DEVICE FOR DETECTING ABNORMAL STATE WHEN POWER SUPPLY IS CUT OFF AND METHOD FOR DETECTING ABNORMAL STATE WHEN POWER SUPPLY IS CUT OFF

摘要

This invention detects an abnormal state when the main power supply of electronic equipment is cut off. In this invention, an antenna includes an antenna element for receiving radiation noise radiated from a device on a circuit board of electronic equipment and a resonant circuit that is connected to the antenna element and has an adjustable resonant frequency. The antenna outputs a reception signal representing the radiation noise. A sensor monitors the reception signal and detects an abnormal state when the main power supply of the electronic equipment is cut off.