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Battery charger

  • US 3,911,349 A
  • Filed: 11/07/1974
  • Issued: 10/07/1975
  • Est. Priority Date: 11/07/1974
  • Status: Expired due to Term
First Claim
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1. In a battery charger, including:

  • 1. current supply means for providing direct current, and;

    2. controllable switch means for supplying direct current to the battery when the switch is closed for charging the battery and for interrupting the direct current to the battery when the switch is open, the improvement comprising;

    a. reference signal means for providing a reference signal;

    b. amplitude sensing means operatively connected to the battery for sensing the battery terminal voltage amplitude;

    c. rate sensing means operatively connected to the battery for sensing the time rate of change of battery terminal voltage and for generating an output signal proportional to the time rate of change of the battery terminal voltage, said output signal being coupled to the reference signal and varying the reference signal in proportion to the time rate of change of the battery terminal voltage;

    d. comparator means operatively connected to reference signal means and to the amplitude sensing means for comparing the sensed battery voltage amplitude to the varying reference signal, the comparator means having a two-state output that is dependent on whether the sensed battery voltage amplitude is greater or lesser than the varying reference signal; and

    e. means for sensing the state of the output of the comparator means for closing said switch means in one of the states and opening said switch means in the other state of the comparator means.

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