| 摘要 |
PURPOSE:To prevent an electric current from flowing through an armature during a stop time of motor and unecessary torque from generation, by equipping this apparatus with a switching element for breaking an output transistor supplying electric current to an armature coil through a stop command signal from the outside. CONSTITUTION:A position signal is synthesized from output of Hall elements 1, 2, 3 by a position signal synthesizing circuit 30; and an electric current is supplied to armature coils 4, 5, 6 by a position signal amplifier 40 and output transistors 11, 12, 13 and 14, 15, 16 to drive a motor. In such constitution, if said motor is stopped, a stop command Es is inputted, switch transistors 17, 18, 19 are turned ON, and the output transistors 14, 15, 16 are cut OFF. Consequently, no current is supplied to the armature coils 4, 5, 6. As a result, influences of an output offset current of the position signal amplifier 40, a leakage current of an internal transistor due to a temperature rise of motor driver and others can be excluded and unnecessary torque can be prevented from generation in said motor during a stop time thereof. |
