Abstract: A handheld AC power tool is provided. The power tool is comprised generally of: a brushless DC motor; a power cord connectable to an AC power socket; a converter circuit configured to receive input power from the power cord and operable to output a DC bus voltage, a switching arrangement interposed between the electric motor and the converter circuit; a motor drive circuit interfaced with the motor switches; and a power switch operable by a user to selectively energize the motor drive circuit and thereby power on the tool. The converter circuit includes a rectifier and a capacitor electrically coupled across the rectifier, such that the capacitor has capacitance sized to produce a DC bus voltage whose magnitude from an AC power source is substantially same as magnitude of voltage from a DC power source.

Abstract: A protective redundancy circuit is provided for a power tool having an electric motor. The protective redundant subsystem is comprised of: a motor switch coupled in series with the motor; a motor control module that controls the switching operation of the motor switch; and a protective control module that monitors switching operation of the motor switch and disables the power tool when the switching operation of the motor switch fails. In the context of an AC powered tool, the switching operation of the motor switch is correlated to and synchronized to the waveform of the AC input signal. During each cycle or half cycle, the motor control module introduces a delay period before closing the motor switch and the protective control module determines the operational status of the motor switch by measuring the voltage across the motor switch during the delay period.

Abstract: A power tool includes a tool body having an output member that drives an accessory. An end effector is coupled for rotation with the output member. A light source is disposed on the end effector. A primary coil assembly is configured on the tool body and mounted concentric to the output member. The primary coil assembly includes a primary coil that is electrically connected to a power source of the power tool. A secondary coil assembly is configured on the end effector and mounted concentric to the output member. The secondary coil assembly includes a secondary coil that is electrically connected to the light source. Current flowing through the primary coil creates a magnetic field that causes current to flow through the secondary winding and power the light source.

Abstract: A handheld grinder comprising a housing; a grinding disk; a motor; an output shaft connected to the grinding disk and the motor to impart rotary motion thereto; and a circuit board residing in the housing and having thereon a rectifier that receives an alternating current and converts the alternating current to a direct current, a switching arrangement having a plurality of motor switches connected electrically between the rectifier and the motor and operates to deliver the direct current from the rectifier to the motor, a capacitor connected electrically between the rectifier and the switching arrangement, wherein the capacitor is coupled in parallel across the rectifier, a driver circuit interfaced with the motor switches and operable to control switching operation of the motor switches, and a power switch connected electrically between the rectifier and the driver circuit and operable to selectively energize the driver circuit and power on the grinder disk.

Abstract: A reverse rotation detection module is provided for a power tool having an electric motor intended to rotate in a first direction but not an opposite second direction. The reverse rotation detection module is comprised of: a switching arrangement having a plurality of motor switches; three position sensors; a first latch circuit; a second latch circuit; and a motor driver module that is configured to receive the shutdown signal from the second latch circuit and discontinue driving the motor in response to the shutdown signal. An overspeed protection module is provided for a handheld power tool. The overspeed protection module is comprised of: an electric motor; a switching arrangement having a plurality of motor switches; a diode pump circuit; a comparator circuit; and a motor driver module that is configured to receive a shutdown signal from the comparator circuit and discontinue driving the motor in response to the shutdown signal.

Abstract: A power tool system includes a tool body with a motor having an output member that drives an accessory. The output member defines an output member axis. An end effector is coupled for rotation with the output member relative to the tool body. The end effector is configured to retain the accessory. A light source is disposed on the end effector. A consumable tool, such as a holesaw, is removably attachable to the end effector, and has an illumination opening configured to be substantially aligned with the light source.

Abstract: A power tool includes a housing, an output shaft having a tool axis, and a motion sensor that senses motion of the tool housing. A control circuit receives an input signal from the motion sensor, to make a first determination, based on the input signal, whether the tool is being operated in a horizontal mode or a vertical mode. The control circuit makes a second determination, based on the input signal, whether the tool axis is substantially level when the tool is being operated in the horizontal mode or the tool axis is substantially plumb when the tool is being operated in the vertical mode. An indicator receives an output signal from the control circuit that causes the indicator to indicate whether the tool axis is level when being operated in the horizontal mode or plumb when being operated in the vertical mode.

Abstract: An overspeed protection subsystem is provided for a power tool having an electric motor. The overspeed protection subsystem is comprised of: a motor switch coupled in series with the motor; a motor control module interfaced with the motor switch to control switching operation of the motor switch; and an overspeed detection module that determines rotational speed of the motor and disables the power tool when the rotational speed of the motor exceeds a threshold.

Abstract: A power tool includes a tool housing, an electric motor inside the housing, and a power interface facilitating a connection to a power source. At least four actively-controlled power components are configured as an H-bridge to modulate a supply of power from the power interface to the electric motor. A user-actuated input unit outputs a first signal indicative of a desired power output level to the electric motor and a second signal indicative of a desired direction of current flow to the electric motor. A control unit controls the supply of power to the electric motor using two of said power components with synchronous rectification for pulse-width modulation (PWM) of the supply of power based on the first signal, and to control the direction of current flow to the electric motor using the other two of said power components based on the second signal.

Abstract: A power tool includes a tool body having an output member that drives an accessory. An end effector is coupled for rotation with the output member. A light source is disposed on the end effector. A primary coil assembly is configured on the tool body and mounted concentric to the output member. The primary coil assembly includes a primary coil that is electrically connected to a power source of the power tool. A secondary coil assembly is configured on the end effector and mounted concentric to the output member. The secondary coil assembly includes a secondary coil that is electrically connected to the light source. Current flowing through the primary coil creates a magnetic field that causes current to flow through the secondary winding and power the light source.

Abstract: A power tool includes a tool housing, an electric motor inside the housing, and a power interface facilitating a connection to a power source. At least four actively-controlled power components are configured as an H-bridge to modulate a supply of power from the power interface to the electric motor. A user-actuated input unit outputs a first signal indicative of a desired power output level to the electric motor and a second signal indicative of a desired direction of current flow to the electric motor. A control unit controls the supply of power to the electric motor using two of said power components with synchronous rectification for pulse-width modulation (PWM) of the supply of power based on the first signal, and to control the direction of current flow to the electric motor using the other two of said power components based on the second signal.

Abstract: A method and apparatus for controlling a plurality of different motors used in a corresponding plurality of power tool applications requiring different operational characteristics. In one implementation a method involves the use of a single universal control module to store a generic, non-application-specific control algorithm. The generic, non-application-specific control algorithm has at least one programmable constant. The programmable constant is selected to transform the generic, non-application-specific control algorithm into an application-specific control algorithm. The programmable constant represents a function parameter relating to a specific functionality of a specific, selected motor used in a specific, selected motor application to implement a phase control over the specific, selected motor.

Abstract: A protective redundancy circuit is provided for a power tool having an electric motor. The protective redundant subsystem is comprised of: a motor switch coupled in series with the motor; a motor control module that controls the switching operation of the motor switch; and a protective control module that monitors switching operation of the motor switch and disables the power tool when the switching operation of the motor switch fails. In the context of an AC powered tool, the switching operation of the motor switch is correlated to and synchronized to the waveform of the AC input signal. During each cycle or half cycle, the motor control module introduces a delay period before closing the motor switch and the protective control module determines the operational status of the motor switch by measuring the voltage across the motor switch during the delay period.

Abstract: An overspeed protection subsystem is provided for a power tool having an electric motor. The overspeed protection subsystem is comprised of: a motor switch coupled in series with the motor; a motor control module interfaced with the motor switch to control switching operation of the motor switch; and an overspeed detection module that determines rotational speed of the motor and disables the power tool when the rotational speed of the motor exceeds a threshold.

Abstract: A method for controlling the operation of a motor utilizing a generic motor control module. The method includes sampling at least one motor operating criterion during operation of the motor and executing a generic control algorithm at a predetermined periodic interval. Execution of the algorithm provides a firing angle, duty cycle, or other suitable control function solution for an electronic valve for each periodic interval, thereby controlling the behavior of the motor. Additionally, the method includes firing the electronic valve at the calculated timing during each periodic interval such that the motor functions in accordance with desired motor operational parameters.

Abstract: A motor control module designed to control operation of a plurality of different motors in a plurality of different tools a power tool uses an electronic clutch in the module in conjunction with a mechanical clutch in the tool to protect the tool against an overload event. The module is adapted to implement methods to provide aural and/or tactile feedback to a tool user as a warning of an impending or current fault condition in the tool. The module can prevent power from inadvertently turning on either after an overload event has cleared with the tool plugged in and its power switch on, or after plugging in the tool within the power switch on. The control module is adapted to provide torque control for the power tool, to estimate tool motor temperature and to inform a tool user when a servicing need in the tool is required.

Abstract: A method for controlling the operation of a motor utilizing a generic motor control module. The method includes sampling at least one motor operating criterion during operation of the motor and executing a generic control algorithm at a predetermined periodic interval. Execution of the algorithm provides a firing angle, duty cycle, or other suitable control function solution for an electronic valve for each periodic interval, thereby controlling the behavior of the motor. Additionally, the method includes firing the electronic valve at the calculated timing during each periodic interval such that the motor functions in accordance with desired motor operational parameters.

Abstract: A motor control module designed to control operation of a plurality of different motors in a plurality of different tools a power tool uses an electronic clutch in the module in conjunction with a mechanical clutch in the tool to protect the tool against an overload event. The module is adapted to implement methods to provide aural and/or tactile feedback to a tool user as a warning of an impending or current fault condition in the tool. The module can prevent power from inadvertently turning on either after an overload event has cleared with the tool plugged in and its power switch on, or after plugging in the tool within the power switch on. The control module is adapted to provide torque control for the power tool, to estimate tool motor temperature and to inform a tool user when a servicing need in the tool is required.

Abstract: A battery monitoring device of a battery pack configured for powering a cordless power tool may include an integrated circuit connected to a microprocessor of the pack that is external to the integrated circuit, and which is connected to each of N battery cells of the pack. The integrated circuit may be configured to take, singly or sequentially, a sampled reading comprising one of an individual cell voltage or a total pack voltage for all cells in the pack. The sampled reading is filtered in the integrated circuit prior to being read by the microprocessor.

Abstract: A motor control module designed to control operation of a plurality of different motors in a plurality of different tools a power tool uses an electronic clutch in the module in conjunction with a mechanical clutch in the tool to protect the tool against an overload event. The module is adapted to implement methods to provide aural and/or tactile feedback to a tool user as a warning of an impending or current fault condition in the tool. The module can prevent power from inadvertently turning on either after an overload event has cleared with the tool plugged in and its power switch on, or after plugging in the tool within the power switch on. The control module is adapted to provide torque control for the power tool, to estimate tool motor temperature and to inform a tool user when a servicing need in the tool is required.