METHOD AND DEVICE FOR DETECTING CABLE

摘要

PROBLEM TO BE SOLVED: To improve reliability in detecting a specific cable by including a waveform for determining polarity with a waveform different from other periods in a specific period of a sinusoidal current and discriminating a magnetic field which occurs around the specific cable from a magnetic field which occurs around cables except for the specific cable on the basis of the waveform. SOLUTION: A sinusoidal current A-1 for detection is transmitted, and a magnetic field which occurs around a cable to be detected is detected by a search coil device to obtain a waveform A-2. The waveform A-2 is converted into a saturation waveform A-3 by an amplifier and is converted into a waveform A-4 by a comparator. The positive components and negative components of the waveform A-4 are processed at an AND circuit to obtain a waveform A-5 and a waveform A-6. As there is more positive components in the case of detecting a magnetic field which occurs around a cable to which the sinusoidal current A-1 for detection is transmitted, it is possible to specify the cable to be detected by an indicator. There is no possibility of errors because a current passing through a cable conductor except for the cable to be detected has a phase different by 180 degrees due to a wraparound current.