Abstract: A protective device of a power tool includes a fixing base having a tube portion and an abutting surface, a restricting ring fitting around the tube portion, several springs disposed between the abutting surface and a first end of the restricting ring, a protective cover having several second projections and several second recesses, and a locking member. The first end has an abutting portion. A second end of the restricting ring has several first projections and several first recesses matching with the second projections and the second recesses. The restricting ring is located between the protective cover and the abutting surface. When a blocking portion of the locking member moves to a first position, the blocking portion restricts the restricting ring from moving toward the abutting surface. When the blocking portion moves to a second position, the blocking portion leaves a position between the abutting surface and the abutting portion.

Abstract: A power tool includes a case, a motor, a plurality of Hall effect sensors, a first circuit board, and a second circuit board. The Hall effect sensors detect a position of a rotor of the motor and correspondingly generate position signals. A plurality of commutating switches and a first controller are disposed on the first circuit board. A second controller is disposed on the second circuit board, and could transmit a driving signal to the first controller according to the operating signal of an operator interface. The first controller regulates the commutating switches to commutate according to the driving signal and the position signals, thereby to activate the rotor to rotate. With such design, a commutation process and a user operating process are regulated by the two different controllers, which could efficiently simplify the program code installed in each of the controllers and facilitate the maintenance of the controllers.

Abstract: A protective device of a power tool includes a fixing base having a tube portion and an abutting surface, a restricting ring fitting around the tube portion, several springs disposed between the abutting surface and a first end of the restricting ring, a protective cover having several second projections and several second recesses, and a locking member. The first end has an abutting portion. A second end of the restricting ring has several first projections and several first recesses matching with the second projections and the second recesses. The restricting ring is located between the protective cover and the abutting surface. When a blocking portion of the locking member moves to a first position, the blocking portion restricts the restricting ring from moving toward the abutting surface. When the blocking portion moves to a second position, the blocking portion leaves a position between the abutting surface and the abutting portion.

Abstract: A power tool includes a case, a motor, a plurality of Hall effect sensors, a first circuit board, and a second circuit board. The Hall effect sensors detect a position of a rotor of the motor and correspondingly generate position signals. A plurality of commutating switches and a first controller are disposed on the first circuit board. A second controller is disposed on the second circuit board, and could transmit a driving signal to the first controller according to the operating signal of an operator interface. The first controller regulates the commutating switches to commutate according to the driving signal and the position signals, thereby to activate the rotor to rotate. With such design, a commutation process and a user operating process are regulated by the two different controllers, which could efficiently simplify the program code installed in each of the controllers and facilitate the maintenance of the controllers.

Abstract: A power tool includes a casing having a motor receiving portion and a holding portion, a motor disposed in the motor receiving portion, a transmission disposed in the motor receiving portion, and a fan module disposed in the motor receiving portion. The holding portion is adapted to be held by a user. The motor has a rotatable shaft, a front side, and a back side opposite to the front side. The transmission is located on the front side of the motor and is connected to the rotatable shaft, and has an output shaft for being connected to a tool bit. The fan module has a driving motor and a fan blade. The driving motor is adapted to drive the fan blade to rotate. With such design, the fan module could cool the motor to remove the heat generated by the motor.

Abstract: A method of forming a semiconductor device includes forming first and second fin structures on a substrate and a patterned polysilicon structure on first portions of the first and second fin structures. The method further includes depositing an insulating layer on second portions of the first and second fin structures and on the patterned polysilicon structure, which may be followed by selectively removing the insulating layer from the second portions and patterning a first hard mask layer on the second portion of the second fin structure. The method also includes growing a first epitaxial region on the second portion of the first fin structure, removing the patterned first hard mask layer from the second portion of the second fin structure, patterning a second hard mask layer on the first epitaxial region, and growing a second epitaxial region on the second portion of the second fin structure.

Abstract: A loudspeaker with low-frequency oscillation, comprising: a housing (21) with a ring portion (211) extending inwardly from the bottom thereof; and a reed element (22) having a top end attached to an oscillatable sound assembly, the reed element (22) further having an external ring (221) and two vibration arms (222) symmetrically extending from the internal side of the external ring (221) to the internal side of the loudspeaker in a bent manner, each of the vibration arms (222) having a free end (223) extending to the center of the reed element (22), the oscillatable sound assembly including either a magnetic ring (25) or a coil (28) disposed within the housing (21), the ring portion (211) being attached to either another coil corresponding to the magnetic ring (25) or another magnetic ring corresponding to the coil (28), whereby, when the coil (28) is fed with electric current, a magnetic force is created to impart an up and down vibration to the oscillatable sound assembly, thereby enhancing the effect of th