Wireless Charger Frequency Switching for AM Radio Interference
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Solution Overview
Problem
Existing contactless chargers for terminal devices, such as smartphones, face interference with AM radio frequencies, requiring manual frequency switching, which is unsafe and inconvenient while driving, and increase costs when equipped with automatic frequency acquisition.
Innovation Solution
A charger with a processor and memory that detects movement of the terminal device and automatically adjusts the charging frequency, using a power transmission unit, communication state detection, and movement detection modules to switch frequencies based on specific movement patterns.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Extent of automation
If the charger is equipped with a function to acquire the receiving frequency of the AM radio for automatic switching, then the charging frequency can be automatically adjusted to avoid interference, but the cost increases
Solution Approach 1:
The terminal device itself performs the frequency detection and notification function that would traditionally require a separate AM radio frequency acquisition module in the charger. The terminal device uses its existing communication capabilities to detect charger vibrations caused by AM radio interference and communicates this information back to the charger, eliminating the need for additional hardware in the charger while achieving automatic frequency switching.
Solution Approach 2:
The terminal device acts as an intermediary between the charger and the AM radio interference source. Instead of the charger directly detecting AM radio frequencies, the terminal device detects the vibration caused by interference and relays this information to the charger, which then adjusts its frequency accordingly. This intermediary approach allows automatic frequency switching without requiring the charger to have direct AM radio detection capabilities.
2Device complexity
If manual button pressing is used to switch charging frequency when noise occurs, then cost is reduced, but user safety is compromised due to repeated pressing while driving
Solution Approach 1:
The system performs frequency switching automatically based on vibration detection, eliminating the need for manual user intervention. The terminal device detects interference through vibration sensing and autonomously communicates with the charger to initiate frequency switching, completely removing the requirement for users to press buttons while driving.
Solution Approach 2:
The system implements a feedback loop where the terminal device continuously monitors for vibration caused by AM radio interference, communicates this information to the charger, and triggers automatic frequency adjustment. This closed-loop feedback mechanism ensures the charging frequency is automatically adapted to avoid interference without requiring manual user input.
3Device complexity
If the charging frequency is fixed, then device complexity is reduced, but interference with AM radio cannot be avoided
Solution Approach 1:
The charging frequency transitions from a static fixed value to a dynamic adjustable parameter. The system continuously monitors for interference conditions through vibration detection and automatically adjusts the charging frequency in response to detected interference, enabling the frequency to adapt dynamically to changing environmental conditions while maintaining relatively simple device architecture.
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 simple and safe automatic switching of charging frequencies, reducing interference with AM radio and eliminating the need for manual intervention, thereby enhancing user safety and reducing costs.
Implementation Method 1
a magnetic flux generated by an AC current flowing through a power transmission coil to pass through a power reception coil incorporated in a terminal device mounted on a charging stand, thereby generating an induced electromotive force by the effect of electromagnetic induction
Data Source
AI summary
A charger performs wireless charging on a terminal device that is placed on a tray (placement unit) and includes a power reception coil (power reception unit) configured to receive wirelessly transmitted power. The charger includes a memory and a processor coupled to the memory. The processor is configured to: instruct a power transmission coil (power transmission unit) to transmit power; detect a communication state between the power transmission coil and the power reception coil; acquire a charging frequency to be used for the wireless charging; detect movement of the terminal device; and change setting of the charging frequency when the movement of the terminal device is detected.