Patent ID: 9369000
Filing Date: 2016-06-14
CPC Classification: H02J,H02M,H04B

Claim Text:
1. A power transmission pad for wireless power transmission comprising: a. a coil; b. a power transmitter having a sweep frequency generator coupled to the coil to provide a frequency varying signal through the coil, thereby generating a variable magnetic field; and c. a controller coupled to the coil and to the sweep frequency generator, wherein when multiple portable electronic devices to be charged are positioned within the variable magnetic field, the power transmission pad is configured to determine resonant frequencies for the multiple portable electronic devices each corresponding to a maximum energy transfer from the power transmission pad to a corresponding one of the multiple portable electronic devices, and to cycle a frequency of a power transmission signal through the determined resonant frequencies of the multiple portable electronic devices, wherein the resonant frequencies are determined by sweeping transmission frequencies of the frequency varying signal across a sweep frequency spectrum, monitoring a characteristic of the pad or of the multiple portable electronic devices in response to the variable magnetic field, and selecting specific frequencies according to the monitored characteristic.