| 摘要 |
PROBLEM TO BE SOLVED: To provide an apparatus by which the service interruption state can be detected quickly in a service interruption. SOLUTION: The service-interruption detection apparatus is provided with a waveform comparison circuit 3 to which the signal of a power-supply voltage 1 and the signal of a reference signal 2 synchronized with the power-supply voltage 1 are applied, an absolute-value circuit 4 to which a signal from the waveform comparison circuit 3 is given and which obtains an output corresponding to a full-wave-rectified waveform because, when input waveforms are compared, their difference appears in both the positive side and the negative side, and a comparison circuit 5 to which a signal from the absolute-value circuit 4 and a detection reference voltage 6 are given. The service-interruption detection signal of the power-supply voltage is obtained from the comparison circuit 5. |
