| 摘要 |
<P>PROBLEM TO BE SOLVED: To set zero power consumption under a no-load condition and stably and reliably supply power under a load condition without requiring a user to perform a special operation. <P>SOLUTION: A power supply circuit includes a latching relay 2 connected to the input side of a switching power supply 1 that converts a commercial power into a current of predetermined voltage, a control circuit 3 that controls on/off of the latching relay 2, a power storage circuit 4 that supplies an operating power to the control circuit 3, and a charging circuit 5 that charges the power storage circuit 4. In this power supply circuit, a load connected to the switching power supply 1 is detected and the remaining capacity of the power storage circuit 4 is detected. The control circuit 3 detects either a load condition under which a load is connected to the switching power supply 1 or a discharging condition under which the remaining capacity of the power storage circuit 4 is lower than a set value and turns on the latching relay 2. When the switching power supply 1 is under a no-load condition and the remaining capacity of the power storage circuit 4 is higher than the set value, the control circuit turns off the latching relay 2. <P>COPYRIGHT: (C)2011,JPO&INPIT |
