Wireless charging is an attractive charging option for peripheral devices like styluses, digital pens, etc. The peripheral devices are commonly charged using the main computing device as a power source. The main device uses an induction transmit coil (Tx coil) to create an alternating electromagnetic field, which a receiver coil (Rx coil) in the peripheral device converts into electricity to be fed into a battery in the peripheral device. Magnets are provided at suitable locations on the peripheral device and the main device to align and attach the peripheral device to the main device, thereby reducing the air-gap between Rx and Tx cores. This enables a relatively high magnetic flux (ΦM) and limits leakage flux (ΦLk), leading to a high coupling coefficient and a high charging efficiency.
Creative Commons License
This work is licensed under a Creative Commons Attribution 4.0 License.
Jia, Liang and Chen, Yungchih, "Efficient wireless charging of peripheral devices", Technical Disclosure Commons, (January 16, 2020)