| 摘要 |
PURPOSE:To make it possible to automatically stop a vibration fatigue testing machine when the disconnection of each constitutional wire of a twisted wire being a sample, by operating an electromagnetic relay by detecting that a stress level reaches a valve lower than a predetermined set valve by a comparator circuit. CONSTITUTION:A vibration fatigue testing machine is constituted from a grasping mechanism of a twisted wire and a vibration imparting mechanism and a constitutional wire stress gauge is adhered to a part of the twisted wire. The stress gauge is connected to a power stress meter 21 and the output thereof is inputted to a comparator circuit 25 through an amplifier 23 and a full-wave rectification circuit 24. When the input signal reaches a set level or less, the base of a transistor 26 is biassed while an electromagnetic relay 27 is operated and a power source circuit 28 is cut off to stop the testing machine 20. A timer 29 is also turned OFF and an accurate stop period is cleared. Because it is unnecessary that a worker goes to a scene one by one in order to examine a disconnection state, continuous operation during night is enabled and testing efficiency can be enhanced. |
