One-Way Field Filter for Microwave-Induction Appliance
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Solution Overview
Problem
Previous attempts to integrate induction cooking into microwave appliances have failed to adequately shield the induction coil from microwave radiation while maintaining a suitable magnetic field strength.
Innovation Solution
A cooking appliance design featuring a cabinet with a magnetron, an induction heating coil, and a one-way field filter that includes multiple parallel conductive bands in two layers, where the bands are spaced to allow magnetic fields to pass through while blocking microwave radiation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a traditional solid shield is used to block microwave radiation from the induction coil, then the induction coil is protected from microwave interference, but the magnetic field strength required for induction cooking is reduced or blocked
Solution Approach 1:
The shield is segmented into multiple parallel conductive bands separated by gaps. This segmentation allows the shield to block microwave radiation through the conductive bands while the gaps permit magnetic field lines to pass through, thus resolving the contradiction between shielding effectiveness and magnetic field transmission
Solution Approach 2:
Different regions of the shield have different properties: the conductive bands provide electromagnetic shielding against microwaves, while the gaps between bands allow magnetic field penetration. This local differentiation of properties enables simultaneous achievement of both shielding and magnetic field transmission
2Object-affected harmful factors
If the spacing between conductive bands is reduced to improve microwave blocking, then shielding effectiveness increases, but the magnetic field strength passing through decreases
Solution Approach 1:
The shield transitions from a two-dimensional continuous surface to a three-dimensional structure with controlled gaps. By introducing the dimensional aspect of spaced bands rather than a solid plane, the design achieves frequency-selective transmission - blocking microwaves while allowing magnetic fields to pass through the gaps
3Object-affected harmful factors
If a one-way field filter with conductive bands is used to shield the induction coil, then microwave radiation is blocked, but the device complexity increases compared to traditional microwave appliances
Solution Approach 1:
The one-way field filter is implemented as a thin structure consisting of conductive bands on a substrate, allowing it to be integrated into the microwave appliance without adding significant bulk or complexity. The thin film approach maintains shielding effectiveness while minimizing structural complexity
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 shields the induction coil from microwave radiation while permitting a strong magnetic field, enabling safe and efficient combined microwave and induction cooking.
Implementation Method 1
a magnetron can generate the microwave radiation or microwaves that are directed specifically to the cooking chamber
Implementation Method 2
an induction coil produces a high frequency magnetic field, which can cause eddy currents to flow through a cooking vessel made of steel or stainless steel
Implementation Method 3
which can cause eddy currents to flow through a cooking vessel made of steel or stainless steel
Implementation Method 4
and thereby heats the foods by the Joule heat produced in the cooking vessel
Implementation Method 5
The one-way field filter may be disposed within the cabinet between the induction heating coil and the cooking chamber to restrict passage of the microwave therethrough while permitting the magnetic field
Data Source
AI summary
A cooking appliance, as provided herein, may include a cabinet, a magnetron, an induction heating coil, and a one-way field filter. The cabinet may define a cooking chamber. The magnetron may be mounted within the cabinet in communication with the cooking chamber to direct a microwave thereto. The induction heating coil may be mounted within the cabinet to direct a magnetic field thereto. The one-way field filter may be disposed within the cabinet between the induction heating coil and the cooking chamber to restrict passage of the microwave therethrough while permitting the magnetic field. The one-way filter may include a lower layer and an upper layer. The lower layer may include a plurality of parallel conductive bands extending in a first direction. The upper layer may be disposed above the lower layer. The upper layer may include a plurality of parallel conductive bands extending in the second direction.