The present disclosure relates to an overcurrent protection inverter, and more particularly, to an inverter, which uses a leg-shunt resistor so as to detect an instantaneous maximum output current and an AD current, thereby performing an inverter protection operation. The present disclosure detects the instantaneous maximum output current and detects the AD current from the leg-shunt resistor so as to perform an overcurrent protection operation when an overcurrent occurs in the entire inverter operation section, thereby enabling protection of the inverter.

A power tool includes a housing, a brushless motor received in the housing, a power switch coupled to the housing and actuatable by a user, a controller configured to control power delivery to the motor in response to actuation of the power switch, and an output spindle configured to rotate when the motor is energized. The controller is configured to maintain an amount of current delivered to the motor to be less than or equal to a current limit by turning off or reducing power to the motor for a time period if the current exceeds the current limit and then restarting power delivery to the motor. The time period is greater than the duration of one full current cycle.

A control device that does not require arithmetic processing of a phase current can be provided. A control device in which a plurality of switching legs including a pair of semiconductor switching elements constituting an upper arm and a lower arm are provided in a number corresponding to the number of phases of a motor that is a load includes a switch short circuit detection unit configured to detect a short circuit failure of the semiconductor switching element, and a control unit configured to execute determination processing of determining whether the short circuit failure has occurred in the upper arm or the lower arm on the basis of a result of detection by the switch short circuit detection unit, and to set all the semiconductor switching elements that constitute an arm in which a short circuit failure has occurred on the basis of a result of the determination processing.

A motor starter and a method for starting an electric motor are disclosed. In an embodiment, the motor starter includes a phase gating unit and a control unit. The phase gating unit is configured to be deactivated via the control unit after an activity period of the phase gating unit has elapsed and is configured to be deactivated during operation after the activity period has elapsed.

Provided is an abnormality diagnosis device capable of diagnosing an abnormality of a motor without setting many parameters. An abnormality diagnosis device includes a current measuring unit that measures a load current of the motor; a frequency analyzing unit that performs frequency analysis of the load current; and a deterioration degree calculating unit that calculates a degree of deterioration by adding up a preset number of intensity values from top in a preset frequency range.

A gate driving power source device can be miniaturized by sharing power source units, and a large current can be prevented from locally flowing in a single chip even when a short-circuit failure occurs in a multi-phase conversion circuit included in a power conversion device. There is provided a shared power source unit supplying a shared DC power source to a gate drive circuit provided in any one of a plurality of lower arms of multi-phase conversion circuits or any one of a plurality of upper arms of the multi-phase conversion circuit and gate drive circuits provided in upper arms or lower arms of other conversion circuits.

A power converter includes a plurality of inverter modules, each having a plurality of switching elements and each configured to convert a direct current voltage into an alternating current voltage by operations of the switching elements, a plurality of surge absorption circuits provided corresponding to the plurality of inverter modules and configured to absorb a generated surge voltage, and a plurality of current detection devices provided corresponding to the plurality of inverter modules, the current detection devices each having a current detection unit for detecting a current flowing in the corresponding inverter module.

An inverter device of an electric drive device may be configured to convert a direct voltage of an intermediate circuit of the electric drive device into a multi-phase alternating current to operate an electric motor of the electric drive device. A safety signal may be received by a control unit of the electric drive device, which instructs the control unit to operate the electric motor in a safe operating mode and to discharge the intermediate circuit at same time. If an active short circuit mode is preset, the inverter device is controlled to operate the electric motor in the active short circuit mode and to discharge the intermediate circuit in the discharge mode. If a freewheel mode is preset, the inverter device is controlled to operate the electric motor in the freewheel mode and, upon satisfaction of a current criterion, controlled to discharge the intermediate circuit in the discharge mode.

A windshield wiper system (WWS) is provided. The WWS includes a brushless direct current (BLDC) motor, a wiper arm and blade, a gearbox/converter operably interposed between the BLDC motor and the wiper arm and blade and a smart motor drive configured to determine a WWS failure condition and to operate the BLDC motor according to the determination.

An impact power tool includes a motor, a controller, and an impact mechanism configured to rotationally drive an output spindle. The controller is configured to control power delivered to the motor, during a third phase of operation after a second phase of operation and starting upon expiration of a predetermined time period. The third phase has one or more of a third non-zero target rotational speed, a third duty cycle setting, a third conduction band setting, or a third advance angle setting. The controller is configured to control power delivered to the motor, during a fourth phase of operation after the third phase upon detection of a reduction in load on the output spindle or cessation of impacting. The fourth phase has one or more of a fourth non-zero target rotational speed, a fourth duty cycle setting, a fourth conduction band setting, or a fourth advance angle setting.