Patent ID: 7476999

Claim:
A device for producing torque, the device comprising: an armature made of a printed circuit board, said armature being rotatable about a rotation axis; at least one winding formed on said armature in a substantially rectangular spiral path; at least one magnetic field inducer, each of said at least one magnetic field inducer being located in the vicinity of a respective corner of said substantially rectangular spiral path, each of said at least one magnetic field inducer producing a magnetic field along a magnetic axis in a selected direction, said selected direction being opposite to another selected direction respective of an adjacent magnetic field inducer, each of said magnetic axes being substantially normal to said substantially rectangular spiral path, said at least one winding and said at least one magnetic field inducer applying said torque on said armature, when electric power is applied to said at least one winding, said torque being at a torque level respective of a selected power level; and a counteractive torque producing element coupled with said armature, said counteractive torque producing element applying a counteractive torque on said armature in a direction opposite to that of said torque.