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

• Current Assignee: Exide Electronics Corporation (Exide Electronics Group, Inc.)
• Original Assignee: Ronald G. Seeley, William H. Seeley
• Inventors: Seeley, Ronald G., Seeley, William H.
• Primary Examiner(s): Hix, L. T.
• Assistant Examiner(s): Hickey, Robert J.
• Application Number:
  US05/521,667
• Time in Patent Office: 334 Days
• Field of Search: 320/20,22-24,39,40
• US Class Current: 320/143
• CPC Class Codes: H02J 7/007184 in response to battery voltage gradient

Abstract

A battery charging apparatus wherein direct current voltage is applied to the battery to be charged through a controllable switch. The battery charger combines quick charge capability with long battery life. The battery charger charges the battery to a high potential in order to charge the battery quickly to full charge and after full charge is obtained maintains the battery at a low voltage in order to avoid damage and obtain maximum life.

Claims

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.

2. In a battery charger as defined in claim 1 wherein said reference signal means includes a divider for deriving a fraction of the reference signal, said output signal of the rate sensing means being coupled to said fraction of the rate sensing means for varying said fraction of the reference signal in proportion to the time rate of change of the battery voltage, and wherein the comparator means compares the sensed battery voltage amplitude to the varying fraction of the reference signal.

3. A battery charger as defined in claim 2 wherein said means for sensing the state of the output of the comparator means includes a control circuit operatively connected to said switch, said control circuit including an optical-coupler operatively connected to said comparator means and to said switch means.

4. A battery charger as defined in claim 3 wherein said control circuit further includes a ramp generator means operatively connected to said optical-coupler.

5. In a battery charger including:

6. A battery charger as defined in claim 5 wherein said amplitude sensing means includes a divider for deriving a fraction of the battery terminal voltage amplitude, said output signal of the rate sensing means being coupled to said fraction of the battery terminal voltage amplitude for varying said fraction of the battery terminal voltage amplitude in proportion to the time rate of change of the battery voltage, and wherein the comparator means compares the reference signal to the fraction of the battery terminal voltage amplitude.

7. A battery charger as defined in claim 6 wherein said means for sensing the state of the output of the comparator means includes a control circuit operatively connected to said switch, said control circuit including an optical-coupler operatively connected to said comparator means and to said switch.

8. A battery charger as defined in claim 7 wherein said control circuit further includes a ramp generator means operatively connected to said optical-coupler.