Rotating Microwave Distribution Standstill Detection via Leakage Radiation

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Solution Overview

Problem

Existing methods for detecting the unintentional standstill of a rotating antenna in a household microwave appliance are unreliable and require significant design effort, leading to potential overheating and reduced heating performance due to undetected motor failures.

Innovation Solution

Monitor microwave leakage radiation for angle-dependent recurring fluctuations during microwave operation, triggering an action if such fluctuations are absent, indicating a standstill of the rotating antenna.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If existing methods for detecting antenna standstill are used, then detection capability is provided, but reliability is insufficient and design effort is significant

Engineering Contradiction:
Improvedetection reliabilityVSAvoiddesign effort
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The system uses the microwave leakage radiation itself as the detection signal, eliminating the need for separate detection components. The microwave generator and leakage radiation measuring device work together to automatically detect standstill conditions through the microwave field's own characteristics, achieving self-diagnosis without additional complex sensing systems.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The patent replaces mechanical rotation detection systems with an electromagnetic field-based detection method. Instead of using mechanical sensors to detect antenna rotation, the system uses microwave leakage radiation measurement to infer rotation status, substituting mechanical detection with electromagnetic field measurement for higher reliability and lower complexity.

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

2Object-affected harmful factors

If no detection method is implemented, then device complexity is minimized, but harmful effects occur due to undetected motor failures

Engineering Contradiction:
Improveoverheating damageVSAvoiddetection system
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The system continuously monitors microwave leakage radiation during microwave generation and provides real-time feedback about antenna rotation status. When standstill is detected through analysis of leakage radiation patterns, the control device can immediately respond by stopping microwave generation or alerting the user, preventing harmful overheating damage before it occurs.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The detection system operates proactively during microwave generation, continuously analyzing leakage radiation patterns to detect standstill conditions before they cause damage. By monitoring the microwave field characteristics in real-time, the system identifies potential motor failures early and takes preventive action to avoid overheating and component damage.

Inventive Principle:
Principle #10Preliminary action

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

Provides a cost-effective and structurally simple method for reliably detecting antenna standstill, ensuring long-term reliability and preventing component damage by detecting the absence of expected microwave leakage patterns.

Implementation Method 1

at least one microwave leakage radiation is measured during a feed of microwaves into a cooking chamber

Methodology Applied
Scientific EffectMicrowave radiation: Microwave Radiation

Data Source

PatentEP4042836B1Detecting a standstill of a rotatable microwave distribution device
Publication Date: 2025.07.16 BOSCH SIEMENS HAUSGERATE GMBH
  • EP4042836B1 patent drawingFigure 1
  • EP4042836B1 patent drawingFigure 2
  • EP4042836B1 patent drawingFigure 3

AI summary

The invention relates to a method which is used to detect a standstill of a rotatable microwave distribution device (8) of a domestic microwave appliance (1), wherein, during a feed of microwaves (MW) into a cooking chamber (2) of the domestic microwave appliance (1), at least one microwave leakage radiation (LS) is monitored for fluctuations (Max1, Min, Max2) that recur according to angle and, if an absence of such fluctuations (Max1, Min, Max2) is detected, at least one action is triggered. A domestic microwave appliance (1) comprises: a cooking chamber (2); a microwave generator (5) for producing microwaves (MW); at least one rotatably microwave distribution device (8) for varying a field distribution of microwaves (MW) that are fed into the cooking chamber (2); at least one leakage radiation measurement device (11) for measuring microwave leakage radiation (LS); and a data processing device (10), which is designed to carryout the method. The invention can be advantageously applied, in particular, to microwave cooking appliances, in particular to ovens having a microwave function.