| 摘要 |
PURPOSE:To prevent a car speed to be kept from being increased limitlessly through a failure of an increase switch, by avoiding the operation of a self-holding circuit from being operated, even by the operation of a set switch, if an increase switch is in operating state. CONSTITUTION:When a set switch 38 is depressed, a switch 16 turns on, and a car speed signal via a reed switch F/V converter 14 is set to a storage circuit 18. Further, a self-holding circuit 34 is set. The deviation between the output of the storage device 18 and a detected car speed signal is obtained at a comparator 20, and an actuator 28 is driven and the car speed is controlled at a constant value. When an increase switch 30 is depressed, a driving signal is outputted via an OR circuit 22 and the car speed can be increased. Even if the set switch 38 is depressed, since the self-holding circuit 34 is not set, the increase in the car speed can not be made limitless through a failure in the switch 30. |
