Wireless Charging Transmitter Redundant Sensing Standby Power

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Conventional wireless power transmitters consume excessive power during standby mode when using inductance-based sensing to detect devices in the charging region, leading to high standby power consumption.

Innovation Solution

Implementing a low-power capacitive or optical sensing method initially to detect device proximity, followed by inductive sensing to confirm device presence, thereby reducing power consumption during standby mode.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If inductive sensing is used to detect devices in the charging region, then device detection accuracy is improved, but standby power consumption increases

Engineering Contradiction:
Improvedevice detection accuracyVSAvoidstandby power consumption
Core Design Contradiction:
Measurement precisionVSUse of energy by stationary object

Solution Approach 1:

The device detection process is segmented into two phases: initial detection using low-power capacitive sensing, and confirmation detection using inductive sensing. This segmentation allows the system to use different sensing methods for different stages of the detection process, reducing overall power consumption while maintaining detection accuracy.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Capacitive sensing is performed as a preliminary action before inductive sensing. The capacitive sensor performs initial device detection and proximity assessment, and only when an object is detected does the system activate the more power-consuming inductive sensing for confirmation. This preliminary action prevents unnecessary activation of high-power sensing.

Inventive Principle:
Principle #10Preliminary action

2Reliability

If continuous inductive sensing is used to monitor charging region, then device presence detection is reliable, but energy consumption increases

Engineering Contradiction:
Improvedevice presence detection reliabilityVSAvoidenergy consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The system uses periodic capacitive sensing to monitor the charging region, activating inductive sensing only periodically when needed for confirmation. This periodic action pattern maintains reliable detection capability while significantly reducing continuous energy consumption compared to constant inductive sensing.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The capacitive sensor acts as an intermediary between the environment and the inductive sensing system. It monitors for potential device presence and triggers inductive sensing only when necessary, serving as a low-power mediator that reduces the burden on the high-power inductive sensing system.

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

Significantly reduces power consumption during device detection in standby mode by using low-power capacitive or optical sensing, followed by inductive confirmation, minimizing unnecessary power usage.

Implementation Method 1

a capacitive sensor that is configured to detect changes in a capacitance signal in response to proximity of an object

Methodology Applied
Scientific EffectCapacitive sensing: Capacitance

Implementation Method 2

an optical sensor that is configured to detect changes in an optical signal in response to proximity of an object

Methodology Applied
Scientific EffectOptical sensing: Light

Implementation Method 3

an inductive sensor configured to detect a change of inductance of the transmit coil

Methodology Applied
Scientific EffectInductive sensing: Electromagnetic Induction

Data Source

PatentEP3065264B1Wireless charging transmitter using redundant sensing for device detection
Publication Date: 2019.11.06 MEDIATEK INC
  • EP3065264B1 patent drawingFigure 1~2
  • EP3065264B1 patent drawingFigure 3~4
  • EP3065264B1 patent drawingFigure 5A~5B

AI summary

Apparatus and methods for detecting the presence of a wireless power receiving device to be charged by a wireless power transmitter are described. A first low-power sensing apparatus and method may be used to detect the presence of a device placed in a charging area of the wireless power transmitter. A second sensing apparatus and method may be used to confirm the presence of a device placed in a charging area, and initiate charging of the device.