| 摘要 |
PURPOSE:To realize torque increase during rotation through the use of mutual inductance while separating a drive circuit and a bias circuit. CONSTITUTION:The driving circuit for feeding a stator sequentially with drive currents for rotating a rotor in predetermined direction and driving a spindle motor for magnetic disc unit comprises a control circuit 7 with which U, V, W phase coils 1-3 are connected in unipolar through MOS-FETs 4-6, bias coils 8-10 and capacitors 11-13 connected in series with the coils 1-3, and a charge-up power supply 14. Charging currents for the capacitors 11-13 are fed variably as bias currents. |
