Redundant Wireless Power Coils With Low Mutual Inductance

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Solution Overview

Problem

Existing power transmission systems for rotating electromechanical systems, such as slip rings, suffer from wear due to friction and reduced service life due to direct contact between electrically conductive components.

Innovation Solution

A wireless power transmission system with channel redundancy, utilizing coils with specific twists and orthogonal configurations on separate substrates to minimize mutual inductance and ensure fail-safe operation, allowing for independent power and data transmission across channels.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Duration of action of moving object

If wireless power transmission is implemented, then wear due to friction is eliminated, but system complexity increases due to multiple coils and channels

Engineering Contradiction:
Improveservice lifeVSAvoidsystem complexity
Core Design Contradiction:
Duration of action of moving objectVSDevice complexity

Solution Approach 1:

The system divides power transmission into multiple independent channels (first channel with one transmitting coil and one receiving coil, second channel with one transmitting coil and two receiving coils). Each channel can operate independently, allowing the system to maintain functionality even if one channel fails, thus eliminating wear while managing complexity through modular segmentation.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different coil configurations are assigned to different channels based on their specific requirements. The first channel uses a simple circular coil configuration, while the second channel uses twisted coil configurations with specific twist counts (Nt1 ≥ 0, Nt2 ≥ 1). This local differentiation optimizes each channel's performance while maintaining overall system reliability.

Inventive Principle:
Principle #3Local quality

2Reliability

If channel redundancy is implemented, then reliability against single-channel failure is improved, but device complexity increases

Engineering Contradiction:
ImprovereliabilityVSAvoiddevice complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The power transmission system is segmented into two independent channels with distinct transmitting and receiving coils. The first channel comprises one transmitting coil and one receiving coil, while the second channel comprises one transmitting coil and two receiving coils. This segmentation enables redundancy where if one channel fails, the other can continue operating, improving reliability without requiring a complete system redesign.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system incorporates redundant coil configurations before failure can occur. By providing alternative power transmission paths through multiple channels with different twist configurations, the system cushions against potential failures in advance, ensuring continuous operation even when one channel becomes defective.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

3Reliability

If coils with twists are used, then mutual inductance between channels is minimized, but manufacturing complexity increases

Engineering Contradiction:
Improvechannel independenceVSAvoidease of manufacture
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The second channel transmitting coil is designed with asymmetric twisted configurations (with Nt2 ≥ 1 twists) while the first channel uses a symmetric circular configuration (Nt1 ≥ 0). This intentional asymmetry in the twisted coils creates specific magnetic field patterns that minimize mutual inductance between channels, improving channel independence while the patent provides detailed guidance on achieving these configurations.

Inventive Principle:
Principle #4Asymmetry

Solution Approach 2:

The patent specifies precise parameter ranges for coil twists (Nt1 ≥ 0, Nt2 ≥ 1) to optimize magnetic coupling characteristics. By controlling the number and configuration of twists as key parameters, the system achieves minimal mutual inductance between channels while providing manufacturable specifications that guide the fabrication process.

Inventive Principle:
Principle #35Parameter 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

The system provides reliable and efficient power and communication signal transmission with redundancy, overcoming single-channel failures and reducing wear, suitable for applications like torque sensors and slip ring replacements.

Implementation Method 1

a first-channel transmitting coil disposed on a first substrate... configured to receive power from the transmission circuitry... a first-channel receiving coil disposed on a second substrate... configured to receive transmitted power from the first-channel transmitting coil

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Data Source

PatentEP4718484A1Wireless power transmission with channel redundancy
Publication Date: 2026.04.01 ALLEGRO MICROSYSTEMS LLC
  • EP4718484A1 patent drawingFigure 1~2
  • EP4718484A1 patent drawingFigure 3(i)~3(iv)
  • EP4718484A1 patent drawingFigure 4

AI summary

Systems, structures, packages, circuits, and methods provide wireless power and communication signal transmission systems with channel redundancy. Embodiments can be used in mechanical systems having rotating components. Two emission coils can have different topologies and can be used with three or four reception coils. The chosen topologies can be selected to ensure and/or facilitate minimal mutual inductance across topologies when the reception coils are rotated relative to the emission coils. To minimize mutual inductance between coils of different power transmission channels, twists can be added to the coil topologies to alter coil field polarity. Angle sensing can be achieved by determining efficiency of power transmission between the transmission and reception coils.