Method and apparatus for detecting a stall condition in a stepping motor

摘要

Stepped rotary motion is imparted to the rotor of a stepping motor by alternately driving at least first and second coils which interact with a plurality of magnetic poles on the rotor. When each of the coils transitions from a driven to a non-driven state, the continued motion of the rotor causes a back electro-motive force to be generated in the coil. The electro-motive forces produced by the coils are rectified, integrated, and then compared with a threshold to determine if a motor stall condition exists.