| 摘要 |
PURPOSE:To exactly detect an abnormal operation state by detecting that a control signal being in proportion to the generation period of a scanning pulse has been omitted extending over a prescribed period or longer. CONSTITUTION:The output of the sensor 18 is led out to the output terminal 32 through the preamplifier 19, the low pass filter 20 and the video process amplifier 21. A control signal being in proportion to the generation period of a scanning pulse in the output of the preamplifier 19 is inputted to the trigger monostable circuit 25 through the amplitude discriminating circuit 24. It is detected by the trigger monostable circuit 25 that the control signal has been omitted extending over a prescribed period or longer, and it is displayed by the pilot lamp 26. |
