Abstract: A fixing member for fixing a riser card with an edge connector includes a board for fixing the riser card, and a blocking piece connected to a bottom side of the board and adjacent to the edge connector. The blocking piece is arranged to abut a top of an expansion slot longer than the edge connector, to prevent the edge connector from being inserted into the expansion slot.

Abstract: A printed circuit board (PCB) comprising a base board, the base board defines a thermal pad and a plurality of pin pads for solder an integrated circuit (IC) with a Quad Flat No-lead (QFN) package, wherein a plurality of thermal vias are defined on the thermal pad through the base board, a solder mask is defined around each of the thermal vias.

Abstract: A circuit board structure includes a circuit board and at least one adsorption strip set on the circuit board. The circuit board defines at least one group of pin holes arranged along a predetermined line to receive a number of pins of an electronic component. The adsorption strip absorbs excess conducting material between adjacent pins during a wave-soldering process.

Abstract: A protection circuit is connected between a fan control chip and a fan connector. The protection circuit includes a first resistor and a diode. A detecting pin of the fan control chip is connected to the anode of the diode. The cathode of the diode is connected to a detecting pin of the fan connector. The anode of the diode is also connected to a first power source through the first resistor.

Abstract: A voltage pin of a PWM controller is electrically connected to a power source. First and second gate pins of the PWM controller are electrically connected to gates of first and second MOSFETs, respectively. A phase pin of the PWM controller is electrically connected to a source of the first MOSFET and a drain of the second MOSFET, and also electrically connected to an input pin of the PWM controller through a second inductor and a first resistor in that order. A drain of the first MOSFET is connected to the power source through a first inductor. The input pin of the PWM controller is grounded through a second resistor and connected to a first terminal of an electronic switch through a third resistor. A second terminal of the electronic switch is grounded. A control terminal of the electronic switch is connected to a motherboard.

Abstract: A fixing member for fixing a riser card with an edge connector includes a board for fixing the riser card, and a blocking piece connected to a bottom side of the board and adjacent to the edge connector. The blocking piece is arranged to abut a top of an expansion slot longer than the edge connector, to prevent the edge connector from being inserted into the expansion slot.

Abstract: A soldering assistance device is used for soldering a multi-pin electronic element with a row of pins on a PCB. The row of pins includes an outer pin at two ends thereof. The soldering assistance device includes a holding portion and a soldering portion connected to the holding portion. The soldering portion is adjacent to the outer pin. An interval between the soldering portion and the outer pin is less than an interval between each two adjacent pins of the row of pins. The soldering portion is made of a metal which is easy to solder. A soldering method using the soldering assistance device is also provided.

Abstract: A time sequence control circuit is provided to control time sequence of a motherboard of a computer. A first voltage received by a power supply receiving terminal is greater than a preset voltage before a signal control terminal on the motherboard receives a second voltage during turning on the computer. During shutting off the computer, the first voltage at the power supply receiving terminal drops and is less than the preset voltage, and the second voltage supplied to the signal control terminal on the motherboard is shut off.

Abstract: A time sequence control circuit that can control time sequence of a computer. After the computer is turned on, a power supply terminal outputs a high level enabling signal to an enabling pin of a power supply circuit, the power supply circuit is active. A power supply pin of the power supply circuit outputs a standard voltage to a power pin of each of the motherboard components. A first electronic switch is turned on, a second electronic switch is turned off, and a power supply state pin of the power supply circuit outputs a high level power supply state signal to a power state input pin of a main chip after the power supply circuit outputs the standard voltage.

Abstract: A time sequence control circuit that can control time sequence of a computer. After the computer is turned on, a power supply terminal outputs a high level enabling signal to an enabling pin of a power supply circuit, the power supply circuit is active. A power supply pin of the power supply circuit outputs a standard voltage to a power pin of each of the motherboard components. A first electronic switch is turned on, a second electronic switch is turned off, and a power supply state pin of the power supply circuit outputs a high level power supply state signal to a power state input pin of a main chip after the power supply circuit outputs the standard voltage.

Abstract: A time sequence control circuit is provided to control time sequence of a motherboard of a computer. A first voltage received by a power supply receiving terminal is greater than a preset voltage before a signal control terminal on the motherboard receives a second voltage during turning on the computer. During shutting off the computer, the first voltage at the power supply receiving terminal drops and is less than the preset voltage, and the second voltage supplied to the signal control terminal on the motherboard is shut off.