Abstract: A total harmonic current distortion (THDi) control circuit includes a power factor correction circuit and a control circuit. The power factor correction circuit includes a boost unit, an inverter unit, and a feedback unit. The boost unit includes a switch element and a current detection element series-coupled to the switch element. The feedback unit operatively detects an output voltage and an output current of the power factor correction circuit. The control circuit calculates an output power according to the output voltage and the output current, and calculates an input voltage and an input current according to the output power. The control circuit outputs a pulse width modulation signal and controls a conduction current generated by the switch element according to the input current. The control circuit adjusts the duty cycle of the pulse width modulation signal according to the conduction current detected by the current detection element.

Abstract: A total harmonic current distortion (THDi) control circuit includes a power factor correction circuit and a control circuit. The power factor correction circuit includes a boost unit, an inverter unit, and a feedback unit. The boost unit includes a switch element and a current detection element series-coupled to the switch element. The feedback unit operatively detects an output voltage and an output current of the power factor correction circuit. The control circuit calculates an output power according to the output voltage and the output current, and calculates an input voltage and an input current according to the output power. The control circuit outputs a pulse width modulation signal and controls a conduction current generated by the switch element according to the input current. The control circuit adjusts the duty cycle of the pulse width modulation signal according to the conduction current detected by the current detection element.

Abstract: A safety device for a pneumatic nailer includes an attached tube connected to the magazine of the nailer and including a first passage for movably receiving a first pine and a second passage for movably receiving a second pin. A driving piece is pivotably connected to the attached tube at a mediated point of the driving piece. A spring is received in the second passage and biased between a closed end of the second passage and a first end of the second pin. A second end of the second pin is retractably extended through an open end of the second passage by the spring and can be inserted in a locking hole of a safety bar movably connected to the barrel of the nailer. Two ends of the driving piece are respectively connected to the first pin and the second pin such that when no nails are located in the barrel, an end of the first pin is extended into the magazine while the second pin is inserted in the locking hole of the safety bar to lock the safety bar.

Abstract: A high-performance water heater is constructed to include a heat absorber, the heat absorber defining an oil chamber that holds an oil, a heat guide defining a water chamber, the heat guide having a cold water pipe adapted to guide cold water into the water chamber and a hot water pipe adapted to guide hot water out of the water chamber, a plurality of heat conducting members connected between the heat absorber and the heat guide and adapted to transfer heat energy from the oil in the oil chamber to water in the water chamber of the heat guide, and a heating device adapted to heat the heat absorber.

Abstract: A nail guiding mechanism of nailing gun composed of a gun body, a nail magazine and the nail guiding mechanism. The nail guiding mechanism includes a bottom board, a middle board and a top board. The bottom board is connected between the gun body and the nail magazine. The middle board is locked on the top face of the bottom board. The middle board is formed with multiple connecting holes for multiple locating members to fit therein. The locating members protrude from the top face of the middle board. The top board is mounted on the top face of the middle board. The top board is formed with multiple locating holes respectively corresponding to the locating members. The locating members are respectively passed through the locating holes to protrude from the top board. A press shank and a latch ring are pivotally disposed on the top board. When pressing down the press shank, the latch ring is tightly latched with the locating members to fixedly connect the top board with the middle board.

Abstract: A seal packing for pneumatic stapler includes a stiff inner layer and a soft outer layer which wraps the stiff inner layer. Four protrusions extend from an inner periphery of the seal packing and each protrusion has a hole defined therethrough. The seal packing is sandwiched between the cap and the body of the pneumatic stapler, screws extend through the cap, the holes in the seal packing and are engaged with holes in the body of the stapler.

Abstract: The invention offers a solution to several problems associated wit IC packages that use a top layer of molded plastic. This has been achieved by inter-posing a dummy layer of dielectric material between the upper surface of the integrated circuit wafer and the molded plastic layer. This dummy layer is patterned and etched so that its surface becomes an alternating series of valleys and ridges, care being taken to ensure that all wiring lines are protected by being within ridges. This structure serves both to protect the wiring lines during the application of the molded plastic and, because of the large surface area of contact between plastic and wafer, excellent adhesion of the molded plastic to the wafer is obtained.