Abstract: A battery charger is provided for implementing a charging method having a stepped output current. The battery charger includes: a power supply circuit that receives an AC input signal and outputs a DC output signal. The power supply circuit includes a power supply controller configured to receive a feedback signal indicative of current being output by the power supply circuit via an amplifier and operates to control current output by the power supply circuit in accordance with the feedback signal. A charger controller is interfaced with the power supply controller to implement a charging method having a stepped output current. The charger controller may set the output current level by adjusting gain of an operational amplifier having a negative feedback configuration with the feedback signal input to a non-inverting input terminal of the operational amplifier, where the charger controller sets the output current level by changing the resistance at an inverting input terminal of the operational amplifier.

Abstract: A method for controlling a driving tool having a power source, a driver, an actuator, a follower, and a control unit. The power source includes a motor and a flywheel that is driven by the motor. The actuator is configured to selectively move the follower to push the driver into frictional engagement with a surface of the flywheel. The control unit is configured to selectively activate the electric motor and the actuator. The control unit includes a speed sensor that is configured to sense a rotational speed of an element of the power source and produce a speed signal in response thereto. The method includes: directly determining a rotational speed of an element in the power source; controlling electrical power provided to the motor based on the rotational speed of the element in the power source to cause the flywheel to rotate at a predetermined speed; and actuating the actuator when a set of actuating criteria has been met, the set of actuating criteria not including a rotational speed of the element.

Abstract: A rechargeable battery pack comprises a battery having a high voltage side and a low voltage side, a positive terminal accessible external of the battery pack and connected to the high voltage side of the battery, a negative terminal accessible external of the battery pack and connected to the low voltage side of the battery, a control terminal accessible external of the battery pack, a switching element electrically connected between the control terminal and the high voltage side of the battery, and a control module operable to control the switching element so that the control terminal is selectively coupled to the high voltage side of the battery.

Abstract: A power tool for operating on a workpiece, the power tool having a housing and a motor disposed within the housing. A controller is connected to the motor and receives user inputs for turning on the motor and a power tool battery pack is connected to the controller and the motor. At least one light is connected to the controller for illuminating the workpiece. The controller can turn on the light in a predetermined pattern to alert the user to a tool condition, such as the charge level being below a predetermined level.

Abstract: A battery charger comprises a first electrical contact that receives a positive contact of an attached battery pack; a second electrical contact that receives a negative contact of the attached battery pack; a plurality of inter-cell electrical contacts that selectively receive inter-cell contacts of the attached battery pack; a measurement module; and a control module. The inter-cell contacts of the attached battery pack are connected to nodes between cells of the attached battery pack.

Abstract: A method comprises discharging each of a plurality of cells of a battery pack, stopping the discharging of a selected cell of the plurality of cells when the selected cell reaches a predetermined capacity, and charging the plurality of cells after the discharging has stopped for all of the plurality of cells.

Abstract: A battery pack may include a plurality of battery cells; a discharge switch in series with the battery cells, a temperature sensor configured to sense temperature in the battery pack, and a battery control unit adapted to receive a signal indicative of temperature from the temperature sensor and operable to control the switch to interrupt current flow from the battery cells when the temperature exceeds an over-temperature threshold. The battery control unit may be adapted to receive a reset signal and operable to control the switch to restore current flow upon receipt of the reset signal and when the temperature is below an operating temperature threshold.

Abstract: A method for monitoring the voltage of each of a plurality of cells of a battery pack is provided. The method may include monitoring a voltage potential for each of a plurality of cells in a battery pack utilizing a single channel of battery control unit within the battery pack. If, during discharge of the battery, e.g., the battery is being used to power a hand tool, the voltage potential of any cell is determined by the battery control unit to be below a predetermined minimum voltage, the battery control unit discontinues a current flow from battery pack to the tool. Additionally, during charging of the battery pack, if a voltage differential between any one of the cells and any other one of the cells is determined to be above a predetermined maximum differential, the battery control unit reduces the voltage potential stored in the cell having the higher voltage potential.

Abstract: A control module is included in a battery charger that is adapted to charge a plurality of battery packs of different types or a power tool that is adapted to be powered by at least one of the battery packs. The control module includes a remote sensing module that communicates remotely with one of the battery packs. The control module also includes a battery pack connection module that determines that the one of the battery packs is in electrical communication with at least one of the battery charger and the power tool. The control module also includes a battery pack identification (ID) module that determines a first type of the battery pack based on remote sensing module signals. The control module also includes a charge control module that determines at least one of a charge setting and a discharge setting for the battery pack based on the first type.

Abstract: An overcurrent protection mechanism is provided for a battery pack that removably attaches to a power tool. The mechanism includes: one or more battery cells disposed in a battery pack; a current sensor configured to sense current supplied by the battery; a switch in a circuit path with the battery cells; and a battery control unit implemented as software instructions in a controller embedded in a battery pack. The battery control unit is configured to receive a signal indicative of current from the current sensor and control the switch to interrupt current flow from the battery cells as a function of current and time.

Abstract: A method for controlling a driving tool having a power source, a driver, an actuator, a follower, and a control unit. The power source includes a motor and a flywheel that is driven by the motor. The actuator is configured to selectively move the follower to push the driver into frictional engagement with a surface of the flywheel. The control unit is configured to selectively activate the electric motor and the actuator. The control unit includes a speed sensor that is configured to sense a rotational speed of an element of the power source and produce a speed signal in response thereto. The method includes: directly determining a rotational speed of an element in the power source; controlling electrical power provided to the motor based on the rotational speed of the element in the power source to cause the flywheel to rotate at a predetermined speed; and actuating the actuator when a set of actuating criteria has been met, the set of actuating criteria not including a rotational speed of the element.

Abstract: A fastening tool having a contact trip switch, a trigger switch, a driver, a motor assembly and a controller. The controller is configured to selectively operate the motor assembly in response to inputs received from the contact trip switch and the trigger switch. The controller includes a mode selector switch having a first switch setting, which can permit bump-feed operation of the fastening tool, and a second switch setting, which prohibits bump-feed operation of the fastening tool.

Abstract: A method for operating a driving tool, such as a fastening tool, that has a driver, a motor assembly with a motor and an output member, and an electrical power source. The methodology includes transmitting electrical power to the motor to rotate the output member and thereafter adjusting one or more control parameters if a rotational speed of the output member is not within a predetermined operating range.

Abstract: A fastening tool having a contact trip switch, a trigger switch, a driver, a motor assembly and a controller. The controller is configured to selectively operate the motor assembly in response to inputs received from the contact trip switch and the trigger switch. The controller includes a mode selector switch having a first switch setting, which can permit bump-feed operation of the fastening tool, and a second switch setting, which prohibits bump-feed operation of the fastening tool.

Abstract: A driving tool having a driver, a power source, a sensor and a controller. The power source selectively provides an input to the driver to cause the driver to translate along an axis. The sensor senses a condition in the power source that is indicative of a level of kinetic energy of an element in the power source and generates a sensor signal in response thereto. The controller is coupled to the power source and the sensor and is responsive to the sensor signal for deactivating the power source to inhibit the power source from providing the input to the driver when the level of kinetic energy of the element in the power source is below a predetermined threshold. A method for operating a driving tool is also provided.