| 摘要 |
<p>PROBLEM TO BE SOLVED: To execute power failure decision having a highly precise power failure deciding time regardless of the size of an input signal. SOLUTION: This power failure deciding circuit is constituted of a circuit including a transistor Tr1 for inputting a signal obtained by half-wave rectifying or full-wave rectifying a commercial power source as an input signal, and for executing waveform shaping into a rectangular wave at the arbitrary threshold of the input signal and a monostable multivibrator MV equipped with a trigger function for outputting a pulse signal in a time longer than at least the two cycles of the input signal according to a rising or falling signal with the rectangular wave. Then, power failure is decided according to the output-off of the monostable multivibrator MV.</p> |
