Patent ID: 7388370

Claim:
A magnetic sensor, comprising: a. a plurality of coil elements, wherein said plurality of coil elements comprise at least first and second coil elements, and said first and second coil elements are either separated from one another or overlapping one another; b. at least one time-varying signal source of at least one time-varying signal operatively coupled to said plurality of coil elements, wherein said first and second coil elements are electrically in series with one another and are driven by said at least one time-varying signal source, said first coil element is adapted to generate a first magnetic field component responsive to said at least one time-varying signal, at least said 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, and 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 first vehicle when said plurality of coil elements are in a cooperative relationship with said first 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 first vehicle.