PURPOSE: To provide a power line measuring apparatus for measuring or monitoring state change of current, voltage, temperature, and the like of a power line such as a distribution line in which power of measuring power supply is taken out from power line.
CONSTITUTION: The power line measuring apparatus comprises an annular power supply current transformer 2 to be noncontact mounted on a power line in order to take outpower supply power from the magnetic field produced by the load current of the power line, an AC power control circuit 3 comprising a semiconductor element 8 connected with the output terminal of the current transformer 2, a rectifying circuit 4 connected across the AC current control circuit 3, and a voltage detecting/controlling circuit 5 connected with the output terminal of the rectifying circuit 4 and actuates the semiconductor element 8 in the AC current control circuit upon detection of an overvoltage to perform current control. This constitution allows stabilized power supply for measuring circuit even upon variation of output current from the power supply current transformer 2 due to variation of load on the power line.
YOKOTA TSUTOMU
YUKIHIRA KENJI
KAYAHARA MASAAKI
| JPH0247565A | 1990-02-16 | |||
| JPH0268569A | 1990-03-08 | |||
| JPH0446519A | 1992-02-17 |