System and method for charging batteries

• US 7,528,579 B2
• Filed: 08/24/2004
• Issued: 05/05/2009
• Est. Priority Date: 10/23/2003
• Status: Active Grant

• Current Assignee: Schumacher Electric Corporation
• Original Assignee: Schumacher Electric Corporation
• Inventors: Johnson, Thomas Finis, Pacholok, David R., Chen, Xiao Ping
• Primary Examiner(s): Berhane; Adolf
• Assistant Examiner(s): Fantu; Yalkew
• Application Number:
  US10/925,073
• Publication Number:
  US 20050088144A1
• Time in Patent Office: 1,715 Days
• Field of Search: 320/145, 320/132, 320/30, 320/48, 320/130
• US Class Current: 320/145
• CPC Class Codes: H02J 2207/20 Charging or discharging characterised by the power electronics converter
• CPC Class Codes: H02J 7/02 for charging batteries from ac mains by converters

Abstract

A high frequency battery charger includes a converter, drive logic, and control logic. The converter transforms a DC voltage into a high frequency AC voltage. The drive logic controls a conversion of the high frequency AC voltage through a train of pulses. The control logic adjusts the output of the converter to maximize a charging cycle of a battery. The method of transforming an AC input into a direct current output used to charge a rechargeable battery includes transforming an AC input into a first DC output; transforming the first DC output into a high frequency AC output; transforming the high frequency AC output into a second DC output; and passing a charging current to an external load when the load is correctly connected to an output.

Claims

1. A high frequency charger for charging a battery, the high frequency charger comprising:

a first converter that transforms an alternating current into a first direct current , and then into a high frequency alternating current;

a synchronous converter circuit including at least two switches for transforming said high frequency alternating current from said first converter to a second direct current output;

drive logic that controls a transformation of the high frequency alternating output current into the second direct current that defines a charging current for charging said battery; and

a processor configured to adjust a level of charging current of the synchronous converter that passes onto a load.

2. The high frequency battery charger of claim 1 wherein the first converter comprises a high frequency transformer.

3. The high frequency transformer of claim 2 further including a switch for coupling the alternating current to the first converter.

4. The high frequency transformer of claim 3 further comprising a second and a third switch that provide a current path to a primary winding of the high frequency transformer, the second and third switch being directly connected to the primary winding.

5. The high frequency battery charger of claim 1 wherein the processor is programmed to provide a bulk charge, an absorption charge.

6. The high frequency battery charger of claim 1 wherein the equalization charge comprise a series of pulse charges that reverses a build up of contaminants on a load'"'"'s electrodes.

7. The high frequency battery charger of claim 1 wherein the high frequency charger includes a sensor that provides a spark resistant protection in a reverse polarity connection of the load.

8. The high frequency battery charger of claim 1 further comprising a switch coupled to the processor for passing a charging current to the load only when the load is correctly connected to output charging connectors.

9. The high frequency battery charger of claim 1 further including a meter coupled to the processor.

10. The high frequency battery charger of claim 1 wherein the first converter and drive logic are optically isolated from the processor.

11. The high frequency battery charger of claim 1 wherein the first converter comprises a bridge rectifier.

12. The high frequency battery charger of claim 1 further comprising a display coupled to the processor.

13. The high frequency battery charger of claim 1 further comprising a sensor that controls the drive logic by monitoring a current flowing through a high frequency transformer.

14. The high frequency battery charger of claim 13 wherein the sensor controls the drive logic by monitoring the current flowing through a primary winding of the high frequency transformer.

15. The high frequency battery charger of claim 13 wherein the charging current is a pulsating current.

16. The high frequency battery charger of claim 1 further comprising a temperature sensor coupled to the processor, an output of the temperature sensor being used to adjust the level of charging current that passes to the load.

17. The high frequency battery charger of claim 1 further comprising a medium that may be read by the processor to detect a defective battery.