power_transfer_architecture_of_the_qi_standard
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| power_transfer_architecture_of_the_qi_standard [2025/05/01 13:23] – [Establishing power transfer] tm | power_transfer_architecture_of_the_qi_standard [2025/05/01 14:11] (current) – [4.Negotiation phase] tm | ||
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| This phase can only be accessed through EPP or MPP capable devices with **[[Foreign object detection in the Qi standard|foreign object detection (FOD)]]**. In this phase the Tx and Rx review their power transfer contract. The purpose of the negotiation phase is to fine-tune this contract. The Rx sends a negotiation request to the Tx to which it replies with a message of granting, denying or not recognising the request. Both the sender and the receiver keep a copy of the current contract. This temporary copy is used to store updated parameters until the negotiation phase is successfully completed. | This phase can only be accessed through EPP or MPP capable devices with **[[Foreign object detection in the Qi standard|foreign object detection (FOD)]]**. In this phase the Tx and Rx review their power transfer contract. The purpose of the negotiation phase is to fine-tune this contract. The Rx sends a negotiation request to the Tx to which it replies with a message of granting, denying or not recognising the request. Both the sender and the receiver keep a copy of the current contract. This temporary copy is used to store updated parameters until the negotiation phase is successfully completed. | ||
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| As part of this phase, the Rx also sends the reference **[[Foreign object detection in the Qi standard|quality factor (Q-factor)]]** value to the Tx. This value reflects the Q-factor measured under ideal conditions without any foreign objects. The Tx uses this value to determine a threshold for FOD by comparing it with the Q-factor measured on its own primary coil. If the measured Q-factor falls below this threshold, the Tx may terminate the power transfer. These Q-factor evaluations and threshold settings are performed during the negotiation phase to ensure safe and efficient operation. | As part of this phase, the Rx also sends the reference **[[Foreign object detection in the Qi standard|quality factor (Q-factor)]]** value to the Tx. This value reflects the Q-factor measured under ideal conditions without any foreign objects. The Tx uses this value to determine a threshold for FOD by comparing it with the Q-factor measured on its own primary coil. If the measured Q-factor falls below this threshold, the Tx may terminate the power transfer. These Q-factor evaluations and threshold settings are performed during the negotiation phase to ensure safe and efficient operation. | ||
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| With the MPP this process is simplified. The magnetic attachment within the new MPP mode tightly secures transmitter and receiver coils in optimal positions. Therefore, the coupling factor always hovers around a value of 1. This makes the negotiation and FOD procedures faster and more predictable than in EPP (The Qi Wireless Power Transfer System Class 0 Specification 1 and 2: Interface Definitions, | With the MPP this process is simplified. The magnetic attachment within the new MPP mode tightly secures transmitter and receiver coils in optimal positions. Therefore, the coupling factor always hovers around a value of 1. This makes the negotiation and FOD procedures faster and more predictable than in EPP (The Qi Wireless Power Transfer System Class 0 Specification 1 and 2: Interface Definitions, | ||
power_transfer_architecture_of_the_qi_standard.txt · Last modified: by tm