摘要 |
<p>In an energy storage device, a charging circuit is electrically coupled to the energy storage section. A first comparator is electrically coupled to an energy storage section, and its output is inverted when voltage Vc of the energy storage section reaches first predetermined voltage Vc1. A second comparator is electrically coupled to the energy storage section, and its output is inverted when voltage Vc of the energy storage section reaches second predetermined voltage Vc2. A control circuit is electrically coupled to the first comparator and the second comparator. The control circuit obtains period tm from inversion of the output of the first comparator to the output of the second comparator. Capacitance C of the energy storage section is calculated based on this period tm and voltage change widthΔVc between the first predetermined voltage Vc1 and the second predetermined voltage Vc2.</p> |