×

Apparatus for charging rechargeable battery

  • US 4,134,056 A
  • Filed: 01/05/1977
  • Issued: 01/09/1979
  • Est. Priority Date: 06/16/1976
  • Status: Expired due to Term
First Claim
Patent Images

1. An apparatus for charging a rechargeable battery adapted to be responsive to a charged state of the battery to stop charging the battery, comprising:

  • direct current voltage source means for supplying a direct current voltage output to said battery for charging said battery,means operatively coupled to said battery for diferentiating the terminal voltage of said battery to produce a differentiated voltage output having a characteristic which decreases as a function of time as the battery is charged in which there is a bottom peak followed by a top peak until the battery is fully charged,means including variable impedance means connected between said direct current voltage source means and said battery and responsive to a differentiated voltage output of said differentiating means of a value less than that of the bottom peak for controlling a charging current to be supplied from said direct current voltage source means to said battery, andlevel detecting means coupled to said differentiating means for level detecting the differentiated voltage output at a predetermined level for detecting a charged state of said battery and providing a control signal to said controlling means to change the impedance of said variable impedance means to stop the charging of said battery.

View all claims
  • 0 Assignments
Timeline View
Assignment View
    ×
    ×