Multi-tapped Coil for Wireless Charging Detection and Efficiency
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current wireless charging systems face a power dissipation tradeoff between detection range and power transfer efficiency, particularly with the introduction of higher power standards like Qi 1.2, where finding an optimal inductance value is challenging, leading to incomplete charging and device discharge issues.
Innovation Solution
A wireless charging system that includes a controller coupled to a multi-tapped coil and rectifier, allowing selective configuration between detection and power receiving circuits, enabling efficient power delivery by adjusting signal levels and inductance values based on detected signal thresholds, and providing feedback to the transmitter for optimized power transfer.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a large inductance is used for signal detection, then detection range is improved, but power transfer efficiency deteriorates
Solution Approach 1:
The patent implements a dynamic switching mechanism that changes the receiver coil configuration between two states: a first configuration with larger inductance for signal detection, and a second configuration with smaller inductance for power transfer. The controller switches between these configurations based on the operational phase (detection vs. charging), allowing the system to optimize for detection range during initialization and for power transfer efficiency during charging, thereby resolving the contradiction between these two parameters.
Solution Approach 2:
The receiver coil is divided into multiple segments or taps with different inductance values. The controller can selectively connect different portions of the coil to achieve different inductance settings. This segmentation allows the system to use a larger inductance portion for detection and a smaller inductance portion for power transfer, eliminating the need to choose a single fixed inductance value that compromises either detection range or power transfer efficiency.
2Loss of energy
If inductance is optimized for power transfer, then power transfer efficiency is improved, but detection range deteriorates
Solution Approach 1:
The system dynamically adjusts the receiver coil inductance based on the operational requirements. During the detection phase, the controller configures the coil for larger inductance to maximize detection range. During the power transfer phase, the controller switches to a configuration with smaller inductance optimized for power transfer efficiency. This dynamic adaptation resolves the contradiction by allowing each parameter to be optimized at the appropriate time.
Solution Approach 2:
The receiver coil is designed with multiple taps or segments that can be selectively connected to achieve different inductance values. One segment configuration provides larger inductance for detection, while another provides smaller inductance for power transfer. The controller selects the appropriate segment configuration based on the current operational mode, thereby resolving the trade-off between detection range and power transfer efficiency.
3Device complexity
If a fixed inductance value is chosen, then device complexity is reduced, but adaptability to different power standards deteriorates
Solution Approach 1:
The receiver coil configuration is made dynamic and adjustable rather than fixed. The controller can switch between different coil configurations (different inductance values) based on the power standard being used (e.g., low power 5W vs. medium power 15W Qi standards). This dynamic capability allows the same hardware to adapt to different power standards without requiring multiple dedicated circuits, thereby maintaining relatively simple device architecture while achieving high adaptability.
Solution Approach 2:
The receiver coil is designed as a multi-functional component that can serve different purposes depending on configuration. By implementing switching circuitry that allows the same physical coil to be configured for different inductance values, the system achieves universality - a single coil structure that can operate with both low power and medium power Qi standards, as well as support both detection and power transfer functions, thereby reducing overall device complexity while enhancing adaptability.
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
This approach optimizes power transfer efficiency, ensuring complete charging without device discharge, even under higher power standards like Qi 1.2, by dynamically adjusting the system configuration and signal levels, thereby enhancing the user experience.
Implementation Method 1
a first signal corresponding to an externally transmitted signal that is magnetically coupled to the multi-tapped coil
Data Source
AI summary
A method, a portable electronic device and a wireless charging system enables a load to be charged by selectively using a detection circuit configuration and a power receiving circuit configuration. A controller is coupled within a wireless power receiver (i) to a sensing circuit having a multi-tapped coil and (ii) to a rectifier that is coupled to the sensing circuit and removably coupled to a load. The controller detects, at an output of the rectifier, a first signal corresponding to an externally transmitted signal that is magnetically coupled to the multi-tapped coil while the sensing circuit is in the detection circuit configuration. In response to detecting the first signal, the controller switches from the detection circuit configuration to the power receiving circuit configuration. The controller then connects the load to the output of the rectifier in order to deliver power to the load.