Microwave Oven Door Switch Circuit for Leakage Prevention

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Solution Overview

Problem

Microwave ovens require frequent reconfiguration based on installation location, and there is a need to prevent microwave leakage when the door is open, which existing technologies do not adequately address.

Innovation Solution

A microwave oven design featuring a series or parallel interconnection of primary, secondary, and monitor switches between the magnetron and power supply, which are activated or deactivated based on the door's open or closed state to prevent microwave generation and leakage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If the microwave oven uses a fixed door hinge configuration (left or right), then the door can be opened and closed properly, but the microwave oven must be replaced when changing installation locations

Engineering Contradiction:
Improveinstallation flexibilityVSAvoiddoor hinge configuration
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The door hinge assembly is designed with universal functionality to accommodate both left-opening and right-opening configurations. The hinge mechanism can be installed on either the left or right side of the microwave oven body, allowing the same door assembly to serve multiple installation scenarios without requiring different door structures.

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

2Reliability

If the microwave oven uses conventional switch connections, then the circuit is simple, but microwaves may leak when the door is open

Engineering Contradiction:
Improvemicrowave leakage preventionVSAvoidswitch interconnection circuit
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The switch circuit is designed with preliminary protective action by interconnecting multiple switches (primary switch, secondary switch, and monitor switch) in a series configuration. This arrangement ensures that if any single switch fails or remains closed when the door is open, the other switches will prevent microwave generation, thereby preemptively preventing microwave leakage before it can occur.

Inventive Principle:
Principle #9Preliminary anti-action

Solution Approach 2:

The monitor switch is added as a redundant safety component that acts as a backup protection mechanism. It is positioned in the circuit to provide an additional layer of safety, cushioning against the possibility of primary or secondary switch failure, ensuring that the magnetron cannot operate when the door is open under any circumstances.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

3Reliability

If multiple switches are interconnected to prevent microwave leakage, then safety is improved, but the circuit complexity increases

Engineering Contradiction:
Improvedoor open detection reliabilityVSAvoidswitch circuit arrangement
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

Multiple switch functions (primary switch for door open/close detection, secondary switch for additional safety, and monitor switch for verification) are merged into a single series-connected circuit arrangement. This integration allows the switches to work together as a unified safety system, where the series connection automatically combines their functions without requiring complex control logic or separate circuit boards.

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 flexible installation without functionality restriction and ensures microwave safety by preventing power application to the magnetron when the door is open, thereby preventing microwave leakage.

Implementation Method 1

a magnetron that generates microwaves in the storage chamber

Methodology Applied
Scientific EffectMicrowave generation: Electromagnetic Induction

Implementation Method 2

The switches may be turned on/off according to opening/closing of the door. Power may be prevented from being applied to the magnetron if one of the primary switches is turned off

Methodology Applied
Scientific EffectElectrical circuit interruption: Electrical Resistance

Data Source

PatentEP2194757B1Microwave oven
Publication Date: 2015.10.07 SAMSUNG ELECTRONICS CO LTD
  • EP2194757B1 patent drawingFigure 1
  • EP2194757B1 patent drawingFigure 2
  • EP2194757B1 patent drawingFigure 3

AI summary

Disclosed is a microwave oven capable of preventing leakage of microwaves by using a plurality of primary switches, a plurality of secondary switches and a plurality of monitor switches. The primary switches are serially connected with each other, the secondary switches are connected in parallel with each other, and the monitor switches are connected in parallel with each other, so that the microwave oven does not operate if a door of the microwave oven is not completely closed.