Grounded Magnetic Structure for Low-Noise Wireless Power Transfer
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Solution Overview
Problem
Wireless charging systems face challenges in directing electromagnetic flux to the receiving device while minimizing errant electromagnetic noise.
Innovation Solution
Incorporating a magnetic structure, such as an arcuate or circular structure made from ferrite and nanocrystalline alloy sheets, with a flexible conductor to couple the magnetic structure to the printed circuit board or housing, and an electromagnetic shielding layer with conductive traces to reduce electromagnetic noise.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a magnetic structure is added to direct electromagnetic flux, then wireless power transfer efficiency is improved, but device complexity increases
Solution Approach 1:
A magnetic structure (ferrite sheet or nanocrystalline alloy sheet) is introduced as an intermediary component between the wireless power transfer coil and the printed circuit board. This magnetic structure directs electromagnetic flux toward the receiving coil, improving power transfer efficiency while being coupled to ground through a conductor to manage its complexity impact
Solution Approach 2:
The magnetic structure serves multiple functions: it directs electromagnetic flux to improve power transfer efficiency, provides a mounting surface for the wireless power transfer coil, and when coupled to ground, helps reduce electromagnetic noise. This multi-functionality addresses the complexity increase by consolidating several functions into a single component
2Object-generated harmful factors
If electromagnetic shielding is implemented to reduce noise, then electromagnetic noise is reduced, but device complexity increases
Solution Approach 1:
The magnetic structure, which could potentially generate or harbor electromagnetic noise, is deliberately coupled to ground through a conductor. This converts the potential harmful effect into a benefit by providing a controlled path for noise dissipation, reducing electromagnetic interference while utilizing the existing magnetic structure
Solution Approach 2:
The grounding conductor is integrated with the magnetic structure and existing ground contacts on the printed circuit board or device housing. This merging of the magnetic structure with the grounding system provides electromagnetic noise reduction without adding completely separate shielding components, thereby limiting the increase in device 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 directs electromagnetic flux to the wireless power transfer coil and reduces electromagnetic noise, enhancing the efficiency and performance of wireless charging systems.
Implementation Method 1
a magnetic structure disposed along a periphery of the printed circuit board... configured to direct the electromagnetic flux created by the power transmitting device to the receiving device
Implementation Method 2
a conductor electrically coupling the magnetic structure to an electrical contact on the printed circuit board and configured to reduce electromagnetic noise produced from the wireless power transfer coil
Implementation Method 3
an electromagnetic shielding layer at least partially overlapping with the magnetic structure and having one or more contacts electrically coupled to the magnetic structure... configured to reduce electromagnetic noise
Data Source
AI summary
A wireless charging system may include a wireless power receiving device that receives wireless power from a wireless power transmitting device. The wireless power receiving device may include a printed circuit board, a magnetic structure disposed along a periphery of the printed circuit board, a wireless power transfer coil disposed on the magnetic structure and configured to receive wireless power from a power transmitting device, and a conductor electrically coupling the magnetic structure to an electrical contact on the printed circuit board for reducing electromagnetic noise produced from the wireless power transfer coil while receiving wireless power from the power transmitting device. The electrical contact can be coupled to a ground of the power receiving device.