Electric circuit abnormality detection device

An electric circuit abnormality detection device comprising:

• a pulse generator which inputs a pulse signal to an electric circuit;
• a directional coupler which is provided between connection lines connecting between the electric circuit and the pulse generator and extracts, from the electric circuit, a reflected wave of the pulse signal inputted from the pulse generator to the electric circuit;
• a detection unit which is connected to the directional coupler and processes the reflected wave inputted from the directional coupler to detect an abnormality in the electric circuit;
• and
• a low-pass filter provided between the directional coupler and the detection unit,
• wherein the detection unit comprises:
• a storage part which stores waveform information of a reference reflected wave inputted from the directional coupler when the pulse signal is inputted to a reference electric circuit that has a same wiring pattern as the electric circuit and does not have an abnormality;
• and
• a calculation part which detects an abnormality in the electric circuit by comparing waveform information of the reflected wave inputted from the directional coupler when the pulse signal is inputted to the electric circuit, with waveform information of the reference reflected wave stored in the storage part,
• wherein the electric circuit and the reference electric circuit comprise a resistance wire arranged in a plurality of turns and comprise a plurality of bends which reflect the pulse signal inputted from the pulse generator, and
• the reflected wave and the reference reflected wave inputted to the detection unit have a waveform obtained after passing, through the low-pass filter, a composite reflected wave in which a plurality of individual reflected waves reflected by the plurality of bends are superimposed.