| 摘要 |
PURPOSE:To detect whether the moving speed of an objective material is measured correctly or not, by providing three speed detectors and a signal processor which has a majority decision logical circuit. CONSTITUTION:The speed detectors 4a-4c are fitted to moving rollers 2A-2C of a conveyance line for the material 3 to be detected. Their detection signals are supplied to the signal processor 5 having the majority decision logical circuit 11. Namely, the outputs of the detectors 4a-4c are converted by frequency- voltage converters 7a-7c, whose conversion outputs are supplied to the logical circuit 11 through pulse generating circuits 10a-10b which generate outputs when the conversion outputs are at a specific level. Therefore, when at lest two of the detectors generate the same output, it is decided from the output of the circuit 11 that the speed detection is carried out correctly. Thus, whether the moving speed of the objective material is measured accurately or not is detected. |
