Abstract: An exemplary power supply system and method for a motherboard includes a power circuit providing power for a south bridge, and a controller having first and second transistors. An input terminal of the power circuit is connected to a power supply. An output terminal of the power circuit is connected to a reset pin of the south bridge. A first terminal of the first transistor is configured for receiving a control signal from the south bridge. A second terminal of the first transistor is connected to a first terminal of the second transistor. A second terminal of the second transistor is connected to the reset pin of the south bridge. Each of the first and second transistors has a third terminal grounded.

Abstract: A start-up circuit which decreases a start-up current and stabilizes running of a DC fan. The start-up circuit includes a digital-analog converter for convert a digital control signal from a control chip to an analog control signal, a voltage sampling device connected to an output terminal of the digital-analog converter, a comparator, a switching device for controlling start-up of the DC fan, and a feedback device adjusting current passing through the switching device. The comparator includes two input terminals and an output terminal. One input terminal is connected to an output terminal of the voltage sampling device. The switching device is connected to the output terminal of the comparator. An output signal of the switching device is inputted to the other input terminal of the comparator via the feedback device.

Abstract: A circuit for controlling rotation speed of a computer fan includes a fan connector providing for controlling the rotation speed of the computer fan, a rotation speed detector providing for detecting the rotation speed of the computer fan, a BIOS chip connected to the fan connector via the rotation speed detector and provided for receiving, and comparing rotation speed signals from the rotation speed detector, a super I/O chip connected to the BIOS chip and provided for outputting either a PWM signal or another PWM signal to be converted to a voltage signal to control rotation speed of the computer fan according to the result of the comparison, a integrated circuit connected to the super I/O chip and the fan connector and configured for converting the another PWM signal to an analog voltage signal.

Abstract: A network overclock control circuit for a computer includes an RC circuit, first and second comparator circuits, and first and second switch circuits. A signal pin of a network indicating lamp is connected to input terminals of the first and second comparator circuits via the RC circuit. Output terminals of the first and second comparator circuits are respectively connected to first and second clock pins of a clock chip via the first and second switch circuits. When network has little traffic, the first and second comparator circuits control the first and second switch circuits to output low level signals. When network has medium to high traffic, the first and second comparator circuits control the first and second switch circuits to output high and low level signals. When network is overloaded, the first and second comparator circuits control the first and second switch circuits to output high level signals.

Abstract: An exemplary voltage regulating circuit for a motherboard includes a selecting switch and a first switch module, the selecting switch comprising a first input terminal arranged to receive a standby power provided by a power supply, a first control terminal arranged to receive a state signal from the motherboard via a first switch module controlled by a power good signal generated by the power supply, and an output terminal, wherein, when the motherboard is turned off, the state signal is at a high level and the first switch module is turned on by the power good signal for turning off the selecting switch to stop outputting the standby power.

Abstract: A power supply circuit for a motherboard includes a first resistor, a second resistor, a Schottky diode, and a direct current (DC) voltage source. The Schottky diode includes a first anode, a second anode, and a cathode. The first anode of the Schottky diode is respectively coupled to terminals of the first and second resistors, another terminal of each of the first and second resistors is respectively coupled to a power supply and ground. The second anode of the Schottky diode is coupled to the DC voltage source, the cathode of the Schottky diode is coupled to a south bridge.

Abstract: An apparatus for automatic testing of a PS/2 interface includes a micro controller unit, a PS/2 port, and a plurality of LEDs. The micro controller unit is coupled with both a data pin and a clock pin of the PS/2 interface. The LEDs coupled to the micro controller unit simulate functions of a keyboard. A related method for testing the PS/2 interface is also provided.

Abstract: An exemplary method for controlling rotation speed of a computer fan includes: judging the type of a fan by comparing two rotation speeds detected before and after changing a duty cycle of a PWM signal respectively; controlling the computer fan as a 4-pin fan the PWM signals if the rotation speeds are different; and controlling the computer fan as a 3-pin fan via voltage signals converted from the PWM signals if the rotation speeds are equal. And an exemplary circuit for controlling rotation speed of a computer fan is capable of controlling rotation speed of the 4-pin fan via PWM signals, and controlling rotation peed of the 3-pin fan via voltage signals converted from PWM signals.

Abstract: In one preferred embodiment, a power indicator circuit for a computer comprises a light-emitting diode (LED) indicating power management states of a computer; a first resister connected between one pole of the LED and a power source; a second resistor connected between the other pole of the LED and a power source, a first branch circuit connected between the one pole and ground; and a second branch circuit connected between the other pole and ground. Wherein the first resistor and the second resistor control a current through the LED. Because the LED emits lights of different colors or turns off according to the different power management states, it is easy for users to see what the power management state of the computer is.

Abstract: An exemplary PCI interface card includes a printed circuit board having a plurality of testing points arranged thereon, and a connecting portion configured to engage in a PCI connector of a motherboard. The connecting portion protrudes from the printed circuit board, and has a plurality of golden fingers disposed thereon. Some of the golden fingers configured to respectively connect with contacts of the PCI connector, which are set to connect with a south bridge chip of the motherboard to transmit address and data signals, are respectively electronically connected to the testing points of the printed circuit board.

Abstract: A pulse width modulation (PWM) generating circuit includes a first comparator, a first resistor, a second resistor, a third resistor, a fourth resistor, a capacitor, and a diode. The first resistor and the second resistor are connected in series between a voltage input and ground. The third resistor, the fourth resistor, and the capacitor are connected in series between the voltage input and ground. The first comparator has a non-inverting input connected to a node between the first resistor and the second resistor, an inverting input connected to a node between the fourth resistor and the capacitor, and an output connected to a node between the third resistor and the fourth resistor. The diode is connected between the non-inverting input and the output. The inverting input of the first comparator provides triangular wave signals to a second comparator by which PWM signals are generated.

Abstract: A sleep/awake circuit includes an infrared receiving/sending module, a micro-control circuit, and a bus control circuit. The micro-control circuit sends a command signal to the infrared receiving/sending module at predetermined intervals. The infrared receiving/sending module detects the presence or absence of a user and then sends a signal back to the micro-control circuit indicating a result. According to the result, the micro-control circuit exchanges data and clock signals with the bus control circuit. The bus control circuit then sends control signals to the computer to control sleep/awake states of the computer.

Abstract: In one preferred embodiment, a power indicator circuit for a computer comprises a light-emitting diode (LED) indicating power management states of a computer; a first resister connected between one pole of the LED and a power source; a second resistor connected between the other pole of the LED and a power source, a first branch circuit connected between the one pole and ground; and a second branch circuit connected between the other pole and ground. Wherein the first resistor and the second resistor control a current through the LED. Because the LED emits lights of different colors or turns off according to the different power management states, it is easy for users to see what the power management state of the computer is.

Abstract: A self-startup circuit for a DC fan includes a voltage sampling device receiving a first control signal, a comparator, and a self-startup device. The comparator includes two input terminals and an output terminal. One input terminal is connected to an output terminal of the voltage sampling device. The self-startup device has a switching device and a diode connected in parallel. The self-startup device has an input terminal connected to the output terminal of the comparator, and outputs a second control signal for keeping the DC fan rotating even when the first control signal has a very low duty cycle.

Abstract: A method for testing a card reader includes the steps of: identifying a logical drive corresponding to the card reader; determining whether the card reader matches a portable storage device connected to the card reader; displaying error information if the card reader does not match the portable storage device; obtaining a control code of the portable storage device if the card reader matches the portable storage device; testing the performance of the card reader by means of reading and writing data in the portable storage device through the card reader according to the control code.

Abstract: A card for simulating peripheral component interconnect (PCI) loads is disclosed. The card in accordance with a preferred embodiment of the invention includes an interface configured for electrically connecting to a motherboard; and a load circuit for simulating the different loads, wherein the load circuit comprises at least one power module receiving a voltage from the interface; and the power module dissipates various loads. Because that the card may dissipates various power according to testing requirement, the stability of the motherboard can be tested in various load power without connecting actual PCI loads to the motherboard.

Abstract: A start-up circuit which decreases a start-up current and stabilizes running of a DC fan. The start-up circuit includes a digital-analog converter for convert a digital control signal from a control chip to an analog control signal, a comparator, a switching device for controlling start-up of the DC fan, and a feedback device adjusting current passing through the switching device. The comparator includes two input terminals and an output terminal. One input terminal is connected to an output terminal of the digital-analog converter. The switching device is connected to the output terminal of the comparator. An output signal of the switching device is inputted to the other input terminal of the comparator via the feedback device.

Abstract: An apparatus for automatic testing of a PS/2 interface includes a micro controller unit, a PS/2 port, and a plurality of LEDs. The micro controller unit is coupled with both a data pin and a clock pin of the PS/2 interface. The LEDs coupled to the micro controller unit simulate functions of a keyboard. A related method for testing the PS/2 interface is also provided.

Abstract: A method for identifying Peripheral Component Interconnect (PCI) device information can identify information on all PCI devices coupled to a PCI bus. The method includes the steps: (a) initializing an address parameter and an address offset to a predetermined first number; (b) writing a first address value to a configuration port; (c) reading data from a data port based on the address value; (d) determining whether there is a corresponding PCI device coupled to the PCI bus based on the data; (e) adding a predetermined second number to the address parameter if there is no corresponding PCI device coupled to the PCI bus, so as to allocate an address for a next PCI device; (f) determining whether all the PCI devices have been searched; and (g) repeating step (b) to step (f) till all the PCI devices have been searched. A related system is also disclosed.

Abstract: A method for displaying debug codes of a BIOS includes the steps of: initializing a host electronic system and sending out a debug code corresponding to the initialization of the host electronic system to a debug card; displaying the debug code on an LED-display screen of the debug card; transmitting the debug code displayed on the LED-display screen to an application software; choosing the BIOS file corresponding to the debug code displayed, then acquiring and displaying the information via the application software. A system implementing this method includes a host electronic system with a BIOS for sending out a debug code during the initialization; a debug card connected electrically to the host electronic system for receiving and displaying the debug code sent out by the host electronic system; an application software for acquiring and displaying the information corresponding the debug code displayed on the debug card.