A high-power wireless charging receiving coil voltage identification circuit
Patent Information
- Application Number
- CN202522055186.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-09-24
- Publication Date
- 2026-09-18
- Estimated Expiration
- 2035-09-24
AI Technical Summary
[0002]大功率无线充电设备通过发射线圈和接收线圈传递电能（见图1），在无线充电发射装置和无线充电接收装置配对识别阶段接收线圈电压最小低至20V左右，而在正常功率传输阶段接收线圈电压最大高至2000V左右，电压变化范围差100倍，常规识别电路做到识别2000V电压后，在识别20V电压时，信号过小难以精确识别，所以需要一种简单、可靠、低成本的宽范围电压幅值和频率识别电路
Smart Images
Figure CN224774686U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the technical field of wireless charging circuits, specifically a high-power wireless charging receiver coil voltage identification circuit. Background Technology
[0002] High-power wireless charging devices transfer electrical energy through transmitting and receiving coils (see...) Figure 1 During the pairing and identification phase of the wireless charging transmitter and receiver, the receiving coil voltage is as low as about 20V, while during the normal power transmission phase, the receiving coil voltage is as high as about 2000V, a difference of 100 times. Conventional identification circuits can identify 2000V voltage, but when identifying 20V voltage, the signal is too small to be accurately identified. Therefore, a simple, reliable, and low-cost wide-range voltage amplitude and frequency identification circuit is needed. Utility Model Content
[0003] To address the aforementioned issues, this invention provides a high-power wireless charging receiver coil voltage identification circuit, which can identify voltage amplitude and frequency over an ultra-wide range of 20V-2000V, thus meeting the voltage identification requirements of high-power wireless charging coils.
[0004] A high-power wireless charging receiver coil voltage identification circuit, characterized in that it includes: input resistor R1, input resistor R2, input resistor R4, input resistor R5, feedback resistor R3, voltage divider resistor R6, general-purpose operational amplifier U1, resistor R7, capacitor C1, switch SW1, switch SW2, and a 1.5V bias voltage. The input resistors R1 and R2 are connected in series. The input terminal of the input resistor R1 is connected to the first input terminal In1. The two ends of the input resistor R2 are also connected in parallel to the switch SW1. The output terminal of the input resistor R2 is connected to the input terminal of the feedback resistor R3 and one end of the general-purpose operational amplifier U1 through connecting lines. The output terminal of the feedback resistor R3 is connected to one end of the resistor R7. One end of the resistor R7 is also connected in parallel to the output terminal of the general-purpose operational amplifier U1. The input resistors R4 and R5 are connected in series. The input terminal of the input resistor R4 is connected to the second input terminal In2. The two ends of the input resistor R5 are also connected in parallel to the switch SW2. The output terminal of the input resistor R5 is connected to the input terminal of the voltage divider resistor R6 and the + terminal of the general-purpose operational amplifier U1 through connecting lines. The voltage divider resistor R6 is connected to a 1.5V bias voltage and then grounded. The other end of the resistor R7 is connected to the capacitor C1, the grounding part, and the output terminal Out3 via connecting wires.
[0005] Its further features are: The input resistors R1, R2, and R5, and the feedback resistor R3 and voltage divider resistor R6, together with the input resistors R1, R2, R4, R5, R3, R6, R7, and capacitor C1, form an RC low-pass filter with a cutoff frequency much higher than 90kHz, having no effect on signals in the 80-90kHz range. Given that R3 / (R1+R2)=1 / 2000 and R3 / R1=1 / 200, when the differential voltage amplitude at the first input terminal In1 and the second input terminal In2 is between 20V and 200V, switches SW1 and SW2 are closed to short-circuit resistors R2 and R5, reducing the input signal to 1 / 200, i.e., 100mV-1000mV. When the differential voltage amplitude at the first input terminal In1 and the second input terminal In2 is between 200V and 2000V, switches SW1 and SW2 are open, reducing the signal to 1 / 2000, i.e., 100mV-1000mV. This circuit ensures that the output signal amplitude at the Out3 terminal is within a suitable range through switch switching.
[0006] After adopting the above technical solution, the voltage of the receiving coil is a high-frequency AC voltage of about 85kHz. This voltage identification circuit, assembled using the above structure (see...),... Figure 3 ), its receiving After the differential amplifier circuit is reduced in size, it is superimposed on a 1.5V bias voltage to form a processable high-frequency AC voltage signal. The high-frequency AC signal is converted into a square wave signal by a zero-crossing comparator circuit for MCU recognition. The high-frequency AC signal is converted into a DC signal by a precision rectification and filtering circuit for MCU recognition. It can recognize an ultra-wide range of voltage amplitude and frequency from 20V to 2000V, meeting the recognition requirements of high-power wireless charging coil voltage. Attached Figure Description
[0007] Figure 1 A schematic diagram of the existing wireless charging principle; Figure 2 This is a schematic diagram of the voltage identification circuit of this utility model; Figure 3 This is a simplified schematic diagram illustrating the application of this utility model in a wireless charging circuit. Figure 4 The simulation results of this utility model Figure 1 ; Figure 5 The simulation results of this utility model Figure 2 . Detailed Implementation
[0008] A high-power wireless charging receiver coil voltage identification circuit, characterized in that it includes: input resistor R1, input resistor R2, input resistor R4, input resistor R5, feedback resistor R3, voltage divider resistor R6, general-purpose operational amplifier U1, resistor R7, capacitor C1, switch SW1, switch SW2, and a 1.5V bias voltage. Input resistors R1 and R2 are connected in series. The input terminal of input resistor R1 is connected to the first input terminal In1. Switch SW1 is also connected in parallel across the two ends of input resistor R2. The output terminal of input resistor R2 is connected to the input terminal of feedback resistor R3 and one end of general-purpose operational amplifier U1 through connecting wires. The output terminal of feedback resistor R3 is connected to one end of resistor R7. The output terminal of general-purpose operational amplifier U1 is also connected in parallel across one end of resistor R7. Input resistors R4 and R5 are connected in series. The input terminal of input resistor R4 is connected to the second input terminal In2. Switch SW2 is also connected in parallel across the two ends of input resistor R5. The output terminal of input resistor R5 is connected to the input terminal of voltage divider resistor R6 and the + terminal of general-purpose operational amplifier U1 through connecting wires. Voltage divider resistor R6 is connected to ground after being connected to a 1.5V bias voltage. The other end of resistor R7 is connected to capacitor C1, ground, and output terminal Out3 via connecting wires.
[0009] In a specific embodiment, input resistor R1 = input resistor R4, input resistor R2 = input resistor R5, feedback resistor R3 = voltage divider resistor R6, and input resistors R1, R2, R4, R5, R3, R6, R7, and capacitor C1 form an RC low-pass filter with a cutoff frequency much higher than 90kHz, which has no effect on signals in the 80-90kHz range. Given that R3 / (R1+R2)=1 / 2000 and R3 / R1=1 / 200, when the differential voltage amplitude input to the first input terminal In1 and the second input terminal In2 is between 20V and 200V, switches SW1 and SW2 are closed to short-circuit resistors R2 and R5, reducing the input signal to 1 / 200, i.e., 100mV-1000mV. When the differential voltage amplitude input to the first input terminal In1 and the second input terminal In2 is between 200V and 2000V, switches SW1 and SW2 are open, reducing the signal to 1 / 2000, i.e., 100mV-1000mV. This circuit ensures that the amplitude of the Out3 signal is within a suitable range through switch switching.
[0010] Simulation results The differential voltages input to In1 and In2 are 20V and 200V, respectively, at 85kHz. At this time, SW1 and SW2 are closed, and out3 outputs the result. The simulation results are shown below. Figure 4 ; The differential input voltages of In1 and In2 are 200V and 2000V, respectively, at 85kHz. At this time, SW1 and SW2 are disconnected, and the output result is output by out3. The simulation structure is shown in the figure.
[0011] The voltage of the receiving coil is a high-frequency AC voltage of about 85kHz. The voltage recognition circuit assembled by the above structure receives a differential amplifier circuit, which then amplifies the signal and superimposes it on a 1.5V bias voltage to form a processable high-frequency AC voltage signal. The high-frequency AC signal is converted into a square wave signal by a zero-crossing comparator circuit for MCU recognition. The high-frequency AC signal is also converted into a DC signal by a precision rectification and filtering circuit for MCU recognition. It can recognize an ultra-wide range of voltage amplitude and frequency from 20V to 2000V, meeting the recognition requirements of high-power wireless charging coil voltage. It achieves wide-range voltage amplitude and frequency recognition through a simple, reliable, and low-cost voltage recognition circuit, meeting the recognition requirements of the horizontal coil voltage during the wireless charging pairing recognition stage and the normal power transmission stage.
[0012] It will be apparent to those skilled in the art that this invention is not limited to the details of the exemplary embodiments described above, and that it can be implemented in other specific forms without departing from the spirit or essential characteristics of this invention. Therefore, the embodiments should be considered illustrative and non-limiting in all respects, and the scope of this invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within this invention. No reference numerals in the claims should be construed as limiting the scope of the claims.
[0013] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.
Claims
1. A high-power wireless charging receiving coil voltage identification circuit, characterized in that, It includes: Input resistors R1, R2, R4, R5, feedback resistor R3, voltage divider resistor R6, general-purpose operational amplifier U1, resistor R7, capacitor C1, switch SW1, switch SW2, and 1.5V bias voltage; The input resistors R1 and R2 are connected in series. The input terminal of the input resistor R1 is connected to the first input terminal In1. The two ends of the input resistor R2 are also connected in parallel to the switch SW1. The output terminal of the input resistor R2 is connected to the input terminal of the feedback resistor R3 and one end of the general-purpose operational amplifier U1 through connecting lines. The output terminal of the feedback resistor R3 is connected to one end of the resistor R7. One end of the resistor R7 is also connected in parallel to the output terminal of the general-purpose operational amplifier U1. The input resistors R4 and R5 are connected in series. The input terminal of the input resistor R4 is connected to the second input terminal In2. The two ends of the input resistor R5 are also connected in parallel to the switch SW2. The output terminal of the input resistor R5 is connected to the input terminal of the voltage divider resistor R6 and the + terminal of the general-purpose operational amplifier U1 through connecting lines. The voltage divider resistor R6 is connected to a 1.5V bias voltage and then grounded. The other end of the resistor R7 is connected to the capacitor C1, the grounding part, and the output terminal Out3 via connecting wires.
2. The voltage identification circuit for a high-power wireless charging receiver coil according to claim 1, characterized in that: The input resistors R1, R2, and R5, and the feedback resistor R3 and voltage divider resistor R6, together with the input resistors R1, R2, R4, R5, R3, R6, R7, and C1, form an RC low-pass filter.
3. The voltage identification circuit for a high-power wireless charging receiver coil according to claim 2, characterized in that: Given that R3 / (R1+R2)=1 / 2000 and R3 / R1=1 / 200, when the differential voltage amplitude input to the first input terminal In1 and the second input terminal In2 is between 20V and 200V, switches SW1 and SW2 close to short-circuit resistors R2 and R5, reducing the input signal to 1 / 200, i.e., 100mV-1000mV; when the differential voltage amplitude input to the first input terminal In1 and the second input terminal In2 is between 200V and 2000V, switches SW1 and SW2 open, reducing the signal to 1 / 2000, i.e., 100mV-1000mV.