Power Transmission Control Device for Foreign Object Detection

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Solution Overview

Problem

Existing non-contact power transmission systems face challenges in reducing power consumption, ensuring safety and reliability, and minimizing size and cost, particularly in detecting foreign objects and managing power transmission efficiently without metal-to-metal contact.

Innovation Solution

A power transmission control device that uses a primary coil and secondary coil for electromagnetic coupling, employing intermittent temporary power transmission to detect the presence of a power-receiving instrument, performing ID authentication, and stopping power transmission when foreign objects or inappropriate loads are detected, thereby reducing unnecessary power consumption and ensuring safety.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If continuous power transmission is performed to ensure reliable power supply, then power transmission reliability is improved, but power consumption increases and battery life decreases

Engineering Contradiction:
Improvepower transmission reliabilityVSAvoidpower consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The system performs intermittent temporary power transmission at predetermined intervals instead of continuous transmission. The control circuit transmits power temporarily multiple times periodically to detect presence of power-receiving instruments, then stops transmission when no instrument is detected, thereby reducing power consumption while maintaining transmission reliability through periodic monitoring.

Inventive Principle:
Principle #19Periodic action

2Ease of operation

If power transmission is performed without detection to improve convenience, then ease of operation is improved, but safety and reliability deteriorate due to foreign object heating

Engineering Contradiction:
Improveease of useVSAvoidsafety and reliability
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The system performs preliminary detection of power-receiving instruments and foreign objects before initiating continuous power transmission. The control circuit temporarily transmits power first to detect the presence of instruments or foreign objects, and only after confirming safety does it proceed to normal power transmission, thereby ensuring safety while maintaining ease of use.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system uses feedback from temporary power transmission to detect the presence of power-receiving instruments and foreign objects. The control circuit monitors the response during temporary transmission and adjusts the power transmission state accordingly, stopping transmission when foreign objects are detected to prevent heating, thus maintaining both safety and ease of operation.

Inventive Principle:
Principle #23Feedback

3Reliability

If manual detection and control operations are implemented to ensure safety, then safety and reliability are improved, but device complexity increases

Engineering Contradiction:
Improvesafety and reliabilityVSAvoidsystem complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The system performs automatic detection and control operations without requiring manual intervention. The control circuit autonomously executes temporary power transmission, detects the presence of instruments or foreign objects, and adjusts the power transmission state automatically, thereby ensuring safety and reliability while minimizing device complexity by eliminating manual detection and control mechanisms.

Inventive Principle:
Principle #25Self-service

4Use of energy by moving object

If intermittent temporary power transmission is performed to reduce power consumption, then power consumption is reduced, but detection accuracy may deteriorate

Engineering Contradiction:
Improvepower consumptionVSAvoiddetection accuracy
Core Design Contradiction:
Use of energy by moving objectVSMeasurement precision

Solution Approach 1:

The system performs intermittent temporary power transmission at predetermined intervals with optimized duration and frequency. This periodic transmission provides sufficient electromagnetic signal strength for accurate detection of power-receiving instruments and foreign objects while minimizing overall power consumption, thereby balancing detection accuracy with energy efficiency.

Inventive Principle:
Principle #19Periodic action

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 solution significantly reduces power consumption, enhances safety and reliability by preventing abnormal heat generation and skin burns, and minimizes system size and cost by automating the detection of foreign objects and appropriate load conditions.

Implementation Method 1

non-contact power transmission (contactless power transmission) that utilizes electromagnetic induction to enable power transmission without metal-to-metal contact

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Data Source

PatentEP2079144B1Power transmission control device, power transmitting device, non-contact power transmission system, electronic instrument, and power transmission control method
Publication Date: 2020.07.29 SEIKO EPSON CORP
  • EP2079144B1 patent drawingFigure 1A~1B
  • EP2079144B1 patent drawingFigure 2
  • EP2079144B1 patent drawingFigure 3A~3B

AI summary

A power transmission control device (20) provided in a power transmitting device (10) of a non-contact power transmission system includes a power-transmitting-side control circuit (22) that controls power transmission to a power receiving device (40), the power-transmitting-side control circuit (22) causing the power transmitting device (10) to perform intermittent temporary power transmission, detecting a response from the power receiving device (40) that has received the power due to the temporary power transmission to automatically detect installation of a power-receiving-side instrument that includes the power receiving device (40) in an area in which power transmitted via non-contact power transmission can be received, and causing the power transmitting device (10) to perform continuous normal power transmission to the power receiving device (40) when the installation of the power-receiving-side instrument has been detected. A foreign object detection process may also be performed in combination.