| 摘要 |
<p>PROBLEM TO BE SOLVED: To reduce power consumption in the state where power consumption reduction is required, while performing low voltage detection on an input voltage.SOLUTION: A power unit includes an operation start/operation suppression circuit 200 to which power is supplied from an all-night power supply section 500 and which outputs a voltage corresponding to a voltage inputted to a primary side of a transformer 115 to a power supply control IC 110. When the voltage outputted from the operation start/operation suppression circuit 200 becomes equal to or higher than an operation start voltage Vstart, the power supply control IC 110 starts controlling FETs 106 and 107. When the voltage outputted from the operation start/operation suppression circuit 200 becomes equal to or lower than an operation suppression voltage Vsens, it is detected that an input AC voltage is a low voltage. The operation start/operation suppression circuit 200 outputs the voltage to the power supply control IC 110 in the case where the power supply control IC 110 is activated, but does not output the voltage to the power supply control IC 110 in the case where the power supply control IC 110 is not activated.</p> |
