Induction Heating Coil Detection via Resonance Signal Conversion

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Solution Overview

Problem

Existing induction heating apparatuses face challenges in accurately controlling the working coil based on the size and position of a container without physical sensors, leading to inefficient power adjustment and increased manufacturing costs.

Innovation Solution

The induction heating apparatus employs an inner and outer working coil with an inverter circuit and a controller that determines the required power mode by detecting the container using sensing currents and converting resonance signals into square waves, allowing for accurate detection and variable operation based on container size and position.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a physical sensor (infrared distance sensor or ultrasonic distance sensor) is used to detect container size, then container size detection capability is improved, but device complexity and manufacturing costs increase

Engineering Contradiction:
Improvecontainer size detectionVSAvoidsensor system complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent extracts the container detection function from the physical sensor system and implements it through the working coil itself. The working coil serves dual purposes: heating the container and detecting its presence and size through electrical parameter changes, eliminating the need for separate physical sensors.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The working coil is designed to perform multiple functions simultaneously: it generates the magnetic field for induction heating and also acts as a sensor to detect container presence, size, and position by monitoring changes in its electrical characteristics such as impedance and resonant frequency.

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

2Adaptability or versatility

If multiple unit heater modules are used to adjust heating zone size, then heating zone adaptability is improved, but device complexity increases

Engineering Contradiction:
Improveheating zone size adjustmentVSAvoidheater module configuration
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent implements dynamic adjustment of the heating zone by controlling the oscillation amplitude of the working coil rather than using multiple discrete heater modules. The controller dynamically modifies the driving signal parameters to expand or contract the effective heating area according to container size.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The heating zone size is adjusted by changing the operational parameters of the working coil, specifically the oscillation amplitude and driving frequency, rather than physically reconfiguring multiple heater modules. This allows continuous and flexible adjustment of the heating area.

Inventive Principle:
Principle #35Parameter changes

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 method enables precise detection of container size without physical sensors, allowing the working coil to operate variably and adjust power output accordingly, improving efficiency and reducing manufacturing costs.

Implementation Method 1

AC current is supplied to a working coil. Accordingly, an induction magnetic field is generated around the working coil disposed in the induction heating apparatus. As the magnetic line of force of the generated induction magnetic field passes through the bottom of the container including a metallic ingredient placed over the working coil, eddy current is generated inside the bottom of the container.

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 2

As the magnetic line of force of the generated induction magnetic field passes through the bottom of the container including a metallic ingredient placed over the working coil, eddy current is generated inside the bottom of the container. As the generated eddy current flows in the container, the container itself is heated.

Methodology Applied
Scientific EffectEddy current: Eddy Currents

Implementation Method 3

determining whether a container is provided in a heating zone corresponding to the inner working coil and/or the outer working coil. The controller may detect a container by using the inner working coil and/or the outer working coil.

Methodology Applied
Scientific EffectResonance: Resonance

Data Source

PatentEP4044769A1Induction heating apparatus and method for controlling the same
Publication Date: 2022.08.17 LG ELECTRONICS INC
  • EP4044769A1 patent drawingFigure 1~2
  • EP4044769A1 patent drawingFigure 3
  • EP4044769A1 patent drawingFigure 4

AI summary

The present disclosure relates to an induction heating apparatus and a method for controlling the same. A controller of the induction heating apparatus of one embodiment determines a required power value of a heating zone, based on a power level set for the heating zone, detects a container by using an inner working coil and an outer working coil, determines a working coil to be driven, based on results of the detection of the container, determines a driving mode of the working coil to be driven, based on the required power value, and supplies a control signal, based on the driving mode.