DC Fan opposite poles

"DC Fan" HALL IC and the strength of the magnetic field changes polarity judgment, output control signals to control operation of the fan motor. When the 9141 closest S-pole permanent magnet rotor, in a strong magnetic field, the Hall voltage generated assembly hall, through a series of signal processing, the final 9141 PIN3 output low, PIN3 conduction (9141 PIN2 high potential output), through the red coil L1 of the stator current I1 4-pole, respectively, to produce the opposite pole: P1 → S; P2 → N; P3 → S; P4 → N; and a rotor (magnetic stripe) 4-pole, the occurrence of magnetic force, pushing against the rotor clockwise rotation.