Inductive Power Transmitter With Multi-Coil Field Control

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Solution Overview

Problem

Inductive power transfer systems face challenges in efficiently charging portable devices without constraining device orientation, as existing solutions require multiple receiving coils or constrained device placement to ensure adequate coupling, which can limit device design and market feasibility.

Innovation Solution

The use of multiple overlapping planar transmitting coils with independent control of coil voltages to manipulate the magnetic field direction, allowing a single receiving coil to be oriented in any 3D direction, and employing a controller to adjust the AC supply signal for each coil to optimize coupling with an unconstrained inductive power transfer receiver.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If multiple receiving coils are used in the receiver, then coupling with the transmitter is improved, but device complexity and manufacturing cost increase

Engineering Contradiction:

Improvecoupling reliabilityVSAvoidreceiver coil configuration

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

Instead of making the receiver complex with multiple coils to adapt to the transmitter, the invention inverts the approach by making the transmitter complex with multiple independently controllable coils to adapt to any simple single-coil receiver design. This allows the receiver to remain simple while achieving universal compatibility.

Inventive Principle:

Principle #13The other way round (Inversion)

Solution Approach 2:

The transmitter employs dynamic control of multiple coils through independent voltage adjustment via control devices, allowing real-time manipulation of magnetic field direction and strength to maintain optimal coupling with receivers in any orientation or position.

Inventive Principle:

Principle #15Dynamics

2Loss of energy

If device orientation is constrained during charging, then coupling efficiency is improved, but ease of operation deteriorates

Engineering Contradiction:

Improvepower transfer efficiencyVSAvoiddevice placement flexibility

Core Design Contradiction:

Loss of energyVSEase of operation

Solution Approach 1:

The system dynamically adjusts the excitation of multiple transmitting coils based on the receiver's position and orientation, continuously optimizing magnetic field coupling without requiring the user to manually align devices in specific orientations.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The control devices monitor coupling conditions and adjust AC supply signals to each transmitting coil accordingly, creating a feedback loop that maintains efficient power transfer regardless of receiver placement or orientation on the charging surface.

Inventive Principle:

Principle #23Feedback

3Adaptability or versatility

If multiple transmitting coils with independent control are used, then adaptability to unconstrained receivers is improved, but transmitter circuit complexity increases

Engineering Contradiction:

Improvereceiver orientation compatibilityVSAvoidtransmitter control circuit

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The transmitter is segmented into multiple independently controllable coil units, each with its own control device, allowing modular management of complexity where each segment handles a specific spatial zone or orientation range.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The array of transmitting coils with independent control creates a universal charging surface that can accommodate receivers in any orientation or position, making the system multi-functional and adaptable to all use scenarios.

Inventive Principle:

Principle #6Universality (Multi-functionality)

4Adaptability or versatility

If coil voltages are independently adjusted to manipulate magnetic field direction, then coupling with unconstrained receivers is improved, but energy loss increases

Engineering Contradiction:

Improvemagnetic field orientation controlVSAvoidpower transfer loss

Core Design Contradiction:

Adaptability or versatilityVSLoss of energy

Solution Approach 1:

The control devices use feedback from coupling detection to optimize voltage adjustment, minimizing energy waste by only activating and adjusting the minimum necessary coil combinations required to achieve effective coupling with the receiver.

Inventive Principle:

Principle #23Feedback

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 enables efficient inductive power transfer without constraining device orientation, simplifies the transmitter circuit, reduces component costs and losses, and allows for charging from a greater distance, making it suitable for mass adoption in consumer markets.

Implementation Method 1

a plurality of planar transmitting coils; and an inverter configured to provide an AC supply signal... a direction of a magnetic field generated by the adjusted AC supply signal in the plurality of transmitting coils

Methodology Applied

Scientific EffectElectromagnetic induction: Electromagnetic Induction

Data Source

PatentUS11251661B2Inductive power transmitter

Publication Date: 2022.02.15 APPLE INC

AI summary

An inductive power transmitter 2 comprising: a plurality of transmitter coils 7; a controller 8 configured to selectively energise the coils 7 in order to couple a receiver 3, the coils 7 selected being dependent on an orientation of the receiver 3, a power transfer optimisation algorithm, or a lookup table.