| 摘要 |
PURPOSE:To eliminate a need for a mechanical stop mechanism by a method wherein, when a power-failure detection means detects a power failure, a speed control means sets the target speed of an object to be conveyed to zero, a linear-motor drive means controls the speed of the object to be conveyed so as to become zero by using the electric power of a built-in battery and the object to be conveyed in a self-propelled state is stopped. CONSTITUTION:When a power failure is caused on the side of a power supply 10, a power-failure detection part 21 for a CPU 20 detects it, and a power-failure detection signal is output to a target-speed setting part 22. Due to the power failure, a secondary battery 12 starts supplying an electric current to the CPU 20 and to the side of a motor drive circuit 30 via a diode D2. That is to say, the target-speed setting part 22 sets a speed 0 as a target speed Vm when the power failure continues after a definite time has lapsed. Thereby, the motor drive circuit 30 (to which the electric current is supplied from the secondary battery 12 at present) drives a linear motor 40, and it decelerates a door which is self-propelled to the closing end side by inertia. |
