Patent ID: 8872472

Claim:
An inductive power supply system comprising: a primary circuit including a power source, a controller electrically coupled to said power source and a primary electrically coupled to said controller, wherein said controller applies power with a frequency to said primary from said power source; a portable device separable from said primary circuit and having a secondary circuit and a feedback circuit electrically coupled to said secondary, said secondary circuit includes a secondary inductively coupled to said primary to receive power therefrom, said feedback circuit configured to selectively shunt current from said secondary through an impedance element, wherein in response to current being selectively shunted through said impedance element, a current flow through said secondary increases generating a single surge in current through said primary via said inductive coupling; wherein said feedback circuit is configured to detect one or more conditions in said portable device, wherein in response to detecting said one or more conditions, said feedback circuit selectively shunts current through said impedance element to generate said single surge in said primary; wherein said primary circuit includes a feedback detector operably coupled to said controller, wherein said feedback detector is configured to sense said single surge in said primary; and wherein said controller is configured to recognize said single surge in said primary as an indication of said one or more conditions being detected, whereby said controller is capable of identifying a state of said one or more conditions in said portable device in response to detection of said single surge in said primary.