| 摘要 |
PURPOSE:To enable accurate data processing on the fatigue testing for a test piece, by completely sampling data the preset frequency of a feedback signal regardless of any lag in the phase from a set signal. CONSTITUTION:A set signal source 1 generates a signal pertaining to the operation of a piston rod mounted on an electrohydraulic type fatigue tester 7 as load system. A CPU3 calculates the mean of a digital signal applied through a detector 8, an amplifier 9 and an A/D conversion circuit 6 and memorizes it. Then, an auxiliary circuit 2 starts the level comparison of the mean signal received through a line L2 and a feed back signal from the amplifier 9 from the time when it receives a synchronous signal through a line L1 and generate a start signal in a line L4 to trigger the sampling operation of the CPU3 at the moment the feedback signal crosses the mean signal. Thus, the sampling of the feed back signal can be done corresponding to one cycle of the set signal regardless of lag in the phase thereof from the set signal. |
