Induction Cooker Transistor Current Imbalance Detection

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Induction cookers face issues due to manufacturing variations and errors, leading to uneven current distribution through switching transistors, which can result in premature failure and require costly repairs or replacements.

Innovation Solution

Incorporating a power circuit with two transistors in series and parallel, each with a current sensor, and a controller to compare and indicate if the current difference exceeds a threshold, providing a visual or auditory warning for potential issues.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If manufacturing variations and errors occur in switching transistors, then current distribution becomes uneven, but this leads to premature failure and costly repairs

Engineering Contradiction:
Improvetransistor reliabilityVSAvoidcurrent distribution uniformity
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

The patent implements current sensing and comparison circuitry that continuously monitors current distribution through parallel transistors before failure occurs. The system detects imbalances early in the operation and can trigger warnings or protective actions, preventing premature transistor failure rather than addressing it after manufacturing variations cause problems.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent employs a feedback mechanism where current sensors monitor the current through each transistor, the controller compares these currents, and the system responds by generating indications when imbalances are detected. This closed-loop feedback allows real-time detection and response to current distribution issues caused by manufacturing variations, improving transistor reliability.

Inventive Principle:
Principle #23Feedback

2Reliability

If current imbalance is detected late, then transistor failure occurs, but early detection requires additional sensing and control components

Engineering Contradiction:
Improvefailure preventionVSAvoidpower circuit complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent integrates current sensors and a controller that continuously monitors and compares currents through parallel transistors. This feedback system enables early detection of current imbalances without requiring overly complex additional components, achieving failure prevention through practical sensing and comparison circuitry.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system uses the existing power circuit transistors and current paths to enable self-diagnosis. The current sensors tap into existing current flow, and the controller utilizes the natural current distribution through parallel transistors to perform self-monitoring, reducing the need for separate complex diagnostic systems while enabling early failure detection.

Inventive Principle:
Principle #25Self-service

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 solution allows for early detection of current imbalances, enabling timely repairs or replacements, reducing the risk of transistor failure and extending the induction cooker's lifespan while also serving as a quality control measure during manufacturing.

Implementation Method 1

a varying electric current is passed through an induction coil, the coil therefore producing a corresponding varying electromagnetic field. The varying electromagnetic field induces a varying eddy current in a ferromagnetic cooking vessel

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 2

a first current sensor for sensing the current flowing through the first transistor; a second current sensor for sensing the current flowing through the second transistor

Methodology Applied
Scientific EffectElectrical conduction sensing: Conduction (electrical)

Data Source

PatentEP3419382B1Induction cooker and a method of operation
Publication Date: 2020.03.18 VESTEL ELEKTRONIK SANAYI & TICARET ANONIM SIRKETI
  • EP3419382B1 patent drawingFigure 1~2
  • EP3419382B1 patent drawingFigure 3A~3B

AI summary

An induction cooker (10) has an induction coil (12). A power circuit provides a varying electric current to the induction coil (12). The power circuit has at least a first transistor (24) and a second transistor (26). A first current sensor (28) senses the current flowing through the first transistor (24). A second current sensor (30) senses the current flowing through the second transistor (26). An indication is output in the case that the current flowing through the first transistor (24) and the current flowing through the second transistor (26) differ by more than a threshold.