Development of 2-Phase/4-Phase Flat-Type Vibration Motor

Due to the mechanical angle error between two brushes and commutation patterns on the rotor PCB, a fatal defect-starting failure-could be detected in the vibration motor. In order to eliminate this failure, we have developed a new winding method, double winding, to make a 4-phase vibration motor with only 2 bunches of coil. By this winding method, we could eliminate the starting failure successfully and save the manufacturing cost