℃, the drive signal is switched.

[0064] In another embodiment, four Hall sensors (spaced 90° apart and 8mm from the center) are installed in the coupling area. The variance threshold for determining the uniformity of the magnetic field is 0.3mT². When the magnetic field is uniform, the pulse output and pause duration are both 400ms and the amplitude is 10V. When there is a concentrated area, the output is 250ms and the pause is 750ms. After waiting for 1.5s, the temperature is confirmed to be ≤40℃ by a temperature sensor with an accuracy of ±0.3℃ before switching the drive signal.

[0065] It should be noted that the Hall sensor is powered by 5V, has a measurement range of 0-50mT, and a linear error of ±1%; the temperature sensor is attached to the corresponding position in the area where the coil's magnetic field is concentrated.

[0066] Most importantly, the process in step S4 until the charging is completed is specifically as follows: During intermittent pulse mode operation, the voltage signal and output current signal of the receiving coil after rectification are synchronously acquired with each pulse output. If the voltage signal collected three times in a row is kept stable at the full charge voltage of the battery and the output current is consistently lower than the trickle threshold, the intermittent pulse output stops and the built-in air cooling unit of the charging box is activated, so that the air cooling unit delivers airflow to the coil area along the ring path. When the temperature detection element next to the coil shows that the coil temperature has dropped to within ±5℃ of the ambient temperature, it outputs two intermittent pulses again and collects voltage and current signals again. If the two acquisition results still meet the requirements of the voltage being the full charging voltage and the current being lower than the trickle threshold, the drive signal output will stop, and charging will be completed.

[0067] In one embodiment, during intermittent pulse mode operation, each time a pulse is output, a DC voltage sensor with an accuracy class of 0.2 and a measurement range of 0-5V at the output terminal of the receiving coil rectifier circuit, and an alloy resistor with an accuracy class of 0.1 and a precision class of 0.05Ω connected in series in the receiving coil circuit, synchronously acquire voltage and current signals at a frequency of 1kHz. After the acquired signals are processed by a 20x amplification circuit, they are transmitted to a 12-bit resolution ADC acquisition circuit to be converted into specific values.

[0068] The battery is set to a full charge voltage of 4.2V and a trickle charge threshold of 50mA. If the voltage signal collected three times in a row is stable at 4.2V (fluctuation ±0.05V) and the current is ≤49mA, a stop command is sent to the drive circuit, the intermittent pulse output stops, and the built-in air-cooling unit of the charging box is started. Four miniature axial flow fans with a rated voltage of 5V and a speed of 5000rpm are arranged along a ring path to deliver airflow with a wind speed of 2m / s to the coil area.

[0069] An NTC thermistor with an accuracy of ±0.5℃ and a measurement range of -20℃ to 125℃ is attached to the side of the coil to collect the coil temperature in real time. The ambient temperature is preset to 25℃. When the coil temperature drops to 20℃-30℃, two intermittent pulses with a period of 1s, a duration of 500ms, and an amplitude of 12V are output again, simultaneously collecting voltage and current signals. If both acquisition results meet the requirements of voltage 4.2V (±0.05V) and current ≤49mA, a permanent stop command is sent to the drive circuit, the drive signal output stops, and charging is complete.

[0070] In another embodiment, the battery has a full charge voltage of 3.7V and a trickle charge threshold of 30mA. The voltage sensor has an accuracy of 0.1 and a measurement range of 0-4V. The current sampling resistor is 0.04Ω. The air-cooling unit consists of three miniature fans with a rated voltage of 3.3V and a speed of 4500rpm, delivering an airflow of 1.8m / s. The temperature detection element is a platinum resistance thermometer with an accuracy of ±0.3℃. At an ambient temperature of 23℃, the coil temperature needs to be reduced to 18℃-28℃. The re-output intermittent pulse has a period of 1.5s and an output duration of 300ms. When the voltage is 3.7V (±0.03V) and the current is ≤29mA after two acquisitions, the drive signal output stops.

[0071] It should be noted that the voltage and current signals are continuously acquired at 100ms intervals. After the air-cooling unit starts up, the wind speed is detected every 5s by the wind speed sensor. When the wind speed is lower than 1.5m / s, the fan speed is automatically increased to 6000rpm. The ambient temperature is acquired every 1min.

[0072] Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of the equivalents of the application are intended to be included within the invention.

[0073] The above description is merely a specific embodiment of the present invention, enabling those skilled in the art to understand or implement the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the present invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features of the invention herein.

Claims

1. A wireless charging device, comprising: The application relates to a wireless charging device for electronic equipment, which comprises the following parts: a transmitting module, which comprises a planar spiral transmitting coil, a magnetic isolation sheet and a ring-shaped magnetic ring, and the magnetic isolation sheet and the magnetic ring jointly define a magnetic flux cavity with a single opening; a receiving module, which is embedded in the wall of a device to be charged and comprises a spiral receiving coil close to the wall of the device to be charged; a charging box, which is provided with a circular positioning groove concentric with the transmitting coil, and the positioning groove is used for accommodating the device to be charged without directionality; when the device to be charged is placed in the positioning groove, the transmitting coil and the receiving coil are axially sleeved and share the same center line, the magnetic flux cavity encloses the external magnetic field of the two coils to improve the coupling efficiency, and a built-in air cooling unit in the charging box discharges the coil heat along an annular path.

2. A wireless charging method, comprising: The application further relates to a charging method, which comprises the following steps: S1: placing the device to be charged in the positioning groove at an arbitrary rotating angle, so that the transmitting coil and the receiving coil are axially sleeved; S2: outputting a high-frequency alternating magnetic field to the transmitting coil, and synchronously collecting the current value of the transmitting coil; if the current value exceeds a preset current range, the duty cycle of the driving signal is adjusted to control the current value in the preset current range; S3: collecting the voltage signal output by the receiving coil after rectification, and calculating the variation of adjacent two voltage signals; if the variation exceeds a preset amplitude, the driving signal is paused and then restored after a fixed interval; S4: when the voltage signal reaches the full charging voltage of the battery and the corresponding output current is lower than a trickle threshold, the driving signal is switched to an intermittent pulse mode until the charging is completed. 3.The wireless charging method of claim 2, wherein, The charging box is provided with a driving circuit and an inverter circuit, and the step S2 of outputting a high-frequency alternating magnetic field to the transmitting coil specifically comprises the following steps: starting the built-in power supply of the charging box, inputting a direct-current voltage to the driving circuit of the transmitting coil, converting the direct-current voltage into an alternating voltage through the inverter circuit, setting the output frequency of the alternating signal according to the inherent resonance frequency of the transmitting coil, so that the planar spiral transmitting coil generates a high-frequency alternating magnetic field under the driving of the alternating voltage, collecting the intensity value of the alternating magnetic field through a magnetic field detection point arranged on the inner side of the ring-shaped magnetic ring, and increasing the output power of the driving circuit if the intensity value is lower than a preset threshold value. The high-frequency alternating magnetic field is kept in an output state, and the magnetic flux cavity formed by the magnetic isolation sheet and the ring-shaped magnetic ring is used for confining the magnetic field in the coupling area of the transmitting coil and the receiving coil. The step S2 of synchronously collecting the current value of the transmitting coil comprises the following steps: synchronously collecting the current signals at the starting end, the middle end and the terminal end of the planar spiral transmitting coil, and taking the arithmetic average of the current signals at the three positions as the judgment basis; 4.The wireless charging method of claim 2, wherein, if the average value is higher than the upper limit of the preset current range, the adjustment amplitude is determined according to the difference between the average value and the upper limit, that is, the duty cycle adjustment amount is increased by 1% of the rated current of the transmitting coil for each increase of the difference; if the average value is lower than the lower limit of the preset current range, the adjustment amplitude is determined according to the difference between the average value and the lower limit, that is, the duty cycle adjustment amount is increased by 1% of the rated current of the transmitting coil for each increase of the difference, and the current signal is collected again after adjustment for verification. The step S2 of adjusting the duty cycle of the driving signal specifically comprises the following steps: confirming that the single opening of the magnetic flux cavity faces the same direction as the receiving coil through a magnetic field direction detection element at the opening of the magnetic flux cavity of the transmitting module. 5.The wireless charging method of claim 2, wherein, ​ ​ If the opening is offset, the emission module is fine-tuned by the position adjustment structure of the emission module so that the opening is directly opposite the receiving coil, and then the deviation of the current value from the preset range is determined, and the deviation value is used to divide the adjustment level; The duty cycle is adjusted step by step according to the amplitude corresponding to the adjustment level, and the high-frequency alternating magnetic field output is maintained and the current value is collected after each adjustment. 6.The wireless charging method of claim 2, wherein, The current value is controlled in the preset current range in step S2, including: The coincidence state of the center of the device to be charged and the center of the positioning groove is judged by the position detection element in the circular positioning groove of the charging box; If the coincidence state of the two is completely coincident, the duty cycle is changed at intervals of 1 / 20 of the driving signal period; If the coincidence state of the two is offset, the duty cycle is changed at intervals of 1 / 10 of the driving signal period; The current value is collected after each adjustment until the current value is controlled in the preset current range. 7.The wireless charging method of claim 2, wherein, In step S3, the voltage signal output by the receiving coil after rectification is collected, and the change amount of the adjacent two voltage signals is calculated, including: Two voltage collection points are set at the output end of the receiving coil rectifier circuit, corresponding to the positive and negative ends of the rectifier output respectively, and the collection points are electrically connected with the spiral end of the receiving coil; The output voltage value of the receiving coil after rectification is continuously obtained through the collection points at a preset time interval to obtain the first voltage signal and the second voltage signal; The value of the second voltage signal is subtracted from the value of the first voltage signal to obtain the change amount of the adjacent two voltage signals, and the relative position state of the transmitting coil and the receiving coil at the time of collection is recorded. 8.The wireless charging method of claim 2, wherein, If the change amount exceeds the preset amplitude in step S3, the driving signal is paused and the driving signal is restored after a fixed interval, including: If the change amount exceeds the preset amplitude, send a stop command to the driving circuit of the transmitting coil to interrupt the high-frequency alternating magnetic field output, and pause the driving signal; Start the timing structure built-in the charging box, start timing according to the preset fixed time, and keep the relative position of the transmitting coil and the receiving coil unchanged during timing; After timing, send a start command to the driving circuit of the transmitting coil to restore the high-frequency alternating magnetic field output and output the driving signal again. 9.The wireless charging method of claim 2, wherein, In step S4, the driving signal is switched to the intermittent pulse mode, including: When the voltage signal reaches the battery full charge voltage and the corresponding output current is lower than the trickle threshold, confirm whether the transmitting coil and the receiving coil share the same center line by the preset position detection structure in the circular positioning groove of the charging box whether the transmitting coil and the receiving coil share the same center line; If the two axes are completely coincident, the driving signal is directly switched to the intermittent pulse mode; If the two axes are offset, the elastic guide element arranged on the inner wall of the circular positioning groove of the charging box pushes the device to be charged, so that the device to be charged moves radially along the positioning groove to the axis of the transmitting coil and the receiving coil, and then the driving signal switching operation is performed.

10. A wireless charging system, comprising: The wireless charging system is used to execute the wireless charging method of claim 2, including: The coil fitting positioning module is used to put the device to be charged into the positioning groove at any rotation angle, so that the transmitting coil and the receiving coil are axially fitted; The current value adjustment module is configured to output a high-frequency alternating magnetic field to the transmitting coil, and synchronously collect a current value of the transmitting coil. If the current value exceeds a preset current range, the duty cycle of the driving signal is adjusted to control the current value within the preset current range. The voltage determination and control module is configured to collect a voltage signal output by the receiving coil after rectification, calculate a variation of two adjacent voltage signals, and pause the driving signal if the variation exceeds a preset amplitude and resume the driving signal after a fixed interval. The full-charge state pulse switching module is configured to switch the driving signal to an intermittent pulse mode when the voltage signal reaches a battery full-charge voltage and a corresponding output current is lower than a trickle threshold, until the charging is completed.

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