Abstract: This invention relates to a voltage sensor for sensing a voltage on an electrically charged object such as a distribution line or the like, the sensor being disposed with an insulation space to the object. The voltage sensor includes an amplifier circuit for outputting a signal having a waveform similar to that of a displacement current inflowing from the electrically charged object via the insulation space, and a filter circuit for extracting a signal having predetermined frequencies from the output of the amplifier circuit and outputting an alternating current waveform similar to the potential of the electrically charged object.

Abstract: This invention relates to a voltage sensor for sensing a voltage on an electrically charged object such as a distribution line or the like, the sensor being disposed with an insulation space to the object. The voltage sensor includes an amplifier circuit for outputting a signal having a waveform similar to that of a displacement current inflowing from the electrically charged object via the insulation space, and a filter circuit for extracting a signal having predetermined frequencies from the output of the amplifier circuit and outputting an alternating current waveform similar to the potential of the electrically charged object.

Abstract: An overcurrent display device is described which is suspended directly from a distribution cable for locating the spots of earthing, short-circuiting or other accidents in a distribution line system and is adapted to display the passage of the transient overcurrent due to such accidents through the cable for a predetermined time and to be restored to the original state before the display of the overcurrent condition. The device consists of an overcurrent sensing circuit, a drive unit including a drive element driven by the sensing circuit and a display unit actuated by the drive unit and adapted to achieve a display operation.