Magnetic Temperature Switch for Cooktop Overheating Prevention

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Solution Overview

Problem

Conventional cooktop appliances lack effective systems for quickly evaluating temperature conditions near the burner, leading to undesirable temperature swings and potential safety issues, such as overheating or nuisance tripping.

Innovation Solution

A cooktop appliance with a magnetic temperature switch that uses a ferromagnetic tab in thermal engagement with an electric heating element, which restricts voltage when the tab exceeds a predetermined temperature, rapidly transitioning between activated and deactivated states to prevent overheating.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Speed

If conventional temperature sensing systems are used, then the system can detect temperature conditions, but the response time is slow leading to undesirable temperature swings

Engineering Contradiction:

Improveresponse time of temperature detectionVSAvoidtemperature control stability

Core Design Contradiction:

SpeedVSReliability

Solution Approach 1:

The patent replaces conventional mechanical or electronic temperature sensing systems with a magnetic field-based detection system. A magnet is coupled to the heating element, and a magnetic sensor detects changes in the magnetic field strength as the magnet heats up, providing rapid temperature detection without the lag inherent in conventional thermal conduction-based sensors.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent introduces a magnet as an intermediary between the heating element and the temperature detection system. The magnet serves as a thermal indicator that translates heating element temperature into detectable magnetic field changes, enabling indirect but rapid temperature measurement that responds quickly to temperature changes.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Object-affected harmful factors

If conventional temperature estimation systems are used, then the system can provide safety features, but the evaluation of current conditions near the burner is insufficient leading to overheating

Engineering Contradiction:

Improveoverheating preventionVSAvoidtemperature condition evaluation accuracy

Core Design Contradiction:

Object-affected harmful factorsVSMeasurement precision

Solution Approach 1:

The patent replaces indirect temperature estimation methods with direct magnetic field-based temperature detection. The magnetic sensor provides accurate, real-time measurement of the actual temperature conditions near the heating element, enabling precise evaluation of thermal conditions rather than relying on estimated or indirect indicators.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent implements a feedback mechanism where the magnetic sensor continuously monitors the magnetic field strength (which correlates with temperature) and provides real-time information about heating element conditions. This feedback enables the control system to respond immediately to temperature changes and prevent overheating by adjusting power delivery based on actual measured 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

The system effectively prevents overheating by rapidly cutting off voltage when the ferromagnetic tab reaches a certain temperature, reducing the risk of unsafe conditions and minimizing nuisance tripping compared to traditional systems.

Implementation Method 1

The ferromagnetic tab may be in thermal engagement with the electric heating element

Methodology Applied

Scientific EffectThermal conduction: Conduction (thermal)

Implementation Method 2

The magnetic temperature switch may be positioned in selective magnetic engagement with the ferromagnetic tab

Methodology Applied

Scientific EffectMagnetic engagement: Magnetism

Data Source

PatentUS10499459B2Cooktop appliance and temperature switch

Publication Date: 2019.12.03 HAIER US APPLIANCE SOLUTIONS INC

AI summary

A cooktop appliance is generally provided herein. The cooktop appliance may include a cooktop panel, an electric heating element, a ferromagnetic tab, and a magnetic temperature switch. The electric heating element may be positioned at the cooktop panel. The electric heating element may include a first terminal and a second terminal. The ferromagnetic tab may be in thermal engagement with the electric heating element. The magnetic temperature switch may be positioned in selective magnetic engagement with the ferromagnetic tab. The magnetic temperature switch may be electrically connected in series with the second terminal and operable to restrict a voltage to the electric heating element above a predetermined temperature.