| 摘要 |
PURPOSE:To trace the cause of falling accidents of a moving bar-like member by a device wherein voltage changes due to a change in self-inductance of detection windings and induced voltage along with movement of the moving bar-like member are stored and thus stored data is transferred to a recorder after falling of the moving bar- like member has occurred. CONSTITUTION:When a moving bar-like member 4 is inserted into a detection winding 1 being excited by an AC power supply 2, self-inductance of the winding is increased so that there occurs a difference among inductances of the respective windings 1a-1e. This difference is detected by a position signal generator 5 and then indicated on a display 6. When the bar-like member 4 moves at a certain speed, the bar-like member magnetized by an alternating magnetic field within the detection winding induces voltage in proportion to the speed on the respective windings. Thus, a change in the inductance and the induced voltage are taken out in the form of an AC component VA and a DC component VO of voltage across a resistor 8, respectively. Both voltages are added by an adder 10 via an AC-DC converter 11 and then stored in a storage 12 for a period of time T. In the event of falling accidents, a signal from the winding 1b is used for a controller 13 to trigger the storage 12 within the period of time T, so that the stored content is recorded on a recorder 14. |
