Wireless Charging Impedance Modulation for Compact Devices
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Solution Overview
Problem
Existing wireless charging technologies, such as those implementing the Qi interface standard, are not suitable for small or simple portable electronic devices due to their complexity and size requirements, limiting their application to devices with sufficient physical size and processing power.
Innovation Solution
A wireless charging system that uses simplified protocols for communication between a power transmitting device and a power receiving device, reducing processing and communication requirements, allowing for implementation in compact devices with reduced power signal modulation through impedance modulation of the receiving coil.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If Qi interface standard is implemented for wireless charging, then power transfer capability is achieved, but device complexity and size requirements increase
Solution Approach 1:
The patent extracts and removes the complex packet-based communication protocol and modulation requirements from the wireless charging system. By eliminating these complex communication elements while retaining the essential magnetic induction power transfer mechanism, the system achieves wireless charging functionality with significantly reduced device complexity and processing requirements, enabling implementation in simple devices like earphones and hearing aids.
2Device complexity
If simplified communication protocols are used, then device complexity is reduced, but communication reliability between power devices may worsen
Solution Approach 1:
The patent implements a self-service mechanism where the power receiving device automatically detects the presence of a power transmitting device and autonomously adjusts its power consumption based on available power, eliminating the need for complex bidirectional communication. The system uses simple presence detection and automatic power adjustment, achieving reliable operation without complex communication protocols.
3Device complexity
If impedance modulation is used for power adjustment, then processing power is reduced, but power signal control precision may worsen
Solution Approach 1:
The patent changes the operating parameters of the power receiving device by adjusting its impedance state based on detected power levels. Instead of using complex modulation techniques, the system simply switches between different impedance states (high and low) to control power reception, achieving adequate power control precision with minimal processing requirements through straightforward parameter changes.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Enables wireless charging in devices with low power requirements, such as earphones or hearing aids, by adjusting the power signal intensity based on impedance modulation, facilitating efficient power transfer without the need for complex circuitry, thus expanding the applicability to smaller portable electronic devices.
Implementation Method 1
The transmitting coil is coupled to the drive signal circuit, and is configured to receive the time-varying drive signal and to convert the time-varying drive signal into an alternating magnetic field that emanates from the power transmitting device
Implementation Method 2
power is transmitted from the power transmitting device to the power receiving device through magnetic inductive coupling between coils in the devices
Data Source
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AI summary
A wireless charging system (100, 200) includes a power transmitting device (110, 210) and a power receiving device (130, 230). In the transmitting device, a transmitting coil (212) converts (302) a drive signal from a drive signal circuit (216) into an alternating magnetic field. In the receiving device, a receiving coil (232) produces (402) an alternating waveform from the magnetic field, and a rectifier (234) rectifies (404) the alternating waveform to deliver power having a rectified voltage. A modulation circuit (248) causes (408) a loading circuit (260) to be coupled to and uncoupled from the receiving coil at a pre-determined modulation rate when, for example, the rectified voltage is greater than a threshold voltage. Back in the transmitting device, a modulation detector circuit (218) detects (304, 306) modulation of the load impedance, and when the load impedance is modulating at the pre-determined modulation rate, causes (310) the drive signal circuit (216) to adjust a characteristic of the drive signal, resulting in an adjustment in an intensity of the magnetic field.