Patent attributes
An electromagnetic motion sensor includes a base, an electromagnetic induction layer, a block, and an emitting coil. The electromagnetic induction layer with a plurality of induction coils is arranged on the bottom of the base. The block is movably connected to the base by a plurality of elastic members. The emitting coil is fixed to a center of the bottom of the block facing the induction layer. A circuit inside the block provides current to the emitting coil. The block moves with the jerk of the motion sensor when the motion sensor is jerked, causing the elastic members to be distorted. The relative movement between the block and the magnetic induction layer causes more than one of the induction coils generate and output voltage signals according to the change of magnetic flux through the plurality of induction coils caused by the moving of the emitting coil.