| 摘要 |
PURPOSE:To rapidly stop a DC (direct drive) motor by cutting the drive current of the motor when a malfunction occurs in a magnetic disk unit and simultaneously shortcircuiting at least two of exciting phases of the motor. CONSTITUTION:A relay 54a is normally opened at power source ON time, the exciting phases of exciting coils 56 of a DD motor are excited, and the motor starts rotating. When power is turned OFF, the relay 54a of a motor stop controller 54 is closed, thereby shortcircuiting the exciting phases of two phases of the coil 56, two of three phases are set to the same potential, thereby generating a braking operation. When a malfunction occurs at normal operation time, a motor OFF signal is input to a terminal 54b, the power of a driver 54 is turned OFF, and a braking operation is generated. |
