| 摘要 |
<p>PURPOSE:To enable preventing a run-away of elevator by instantaneously finding out a failure without an erroneous detection of abnormality in a rotary encoder. CONSTITUTION:A driving voltage of motor 5 at the time when the elevator 1 is moved at a safety speed is made to the threshold VS, and in the case a pulse is not generated from the rotary encoder 6 at the time when the driving voltage higher than the threshold VS is supplied to the motor 5, the rotary encoder 6 is decided as defective, meanwhile, when the driving voltage lower than the threshold Vs is supplied to the motor 5, the decision for the defect is not performed.</p> |
