| 摘要 |
PURPOSE:To reliably hold a system driven by a motor drive even if the motor is stepped out by detecting the stepout of the motor and inhibiting the release of a holding torque by a detection signal. CONSTITUTION:When a motor 1 is stepped out, a stepout detector 9 does not correspond between an output signal from a rotation detector 6 and a rotary pulse signal outputted from a drive circuit 7, and detects that the motor 1 is stepped out. When the stepout is detected, a signal for stopping a drive command to the motor 1 is outputted to a drive instructing circuit 8. Further, the detector 9 outputs a logic ''0'' to an AND gate 10. As a result, the switch 12 is opened, a reverse exciting winding 5 is deenergized. Thus, the rotor 3 secured to a drive shaft 2 is held by the magnetic force of a permanent magnet, and the rotation of the motor 1 is reliably held. |
