Wireless Charging Coil Repositioning for Misalignment Detection

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Solution Overview

Problem

Wireless power transfer efficiency is reduced due to misalignment of coils in wireless charging systems.

Innovation Solution

An electronic device is equipped with a wireless power transfer coil, an inverter, positioning equipment, and control circuitry to adjust the coil alignment by pausing the transfer session, determining the inductive coupling factor, or using baseline efficiency information to move the coil based on detected alignment or efficiency changes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If the wireless power transfer coils are misaligned, then the wireless power transfer efficiency is reduced, but if the coils are continuously adjusted during operation, then the system complexity increases

Engineering Contradiction:

Improvewireless power transfer efficiencyVSAvoidsystem complexity

Core Design Contradiction:

Loss of energyVSDevice complexity

Solution Approach 1:

The system performs alignment detection and coil positioning before the wireless power transfer session begins. The control circuitry determines an initial alignment metric between the transmitting and receiving coils, and the positioning equipment adjusts the coil positions to achieve optimal alignment before power transfer commences, preventing efficiency losses from misalignment.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The system uses the existing wireless power transfer signals and components to perform alignment detection and adjustment. The control circuitry utilizes the inductive coupling factor measurements from the power transfer process itself to determine alignment status, and the positioning equipment automatically adjusts coil positions based on these measurements, making the system self-aligning without requiring separate alignment mechanisms.

Inventive Principle:

Principle #25Self-service

2Measurement precision

If pauses are introduced in the wireless power transfer session to determine alignment, then alignment accuracy is improved, but the charging time increases

Engineering Contradiction:

Improvealignment measurement accuracyVSAvoidcharging time

Core Design Contradiction:

Measurement precisionVSLoss of time

Solution Approach 1:

The system performs alignment detection at selected intervals during the wireless power transfer session rather than continuously. The control circuitry determines the alignment metric at specific moments (such as at the beginning of the session or when efficiency drops below a threshold), achieving sufficient alignment accuracy without requiring continuous pauses that would extend charging time.

Inventive Principle:

Principle #16Partial or excessive action

Solution Approach 2:

The system implements periodic alignment checks during the power transfer session. The control circuitry monitors the inductive coupling factor at regular intervals or when triggered by efficiency degradation, and performs positioning adjustments only when misalignment is detected, balancing measurement accuracy with minimal disruption to the charging process.

Inventive Principle:

Principle #19Periodic action

3Reliability

If the positioning equipment moves the coil during operation, then alignment is maintained, but the device complexity and control requirements increase

Engineering Contradiction:

Improvealignment maintenanceVSAvoidcontrol requirements

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The system implements a feedback control mechanism where the control circuitry continuously or periodically measures the inductive coupling factor between the transmitting and receiving coils. Based on these measurements, the control circuitry determines whether alignment has degraded and triggers positioning adjustments only when necessary, maintaining reliable alignment while minimizing control complexity through event-driven operation.

Inventive Principle:

Principle #23Feedback

Solution Approach 2:

The system replaces complex mechanical alignment mechanisms with electromagnetic field-based detection and control. The control circuitry uses electrical measurements of the inductive coupling factor to assess alignment status and triggers electronic control of the positioning equipment, substituting direct mechanical alignment systems with field-based sensing and electronic actuation.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

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

Improves wireless power transfer efficiency by aligning coils, ensuring optimal power transfer and reducing inefficiencies caused by misalignment.

Implementation Method 1

determine an inductive coupling factor between the electronic device and the additional electronic device

Methodology Applied

Scientific EffectInductive coupling: Electromagnetic Induction

Data Source

PatentUS20250323537A1Detecting Coil Misalignment in Wireless Charging Systems

Publication Date: 2025.10.16 APPLE INC

AI summary

A wireless charging system may include a wireless power receiving device that receives wireless power signals from a wireless power transmitting device. The wireless power transmitting device may include positioning equipment that moves a wireless power transfer coil to align the wireless power transfer coil for wireless power transfer. The wireless power transmitting device may periodically assess coil alignment during a wireless power transfer session by intermittently checking efficiency or an inductive coupling factor.