Electric device with power stoppage detection

摘要

This invention is intended to be capable of accurately detecting whether an electric device is in a stand-by mode or power stoppage occurs. An electric device 20 includes a power supply circuit 12, a power stoppage detection circuit 15, and a control microcomputer 10. The power stoppage detection circuit 15 generates a detection signal based on a voltage input from the power supply circuit 12. This detection signal is input from the power stoppage detection circuit 15 to the control microcomputer 10. The control microcomputer 10 detects a state of an operation of the power supply circuit 12 based on the detection signal input from the power stoppage detection circuit 15. If the detection signal is not detected for a constant time or more, the control microcomputer 10 determines that the power stoppage occurs to the power supply circuit 12. It is thereby possible to prevent the control microcomputer 10 from erroneously determining that the power stoppage occurs even if the power supply circuit 12 performs an intermittent oscillation operation while the electric device 20 is in the stand-by mode.