Patent ID: 7839142

Claim:
A magnetic sensor, comprising: a. a plurality of coil elements; b. at least one time-varying signal source of at least one time-varying signal operatively coupled to said plurality of coil elements, wherein a first coil element of said plurality of coil elements is adapted to generate a first magnetic field component responsive to said at least one time-varying signal, at least a second coil element of said plurality of coil elements is adapted to generate at least a second magnetic field component responsive to said at least one time-varying signal, said first coil element and said at least said second coil element are adapted so that said first magnetic field component and said at least said second magnetic field component interact with different first and at least second portions of a vehicle when said plurality of coil elements are in a cooperative relationship with said vehicle, and said first coil element and said at least said second coil element are each proximally adjacent to corresponding separate conductive portions of a common surface of said vehicle; and c. at least one detection circuit operatively coupled to said plurality of coil elements, wherein said at least one detection circuit generates a detected signal responsive to a first sensed signal component from said first coil element responsive to said first magnetic field component and responsive to at least a second sensed signal component from said at least said second coil element responsive to said at least said second magnetic field component, and said detected signal provides for detecting a change in a magnetic condition of or associated with said vehicle.