Multi-coil Wireless Charger Interference Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Multi-coil wireless chargers experience inter-coil interference due to overlapping coils connected to different drivers, leading to unstable receiver operations, in-band communication interference, and incorrect foreign object detection.
Innovation Solution
A controller is used to manage multiple transmitter coils by enabling only one driver at a time during the initial communication stage, and synchronizing PWM signals across channels to eliminate phase differences and minimize interference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If multiple transmitter coils are arranged close to and/or overlap with each other to enable simultaneous charging of multiple devices, then the charging capacity and versatility are improved, but inter-coil interference occurs leading to unstable receiver operations and incorrect foreign object detection
Solution Approach 1:
The controller implements time-division multiplexing by enabling only one driver at a time during the first stage (communication stage), creating periodic action where each transmitter coil operates in alternating time slots. This resolves the contradiction by allowing multiple coils to serve multiple devices (improving versatility) while preventing simultaneous operation that causes interference (maintaining reliability).
Solution Approach 2:
The charging process is segmented into distinct stages: first stage (communication stage) where only one driver is enabled at a time, and second stage (power transmission stage) where multiple drivers can operate. This segmentation allows the system to achieve both multiple device charging capability and stable receiver operation by separating communication functions from power transmission functions in time.
2Productivity
If multiple transmitter coils operate simultaneously to charge multiple devices, then the productivity is improved, but inter-coil interference causes communication errors and detection inaccuracies
Solution Approach 1:
During the communication stage, the controller enables drivers periodically and sequentially rather than simultaneously, creating time-division multiplexed operation. This ensures that communication data packets are transmitted without interference from adjacent coils, preventing information loss while maintaining the ability to charge multiple devices through coordinated sequential operation.
Solution Approach 2:
The system maintains continuous useful action by seamlessly transitioning between drivers during the communication stage and coordinating their operation during the power transmission stage. The controller ensures that when one driver completes its communication task, another driver can immediately take over, maintaining continuous productivity without gaps while avoiding simultaneous operation that would cause interference.
3Adaptability or versatility
If transmitter coils are arranged to overlap for seamless charging coverage, then the adaptability is improved, but inter-coil interference increases causing unstable operations
Solution Approach 1:
The controller implements periodic enabling of adjacent transmitter coils during the communication stage, where each coil is activated in sequence rather than simultaneously. This periodic action allows overlapping coils to provide seamless charging coverage (improving adaptability) while preventing the harmful interference that would occur if all overlapping coils operated at the same time (reducing harmful factors).
Solution Approach 2:
The controller acts as an intermediary that manages the operation of multiple overlapping transmitter coils. It coordinates the enabling and disabling of each coil, inserting control signals that prevent simultaneous operation during the communication stage. This intermediary control allows the overlapping arrangement to provide seamless coverage while the controller mediates the interference by sequencing operations.
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
This approach reduces inter-coil interference, ensuring stable charging and accurate foreign object detection by preventing simultaneous signal transmission from adjacent coils, thereby enhancing the reliability of wireless charging operations.
Implementation Method 1
The transmitter coils are arranged close to and/or overlap with each other. The first driver is coupled with at least one of the plurality of transmitter coils, to drive the transmitter coil coupled therewith to communicate with and/or provide power to one or more receiver devices
Data Source
AI summary
A wireless charger includes multiple transmitter coils, first and second drivers, and a controller. The transmitter coils are arranged close to and/or overlap with each other. The first driver is coupled with at least one of the transmitter coils to drive the transmitter coil to communicate with and/or provide power over a first channel to receiver devices. The second driver is coupled with at least another one of the transmitter coils to drive the transmitter coil to communicate with and/or provide power over a second channel to receiver devices. The controller is coupled with the first and second drivers and enables only one of the first and second drivers at a time during a first stage.