Wireless Power Receiver Time-Division Charging Control

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Solution Overview

Problem

Wireless charging systems using magnetic resonance technology often result in uneven charging times for multiple devices due to power distribution being affected by distance and geometry, leading to frustration as closer devices charge faster than those farther away.

Innovation Solution

Implementing a time division wireless charging method where a device nearer to the transmitter temporarily suspends power reception to allow more power to be received by devices farther away, using a flickering mechanism to regulate power distribution and balance charging times.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If magnetic resonance wireless charging is used to charge multiple devices simultaneously, then power transfer efficiency is improved, but charging time becomes uneven across devices at different distances

Engineering Contradiction:
Improvepower transfer efficiencyVSAvoidcharging time
Core Design Contradiction:
Use of energy by moving objectVSDuration of action of moving object

Solution Approach 1:

The patent implements time-division multiplexing where the nearer device periodically suspends power reception in time slots, allowing the farther device to receive power during those intervals. This periodic on-off cycling balances the total energy distribution across devices while maintaining magnetic resonance charging efficiency.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The system dynamically adjusts power distribution by having the nearer device flexibly switch between receiving power and suspending reception based on real-time charging status of multiple devices. This dynamic control enables adaptive power allocation to achieve uniform charging times.

Inventive Principle:
Principle #15Dynamics

2Speed

If the nearer device receives power continuously, then its charging speed is maximized, but the farther device experiences significantly longer charging time

Engineering Contradiction:
Improvecharging speedVSAvoidcharging completion time
Core Design Contradiction:
SpeedVSLoss of time

Solution Approach 1:

The nearer device operates in periodic cycles, alternating between active power reception phases and suspension phases. During suspension phases, the farther device receives enhanced power allocation, ensuring both devices complete charging in comparable total time despite different distances.

Inventive Principle:
Principle #19Periodic action

3Adaptability or versatility

If a single transmitter serves multiple receivers, then device versatility is improved, but power distribution becomes uneven due to distance variations

Engineering Contradiction:
Improvemulti-device charging capabilityVSAvoidpower distribution
Core Design Contradiction:
Adaptability or versatilityVSPower

Solution Approach 1:

The system uses time-division multiplexing to allocate power transmission slots dynamically. The nearer device suspends reception during designated time slots, allowing the transmitter to redirect power to the farther device, thereby achieving equitable power distribution across multiple devices with varying distances.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The power distribution system dynamically adjusts transmission parameters based on real-time device positions and charging states. This dynamic control enables a single transmitter to efficiently serve multiple receivers at different distances with balanced power allocation.

Inventive Principle:
Principle #15Dynamics

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 ensures more even battery charge levels across multiple devices by temporarily disconnecting the nearer device from resonance, allowing the farther device to receive more power and charge faster, thereby reducing the latency in charging completion.

Implementation Method 1

Wireless charging systems allow powering and charging of portable devices by using energy from electrical or magnetic fields at proximity to the portable devices

Methodology Applied
Scientific EffectMagnetic induction: Electromagnetic Induction

Implementation Method 2

Wireless charging using magnetic resonance (MR) technology enables charging of multiple Rx devices to be charged simultaneously positioned in proximity to the Tx

Methodology Applied
Scientific EffectMagnetic resonance: Resonance

Data Source

PatentEP2815481B1Regulation of wirelessly charging multiple devices from the same source
Publication Date: 2020.06.24 SANDISK TECHNOLOGIES LLC
  • EP2815481B1 patent drawingFigure 1
  • EP2815481B1 patent drawingFigure 2~3
  • EP2815481B1 patent drawingFigure 4~5

AI summary

A method performed in a wireless power transfer receiver includes determining whether a power transfer rate of the wireless power transfer receiver is at or above a threshold. The method further includes, in response to the power transfer rate being at or above the threshold, alternating between a power receiving mode and a non-power receiving mode in the wireless power transfer receiver. The wireless power transfer receiver being in the non-power receiving mode increases an amount of transmitted power that is available to be received by one or more other wireless power transfer receivers.