| 摘要 |
PROBLEM TO BE SOLVED: To utilize the accumulated energy of an electric double layer capacitor effectively, and besides, to charge the electric double layer capacitor by a secondary battery, in a power unit which utilizes the electric double layer capacitor and the secondary battery as a power supply. SOLUTION: Power is supplied from an electric double layer capacitor 2 to load L via a DC-DC converter 9 controlled so that the output voltage may be constant. A circuit which charges the electric double layer capacitor 2 by the secondary battery 1 includes a switching element 10 for charge control. A charge current is let flow to the electric double layer capacitor 2 during ON period by turning on or turning off the switching element 10, according to the control signal from the control circuit 8a. The control circuit 8a outputs a control signal to charge the electric double layer capacitor 2 by turning on or turning off the switching element 10 for charge control without hindering the electric double layer capacitor from supplying power to load L. |
