A.C. line connected battery charger

• US 5,525,893 A
• Filed: 04/29/1994
• Issued: 06/11/1996
• Est. Priority Date: 04/29/1994
• Status: Expired due to Fees

• Current Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Original Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Inventors: Alberkrack, Jade H., Lester, Theodore V.
• Primary Examiner(s): Wong, Peter S.
• Assistant Examiner(s): TSO, EDWARD H
• Application Number:
  US08/235,749
• Time in Patent Office: 774 Days
• Field of Search: 320/39, 320/40, 320/49, 320/54, 320/57
• US Class Current: 320/148
• CPC Class Codes: H02J 7/00711 with introduction of pulses during the charging process
• CPC Class Codes: H02J 7/00714 in response to battery charging or discharging current

Abstract

A battery charging circuit device (10) includes a rectifier (16) and current controller (44) for directing current away from the battery (30). The rectifier (16) provides a current curve which is controlled by the current controller (44) so as to prevent the application of excess current to the battery (30) being charged in the circuit (10).

Claims

1. A battery charging circuit for use in an apparatus adapted to charge a rechargeable battery, said circuit comprising:

rectification means including, a full-wave bridge rectifier;

a current sensing resistor;

a MOSFET operatively disposed between said current sensing resistor and a battery to be charged by said charging circuit;

peak current setting means; and

a current peak limiting means.

2. A charging circuit as defined in claim 1, wherein said current peak setting means comprises at least a first and a second resistor, said first and second resistors operatively disposed between said MOSFET and said current peak limiting means and connected to said current peak limiting means.

3. A charging circuit as defined in claim 1, wherein the peak current setting means comprises a latching circuit means electrically coupled to said full-wave bridge rectifier.

4. A charging circuit as defined in claim 3, wherein said latching circuit means further comprise a silicon control rectifier.

5. A charging circuit as defined in claim 3, wherein said current sensing resistor is electrically coupled to said peak current setting means.

6. A charging circuit as defined in claim 1, further including at least one diode operatively disposed between said low frequency series pass switch and said rechargeable battery, so as to provide said battery with reverse conduction protection.

7. A battery charging apparatus comprising:

a source of power adapted to provide alternating current;

a full-wave bridge rectifier adapted to convert alternating current from said source of power to direct current;

at least a first and second battery contact for engaging a battery in said charging apparatus, said battery contacts further adapted to apply a charging current to said battery;

a disabling device adapted to sense the current supplied by said source of power;

an enabling resistor electrically disposed between said full-wave bridge rectifier, said first battery contact and said disabling device; and

a low frequency series pass switch electrically disposed between said second battery contact and disabling device.

8. A battery charging apparatus as in claim 7, wherein said disabling device further includes;

a current sensing resistor;

a peak current setting means; and

a silicon control rectifier.

9. A battery charging apparatus as defined in claim 8, wherein said low frequency series pass switch is a MOSFET operatively disposed between said current sensing resistor and a battery to be charged.

10. A battery charging apparatus as defined in claim 7, wherein said peak current setting means comprises at least a first and a second resistor, said first and second resistors operatively disposed between said low frequency series pass switch and said silicon control rectifier.

11. A battery charging apparatus as defined in claim 10, wherein said current sensing resistor is electrically coupled to said peak current setting means.

12. A battery charging apparatus as defined in claim 7, further including at least one diode operatively disposed between said low frequency series pass switch and said rechargeable battery, so as to provide said battery with reverse conduction protection.