Patent ID: 9685795
Date: 2017-06-20
CPC Classifications: H01F,H02J

Claim:
1. A wireless power transmitter operable to transfer power wirelessly to a wireless power receiver, said wireless power transmitter comprising: a primary coil operable to form an inductive couple with a secondary coil associated with said wireless power receiver and to transfer power wirelessly thereto; a detector operable to activate said wireless power transmitter when a wireless power receiver is brought into proximity therewith; a driver operable to be triggered by said detector and to provide a driving voltage across said primary coil; and a peak detector for monitoring transmission voltage of said wireless power transmitter, wherein said detector is operable to detect resonance of said inductive couple, said driver is operable to select a transmission frequency significantly different from a resonant frequency of said inductive couple, and said peak detector is configured to detect large increases in the transmission voltage indicating an increase in resonant frequency.