Abstract: 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 first switch path associated with a positive half cycle of the alternating current and a second switch path associated with a negative half cycle of the alternating current, both coupled across the AC power supply. Each switch path includes a switchable capacitor in series with a switch.

Abstract: 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.

Abstract: 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 first switch path associated with a positive half cycle of the alternating current and a second switch path associated with a negative half cycle of the alternating current, both coupled across the AC power supply. Each switch path includes a switchable capacitor in series with a switch.

Abstract: 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.

Abstract: A power adapter for use with a power tool having an electric motor, and configured to supply electric power from an alternating current power supply to the power tool, is provided. The adapter includes a housing and an auxiliary capacitor circuit housed within the housing. The auxiliary capacitor circuit includes an auxiliary capacitor, a switch in series with the auxiliary capacitor, and a switch control circuit. A state of the switch creates either a charging path for the auxiliary capacitor or both the charging path and a discharging path for the auxiliary capacitor, and the switch control circuit is configured to detect voltage associated with the power supply or the power tool and to control state of the switch in accordance with magnitude of the detected voltage.

Abstract: A power tool is provided including an elongated housing. The housing includes a motor case disposed at a front end thereof and a handle portion extending along a longitudinal axis of the housing from the motor case to a rear end of the housing. The handle portion includes two elongated walls extending from the motor case along the longitudinal axis of the housing to form a planar opening within the handle portion. A partition wall is arranged along an axis substantially perpendicular to the longitudinal axis of the housing, separating the handle portion from the motor case. An electric motor having a drive shaft is mounted within the motor case, and a module casing supporting a planar circuit board is received within the planar opening and supported by the elongated walls within the handle portion of the housing axially along the longitudinal axis of the housing.

Abstract: Typically, power factor is improved by adding a full power factor correction (PFC) stage between the rectifier and the power converter. This disclosure applies line voltage modulation to the control feedback of an isolated full bridge converter, thereby combining the PFC stage with the isolated power stage and forming a single state isolated power converter.

Abstract: A handheld grinder includes an elongated housing, an electric motor, an output shaft, a wall, a planar circuit board, and a motor drive circuit. The elongated housing defines a cavity therein and includes a motor case disposed at a front end and a handle portion to a rear end. The electric motor has a drive shaft that is mounted within the motor case. The output shaft is drivably coupled to the drive shaft of the electric motor. The wall separates the cavity between the motor case and the handle portion of the housing. The planar circuit board is disposed in the handle portion of the housing. The motor drive circuit is accommodated entirely within the handle portion of the housing on the planar circuit board.

Abstract: A power adapter for use with a power tool having an electric motor, and configured to supply electric power from an alternating current power supply to the power tool, is provided. The adapter includes a housing and an auxiliary capacitor circuit housed within the housing. The auxiliary capacitor circuit includes an auxiliary capacitor, a switch in series with the auxiliary capacitor, and a switch control circuit. A state of the switch creates either a charging path for the auxiliary capacitor or both the charging path and a discharging path for the auxiliary capacitor, and the switch control circuit is configured to detect voltage associated with the power supply or the power tool and to control state of the switch in accordance with magnitude of the detected voltage.

Abstract: 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.

Abstract: Typically, power factor is improved by adding a full power factor correction (PFC) stage between the rectifier and the power converter. This disclosure applies line voltage modulation to the control feedback of an isolated full bridge converter, thereby combining the PFC stage with the isolated power stage and forming a single state isolated power converter.

Abstract: 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.

Abstract: A power tool is provided including an elongated housing. The housing includes a motor case disposed at a front end thereof and a handle portion extending along a longitudinal axis of the housing from the motor case to a rear end of the housing. The handle portion includes two elongated walls extending from motor along the longitudinal axis of the housing to form a planar opening within the handle portion. A partition wall is arranged along an axis substantially perpendicular to the longitudinal axis of the housing, separating the handle portion from the motor case. An electric motor having a drive shaft is mounted within the motor case, and a module casing supporting a planar circuit board is received within the planar opening and supported by the elongated walls within the handle portion of the housing axially along the longitudinal axis of the housing.

Abstract: A portable power supply includes a housing, and power circuitry providing an output AC waveform having a first positive voltage step level, a second higher positive voltage step level, a third lower positive voltage step level, a fourth negative voltage step level, a fifth higher negative voltage step level, and a sixth lower negative voltage step level.

Abstract: A portable power supply includes a housing, and power circuitry providing an output AC waveform having a first positive voltage step level, a second higher positive voltage step level, a third lower positive voltage step level, a fourth negative voltage step level, a fifth higher negative voltage step level, and a sixth lower negative voltage step level.

Abstract: A power tool includes a housing, a brushless DC motor housed inside the housing, a power supply, a control unit, and an input unit such as a trigger switch actuated by a user. The control unit controls the commutation of the motor through a series of power switches coupled to the power supply. The control unit initiates electronic braking of the motor after occurrence of a condition in the input unit, such as trigger release or reduced speed, indicative of the power tool shut-down. A mechanism is provided to power the control unit for a predetermined amount of time after the detection of the condition from the input unit in order to complete the electronic braking of the motor.

Abstract: A power tool includes a brushless DC motor housed inside a tool housing, an input unit, and a control unit. The motor includes a rotor, a stator, and at least one sensor positioned to sense a state of the rotational position of the rotor inside the stator. A control unit controls commutation of the motor through a series of power switches coupled to the power supply. The control unit receives a current sensor state from the sensor and a user-selected speed from the input unit and determines whether the motor has reversed direction using the user-selected speed and the current sensor state. The control unit disables commutation of the motor if the motor has reversed direction until a proper current sensor state is received from the sensor.

Abstract: A power tool includes a housing, a brushless DC motor housed inside the housing, a power supply, a control unit, and an input unit such as a trigger switch actuated by a user. The control unit controls the commutation of the motor through a series of power switches coupled to the power supply. The control unit initiates electronic braking of the motor after occurrence of a condition in the input unit, such as trigger release or reduced speed, indicative of the power tool shut-down. A mechanism is provided to power the control unit for a predetermined amount of time after the detection of the condition from the input unit in order to complete the electronic braking of the motor.

Abstract: A power tool includes a brushless DC motor housed inside a tool housing, an input unit, and a control unit. The motor includes a rotor, a stator, and at least one sensor positioned to sense a state of the rotational position of the rotor inside the stator. A control unit controls commutation of the motor through a series of power switches coupled to the power supply. The control unit receives a current sensor state from the sensor and a user-selected speed from the input unit and determines whether the motor has reversed direction using the user-selected speed and the current sensor state. The control unit disables commutation of the motor if the motor has reversed direction until a proper current sensor state is received from the sensor.

Abstract: A portable power supply includes a housing, at least one battery cell, and an inverter connected to the at least one battery cell, wherein the inverter outputs at least about 3 kilowatts. A combination power supply and generator is also disclosed.