| 摘要 |
PURPOSE:To display exactly height of a suspended object, by detecting a fact that the suspended object reaches the upper limit, sending a reset signal of a counter and a preset data for a base point, to the counter, and using this data as a reference for measuring the height. CONSTITUTION:When a motor 21 is rotated, suspended object 7 goes up and it reaches a limit switch 23, the motor 21 stops, a signal is sent to a controlling circuit, a counter 22 is reset, and ''0'' is displayed on an indicator 13. Subsequently, when a reset signal falls, a load signal is sent to the counter 22, also a preset start signal is sent to a nonvolatile memory 25 from a circuit 24, and stored value of height between the suspended object 7 and a floor face F is sent to the counter 22. When the suspended object 7 starts to descend, the limit switch 23 becomes off, the counter 22 counts down, and height of the suspended object is derived. The base point is set newly whenever the suspended object 7 reaches the switch 23, therefore, exact height of the suspended object 7 is displayed at all times. |
