Slotted Wireless Charging Coil for Lower Eddy Current Loss
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Solution Overview
Problem
Current wireless charging technologies face inefficiencies due to high eddy current losses in coils, leading to low charging speeds and reduced efficiency, especially when coils are large or not aligned properly with the charging magnetic field.
Innovation Solution
A coil structure with a slot disposed on its wire-winding part to reduce eddy current losses by cutting off the closed-loop path generated by the magnetic field, thereby decreasing alternating current resistance and increasing charging efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If the coil area is increased to improve wireless charging coverage, then the charging area is enlarged, but the eddy current loss increases proportionally, reducing charging efficiency
Solution Approach 1:
The patent applies segmentation by dividing the continuous wire-winding part into separate sections using slots. These slots break the eddy current paths into smaller segments, preventing large-scale circulating currents while maintaining the overall coil structure and charging area. The wire-winding part is segmented into multiple independent winding sections that are electrically isolated by the slots.
Solution Approach 2:
The patent extracts the harmful eddy current paths by introducing slots that remove continuous conductive regions. The slots take out the problematic closed-loop paths that generate eddy currents, while preserving the functional wire-winding structure needed for magnetic field generation and wireless charging operation.
2Area of stationary object
If a large coil is used to ensure proper magnetic field coverage, then the charging coverage is improved, but the eddy current loss becomes very large, reducing wireless charging efficiency
Solution Approach 1:
The slots divide the large wire-winding structure into multiple smaller conductive sections, preventing large eddy currents while maintaining the overall large coil area for adequate charging coverage. Each segmented section generates smaller eddy currents that are less harmful to efficiency.
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 slot design reduces eddy current losses by approximately 30% compared to direct current resistance, enhancing wireless charging efficiency and maintaining efficiency even when the mobile device is not aligned perfectly with the charger.
Implementation Method 1
the alternating current magnetic field cuts through a metal conductor and induces an eddy current, leading to an eddy current loss
Implementation Method 2
energy is transmitted mainly based on a magnetic coupling principle of a transmission coil and a receiving coil
Data Source
AI summary
This application describes a coil. The coil includes an output terminal, an input terminal, and a wire-winding part that is connected between the output terminal and the input terminal. A slot is disposed on at least a part of the wire-winding part, and a depth of the slot in any direction of a cross section of the wire-winding part is less than or equal to a distance between two points that are the farthest away from each other on the cross section of the wire-winding part. The wire-winding part is a metal conductor made through spiral winding. The input terminal and the output terminal are configured to connect the wire-winding part to an external circuit.