Vehicular Contactless Charging Coil Frequency Switching for Radio Noise

Solution Overview

Problem

Vehicular contactless charging devices introduce noise into vehicle-mounted radios due to harmonic frequencies, necessitating a switch for frequency adjustment, increasing device size and component count.

Innovation Solution

A vehicular contactless charging device with circuitry that automatically adjusts power feeding coil frequency based on the proximity of the device to be charged, switching between charging and standby states, and changing frequency when a user-initiated state change occurs.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If a manual switch is provided for frequency adjustment, then radio interference can be addressed, but device size and component count increase

Engineering Contradiction:

Improveradio interferenceVSAvoidcomponent count

Core Design Contradiction:

Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The system automatically detects when a device is placed on the charging surface and autonomously switches between first and second frequencies without requiring manual user input. The control unit monitors the charging state and performs frequency switching based on detected conditions, making the system self-regulating and eliminating the need for manual intervention.

Inventive Principle:

Principle #25Self-service

Solution Approach 2:

The patent replaces the mechanical switch with an electronic control system that uses detection circuits and control logic to automatically manage frequency switching. This substitution of mechanical components with electronic control mechanisms reduces physical components while maintaining or improving functionality.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Object-affected harmful factors

If a manual switch is provided for frequency adjustment, then radio interference can be addressed, but device size increases

Engineering Contradiction:

Improveradio interferenceVSAvoiddevice size

Core Design Contradiction:

Object-affected harmful factorsVSArea of stationary object

Solution Approach 1:

The system automatically detects when a device is placed on the charging surface and autonomously switches between first and second frequencies without requiring manual user input. The control unit monitors the charging state and performs frequency switching based on detected conditions, making the system self-regulating and eliminating the need for manual intervention.

Inventive Principle:

Principle #25Self-service

Solution Approach 2:

The patent replaces the mechanical switch with an electronic control system that uses detection circuits and control logic to automatically manage frequency switching. This substitution of mechanical components with electronic control mechanisms reduces physical components while maintaining or improving functionality.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Stability of the object's composition

If frequency is changed only during state transitions, then unnecessary frequency changes are prevented, but frequency adjustment responsiveness may be reduced

Engineering Contradiction:

Improvefrequency stabilityVSAvoidfrequency adjustment responsiveness

Core Design Contradiction:

Stability of the object's compositionVSProductivity

Solution Approach 1:

The system employs periodic state transitions (charging state to non-charging state and vice versa) as triggers for frequency switching. This periodic action ensures that frequency changes occur at predetermined intervals tied to actual usage patterns, preventing both unnecessary changes and ensuring timely adjustments when needed.

Inventive Principle:

Principle #19Periodic action

Solution Approach 2:

The control unit continuously monitors the charging state through detection circuits and uses this feedback to determine when to switch frequencies. This closed-loop feedback mechanism ensures frequency changes are synchronized with actual charging needs, maintaining stability while responding appropriately to changing 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

Prevents unnecessary component increase and device enlargement by eliminating the need for a manual frequency adjustment switch, ensuring easy and precise frequency changes only when intended, thus reducing radio interference.

Implementation Method 1

a voltage is induced in a power receiving coil of the device to be charged through power supply to the power feeding coil

Methodology Applied

Scientific EffectElectromagnetic induction: Electromagnetic Induction

Data Source

PatentUS20250337278A1Vehicular contactless charging device

Publication Date: 2025.10.30 TOYODA GOSEI CO LTD

AI summary

A vehicular contactless charging device includes a power feeding coil and circuitry configured to supply power to the power feeding coil, and to stop the supply of power to the power feeding coil. The circuitry is configured to set the power feeding coil to a charging state when a device to be charged is brought close to the power feeding coil to reach a position enabling charging. The circuitry is also configured to set the power feeding coil to a standby state when the device to be charged moves away from the power feeding coil to be separated from the position enabling charging. The circuitry is further configured to change a frequency of the power when switching the power feeding coil from the standby state to the charging state after switching the power feeding coil from the charging state to the standby state.