A power tool is provided including a power supply interface receiving a removable battery pack, a brushless direct current (BLDC) motor including a rotor and a stator, and a multi-phase inverter bridge circuit. A controller is provided to output drive signals to the inverter bridge circuit to control flow of current from to the motor, where each drive signal is activated within each corresponding phase of the motor within a conduction band. The controller is configured to control a length of the conduction band at a variable value within a first torque range below a torque threshold and at a substantially constant value within a second torque range above the torque threshold. The torque threshold is greater than approximately 1 Newton-meters and the motor produces a maximum power output of at least approximately 1250 watts at the torque of approximately 1 Newton-meters.

A power tool is provided including a power supply interface receiving a removable battery pack, a brushless direct current (BLDC) motor including a rotor and a stator, and a multi-phase inverter bridge circuit. A controller is provided to output drive signals to the inverter bridge circuit to control flow of current from to the motor, where each drive signal is activated within each corresponding phase of the motor within a conduction band. The controller is configured to control a length of the conduction band at a variable value within a first torque range below a torque threshold and at a substantially constant value within a second torque range above the torque threshold. The torque threshold is greater than approximately 1 Newton-meters and the motor produces a maximum power output of at least approximately 1250 watts at the torque of approximately 1 Newton-meters.

The disclosure relates to a brake device for an electric motor, which has at least one armature winding and at least one field winding, comprising at least one open-loop and/or closed-loop control unit at least for open-loop control and/or closed-loop control of at least one electric current through the armature winding and/or through the field winding. According to the disclosure, in the event of short-circuit braking of the electric motor, the open-loop and/or control-loop unit is intended to reduce, at least temporarily, an electric armature current flowing through the armature winding.

A power adapter is provided to supply electric power from an alternating current from an alternating current (AC) power supply to a powered apparatus. It includes a switchable capacitor circuit housed within a housing and including a switchable capacitor switchably coupled across the AC power supply and a H-bridge circuit including four switches. An OFF-state of the four switches creates a charging path for the switchable capacitor, an ON-state of a first pair of the four switches creates a discharge path for the switchable capacitor during a positive half cycle of the alternating current, and an ON-state of a second pair of the four switches creates a discharge path for the switchable capacitor during a negative half cycle of the alternating current.

A power adapter is provided to supply electric power from an alternating current from an alternating current (AC) power supply to a powered apparatus. It includes a switchable capacitor circuit housed within a housing and including a switchable capacitor switchably coupled across the AC power supply and a H-bridge circuit including four switches. An OFF-state of the four switches creates a charging path for the switchable capacitor, an ON-state of a first pair of the four switches creates a discharge path for the switchable capacitor during a positive half cycle of the alternating current, and an ON-state of a second pair of the four switches creates a discharge path for the switchable capacitor during a negative half cycle of the alternating current.

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.

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.

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.

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.