Heating Circuit Measurement Coil for Accurate Temperature Control

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Solution Overview

Problem

Existing electromagnetic heating cookers face inaccuracies and delays in temperature measurement, which hinder intelligent cooking operations such as precise temperature control and water boiling sensing.

Innovation Solution

A heating circuit with a measurement coil that undergoes mutual induction with both the heating coil and the object to be heated, outputting a measurement signal used in conjunction with resonance electric parameters to determine the object's temperature, comprising a first measurement sub-coil close to the heating coil and a second sub-coil wound around a magnetizer, allowing for accurate real-time temperature measurement.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If N·TC (thermosensitive resistance) is used to indirectly measure the temperature of the cookware, then the temperature measurement can be performed, but the measurement accuracy is poor and there is time delay

Engineering Contradiction:
Improvetemperature measurement accuracyVSAvoidtemperature measurement reliability
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The patent replaces the traditional N·TC thermosensitive resistance method with an electromagnetic induction-based measurement system. The measurement coil detects temperature through electromagnetic coupling with the heating coil and cookware, substituting the mechanical/thermal contact method with a non-contact electromagnetic field method, thereby improving both accuracy and reliability of temperature measurement

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent introduces a measurement coil as an intermediary element that couples electromagnetically with both the heating coil and the cookware. This intermediary enables indirect temperature measurement through electromagnetic field interaction, avoiding the need for direct thermal contact and improving measurement precision while eliminating time delay

Inventive Principle:
Principle #24Intermediary (Mediator)

2Measurement precision

If a measurement coil with dual mutual induction configuration is used, then real-time accurate temperature measurement is achieved, but the device structure becomes more complex

Engineering Contradiction:
Improvetemperature measurement accuracyVSAvoidmeasurement coil structure complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The measurement coil is designed to perform multiple functions simultaneously: it couples with the heating coil for temperature sensing and also couples with the cookware for verification. This multi-functional design allows a single component to achieve complex measurement objectives, reducing the need for additional separate sensors and overall system complexity

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

Solution Approach 2:

The patent merges the temperature sensing function with the existing electromagnetic induction heating system by using the measurement coil to interact with both the heating coil and cookware. This consolidation integrates temperature measurement into the heating control system rather than adding a separate measurement subsystem, thereby managing complexity

Inventive Principle:
Principle #5Merging (Combining)

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

Enables accurate real-time temperature control and intelligent cooking operations by accurately measuring the thermal resistance of the object, improving precision and reliability in cooking processes.

Implementation Method 1

a heating device comprising a heating coil to perform resonance heating on an object to be heated

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 2

a heating device comprising a heating coil to perform resonance heating on an object to be heated

Methodology Applied
Scientific EffectResonance heating: Resonance

Implementation Method 3

a portion of the measurement coil is in mutual induction with the heating coil, and another portion separately is in mutual induction with the heating coil and the object to be heated

Methodology Applied
Scientific EffectMutual induction: Electromagnetic Induction

Data Source

PatentEP4043846B1Heating circuit and cooking apparatus
Publication Date: 2024.11.20 FOSHAN SHUNDE MIDEA ELECTRICAL HEATING APPLIANCES MFG CO LTD
  • EP4043846B1 patent drawingFigure 1~3
  • EP4043846B1 patent drawingFigure 4~6
  • EP4043846B1 patent drawingFigure 7~9

AI summary

The present invention provides a heating circuit (100) and a cooking apparatus. The heating circuit (100) comprises: a heating device (110), comprising a heating coil (L1) to perform resonance heating on an object (200) to be heated; and a measurement coil (120), wherein a portion of the measurement coil is in mutual induction with the heating coil (LI), and another portion separately is in mutual induction with the heating coil (L1) and the object (200) to be heated, and outputs a corresponding measurement signal, and the measurement signal is used for cooperating with a measured and collected resonance electric parameter of the heating coil (L1) to determine the temperature of the object (200) to be heated. By means of the foregoing mode, the present invention can determine, according to the measurement signal, the temperature of the object (200) to be heated, thereby achieving accurate temperature control, and accurately measuring the real-time temperature of the object (200) to be heated.