Induction Hob Control Entity for Current Measurement

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing induction hobs require current transducers to determine peak current and power factor, increasing the total costs and footprint of the power circuit board.

Innovation Solution

An induction hob that replaces the current transducer with a control entity capable of calculating peak current and power factor using mathematical approaches based on available power circuit information, reducing costs and footprint by eliminating the need for a current transducer.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a current transducer is used to determine peak current and power factor, then measurement precision is improved, but device complexity and cost increase

Engineering Contradiction:
Improvepeak current measurementVSAvoidpower circuit board complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent extracts the current measurement function from a dedicated current transducer and relocates it to the control entity's calculation unit. The control entity calculates peak current and power factor by processing voltage signals already present in the circuit, eliminating the need for a separate current transducer component while maintaining measurement capability.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The control entity is given a dual function: it continues to control the power circuit operation while simultaneously performing current measurement and power factor calculation through mathematical processing of available voltage signals. This multi-functionality eliminates the need for dedicated measurement hardware.

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

2Measurement precision

If a current transducer is used to determine peak current and power factor, then measurement precision is improved, but manufacturing cost increases

Engineering Contradiction:
Improvepower factor measurementVSAvoidmanufacturing cost
Core Design Contradiction:
Measurement precisionVSEase of manufacture

Solution Approach 1:

The patent removes the current transducer component from the bill of materials and extracts its measurement function to be performed computationally. This elimination of hardware components directly reduces manufacturing costs while the control entity's calculation capabilities maintain the necessary measurement precision for power factor determination.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

Instead of using a physical current transducer, the system creates a virtual copy of the current measurement function through mathematical calculation. The control entity computes equivalent current values by processing voltage waveforms, providing the same measurement information without the associated hardware cost.

Inventive Principle:
Principle #26Copying

3Device complexity

If voltage signals are processed mathematically to determine current values, then device complexity is reduced, but calculation complexity increases

Engineering Contradiction:
Improvepower circuit simplicityVSAvoidcalculation complexity
Core Design Contradiction:
Device complexityVSDifficulty of detecting and measuring

Solution Approach 1:

The patent introduces voltage signals as an intermediary medium. Instead of directly measuring current, the system measures voltage (which is easier and already available) and uses this voltage information as an intermediary to calculate the current values and power factor through mathematical relationships in the control entity.

Inventive Principle:
Principle #24Intermediary (Mediator)

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 solution effectively reduces the complexity and cost of the power circuit by using existing resources like microprocessors to calculate peak current and power factor values, thereby minimizing the overall circuit size.

Implementation Method 1

at least one induction coil placed below a hob plate in order to heat a piece of cookware

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 2

Induction hobs for preparing food are well known in prior art. Induction hobs typically comprise at least one induction coil placed below a hob plate in order to heat a piece of cookware

Methodology Applied
Scientific EffectInduction heating: Induction Heating

Data Source

PatentEP3405004B1Induction hob and method for operating an induction hob
Publication Date: 2019.12.04 ELECTROLUX APPLIANCES
  • EP3405004B1 patent drawingFigure 1~2
  • EP3405004B1 patent drawingFigure 3
  • EP3405004B1 patent drawing

AI summary

The invention relates to an induction hob comprising a circuitry (1a) for powering at least one induction coil (6), the circuitry (1a) comprising a power circuit portion (7) with at least one switching element (4, 5) adapted to provide pulsed electric power to said induction coil (6) and an oscillating circuit portion (9), said induction coil (6) being electrically coupled with said power circuit portion (7) and said oscillating circuit (9), wherein said induction hob comprises a control entity (10), said control entity (10) being configured to receive first information correlated with a first voltage provided at said power circuit portion (7) and second information correlated with a second voltage correlated with said oscillating circuit (9), said control entity (10) being further configured to calculate information regarding a peak value and a power factor of the electric current provided through said induction coil (6) based on said received first and second information.