Wire-Wound Structures for Electromagnetic Sensing of Objects

This disclosure provides an apparatus for detecting a presence of an object in a predetermined area of an inductive wireless power transfer system. The apparatus comprises a first wire-wound structure having an electrical characteristic configured for electromagnetic sensing of the object. The first wire-wound structure is formed, carried, and held in place by a coil-former substantially from a non-conductive material. The coil-former also forms, carries, and holds in place a second wire-wound structure configured for transferring power inductively. The apparatus further comprises a detection circuit coupled to the first wire-wound structure and configured to measure the electrical characteristic of the first wire-wound structure and to detect the presence of the object in response to a change in the electrical characteristic.