US 9,813,041 B1
Automatic boost control for resonant coupled coils
David W. Ritter, Cupertino, CA (US)
Assigned to Apple Inc., Cupertino, CA (US)
Filed by Apple Inc., Cupertino, CA (US)
Filed on Jul. 31, 2014, as Appl. No. 14/449,075.
Int. Cl. H02J 7/00 (2006.01); H03H 7/38 (2006.01); H02J 7/02 (2016.01); H02J 5/00 (2016.01)
CPC H03H 7/38 (2013.01) [H02J 5/005 (2013.01); H02J 7/025 (2013.01); H02J 7/0042 (2013.01)] 18 Claims
OG exemplary drawing
 
1. A coupled coil system for wireless power transfer between a transmitter and receiver, comprising:
a receive coil operatively associated with the receiver;
a transmit coil operatively associated with the transmitter and having an output impedance, further operative to wireless transmit power to the receiver;
a rectifier connected to the transmit coil; and
an input impedance regulator between the receive coil and the rectifier and comprising a boost converter adapted to boost an output voltage of the receive coil by charging and discharging a leakage inductance of the receive coil; wherein
the input impedance regulator is adapted to provide an input impedance for the receiver that is substantially equal to the output impedance of the transmit coil.