Abstract: A method for charging an energy storage system (ESS) from an AC line voltage having differing input voltages (e.g., 120 Vac or 240 Vac), the method includes a) determining which of the AC line voltages is provided for charging the ESS as a charging AC voltage; b) boosting the charging AC voltage to an intermediate voltage responsive to the provided AC line voltage; c) scaling, responsive to the particular one of the AC line voltages, the intermediate voltage to a secondary voltage using a scaling factor; and d) converting the secondary voltage to a charging voltage applied to the ESS.

Abstract: The apparatus for charging an energy storage system (ESS) from an AC line voltage includes a boost stage for converting the AC line voltage to a first ESS charging voltage; an isolation stage, coupled to the boost stage, for converting the first ESS charging voltage to a second ESS charging voltage with the second ESS charging voltage less than the first ESS charging voltage, the isolation stage removing a common mode current between the ESS and the boost stage; a configurator, responsive to a control signal, to set a direct communication of the first ESS charging voltage to the ESS in a bypass mode and to open the direct communication of the first ESS charging voltage to the ESS in an isolation mode; and a controller, coupled to the configurator, for setting the modes responsive to a battery voltage, a peak of the AC line voltage, and a total leakage current at an input of the AC line voltage, the controller asserting the control signal to the configurator.

Abstract: A charging method using a multiphase line voltage for charging an energy storage system (ESS) using a polyphase motor drive circuit communicated to a polyphase motor, the polyphase motor drive circuit including a plurality M of driver stages, one driver stage for each phase of the polyphase motor with each driver stage coupled across the energy storage system.

Abstract: A charging method using a multiphase line voltage for charging an energy storage system (ESS) using a polyphase motor drive circuit communicated to a polyphase motor, the polyphase motor drive circuit including a plurality M of driver stages, one driver stage for each phase of the polyphase motor with each driver stage coupled across the energy storage system.

Abstract: A charging method using a multiphase line voltage for charging an energy storage system (ESS) using a polyphase motor drive circuit communicated to a polyphase motor, the polyphase motor drive circuit including a plurality M of driver stages, one driver stage for each phase of the polyphase motor with each driver stage coupled across the energy storage system, the method including the steps of: (a) determining a charge mode responsive to a comparison of the multiphase line voltage to a voltage of the energy storage system, the determined charge mode including a boost mode when the voltage of the energy storage system has a first predetermined relationship to the multiphase line voltage and the determined charge mode including a boost-buck mode when the voltage of the energy storage system has a second predetermined relationship to the multiphase line voltage; (b) converting, when the charge mode includes the boost mode, the multiphase line voltage to a first charging voltage using a first set of N number of t

Abstract: A method of charging a rechargeable battery pack installed in an electric vehicle is provided in which the charging system includes a switching circuit that is operable in at least a first mode and a second mode. In the first mode the switching circuit couples the power supply and an external power source to both a heater and the charging circuit, the heater providing a voltage divider circuit within the charging circuit. In the second mode the switching circuit couples the power supply and the external power source only to the charging circuit, bypassing the heater.

Abstract: A saw includes a surface defining an opening therein, a plate structure configured to be attached to the saw below the surface, and an arm attached to the plate structure about a first shaft. A blade is configured to be engaged with the arm at a location spaced from the first shaft. The blade extends through the opening when the saw is in a normal operating position. The saw includes a firing mechanism including a barrel end portion having a bore defined therein and an extendable piston at least partially positioned within the bore. The barrel end portion is attached to the plate structure. The extendable piston engages the arm during its extension and causes the arm to pivot about the first shaft when the firing mechanism is activated by an activation signal. The pivoting of the arm causes the blade to be moved downwardly below the surface.

Abstract: A method for charging an energy storage system (ESS) from an AC line voltage having differing input voltages (e.g., 120Vac or 240Vac), the method includes a) determining which of the AC line voltages is provided for charging the ESS as a charging AC voltage; b) boosting the charging AC voltage to an intermediate voltage responsive to the provided AC line voltage; c) scaling, responsive to the particular one of the AC line voltages, the intermediate voltage to a secondary voltage using a scaling factor; and d) converting the secondary voltage to a charging voltage applied to the ESS.

Abstract: The apparatus for charging an energy storage system (ESS) from an AC line voltage includes a boost stage for converting the AC line voltage to a first ESS charging voltage; an isolation stage, coupled to the boost stage, for converting the first ESS charging voltage to a second ESS charging voltage with the second ESS charging voltage less than the first ESS charging voltage, the isolation stage removing a common mode current between the ESS and the boost stage; a configurator, responsive to a control signal, to set a direct communication of the first ESS charging voltage to the ESS in a bypass mode and to open the direct communication of the first ESS charging voltage to the ESS in an isolation mode; and a controller, coupled to the configurator, for setting the modes responsive to a battery voltage, a peak of the AC line voltage, and a total leakage current at an input of the AC line voltage, the controller asserting the control signal to the configurator.

Abstract: A charging system and method that accommodates and reduces potential residual or leakage current when electrical grounds of a charger and an energy storage system are equalized at the moment of initiating charging. The charging system using an alternating current (AC) line voltage for conductive charging of an energy storage system (ESS) coupled to a polyphase motor drive circuit communicated to a polyphase motor, and converting the line voltage to a charging voltage communicated to the energy storage system using a set of the plurality of driver stages.

Abstract: A charging method using an alternating current (AC) line voltage for conductive charging of an energy storage system (ESS) coupled to a polyphase motor drive circuit communicated to a polyphase motor, the polyphase motor drive circuit including a plurality M of driver stages, one driver stage for each phase of the polyphase motor with each driver stage coupled across the energy storage system, the method including the steps of: (a) coupling a first connector providing the line voltage to a second connector coupled to the plurality of driver stages; (b) interrupting selectably the line voltage from communication with the plurality of driver stages; (c) measuring both an ESS common mode voltage of the energy storage system with respect to a voltage reference and a line common mode voltage of the line voltage with respect to the voltage reference while the line voltage communication to the plurality of driver stages is interrupted; (d) operating a particular one of the driver stages to power a common mode voltag

Abstract: A charging method using a multiphase line voltage for charging an energy storage system (ESS) using a polyphase motor drive circuit communicated to a polyphase motor, the polyphase motor drive circuit including a plurality M of driver stages, one driver stage for each phase of the polyphase motor with each driver stage coupled across the energy storage system, the method including the steps of: (a) determining a charge mode responsive to a comparison of the multiphase line voltage to a voltage of the energy storage system, the determined charge mode including a boost mode when the voltage of the energy storage system has a first predetermined relationship to the multiphase line voltage and the determined charge mode including a boost-buck mode when the voltage of the energy storage system has a second predetermined relationship to the multiphase line voltage; (b) converting, when the charge mode includes the boost mode, the multiphase line voltage to a first charging voltage using a first set of N number of t

Abstract: A saw includes a surface defining an opening therein, a plate structure configured to be attached to the saw below the surface, and an arm attached to the plate structure about a first shaft. A blade is configured to be engaged with the arm at a location spaced from the first shaft. The blade extends through the opening when the saw is in a normal operating position. The saw includes a firing mechanism including a barrel end portion having a bore defined therein and an extendable piston at least partially positioned within the bore. The barrel end portion is attached to the plate structure. The extendable piston engages the arm during its extension and causes the arm to pivot about the first shaft when the firing mechanism is activated by an activation signal. The pivoting of the arm causes the blade to be moved downwardly below the surface.

Abstract: A method of charging a rechargeable battery pack installed in an electric vehicle is provided in which the charging system includes a switching circuit that is operable in at least a first mode and a second mode. In the first mode the switching circuit couples the power supply and an external power source to both a heater and the charging circuit, the heater providing a voltage divider circuit within the charging circuit. In the second mode the switching circuit couples the power supply and the external power source only to the charging circuit, bypassing the heater.

Abstract: An apparatus comprising a rechargeable battery pack installed in an electric vehicle, a power supply coupled to the rechargeable battery pack, the power supply operable to provide a charge voltage to perform charging operations on the rechargeable battery pack, a heater to heat a fluid to be circulated through the rechargeable battery pack, the fluid thermally coupled to a plurality of battery cells within the rechargeable battery pack, a switching circuit, the switching circuit coupled to the heater and to the power supply, the switching circuit operable in a first mode to couple the source of electrical power to the heater without coupling the source of electrical power to the rechargeable battery pack, the switching circuit operable in a second mode to couple a source of electrical power external to the electric vehicle to the power supply to form a recharging circuit in order to perform charging operations on the rechargeable battery pack.

Abstract: A capacitive sensing system for use with a power cutting tool of the type which has an exposed, moveable blade adjacent a work surface is disclosed. The sensing system drives an excitation voltage onto the exposed blade and monitors the current drawn from the blade, detects changes in the amplitude and phase and analyzes the characteristics of the changes to selectively trigger a reaction system.

Abstract: A capacitive sensing system for use with a power cutting tool of the type which has an exposed, moveable blade adjacent a work surface is disclosed. The sensing system drives an excitation voltage onto the exposed blade and monitors the current drawn from the blade, detects changes in the amplitude and phase and analyzes the characteristics of the changes to selectively trigger a reaction system.

Abstract: An apparatus including a rechargeable battery pack installed in an electric vehicle, the rechargeable battery pack coupled to a power supply, the power supply operable to provide a charge voltage to perform charging operations on the battery pack, a heating element to heat a fluid to be circulated through the rechargeable battery pack, a comparator circuit to compare a battery voltage of the rechargeable battery pack to a line source voltage, the comparator circuit operable to compare the battery voltage to the line source voltage and to provide an output signal when the battery voltage is less than a line voltage offset value, and a control circuit coupled to receive the output signal of the comparator, and to couple the line source voltage to the power supply, an to bypass the heating element if the comparator is not providing the output signal.

Abstract: A power cutting tool, such as a table saw, comprising a sensing system for detecting certain conditions with respect to an exposed blade of the power cutting tool is disclosed. Several embodiments of the sensing system comprise at least one sensor located above the blade and positioned to (1) monitor one or more volume zones adjacent the blade, (2) detect when an object enters one or more of the zones, and (3) trigger a reaction system in response to the detection. Another embodiment uses an optical sensor to measure the height of objects approaching the blade to detect an increase in the height beyond a predetermined threshold. Still another embodiment uses an optical distance sensor to detect the occurrence of a work piece lifting from the table top which can indicate that a kick-back condition is imminent. The reaction system can be triggered when such a condition is detected.

Abstract: A saw comprises a surface having an opening defined therein, a plate structure configured to be attached to the saw below the surface, and an arm pivotally attached to the plate structure about a first shaft. A blade is configured to be engaged with the arm at a location spaced from the first shaft. A portion of the blade extends through the opening when the saw is in a normal operating position. The saw comprises a firing mechanism comprising a barrel end portion having a bore defined therein and an extendable piston at least partially positioned within the bore. The barrel end portion is attached to the plate structure. The extendable piston engages the arm during its extension and causes the arm to pivot about the first shaft when the firing mechanism is activated by an activation signal. The pivoting of the arm causes the blade to be moved downwardly below the surface.