Thermocouple Flame Control via Magnetic Coupling

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Solution Overview

Problem

Existing thermocouple-based flame detection systems in gas burners are limited to simple on/off safety checks due to low voltage generation, making them unsuitable for modern appliances requiring temperature control and timing, and are difficult to implement in high-temperature environments without expensive amplification and filtration.

Innovation Solution

Incorporating a coil in series with the thermocouple and safety valve, connected to a sensor that converts the magnetic field into a control signal, allowing for automatic isolation and enabling advanced control features like temperature control and automatic ignition/reignition, without the need for additional amplification or filtration.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a thermocouple is used for flame detection, then the system can detect flame presence and provide safety control, but the generated voltage is too low for advanced control functions requiring amplification systems

Engineering Contradiction:
Improveflame detection reliabilityVSAvoidamplification system complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

A magnetic coupling intermediary is introduced between the thermocouple circuit and the control electronics. The coil generates a magnetic field proportional to the thermocouple current, which is then detected by a magnetometer sensor. This intermediary allows signal transfer without direct electrical connection, avoiding the need for amplification while enabling advanced control functions.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent replaces the traditional electrical amplification system with a magnetic field-based detection system. Instead of using electronic amplifiers to boost the weak thermocouple signal, the system uses magnetic coupling to transfer the signal to a sensor that can directly interface with microcontrollers, eliminating complex amplification circuitry.

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

2Ease of manufacture

If traditional thermocouple systems are used, then manufacturing costs are low and implementation is simple, but only one burner safety control is provided with no temperature control or timing capabilities

Engineering Contradiction:
Improvesystem implementation simplicityVSAvoidcontrol functionality versatility
Core Design Contradiction:
Ease of manufactureVSAdaptability or versatility

Solution Approach 1:

The patent makes the thermocouple system multi-functional by adding a coil and magnetometer sensor. The same basic thermocouple circuit now serves both traditional safety detection and enables advanced functions like temperature control, timing, and multiple burner control through the magnetic coupling interface, all without requiring separate sensor systems.

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

Solution Approach 2:

The magnetic coupling acts as a universal interface that allows the simple thermocouple system to communicate with various control functions. Through this intermediary, the system can control igniters, regulate gas flow, provide timing functions, and monitor temperature across multiple burners while maintaining the simplicity of the original thermocouple design.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Device complexity

If the thermocouple voltage is used directly for control signals, then the system structure remains simple, but the low voltage cannot provide stable control signals for modern electrical appliances

Engineering Contradiction:
Improvesystem structure complexityVSAvoidcontrol signal stability
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The magnetic coupling intermediary transforms the unstable low-voltage thermocouple signal into a stable magnetic field that can be reliably detected by the magnetometer sensor. This provides stable control signals for modern appliances without requiring complex signal conditioning or amplification circuits, maintaining structural simplicity while improving reliability.

Inventive Principle:
Principle #24Intermediary (Mediator)

4Measurement precision

If amplification systems are added to read the thermocouple voltage, then the voltage can be measured, but expensive amplification and filtration devices are required

Engineering Contradiction:
Improvethermocouple voltage measurement capabilityVSAvoidamplification and filtration device complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent replaces the electronic amplification and filtration system with a magnetic field detection system. The magnetometer sensor directly detects the magnetic field generated by the coil, providing precise measurement capability without requiring expensive amplification or filtration electronics. The measurement is achieved through magnetic coupling rather than direct voltage measurement.

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

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 stable and precise control of flame intensity and safety features, allowing for temperature control and automatic ignition/reignition in high-temperature environments, enhancing the functionality of gas burners in domestic and industrial applications.

Implementation Method 1

The thermocouple comprises a first conductor element and a second conductor element, which are in electrically conductive contact at one detection end, known as hot junction, to generate a potential difference at the two free ends of each conductor element, known as cold junction, which is a function of the temperature detected at the detection end.

Methodology Applied
Scientific EffectSeebeck effect: Seebeck Effect

Implementation Method 2

A coil is connected in series with one of the two transmission conductors, the magnetic signal generated by the coil being detected by at least one sensor

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 3

the magnetic signal generated by the coil being detected by at least one sensor, which is adapted to convert the magnetic signal into an electric signal, whose current strength controls the operation of at least the igniter device

Methodology Applied
Scientific EffectMagnetic field detection: Hall Effect

Data Source

PatentEP2783161B1Flame ignition and control system
Publication Date: 2019.08.21 CASTFUTURA
  • EP2783161B1 patent drawingFigure 1
  • EP2783161B1 patent drawingFigure 2a
  • EP2783161B1 patent drawingFigure 2b

AI summary

A flame ignition and control system, comprising at least one gas burner (1) which is connected to a gas source (11) via flame control means (12) and a safety valve (13) controlled by a flame sensor consisting of a thermocouple (2). The safety valve has an open state, in which the source supplies gas to the burner and a closed sate, in which gas flow is obstructed, switching from the open state to the closed state and vice versa being controlled by the electric signal generated by the thermocouple. An igniter device (3) is provided, which consists of an ignition electrode (31) and power supply means (32) thereof. Furthermore, at least the operation of the igniter device is controlled according to the current strength of the electric signal generated by the thermocouple.