| 摘要 |
<p>PURPOSE:To enable a power supply voltage monitoring device to monitor the fluctuation of an AC voltage and notify its operator of the abnormality of the voltage when the abnormality occurs. CONSTITUTION:This power supply voltage monitoring device is provided with a count signal generation circuit 2A which generates a count signal SC synchronized to an AC voltage ACV, reset signal generation circuit 2B which generates a reset signal SR when the AC voltage ACV exceeds a prescribed voltage value, count circuit 3 which counts the count signal SC and resets the count value (m) of the count signal SC based on the reset signal SR, count preset circuit 6 which presets a prescribed value (n), and comparator circuit 4 which compares the count value (m) with the prescribed value (n).</p> |
