Methods of discharge control for a battery pack of a cordless power tool system, a cordless power tool system and battery pack adapted to provide over-discharge protection and discharge control
First Claim
1. A battery pack adapted to power a first type of power tool and a second type of power tool configured to operate at a higher power than the first type of power tool, comprising:
- a positive terminal;
a negative terminal;
a third terminal adapted to receive a sense signal from the first type of power tool, wherein the third terminal senses a signal from the first type of power tool when the pack is connected to the first type of power tool and the third terminal is open when the pack is connected to the second type of power tool;
a control circuit operable to identify the type of power tool attached thereto based on a sense signal received via the third terminal; and
a discharge control circuit operably coupled to the control circuit and operable to selectively control voltage output by the battery pack based on the identified type of power tool.
0 Assignments
0 Petitions
Accused Products
Abstract
In a cordless power tool system, a battery pack which may removably attachable to a cordless power tool and to a charger may include at least one battery cell and a power limiting device. The power limiting device may be arranged in series with the at least one battery cell for limiting power output of the battery pack based on the component that is connected to the pack. Current and hence power out of the battery pack may be controlled as a function of total internal impedance in the battery pack, which may be adjusted depending on the component that is connected to the pack.
-
Citations
14 Claims
-
1. A battery pack adapted to power a first type of power tool and a second type of power tool configured to operate at a higher power than the first type of power tool, comprising:
-
a positive terminal; a negative terminal; a third terminal adapted to receive a sense signal from the first type of power tool, wherein the third terminal senses a signal from the first type of power tool when the pack is connected to the first type of power tool and the third terminal is open when the pack is connected to the second type of power tool; a control circuit operable to identify the type of power tool attached thereto based on a sense signal received via the third terminal; and a discharge control circuit operably coupled to the control circuit and operable to selectively control voltage output by the battery pack based on the identified type of power tool. - View Dependent Claims (2, 3, 4, 8)
-
-
5. A power tool system comprising:
-
a first power tool being of a first type; a second power tool being of a second type configured to operate at a higher power than the first type of power tool; a battery pack having a plurality of serially-connected battery cells therein and configured to attach to the first power tool and the second power tool, the battery pack including a control circuit operable to identify the type of power tool attached thereto and a discharge control circuit operably coupled to the control circuit and operable to selectively control voltage output by the battery pack based on the identified type of power tool, wherein the battery pack having a positive terminal, a negative terminal and a third terminal, the control circuit receives a sense signal via the third terminal from the first type of power tool when the pack is coupled to the first type of power tool and detects an open circuit at the third terminal when the pack is connected to the second type of power tool. - View Dependent Claims (6, 7)
-
-
9. A battery pack configured for use with a first type of power tool and a second type of power tool that operates at a higher power than the first type of power tool, comprising:
-
a positive terminal; a negative terminal; a plurality of battery cells coupled between the positive terminal and the negative terminal; a third terminal adapted to receive an input from a power tool attached thereto; a control circuit operable to identify the type of power tool attached to the battery pack; and a discharge control circuit operably coupled to the control circuit and a semiconductor device disposed in series with the plurality of battery cells to set voltage output by the battery pack based on the identified type of power tool, wherein the discharge control circuit receives a signal indicative of current output by the battery pack and pulse width modulates a control terminal of the semiconductor device to gradually reduce the voltage output when the current output approaches a maximum current threshold. - View Dependent Claims (10, 11, 12, 13, 14)
-
Specification