A capacitive door edge sensor

摘要

A system and method for sensing capacitance at the edge of a movable barrier such as a garage door (302) or sliding door comprises a conductive member such as a wire or rod (304) mounted within a holder (306) mounted pivotally (305) on the door. As the door closes (311) the conductive member is maintained at a minimum distance from a physical reference, in this case the ground (308), such that the sensed capacitance between the conductive member and the ground remains below a predetermined threshold value. If an object obstructs the door then the capacitance will increase above the threshold and the obstruction will be sensed by a controller.