| 摘要 |
PURPOSE: An apparatus for measuring phase of underground lines is provided to prevent failure generation of the lines by measuring phase of the lines exactly upon opening operation of the underground lines. CONSTITUTION: The first comparator(10) compares ground potential of the underground lines with reference potential. The second comparator(20) compares the signal for the ground potential with potential of measurement line. The third comparator(30) compares the signal for the ground potential with potential of reference line. The first and second invertor(40,50) inverts the output signals from the second and third comparator(20,30). The first flipflop(60) is supplied with the output signal from the first invertor as clock signal and the data signal from the any output terminal of the second invertor and executes internal operation for them. The second flipflop(70) is supplied with the output signal from the second invertor as clock signal and the data signal from the any output terminal of the first invertor and executes internal operation for them. The drive(80) analyzes the output signals from the first and second flipflops(60,70) and detects and displays the information for the underground lines.
|
