Ferrite-Shielded Wireless Power Transmitter for Wider Coil Gaps
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current wireless power transfer systems are limited to operation within a narrow separation gap of 3-5 mm, restricting their applicability in commercial applications due to near-field limitations, and lack precision power control, which is necessary for efficient and safe power transmission.
Innovation Solution
A wireless power transmitter design that operates at frequencies between 87 kHz and 205 kHz, utilizing a ferrite core shielding around the transmitter antenna except at the top, allowing for extended separation gaps up to 15 mm, and incorporates a control and communications unit to manage power levels through external power supply communication, enabling precise power control without internal voltage regulation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of stationary object
If the separation gap between transmitter and receiver coils is increased beyond 3-5 mm, then the range of commercial applications is expanded, but the power transfer efficiency and operability deteriorate due to near-field limitations
Solution Approach 1:
The patent changes the operating frequency parameter from the standard 6.78 MHz to an extended frequency range of 87 kHz to 205 kHz. This parameter change enables the system to operate effectively at larger separation gaps (up to 15 mm or more) while maintaining power transfer efficiency, resolving the contradiction between increased separation distance and energy loss.
2Reliability
If precision power control is implemented to meet particular power levels and safety requirements, then safety and efficiency are improved, but device complexity increases
Solution Approach 1:
The patent implements a control and communications unit that provides power control signals to the inverter circuit based on feedback about the power transfer status. This feedback mechanism enables precise power level control to meet safety requirements and particular power levels while managing system complexity through intelligent control rather than hardware 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
Enables wireless power transfer over larger separation gaps while maintaining efficiency and safety, expanding the range of commercial applications and reducing costs by utilizing off-the-shelf power supplies.
Implementation Method 1
an inverter circuit configured to receive a direct current (DC) power from a power supply external to the power transmitter and convert the input power to a power signal
Implementation Method 2
a coil configured to transmit the power signal to a power receiver
Implementation Method 3
shielding comprising a ferrite core and defining a cavity, the cavity configured such that the ferrite core substantially surrounds all but the top face of the coil
Data Source
AI summary
A power transmitter for wireless power transfer includes a control and communications unit configured to provide power control signals to a power supply external to the power transmitter for controlling a power level of a power signal configured for transmission to a power receiver, the power supply configured to configure a direct current (DC) power based on the power control signals. The power transmitter further includes an inverter circuit configured to receive the DC power from the power supply external to the power transmitter and convert the input power to a power signal. The power transmitter further includes a coil formed of wound Litz wire and including at least one layer, the coil defining, at least, a top face and shielding comprising a ferrite core and defining a cavity, the cavity configured such that the ferrite core substantially surrounds all but the top face of the coil.