Stacked Two-Sided Charging Coils With Magnetic Insulation

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Solution Overview

Problem

Conventional inductive charging systems for wireless accessory devices require precise positioning of coils, leading to inefficient power transmission due to rapid power loss with distance, and can cause magnetic coupling issues that may damage charging circuitry.

Innovation Solution

A system with two transmission coils and two receiving coils, stacked with a spacer to prevent magnetic coupling, allowing efficient charging in multiple positions by positioning coils close to the device surfaces, reducing size and power requirements.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If two transmission coils are stacked close to opposite surfaces for efficient charging in multiple positions, then charging efficiency is improved, but magnetic coupling between coils causes power loss and potential damage to charging circuitry

Engineering Contradiction:
Improvepower lossVSAvoidcharging position flexibility
Core Design Contradiction:
Loss of energyVSAdaptability or versatility

Solution Approach 1:

A non-conductive spacer is positioned between the first transmission coil and the second transmission coil to physically separate them and prevent magnetic coupling. This intermediary element allows the coils to be stacked close to opposite surfaces for efficient charging while maintaining sufficient distance to avoid harmful magnetic interactions and power loss.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Loss of energy

If transmission coil and receiving coil are positioned close together for efficient power transmission, then power transmission efficiency is improved, but precise positioning requirements increase device complexity

Engineering Contradiction:
Improvepower transmission efficiencyVSAvoidpositioning precision requirements
Core Design Contradiction:
Loss of energyVSDevice complexity

Solution Approach 1:

The system transitions from a single-plane coil arrangement to a three-dimensional stacked configuration with coils on opposite surfaces. This dimensional change allows the accessory to be charged in multiple orientations (e.g., lid-up or lid-down for laptops) while maintaining close proximity between transmission and receiving coils for efficient power transfer.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

3Adaptability or versatility

If two transmission coils are used for multi-position charging, then charging versatility is improved, but device size and power requirements increase

Engineering Contradiction:
Improvecharging position flexibilityVSAvoiddevice size
Core Design Contradiction:
Adaptability or versatilityVSVolume of moving object

Solution Approach 1:

The first and second transmission coils are stacked in a nested configuration on opposite surfaces of the electronic device, with a non-conductive spacer between them. This nesting approach allows both coils to be integrated into the same device footprint without significantly increasing overall size, enabling multi-position charging while maintaining compact form factor.

Inventive Principle:
Principle #7Nested doll (Nesting)

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 efficient wireless charging in multiple positions with reduced power consumption and size, maintaining power transmission efficiency while preventing magnetic coupling damage.

Implementation Method 1

Inductive charging provides a current through transmission coil to generate a magnetic field

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 2

The spacer material magnetically insulates the second transmission coil from the first magnetic field

Methodology Applied
Scientific EffectMagnetic insulation: Magnetic Field

Data Source

PatentEP4014299B1Two-sided inductive charging coil
Publication Date: 2024.01.24 MICROSOFT TECHNOLOGY LICENSING LLC
  • EP4014299B1 patent drawingFigure 1-1~1-2
  • EP4014299B1 patent drawingFigure 2-1~2-2
  • EP4014299B1 patent drawingFigure 3~4

AI summary

A device for inductively charging an electronic accessory includes a first portion, a second portion, and a spacer. The first portion includes a first transmission coil in a first plane where the first transmission coil is configured to generate a first magnetic field, and the second portion includes a first transmission coil in a second plane where the second transmission coil is configured to generate a second magnetic field. The spacer is positioned between the first transmission coil and the second transmission coil and between the first plane and the second plane. The spacer material magnetically insulates the second transmission coil from the first magnetic field.