| 摘要 |
PURPOSE:To perform a nonmechanical brake function having high reliability without noise by shortcircuiting at least two phases of exciting phases of a polyphase direct drive motor when a power source is turned OFF to stop the motor. CONSTITUTION:A relay 54a is opened at normal operation time, and the exciting currents of the phases of a DC motor are sequentially output from a DD motor speed controller 52 and a logic drive circuit 53 to an exciting coil 56 on the basis of a rotating pulse from a Hall IC 55k in the DD motor. When a power source is turned OFF, a relay 54a is closed to shortcircuit the two phases of the coil 56, and two of three phases are set to the same potential. Thus, a braking action due to an inertial rotation arises to rapidly stop a rotor. |
