Wireless Power NFC Card Detection via Receiver-Mediated Signaling
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Solution Overview
Problem
Wireless power transmitters without RFID/NFC detection capabilities fail to detect RFID/NFC cards, leading to potential damage due to continuous exposure to strong magnetic fields and heat generation issues, as existing detection methods rely on power loss measurements and frequency mismatches.
Innovation Solution
A method involving a power transmitter and receiver that includes a digital ping mechanism, capability packets with NFC detection fields, and End Power Transfer packets to detect and manage the presence of RFID/NFC cards, allowing for temporary power signal removal and user notification to prevent damage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a power transmitter without RFID/NFC detection function is used, then the device complexity is reduced, but the reliability deteriorates because RFID/NFC cards cannot be detected and may be damaged by continuous exposure to strong magnetic fields
Solution Approach 1:
The patent introduces an intermediary detection mechanism that uses the power receiver as a mediator to detect RFID/NFC cards. The power receiver performs the detection function and communicates results to the power transmitter, allowing detection capability to be added without requiring the transmitter itself to have direct detection hardware, thus resolving the contradiction between device complexity and reliability.
Solution Approach 2:
The patent implements preliminary detection of RFID/NFC cards before initiating full power transmission. By detecting the presence of RFID/NFC cards in advance during the selection or ping phase, the system can prevent damage by avoiding continuous exposure to strong magnetic fields, thereby improving reliability without adding complex detection functions to the transmitter.
2Device complexity
If FOD method based on power loss measurement is used, then the device complexity is reduced, but the measurement precision deteriorates because RFID/NFC cards do not cause power loss
Solution Approach 1:
The patent changes the detection parameter from power loss measurement to magnetic field interaction detection. By using detection methods that respond to the magnetic properties of RFID/NFC cards rather than power consumption, the system achieves precise detection of RFID/NFC cards without increasing device complexity, as the same power transmission infrastructure is used for both power delivery and detection.
Solution Approach 2:
The patent uses the power receiver as an intermediary detection device that can identify RFID/NFC cards through their magnetic field characteristics. This intermediary approach enables precise detection of RFID/NFC cards without requiring the transmitter to have specialized detection hardware, maintaining simplicity while improving measurement precision.
3Productivity
If power transmission continues without detecting RFID/NFC cards, then the productivity is maintained, but the object-affected harmful factors increase due to heat generation and potential damage to RFID/NFC cards
Solution Approach 1:
The patent performs preliminary detection of RFID/NFC cards before initiating continuous power transmission. By detecting the presence of RFID/NFC cards in advance, the system can prevent harmful effects such as heat generation and magnetic field damage, allowing productivity to be maintained only when it is safe to do so.
Solution Approach 2:
The patent implements a feedback mechanism where detection results are used to control power transmission. When RFID/NFC cards are detected, the system provides feedback to stop or reduce power transmission, preventing harmful effects while maintaining productivity when no RFID/NFC cards are present. This feedback loop ensures that productivity is optimized without causing damage.
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
Efficient detection and protection of RFID/NFC cards are ensured, maintaining compatibility with WPC standards, preventing damage and ensuring safety by temporarily stopping power transmission during detection.
Implementation Method 1
In the electromagnetic induction method, a power transmission unit generates a magnetic field through a power transmission coil (i.e., a primary coil), and a power reception coil (i.e., a secondary coil) is placed at the location where an electric current may be induced so that power is transferred.
Implementation Method 2
In the resonant method, energy is transmitted using a resonant phenomenon between the transmission coil and the reception coil. In this case, a system is configured so that the primary coil and the secondary coil have the same resonant frequency, and resonant mode energy coupling between the transmission and reception coils is used.
Data Source
AI summary
According to an embodiment of the present invention, a method for transferring wireless power by an electric power transmitter may comprise: a selection step of monitoring a placement or a removal of an object on or from an interface surface of the power transmitter; a ping step of performing a digital ping and receiving a response from a power receiver; an identifying/configuring step of receiving a configuration packet including configuration information of the power receiver; and a negotiating step of transmitting a capability packet including information on a level of power transferred by the power transmitter, wherein the capability packet may include an NFC detection field indicating whether the power transmitter has a capability of detecting an RFID and/or an NFC, and/or whether the RDID and/or the NFC is detected.