Patent ID: 8398297

Claim:
A stirring device comprising: a magnetics board containing at least two adjacent groups of air core coils; a cover having a top surface, said cover being situated above said coils, said cover having an array of pole standoffs arranged such that the air core of each coil contains a portion of one pole standoff; said pole standoffs having a head and a distal end, said heads of said pole standoffs extend through said cover and are flush with the top surface of said cover; a stepper motor driver outputting a first phase and a second phase of electrical power; each of said groups of coils having four coils arranged in a rectangular pattern; said four coils comprising a first pair of two coils and a second pair of two coils; said two coils in said first pair are positioned diagonally in the rectangular pattern; said two coils in said first pair are connected in series and wound in opposite directions; said two coils in said first pair are energized by said first phase of electrical power, thereby producing oppositely oriented magnetic fields; said two coils in said second pair are positioned diagonally in the rectangular pattern; said two coils in said second pair are connected in series and wound in opposite directions; said two coils in said second pair are energized by said second phase of electrical power, thereby producing oppositely oriented magnetic fields; adjacent coils from said adjacent groups of coils are energized by the same phase of power and produce a magnetic field oriented in the same direction.