| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To maintain reliability in a power supply backup device having an electric double-layer capacitor. <P>SOLUTION: In the power supply backup device, DC power is supplied from a DC power supply to a load circuit 2 via a first diode D1; boosting is performed by a boosting circuit 5 and the electric double-layer capacitor C1 is charged; and charging voltage of the electric double layer capacitor C1 is supplied to the load circuit 2 via a switching circuit 4 and a second diode D2, when the DC power supply is abnormal. The device is provided with a voltage/current detecting circuit 7 for detecting a charging voltage and a discharging current; a voltage detecting circuit 8 detecting the voltage supplied to the load circuit 2 via the first and second diodes D1 and D2 and a control processing circuit 1 for detecting DC current and DC voltage from the electric double-layer capacitor C1 by the voltage/current detecting circuit 7, by turning on the switching circuit 4; calculating capacitance and internal resistance of the electric double-layer capacitor C1 and determining the presence or the absence of abnormality state of the electric double-layer capacitor C1, based on the capacitance and the internal resistance. <P>COPYRIGHT: (C)2011,JPO&INPIT</p> |
