Wireless Charging Resonator Segmentation Using MEMS Switches

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Solution Overview

Problem

Existing wireless charging systems face the risk of damage to devices due to high currents or voltages when using passive detuning or reconfiguration methods, which requires costly high-power transistors to mitigate these risks.

Innovation Solution

The use of microelectromechanical system (MEMS) switches in the charging resonator assembly allows for safe detuning or disconnection of the resonator, dividing it into multiple electrically unconnected portions to manage induced currents and voltages, eliminating the need for high-power transistors.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If passive detuning or reconfiguration of the target device's antenna is used to protect from excessive charging power, then the risk of damage from overcharging is reduced, but high currents or voltages can still develop in the antenna requiring costly high-power transistors

Engineering Contradiction:

Improveprotection from overchargingVSAvoidhigh currents or voltages in antenna

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The antenna is divided into multiple segments that can be independently controlled. When overcharging is detected, specific segments are detuned or disconnected rather than the entire antenna, which reduces the magnitude of harmful currents and voltages while maintaining protection capability.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

A control circuit acts as an intermediary between the charging system and the antenna. This control circuit monitors charging conditions and selectively detunes antenna segments using standard-power transistors, eliminating the need for expensive high-power transistors while maintaining effective protection.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Reliability

If the antenna is detuned to open circuit or disconnected to protect from high currents, then damage from excessive power is mitigated, but costly high-power transistors are required to handle the resulting high currents or voltages

Engineering Contradiction:

Improveprotection from high currentsVSAvoiduse of high-power transistors

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The antenna structure is segmented into multiple sections with individual control. By detuning only specific segments rather than disconnecting the entire antenna, the harmful currents are reduced to levels that can be handled by standard-power transistors, eliminating the need for expensive high-power components.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different segments of the antenna are independently controlled based on local conditions. When overcharging is detected, only the affected segments are detuned, allowing standard-power transistors to manage the reduced local currents while other segments remain operational.

Inventive Principle:

Principle #3Local quality

3Reliability

If high-power transistors are used to disconnect the antenna from downstream components to prevent damage, then the target device is protected from high currents, but the bill of materials cost increases significantly

Engineering Contradiction:

Improveprotection from high currentsVSAvoidbill of materials cost

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The antenna is divided into multiple segments that can be independently controlled. This segmentation allows standard-power transistors to manage the detuning of individual segments, reducing the current handling requirements and eliminating the need for expensive high-power transistors, thereby reducing bill of materials cost.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

A control circuit serves as an intermediary that monitors charging conditions and selectively detunes antenna segments using standard-power transistors. This intermediary approach enables effective protection against high currents while using cost-effective components, significantly reducing the bill of materials cost.

Inventive Principle:

Principle #24Intermediary (Mediator)

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 safely manages induced currents and voltages, reducing the risk of damage to devices and lowering material costs by utilizing MEMS switches, which can handle higher currents and voltages than traditional transistors.

Implementation Method 1

a charging resonator assembly for converting energy from a magnetic field external to the apparatus into an electric current

Methodology Applied

Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 2

the charging resonator assembly includes a plurality of microelectromechanical system (MEMS) switches which, when open, divide the charging resonator into a plurality of electrically unconnected resonator portions

Methodology Applied

Scientific EffectElectrical resistance: Electrical Resistance

Data Source

PatentUS9325184B2Apparatus for wirelessly charging a rechargeable battery

Publication Date: 2016.04.26 QUALCOMM TECH INT

AI summary

The present application relates to apparatus for wirelessly charging a rechargeable battery, the apparatus comprising: a charging resonator assembly for converting energy from a magnetic field external to the apparatus into an electric current; and a charging circuit for charging the battery using the electric current, wherein the charging resonator assembly includes a plurality of microelectromechanical system (MEMS) switches which, when open, divide the charging resonator into a plurality of electrically unconnected resonator portions, and which, when closed, connect the plurality of resonator portions to form a continuous resonator.