BATTERY PACK ADAPTOR WITH OVERSTRESS DETECTION CIRCUIT

• US 20180138690A1
• Filed: 01/15/2018
• Published: 05/17/2018
• Est. Priority Date: 09/01/2015
• Status: Active Grant

• Current Assignee: Black & Decker Incorporated (Stanley Black & Decker, Inc.)
• Original Assignee: Black & Decker Incorporated (Stanley Black & Decker, Inc.)
• Inventors: Friedman, Brian E., Gorti, Bhanuprasad V., Held, Christopher R., Moturu, Abhisheka, Varipatis, Michael, Wisniewski, Paul J., Roberts, Michael W.
• Granted Patent: US 10,454,264 B2
• Time in Patent Office: Days
• CPC Class Codes: B25F 5/00 Details or components of portable power-driven tools not particularly related to the operations performed and not otherwise provided for
• CPC Class Codes: H01M 10/6235 Power tools
• CPC Class Codes: H02H 3/087 for dc applications
• CPC Class Codes: H02H 7/20 for electronic equipment for converters H02H7/10; for electric measuring instruments G01R1/36; for dc voltage or current semiconductor regulators G05F1/569; for amplifiers H03F1/52; for electronic switching circuits H03K17/08
• CPC Class Codes: Y02E 60/10 Energy storage using batteries

Abstract

An adaptor for connecting a power source to a power tool includes a housing having a first end that is configured to connect to a power source and a second end that is configured to connect to a power tool. The adaptor includes a control circuit disposed within the housing. The control circuit is configured to detect an overstress condition in the power tool and to control the power tool responsive to detecting the overstress condition.

Claims

1. An adaptor for connecting a power source to a power tool, the adaptor comprising:

a housing having a first end that is configured to connect to a power source and a second end that is configured to connect to a power tool; and

a control circuit disposed within the housing, the control circuit being configured to detect an overstress condition in the power tool and to control the power tool responsive to detecting the overstress condition.

2. The adaptor of claim 1, wherein:

the first end of the housing is configured to slidably connect with a battery pack; and

the second end of the housing comprises a tower portion that is configured to insertably connect with the power tool.

3. The adaptor of claim 1, wherein the control circuit controls the power tool responsive to detecting the overstress condition by causing the power tool to stop.

4. The adaptor of claim 1, wherein the control circuit comprises:

a microcontroller; and

a transistor that is operably connected to the microcontroller.

5. The adaptor of claim 4, wherein:

the transistor is configured to measure a power source current; and

the microcontroller is configured to control the transistor to cause the power tool to stop in response to the measured current exceeding a threshold current limit.

6. The adaptor of claim 4, wherein the microcontroller is configured to:

determine if the power tool is in a pulse width modulation mode;

determine if a current through the transistor is greater than a threshold current limit; and

responsive to determining the power tool is in the pulse width modulation mode and the current is greater than the threshold current limit, open the transistor to prevent current flow from the power source to the power tool.

7. The adaptor of claim 4, wherein the control circuit further comprises a diode that is operably connected between the transistor and a positive leg of the power source.

8. A method for detecting and controlling an overstress condition in a power tool, the method comprising:

detecting an overstress condition in a power tool by a control circuit disposed within a housing of an adaptor, wherein the adaptor is operably connected between a power source and the power tool; and

controlling the power tool by the control circuit disposed within the housing of the adaptor responsive to detecting the overstress condition in the power tool.

9. The method as in claim 8, wherein controlling the power tool comprises:

causing the power tool to stop responsive to detecting the overstress condition in the power tool.

10. The method as in claim 8, wherein detecting the overstress condition comprises:

measuring a power source current by the control circuit; and

comparing the power source current to a threshold current limit.

11. The method as in claim 10, wherein controlling the power tool comprises:

causing the power tool to stop in response to the measured current exceeding the threshold current limit.

12. The method as in claim 8, wherein the control circuit comprises:

a microcontroller; and

a transistor that is operably coupled to the microcontroller.

13. The method as in claim 12, wherein:

detecting the overstress condition includes determining if the power tool is in a pulse width modulation mode and determining if a current through the transistor is greater than a threshold current limit; and

controlling the power tool includes responsive to determining the power tool is in the pulse width modulation mode and the current is greater than the threshold current limit, opening the transistor to prevent current flow from the power source to the power tool.

14. A cordless power tool system, comprising:

a cordless power tool configured to receive a power source to power the power tool;

a power source; and

an adaptor for connecting the power source to the cordless power tool, the adaptor comprising;

a housing having a first end that is configured to connect to the power source and a second end that is configured to connect to the cordless power tool; and

a control circuit disposed within the housing, the control circuit being configured to detect an overstress condition in the power tool and to control the power tool responsive to detecting the overstress condition.

15. The cordless power tool system of claim 14, wherein:

the first end of the housing is configured to slidably connect with a battery pack; and

the second end of the housing comprises a tower portion that is configured to insertably connect with the power tool.

16. The cordless power tool system of claim 14, wherein the control circuit controls the power tool responsive to detecting the overstress condition by causing the power tool to stop.

17. The cordless power tool system of claim 14, wherein the control circuit comprises:

a microcontroller; and

a transistor that is operably connected to the microcontroller.

18. The cordless power tool system of claim 17, wherein:

the transistor is configured to measure a power source current; and

the microcontroller is configured to control the transistor to cause the power tool to stop in response to the measured current exceeding a threshold current limit.

19. The cordless power tool system of claim 17, wherein the microcontroller is configured to:

determine if the power tool is in a pulse width modulation mode;

determine if a current through the transistor is greater than a threshold current limit; and

responsive to determining the power tool is in the pulse width modulation mode and the current is greater than the threshold current limit, open the transistor to prevent current flow from the power source to the power tool.

20. The cordless power tool system of claim 17, wherein the control circuit further comprises a diode that is operably connected between the transistor and a positive leg of the power source.