Non-Contact Power Supply Standby Control

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Solution Overview

Problem

Conventional non-contact power supply systems consume excessive power in standby mode and require multiple coils in the load device, leading to increased space and cost, as well as potential heating of foreign substrates due to inefficient power management.

Innovation Solution

A non-contact power supply system with a control unit that stops power transmission when no signal is detected, using a single secondary signal coil for both power reception and signal transmission, and coaxial arrangement of coils to minimize power consumption and prevent foreign substrate heating.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If the inverter circuit is intermittently driven in standby mode to suppress power consumption, then power consumption is reduced, but the system cannot respond quickly when power transmission is needed

Engineering Contradiction:
Improvepower consumptionVSAvoidresponse speed
Core Design Contradiction:
Use of energy by moving objectVSSpeed

Solution Approach 1:

The system dynamically adjusts the operating state of the inverter circuit based on real-time detection of foreign substrates. When a foreign substrate is detected, the inverter switches from intermittent operation to continuous operation, optimizing both power consumption and response speed according to actual conditions

Inventive Principle:
Principle #15Dynamics

2Power

If the inverter circuit is continuously driven to supply large amount of power, then power transmission capability is improved, but power consumption increases significantly

Engineering Contradiction:
Improvepower transmission capabilityVSAvoidpower consumption
Core Design Contradiction:
PowerVSUse of energy by moving object

Solution Approach 1:

The inverter circuit operates intermittently in standby mode, switching between on and off states. This periodic operation reduces average power consumption while maintaining the capability to provide continuous power when needed, based on foreign substrate detection results

Inventive Principle:
Principle #19Periodic action

3Object-affected harmful factors

If coils for signal transmission are provided in both power supply device and electric device, then foreign substrate heating is prevented, but device complexity increases

Engineering Contradiction:
Improveforeign substrate heatingVSAvoidnumber of coils
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The secondary coil in the electric device serves dual purposes: it functions as both a power receiving coil and a signal transmission coil. This multi-functionality eliminates the need for separate signal transmission coils, reducing device complexity while maintaining the capability to prevent foreign substrate heating through bidirectional communication

Inventive Principle:
Principle #6Universality (Multi-functionality)

4Reliability

If two secondary coils are provided in the electric device for power reception and signal transmission, then reliable communication is achieved, but space and cost increase

Engineering Contradiction:
Improvecommunication reliabilityVSAvoidspace requirement
Core Design Contradiction:
ReliabilityVSArea of stationary object

Solution Approach 1:

A single secondary coil performs both power reception and signal transmission functions. The coil receives power from the primary coil and simultaneously transmits signals back to the power supply device by modulating its impedance, achieving reliable bidirectional communication without requiring a second coil, thus saving space and reducing costs

Inventive Principle:
Principle #6Universality (Multi-functionality)

5Loss of energy

If the primary coil is magnetically coupled with the secondary coil, then power transmission efficiency is improved, but foreign substrate may be heated by induction heating

Engineering Contradiction:
Improvepower transmission efficiencyVSAvoidforeign substrate heating
Core Design Contradiction:
Loss of energyVSObject-affected harmful factors

Solution Approach 1:

The system uses feedback from the secondary coil to detect the presence of foreign substrates. When a foreign substrate is detected through impedance changes in the secondary coil, the system adjusts or stops power transmission to prevent heating, while maintaining efficient power transfer under normal conditions

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

Reduces power consumption in standby mode, minimizes the number of coils required in the load device, and prevents foreign substrate heating by optimizing power transmission and signal detection using a single secondary signal coil and coaxial coil arrangement.

Implementation Method 1

a power supply device for transmitting high frequency power; and a load device which contactlessly receives the high frequency power transmitted from the power supply device by electromagnetic induction

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 2

an inquiry unit having a primary signal coil for receiving a signal from the load device; a secondary signal coil which is magnetically coupled to the primary signal coil

Methodology Applied
Scientific EffectMagnetic coupling: Electromagnetic Induction

Implementation Method 3

an oscillation circuit, the primary signal coil being connected between output terminals of the oscillation circuit

Methodology Applied
Scientific EffectOscillation: Harmonic Oscillator

Implementation Method 4

an inverter circuit for supplying high frequency current to the primary power coil

Methodology Applied
Scientific EffectInversion:

Data Source

PatentEP2244351B1Non-contact power supply system
Publication Date: 2015.09.16 PANASONIC INTELLECTUAL PROPERTY MANAGEMENT CO LTD
  • EP2244351B1 patent drawingFigure 1~2
  • EP2244351B1 patent drawingFigure 3A~3B
  • EP2244351B1 patent drawingFigure 4

AI summary

A non-contact power supply system includes a power supply device (A) for transmitting high frequency power and a load device (B) which receives the high frequency power in a non-contact mode by electromagnetic induction to supply it to a load (100). The power supply device (A) includes a power transmission unit (1) having a primary power coil (10) and an inverter circuit (11), an inquiry unit (2) having at least one primary signal coil (20) and an oscillation circuit (21), a signal detection unit (3) and a control unit (4). The load device (B) includes a power reception unit (110) having a secondary power coil (111) magnetically coupled to the primary power coil (10) and a power conversion unit (112), a secondary signal coil (121) magnetically coupled to the primary signal coil (10), and a response unit (120) which is operated by electromotive force induced in the secondary signal coil (121). The control unit (4) stops power transmission when no signal is detected and executes power transmission when a signal is detected.