Patent ID: 8314671

Claim:
A system for operating a first device and a second device, comprising: a first magnetic structure associated with a first part, said first magnetic structure having a first plurality of magnetic sources arranged in accordance with a first code; a second magnetic structure associated with a second part, said second magnetic structure having a second plurality of magnetic sources arranged in accordance with a second code, said second part being movable relative to said first part, said first part and said second part achieving a match when said first plurality of magnetic sources and said second plurality of magnetic sources are in a first alignment, said first alignment producing a first peak force in accordance with a cross correlation property of said first code and said second code, said first peak force greater than a first predefined threshold; said first part enabling operation of said first device when said first part and said second part are in said first alignment; a third magnetic structure associated with a third part, said third magnetic structure having a third plurality of magnetic sources arranged in accordance with a third code; and a fourth magnetic structure associated with a fourth part, said fourth magnetic structure having a fourth plurality of magnetic sources arranged in accordance with a fourth code, said fourth part being movable relative to said third part, said third part and said fourth part achieving a match when said third plurality of magnetic sources and said fourth plurality of magnetic sources are in a second alignment, said second alignment producing a second peak force in accordance with a cross correlation property of said third code and said fourth code, said second peak force greater than a second predefined threshold; said third part enabling operation of said second device when said third part and said fourth part are in said second alignment; said fourth part being movable relative to said first part within a range of motion, said first part and said fourth part producing a force function within said range of motion having a first maximum value less than said first predefined threshold, said first maximum value failing to enable operation of said first device; wherein said first code and said third code are from a set of codes having a low mutual cross correlation among all codes in the set of codes, said low mutual cross correlation being less than half of a peak autocorrelation for a code in the set of codes; and wherein the set of codes is a Kasami set or a Gold set.