Development of brushless and sensorless vibration motor used for mobile phone

Summary form only given. A paging signal by a sound-transducer often acts as an environmental noise in some places, thus necessitating a paging signal by a vibration motor. Conventional vibration motors employ mechanical brushes for commutation, which is disadvantageous to manufacturing cost and productivity. In this paper, a new brushless and sensorless vibration motor is introduced utilizing DSP chips in mobile phones. For electromagnetic field analysis, 2-D modeling can be implemented to determine the output torque using axisymmetric boundary conditions. The same performance can be achieved with a reduced number of parts, thus enhancing manufacturing productivity and reducing manufacturing cost.