MULTI-PHASE MODE MULTIPLE COIL DISTANCE DEACTIVATOR FOR MAGNETOMECHANICAL EAS MARKERS

摘要

A device for deactivating a magnetomechanical electronic article surveillance marker (126) includes first (L11), second (L12), third (L13) and fourth (L14) rectangular coils arranged in a two-by-two array in a common plane. Drive circuitry energizes the coils according to an operating cycle which includes three modes. Taking into account the three modes of operation, substantial magnetic fields are generated in each of three mutually orthogonal directions so that a substantial deactivation field is provided along the length of the marker to be deactivated, regardless of the direction of orientation of the marker relative to the coil array. Two-coil and quadrature-driven deactivators are also disclosed.