| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To reduce a power consumption of an AC input monitoring circuit which monitors an AC input of a power supply device. <P>SOLUTION: The voltage corresponding to the AC input is divided by a voltage dividing circuit 2 and compared by first and second comparators 3 and 4 with first and second reference voltages corresponding to first and second monitoring voltages. Based on outputs of the two comparators 3 and 4, an output circuit 7 outputs a pulse corresponding to a period when the voltage corresponding to the AC input is present between the first and second monitoring voltages and the pulse is passed through an insulated circuit 9 and counted by a counter 10 or integrated by an integrator 11. That is, the AC input voltage is monitored discretely in the period when the level of the voltage corresponding to the AC input is present between the respective voltage levels of the first and second monitoring voltages, differently from a conventional way wherein the AC input voltage is always monitored. <P>COPYRIGHT: (C)2011,JPO&INPIT</p> |
