×

ENERGY STORAGE DEVICE

  • US 20110115427A1
  • Filed: 08/23/2010
  • Published: 05/19/2011
  • Est. Priority Date: 11/13/2009
  • Status: Active Grant
First Claim
Patent Images

1. An energy storage device comprising:

  • an energy storage section;

    a charging circuit electrically coupled to the energy storage section;

    a first comparator electrically coupled to the energy storage section, an output of the first comparator being inverted when a voltage (Vc) of the energy storage section reaches a first predetermined voltage (Vc1);

    a second comparator electrically coupled to the energy storage section, an output of the second comparator being inverted when the voltage (Vc) of the energy storage section reaches a second predetermined voltage (Vc2), the second predetermined voltage (Vc2) being greater than the first predetermined voltage (Vc1); and

    a control circuit electrically coupled to the charging circuit, the first comparator, and the second comparator;

    wherein the control circuit obtains a period (tm) from inversion of the output of the first comparator to inversion of the output of the second comparator at charging the energy storage section with a constant current (Ics), and calculates a capacitance C of the energy storage section based on the period (tm) and a voltage change width (Δ

    Vc) between the first predetermined voltage (Vc1) and the second predetermined voltage (Vc2) that are previously identified.

View all claims
  • 1 Assignment
Timeline View
Assignment View
    ×
    ×