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 power tool system includes a first power tool having a first power tool rated voltage, a second power tool having a second power tool rated voltage that is different from the first power tool rated voltage, and a first battery pack coupleable to the first power tool and to the second power tool. The first battery pack is switchable between a first configuration having a first battery pack rated voltage that corresponds to the first power tool rated voltage such that the first battery pack enables operation of the first power tool, and a second configuration having a convertible battery pack rated voltage that corresponds to the second power tool rated voltage such that the battery pack enables operation of the second power tool.

A power tool system includes a first power tool having a first power tool rated voltage, a second power tool having a second power tool rated voltage that is different from the first power tool rated voltage, and a first battery pack coupleable to the first power tool and to the second power tool. The first battery pack is switchable between a first configuration having a first battery pack rated voltage that corresponds to the first power tool rated voltage such that the first battery pack enables operation of the first power tool, and a second configuration having a convertible battery pack rated voltage that corresponds to the second power tool rated voltage such that the battery pack enables operation of the second power tool.

The subject matter of this specification can be embodied in, among other things, a system that includes a flexible structure, a power inverter, a first electromechanical device configured to urge movement of a first portion of the flexible structure based on power received from the power inverter, a second electromechanical device configured to urge movement of a second portion of the flexible structure based on power received from the power inverter, a feedback sensor configured to provide a feedback signal indicative of alignment between the first portion and the second portion, and a controller configured to control operation of at least one of the first electromechanical device and the second electromechanical device based on the feedback signal.

A rechargeable air-moving system (e.g., a hair drier, a pet groomer, a liquid sprayer, a vacuum cleaner, etc.) has a rather high voltage universal motor powered by a relatively low voltage rechargeable battery. The battery provides the benefits of portability and low-voltage safety, and the high voltage motor provides the benefits of speed, being lightweight and compact. In some examples, high voltage from a domestic AC power source is reduced to low voltage to charge the battery, and then a step-up converter increases the low DC voltage from the battery to a much higher voltage for the motor. The magnitude of the high voltage from the converter is comparable to the high voltage of the domestic AC power source. The relatively high voltage from the converter powers a high voltage universal motor that is lighter and more compact than a low voltage universal motor of equivalent power.

A power tool system includes a first power tool having a first power tool rated voltage, a second power tool having a second power tool rated voltage that is different from the first power tool rated voltage, and a first battery pack coupleable to the first power tool and to the second power tool. The first battery pack is switchable between a first configuration having a first battery pack rated voltage that corresponds to the first power tool rated voltage such that the first battery pack enables operation of the first power tool, and a second configuration having a convertible battery pack rated voltage that corresponds to the second power tool rated voltage such that the battery pack enables operation of the second power tool.

A power tool system includes a first power tool having a first power tool rated voltage, a second power tool having a second power tool rated voltage that is different from the first power tool rated voltage, and a first battery pack coupleable to the first power tool and to the second power tool. The first battery pack is switchable between a first configuration having a first battery pack rated voltage that corresponds to the first power tool rated voltage such that the first battery pack enables operation of the first power tool, and a second configuration having a convertible battery pack rated voltage that corresponds to the second power tool rated voltage such that the battery pack enables operation of the second power tool.

A power tool includes a housing, a brushless direct current (BLDC) motor including 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, each phase being characterized by a corresponding voltage waveform energizing the corresponding stator winding, the motor being configured to operate within an operating voltage range, and a power supply interface arranged to receive at least one of AC power from an AC power supply having a first nominal voltage or DC power from a DC power supply having a second nominal voltage, the power supply interface configured to output the AC power via an AC power line and the DC power via a DC power line. A motor control circuit is provided to receive the AC power line and the DC power line and supply electric power to the motor at a voltage level corresponding to the operating voltage range of the motor from at least one of the AC power supply and/or the DC power supply, the motor control circuit including: a rectifier circuit configured to convert an alternating signal on the AC power line to a rectified voltage signal on a DC bus line, and a power switch circuit configured to regulate a supply of electric power from at least one of the DC bus line and/or the DC power line to the motor.

A power tool includes a housing, a brushless direct current (BLDC) motor including 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, each phase being characterized by a corresponding voltage waveform energizing the corresponding stator winding, the motor being configured to operate within an operating voltage range, and a power supply interface arranged to receive at least one of AC power from an AC power supply having a first nominal voltage or DC power from a DC power supply having a second nominal voltage, the power supply interface configured to output the AC power via an AC power line and the DC power via a DC power line. A motor control circuit is provided to receive the AC power line and the DC power line and supply electric power to the motor at a voltage level corresponding to the operating voltage range of the motor from at least one of the AC power supply and/or the DC power supply, the motor control circuit including: a rectifier circuit configured to convert an alternating signal on the AC power line to a rectified voltage signal on a DC bus line, and a power switch circuit configured to regulate a supply of electric power from at least one of the DC bus line and/or the DC power line to the motor.