Battery charger

• US 6,605,926 B2
• Filed: 08/26/2002
• Issued: 08/12/2003
• Est. Priority Date: 08/14/1998
• Status: Expired due to Term

• Current Assignee: Milwaukee Electric Tool Corporation (Techtronic Industries Company Limited)
• Original Assignee: Milwaukee Electric Tool Corporation (Techtronic Industries Company Limited)
• Inventors: Willhide, Joseph, Glasgow, Kevin, Spence, Glen C., Crisp, Robert
• Primary Examiner(s): Tso, Edward H.
• Application Number:
  US10/228,168
• Publication Number:
  US 20030052651A1
• Time in Patent Office: 351 Days
• Field of Search: 320/106, 320/110, 320/128, 320/134, 320/136, 320/138, 320/150
• US Class Current: 320/138
• CPC Class Codes: H02J 2207/40 adapted for charging from various sources, e.g. AC, DC or multivoltage
• CPC Class Codes: H02J 7/00038 using passive battery identification means, e.g. resistors or capacitors identification by mechanical connections H02J7/0045
• CPC Class Codes: H02J 7/00041 in response to measured battery parameters, e.g. voltage, current or temperature profile
• CPC Class Codes: H02J 7/00047 with provisions for charging different types of batteries
• CPC Class Codes: H02J 7/00302 Overcharge protection
• CPC Class Codes: H02J 7/00308 Overvoltage protection
• CPC Class Codes: H02J 7/0031 using battery or load disconnect circuits H02J9/002 takes precedence

Abstract

A battery charger, a method for charging a battery, and a software program for operating the battery charger. The battery charger is capable of charging different types of batteries and capable of operating on alternate sources of AC power or alternate sources of DC power. Also, the battery charging circuit will not operate if one of the power source, the battery, the power switch means and the control means (including the microcontroller) malfunctions. In addition, in the battery charging circuit, the battery under charge enables the operation of the battery charging circuit.

Claims

1. An apparatus for charging a battery with power from a power source, the apparatus comprising:

an input terminal electrically connectable to the power source;

an output terminal electrically connectable to the battery;

a power switch that controllably transfers power from the power source to the battery in response to a control signal; and

a controller electrically connected to the power switch and to the output terminal, the controller being activated by the battery when the battery is connected to the output terminal and being operable to generate the control signal in response to being activated.

2. An apparatus as set forth in claim 1 wherein the controller is powered by the battery when the battery is connected to the output terminal.

3. An apparatus as set forth in claim 2 wherein the apparatus charges the battery from a depleted state having a depleted-state voltage to a non-depleted state, and wherein the controller is operable to be powered by the battery having the depleted-state voltage.

4. An apparatus as set forth in claim 3 wherein the depleted-state voltage is less than five volts.

5. An apparatus as set forth in claim 3 wherein the depleted-state voltage is less than three volts.

6. An apparatus as set forth in claim 1 and further comprising a switch driver electrically connected to the power switch and the controller, wherein the control signal generated by the controller is a first control signal, wherein the power switch receives the first control signal and generates a second control signal in response to the first control signal, and wherein the power switch receives the second control signal and transfers power from the power source to the battery in response to receiving the second control signal.

7. An apparatus as set forth in claim 6 wherein the controller powers the switch driver.

8. An apparatus as set forth in claim 7 further comprising a voltage tripler electrically connected to the controller and to the switch driver, wherein the controller generates a power signal having a first voltage, wherein the voltage tripler receives the power signal from the controller and increases the power signal to a second voltage, and wherein the power signal having the second voltage powers the switch driver.

9. An apparatus as set forth in claim 1 wherein the power source is an alternating current power source.

10. An apparatus as set forth in claim 1 wherein the power source is a direct current power source.

11. An apparatus comprising:

a first terminal electrically connectable to a power source;

a second terminal electrically connectable to a battery;

a power switch that makes an electrical connection to conduct a first power originating from the power source to the battery when the first terminal is connected to the power source and when the power switch receives a control signal; and

a microcontroller electrically connected to the power switch and to the second terminal, the microcontroller being activated upon a second power being provided to the microcontroller, the second power arising after the second terminal connects to the battery and relating to a stored power of the battery, and being adapted to controllably generate the control signal when activated.

12. An apparatus as set forth in claim 11 and further comprising a switch driver electrically connected to the power switch and the microcontroller, wherein the control signal generated by the microcontroller is a first control signal, wherein the switch driver receives the first control signal and generates a second control signal in response to the first control signal, and wherein the power switch makes the electrical connection in response to receiving the second control signal.

13. An apparatus as set forth in claim 12 wherein the microcontroller powers the switch driver.

14. An apparatus as set forth in claim 12 wherein the apparatus further comprises a voltage tripler electrically connected to the microcontroller and to the switch driver, wherein the microcontroller generates a power signal having a first voltage, wherein the voltage tripler receives the power signal from the microcontroller and increases the first voltage to a second voltage, and wherein the power signal having the second voltage powers the switch driver.

15. An apparatus as set forth in claim 11 wherein the power source is an alternating current power source.

16. An apparatus as set forth in claim 11 wherein the power source is a direct current power source.

17. An apparatus as set forth in claim 11 wherein the battery powers the microcontroller when the battery is connected to the second terminal.

18. An apparatus as set forth in claim 17 wherein the apparatus further includes a supply circuit electrically connected to the second terminal and the microcontroller, the supply circuit including a voltage regulator and being adapted to receive a third power from the battery and supply the second power with a regulated voltage.

19. An apparatus as set forth in claim 18 wherein the second power results from the third power.

20. An apparatus as set forth in claim 17 wherein the battery is powered from a depleted state having a depleted-state voltage to a non-depleted state, and wherein the microcontroller is operable to be powered by the battery having the depleted-state voltage.

21. An apparatus as set forth in claim 20 wherein the apparatus further includes a supply circuit electrically connected to the second terminal and the microcontroller, the supply circuit including a voltage regulator, and wherein, when the battery is connected to the second terminal, the supply circuit receives a voltage from the battery and supplies the second power with a regulated voltage.

22. An apparatus as set forth in claim 20 wherein the second power results from the third power.

23. An apparatus as set forth in claim 21 wherein the supply circuit further includes a switch electrically connected to the first terminal, the second terminal, and the voltage regulator, and wherein, when the battery is connected to the second terminal, the switch receives the voltage from the battery and makes a second electrical connection to conduct a third power originating from the power source to the voltage regulator.

24. An apparatus as set forth in claim 23 wherein the switch is a transistor.

25. An apparatus comprising:

a first terminal electrically connectable to a power source;

a second terminal electrically connectable to a power storage device;

a switch that makes an electrical connection to conduct a first power originating from the power source to the second terminal when the first terminal is connected to the power source and when the switch receives a control signal; and

a microcontroller electrically connected to the switch and to the second terminal, the microcontroller being activated upon a second power being provided to the microcontroller, the second power arising after the second terminal connects to the storage device and relating to a stored power of the storage device, and being adapted to controllably generate the control signal when activated.

26. An apparatus as set forth in claim 25 wherein the power storage device is a direct current power storage device.

27. An apparatus as set forth in claim 26 wherein the power storage device is a battery.

28. An apparatus as set forth in claim 25 and further comprising a switch driver electrically connected to the switch and the microcontroller, wherein the control signal generated by the microcontroller is a first control signal, wherein the switch driver receives the first control signal and generates a second control signal in response to the first control signal, and wherein the switch makes the electrical connection in response to receiving the second control signal.

29. An apparatus as set forth in claim 28 wherein the apparatus further comprises a voltage tripler electrically connected to the microcontroller and to the switch driver, wherein the microcontroller generates a power signal having a first voltage, wherein the voltage tripler receives the power signal from the microcontroller and increases the first voltage to a second voltage, and wherein the power signal having the second voltage powers the switch driver.

30. An apparatus as set forth in claim 25 wherein the power storage device powers the microcontroller when the power storage device is connected to the second terminal.

31. An apparatus as set forth in claim 30 wherein the apparatus further includes a supply circuit electrically connected to the second terminal and the microcontroller, the supply circuit including a voltage regulator and being adapted to receive a third power from the power storage device and supply the second power with a regulated voltage.

32. An apparatus as set forth in claim 30 wherein the second power results from the third power.

33. An apparatus as set forth in claim 30 wherein the power storage device is powered from a depleted state having a depleted-state voltage to a non-depleted state, and wherein the microcontroller is operable to be powered by the power storage device having the depleted-state voltage.

34. An apparatus as set forth in claim 25 wherein the apparatus further includes a supply circuit electrically connected to the second terminal and the microcontroller, the supply circuit including a voltage regulator, and wherein, when the power storage device is connected to the second terminal, the supply circuit receives a voltage from the power storage device and supplies the second power with a regulated voltage.

35. An apparatus as set forth in claim 34 wherein the supply circuit further includes a second switch electrically connected to the first terminal, the second terminal, and the voltage regulator, and wherein, when the power storage device is connected to the second terminal, the second switch receives the voltage from the power storage device and makes a second electrical connection to conduct a third power originating from the power source to the voltage regulator.

36. An apparatus as set forth in claim 35 wherein the second power results from the third power.

37. An apparatus as set forth in claim 25 wherein the switch is a transistor.

38. An apparatus as set forth in claim 25 wherein the power storage device is a power storage device of a second apparatus and the connection with the power storage device is via a third terminal of the second apparatus.

39. An apparatus as set forth in claim 38 wherein the first apparatus includes a battery charger and the second apparatus is a battery pack including the power storage device.

40. A method of controlling power through an apparatus, the apparatus including a first terminal electrically connectable to a power source, a second terminal electrically connectable to a power storage device, and a microcontroller, the method comprising:

electrically connecting the first terminal to the power source;

electrically connecting the second terminal to the power storage device;

activating the microcontroller after electrically connecting the second terminal to the power storage device, the activating act including receiving a first power from the power storage device at the second terminal and powering the microcontroller with a second power related to the first power received from the power storage device;

generating a control signal with the microcontroller after activating the microcontroller; and

conducting a third power from the first terminal to the second terminal in response to the generation of the control signal.

41. A method as set forth in claim 40 wherein the act of activating the microcontroller occurs after the electrically connecting acts.

42. A method as set forth in claim 40 wherein the apparatus further includes a switch configurable to create an electrical connection between the first and second terminals, and wherein the act of transferring a third power includes providing the control signal to the switch, and making the electrical connection with the switch when the control signal is provided to the switch.

43. A method as set forth in claim 40 wherein the apparatus further includes a supply circuit electrically connected to the second terminal and the microcontroller, the supply circuit including a voltage regulator, and wherein the act of powering the microcontroller includes providing the first power to the supply circuit and generating the second power with a regulated voltage.

44. A method as set forth in claim 43 wherein the second power results from the first power.

45. A method as set forth in claim 40 wherein the first power has a voltage, wherein the apparatus further includes a supply circuit electrically connected to the second terminal and the microcontroller, and wherein the act of powering the microcontroller includes providing the voltage to the supply circuit when the power storage device is connected to the second terminal and generating the second power with a regulated voltage when the supply circuit receives the voltage from the power storage device.

46. A method as set forth in claim 45 wherein the supply circuit further includes a switch electrically connected to the first terminal, the second terminal, and a voltage regulator, wherein the act of generating the second power includes providing the voltage to the switch and making an electrical connection to conduct a third power originating from the power source to the voltage regulator.

47. A method as set forth in claim 40 wherein the power storage device is a power storage device of a second apparatus and the connection with the power storage device is via a third terminal of the second apparatus.

48. A method as set forth in claim 47 wherein the first apparatus includes a battery charger and the second apparatus is a battery pack including the power storage device.

49. A method as set forth in claim 40 wherein the power storage device is a direct current power storage device.

50. A method as set forth in claim 40 wherein the power storage device is a battery.