On-line monitoring device for lightning arrester terminal signals

The object of the utility model is to provide an on-line monitoring device for lightning arrester terminal signals, on-line monitoring of overvoltage and leakage current flowing through a lightning arrester terminal is realized via the improvement of a double-valve-block type counter voltage-dividing resistor structure, and the problem that currently, the same device cannot be employed to simultaneously monitor faults and overvoltage of a lightning arrester is solved. The device comprises a resistance voltage-dropping signal extraction device, an isolation transformer, a photoelectric isolation device, a preposed circuit device, a signal acquisition device, a resistive current extraction device, a trigger unit, and a signal analysis and processing device. According to the on-line monitoring device, the on-line monitoring of the aging performance of the lightning arrester is guaranteed, and the functions of overvoltage signal extraction and on-line monitoring are designed.