A power tool is configured to receive power from a power supply. The power tool may include a rectifier that may output a rectified signal to a DC power bus. A switching arrangement may operate to deliver electric power from the DC power bus to an electric motor. A switch path may be electrically coupled in parallel with the rectifier on the DC power bus. The switch path includes an auxiliary capacitor in series with a switch and a state of the switch controls a discharging path for the auxiliary capacitor. A switch control circuit may be configured to detect voltage associated with at least one of the AC power supply or the DC power bus and to control state of the switch in accordance with magnitude of the detected voltage.

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.

A power tool is provided including a power supply interface receiving a medium-voltage-rated removable battery pack having a maximum rated voltage in the range of 40 to 80 volts, and a brushless direct current (BLDC) motor. The motor includes a rotor and a stator having at least three stator windings corresponding to at least three phases of the motor, the rotor being moveable by the stator when the stator windings are appropriately energized within the corresponding phases. A multi-phase inverter bridge circuit is disposed between the power supply interface and the motor, and a controller is configured to output drive signals to the inverter bridge circuit to control flow of current from the battery pack to the motor such that the motor produces a maximum power output of at least approximately 1750 watts at a torque of approximately 1.5 to 2 Newton-meters.

A power tool is provided including a power supply interface receiving a medium-voltage-rated removable battery pack having a maximum rated voltage in the range of 40 to 80 volts, and a brushless direct current (BLDC) motor. The motor includes a rotor and a stator having at least three stator windings corresponding to at least three phases of the motor, the rotor being moveable by the stator when the stator windings are appropriately energized within the corresponding phases. A multi-phase inverter bridge circuit is disposed between the power supply interface and the motor, and a controller is configured to output drive signals to the inverter bridge circuit to control flow of current from the battery pack to the motor such that the motor produces a maximum power output of at least approximately 1750 watts at a torque of approximately 1.5 to 2 Newton-meters.

A safety procedure is provided for a vehicle having high-current components and high-voltage components, in particular in a hybrid or electric vehicle. In the event of a crash, in addition to a physical separation of a battery from a HV intermediate circuit, the HV intermediate circuit is discharged.

A power tool is provided including a power supply interface receiving a medium-voltage-rated removable battery pack having a maximum rated voltage in the range of 40 to 80 volts, and a brushless direct current (BLDC) motor. The motor includes a rotor and a stator having at least three stator windings corresponding to at least three phases of the motor, the rotor being moveable by the stator when the stator windings are appropriately energized within the corresponding phases. A multi-phase inverter bridge circuit is disposed between the power supply interface and the motor, and a controller is configured to output drive signals to the inverter bridge circuit to control flow of current from the battery pack to the motor such that the motor produces a maximum power output of at least approximately 1750 watts at a torque of approximately 1.5 to 2 Newton-meters.

A power tool is provided including a power supply interface receiving a medium-voltage-rated removable battery pack having a maximum rated voltage in the range of 40 to 80 volts, and a brushless direct current (BLDC) motor. The motor includes a rotor and a stator having at least three stator windings corresponding to at least three phases of the motor, the rotor being moveable by the stator when the stator windings are appropriately energized within the corresponding phases. A multi-phase inverter bridge circuit is disposed between the power supply interface and the motor, and a controller is configured to output drive signals to the inverter bridge circuit to control flow of current from the battery pack to the motor such that the motor produces a maximum power output of at least approximately 1750 watts at a torque of approximately 1.5 to 2 Newton-meters.

A battery pack and charger system includes a first battery pack having a first set of battery cells and configured to provide only a first operating voltage and a second battery pack having a second set of battery cells and configured to provide the first operating voltage and a second operating voltage that is different from the first operating voltage and a battery pack charger configured to be able to charge the first battery pack and the second battery pack.

A battery pack and charger system includes a first battery pack having a first set of battery cells and configured to provide only a first operating voltage and a second battery pack having a second set of battery cells and configured to provide the first operating voltage and a second operating voltage that is different from the first operating voltage and a battery pack charger configured to be able to charge the first battery pack and the second battery pack.

In a loaded condition, the controller increases at least one of the conduction band or the advance angle from a baseline value up to a maximum value within a first torque range below a torque threshold to as to maintain the output speed of the motor at a linear speed-torque profile. After the at least one of the conduction band or the advance angle reaches the maximum value, the controller maintains the at least one of the conduction band or the advance angle at the maximum value within a second torque range greater than or equal to the torque threshold so as to maintain the output speed of the motor at a naturally-curved speed-torque profile.