Switchable Ferrimagnetic Core for Wireless Charging Through Cases
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Solution Overview
Problem
Existing wireless charging systems face challenges in efficiently transferring power through removable accessories, particularly when these accessories are used with or without a wireless charging mat, due to variations in magnetic permeability and reluctance.
Innovation Solution
Incorporating a switchable ferrimagnetic core in the removable accessory that adjusts its magnetic permeability and reluctance based on the presence of a wireless charging mat, allowing for optimal power transfer in different scenarios.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a removable accessory is used with wireless power transfer, then the device can be charged through the accessory, but the magnetic permeability and reluctance variations cause inefficient power transfer when used with or without a charging mat
Solution Approach 1:
The magnetic core's permeability is made dynamically adjustable through a switching mechanism that connects different magnetic path configurations. When a charging mat is detected, the switch reconfigures the magnetic core to provide an optimal magnetic path through the mat, thereby adapting to different charging scenarios and maintaining efficient power transfer across both standalone and mat-based charging modes
Solution Approach 2:
The invention changes the magnetic circuit parameters (permeability and reluctance) by reconfiguring the magnetic core connections via a switch. This parameter adjustment optimizes the magnetic flux path depending on whether a charging mat is present, resolving the contradiction between maintaining high efficiency and adapting to different charging environments
2Productivity
If the magnetic core is designed for high permeability to improve power transfer, then charging efficiency increases, but interference and reluctance issues arise when placed on a charging mat
Solution Approach 1:
The magnetic core transitions from a static high-permeability design to a dynamic configuration where the switch can alter the magnetic path. This allows the system to maintain high permeability for efficient charging when needed, while switching to a configuration that redirects or contains magnetic flux to reduce interference when placed on a charging mat
Solution Approach 2:
The invention converts the potential harmful magnetic interference into a beneficial controlled magnetic path. By using the switch to reconfigure the magnetic core, the system directs magnetic flux through intended paths during charging, while preventing unwanted leakage or interference when on a mat, thus transforming a harmful effect into a controllable parameter
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 enables efficient wireless power transfer by ensuring the switchable ferrimagnetic core maintains high permeability and low reluctance when not on a charging mat, and reduces interference when on a mat, thereby enhancing charging efficiency and compatibility.
Implementation Method 1
the switchable ferrimagnetic core may be operable in a first state where the switchable ferrimagnetic core is unsaturated and has a high magnetic permeability and low magnetic reluctance
Implementation Method 2
the switchable ferrimagnetic core may be operable in a first state where the switchable ferrimagnetic core is unsaturated and has a high magnetic permeability and low magnetic reluctance
Implementation Method 3
the switchable ferrimagnetic core may be operable in a second state where the switchable ferrimagnetic core is saturated by a magnetic field from a permanent magnet in the wireless charging mat
Implementation Method 4
The coil receives alternating-current wireless power signals from the wireless charging mat
Data Source
AI summary
An electronic device in a wireless power system may be operable with a removable accessory such as a case. The device may convey wireless power to, from, or through the case while the device is coupled to the case. The device may have coplanar power transmitting and power receiving coils. The removable accessory may have an embedded switchable ferrimagnetic core and a coil that overlaps the switchable ferrimagnetic core. The switchable ferrimagnetic core may be operable in a first state where the switchable ferrimagnetic core is unsaturated. The switchable ferrimagnetic core may be operable in a second state where the switchable ferrimagnetic core is saturated by a magnetic field from a permanent magnet in a wireless power transmitting device. In the second state, the switchable ferrimagnetic core may have a lower magnetic permeability and higher magnetic reluctance than in the first state.