Patent ID: 8651386

Claim:
A method for processing data stored in an electronic card, said method comprising: accessing a sequence of binary bits, for each data track of at least one data track, from a memory in the electronic card; determining a time varying electrical current configured to flow in two adjacent wire structures of N wire structures disposed in each data track of the at least one data track to generate a time varying magnetic field that encodes the sequence of binary bits, N being at least 3; and generating the time varying magnetic field as the card is swiped through a card reader in a minus X direction by driving the time varying electrical current through the two adjacent wire structures, said time varying magnetic field inducing a readback signal in the card reader; wherein the card comprises a substrate, a processor disposed in the substrate, the at least one data track disposed in the substrate such that each data track is oriented in the X direction, the memory disposed in the substrate, a switch apparatus disposed in the substrate, the N wire structures disposed in each data track, and a power source disposed in the substrate, wherein the power source provides electrical power to the processor, the switch apparatus, and the N wire structures disposed in each data track, wherein said generating the time varying magnetic field comprises said processor operating the switch apparatus with respect to the N wire structures, wherein said operating the switch apparatus comprises electrically coupling the two adjacent wire structures of the N wire structures in each data track to the power source and to electrically decoupling all other wire structures of the N wire structures from the power source, and wherein said electrically coupling the two adjacent wire structures and said electrically decoupling all other wire structures causes the power source to generate a voltage drop that drives the time varying electrical current through each wire structure of the two adjacent wire structures but no electrical current through any other wire structure of the N wire structures, which generates the time varying magnetic field above each wire structure of the two adjacent wire structures but not above any other wire structures of the N wire structures.