| 摘要 |
PURPOSE:To improve reliability by comparing signals from doubled detectors with each other and a set value to be controlled from a setter, and logically comparing and judging the troubles of detectors. CONSTITUTION:Two speed signals detected by two speed detectors 6a, 6b are supplied to a high value selector 8 in a selecting device 12. A switch unit 11 selects an output signal from the selector 8 at the time of normal state, and outputs a deviation from a set signal from a setter 9 to a speed controller 10. The signals from the detectors 6a, 6b and a set signal from the setter 9 are input to a logical comparing discriminator 13, a difference from the signals of the detectors 6a, 6b is obtained with the set signal as a reference, and the difference of the two speed signals is also detected. If it is judged that the deviation from the set signal is large and the deviation of the signals is large, a switching command to a normal side speed signal is generated to the unit 11 of the device 12. |
