Variable Turntable Speed and Microwave Duty Cycle Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Cooking appliances with variable power levels, such as microwave ovens, often result in uneven heating due to the consistent activation of the energy source during a portion of the duty cycle, leading to areas of the turntable being repeatedly exposed while others are not, causing thermal concentration and uneven energy distribution.
Innovation Solution
A method where a controller adjusts the speed of the turntable and the duty cycle of the microwave module during cooking operations, varying the exposure time and speed to ensure more uniform energy distribution across the turntable, particularly by activating the microwave module during different segments of the turntable's rotation and altering the rotation speed accordingly.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If the energy source is activated during the same portion of each duty cycle, then the control system is simple, but the heating uniformity deteriorates
Solution Approach 1:
The patent applies dynamics by making the energy source activation dynamic rather than static. Instead of activating the energy source during the same fixed portion of each duty cycle, the system varies the activation timing so that different portions of the turntable are exposed to energy during different duty cycles. This dynamic adjustment ensures all areas receive energy exposure while maintaining relatively simple control logic.
Solution Approach 2:
The patent utilizes periodic action by coordinating the turntable rotation with periodic duty cycles of the energy source. The turntable completes one full revolution for every duty cycle, and the energy source is activated during specific portions of each cycle. By varying which portion is activated in each cycle, the system achieves uniform heating through periodic exposure of different turntable areas to microwave energy.
2Device complexity
If the turntable rotates at a fixed speed synchronized with the duty cycle, then the synchronization is simple, but the energy distribution uniformity deteriorates
Solution Approach 1:
The patent applies dynamics by varying the energy source activation timing within duty cycles while maintaining turntable rotation synchronization. The turntable continues to rotate at a fixed speed completing one revolution per duty cycle, but the portion of the turntable exposed to energy varies across duty cycles, achieving uniform energy distribution without complex speed variation.
Solution Approach 2:
The patent changes the parameter of energy source activation timing within the duty cycle rather than changing the turntable rotation speed. By modifying which time portion of each duty cycle activates the energy source, the system achieves different areas of the turntable receiving energy exposure, improving uniformity while keeping the rotation speed parameter constant and simple to control.
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 approach ensures more even heating by adjusting the exposure of the turntable to microwave energy, reducing thermal concentration and providing a more uniform cooking experience by varying the duty cycle and rotation speed to cover the entire surface effectively.
Implementation Method 1
activating a microwave module to deliver microwave energy into a cooking cavity during at least a portion of the rotation of the turntable
Data Source
AI summary
A method of operating cooking appliance includes receiving, by a controller of the cooking appliance, an input indicating a time of a cooking operation. The method also includes activating a motor to rotate a turntable within a cooking cavity defined in a casing of the cooking appliance throughout the time of the cooking operation and activating a microwave module to deliver microwave energy into the cooking cavity during at least a portion of the rotation of the turntable. The method further includes varying at least one of a speed of the rotation of the turntable and a duty cycle of the microwave module during the cooking operation.