| 摘要 |
PURPOSE:To discover trouble early and prevent the breakage of apparatuses by conducting the decision of abnormality by means of a decision circuit in a case in which variation between the speed of a motor and the speed of a car is excessive at the time of elevator travel, conducting the emergency stop of the motor by means of an emergency stop circuit on the basis of its decision output, and at the same time conducting the emergency stop of the elevator. CONSTITUTION:The speed of a car 5 and the speed of a motor 13 are respectively detected by means of a car speed detector 8 and a motor speed detector 14, and inputted at a safety device 60. The outputs of the speed detector 8 and the motor speed detector 14 which have been inputted at the safety device 60, are respectively converted into pattern signal levels by means of conversion circuits 61, 62. Next, a difference speed between the car speed and the motor speed that have been converted into pattern signal levels, is calculated by means of a subtractor 63, and the absolute value of the difference speed calculated by means of the subtractor 63 is outputted by means of an absolute value conversion circuit 64. When this output value becomes larger than a reference difference speed level 65, a decision circuit 66 outputs an abnormality deciding output signal, and an emergency stop circuit 67 outputs an emergency stop signal to a speed controller 25. |
