Abstract: A power supply circuit includes a PWM controller, which is capable of providing pulse signals to the CPU, a temperature feedback circuit coupled to the PWM controller, and a temperature sensor. The temperature sensor is coupled to the temperature feedback circuit, the temperature sensor is located adjacent the CPU, and capable of detects a temperature of the CPU. The PWM controller is capable of adjusting the pulse signals to maintain the pulse signals stably when the temperature sensor detects the temperature of the CPU rising.

Abstract: An alarm system for alarming whenever there is a power leakage from an electronic device, includes a voltage decreasing circuit, a switch circuit and an alarm circuit. The voltage decreasing circuit receives a first voltage from a live wire output terminal and outputs a second voltage. The switch circuit outputs a control signal when the power leakage is detected. The switch circuit is electrically connected to a connection port. The connection port is electrically connected to the live wire output terminal and a neutral wire output terminal. The alarm circuit receives the control signal and alarms. If there is power leakage from the electronic device, the first voltage from the live wire input terminal flows into the ground wire input terminal via the electronic device; the switch circuit turns on and the alarm circuit is closed to alarm.

Abstract: A power supply circuit includes a voltage regulating module; a voltage selecting circuit and a voltage regulating chip. The voltage regulating module outputs corresponding control signals according to a type of a CPU installed on a motherboard. The voltage selecting circuit receives the control signals and converts the corresponding control signal to a voltage selecting signal. The voltage regulating chip receives the voltage selecting signal and outputs the corresponding working voltage to the CPU.

Abstract: A motherboard includes an I/O chip, a south bridge chip, and a delay circuit. The I/O chip detects a standby voltage on the motherboard and outputs an indicating signal that indicates whether the standby voltage is at high level. The south bridge chip is connected to the I/O chip to receive the indicating signal. The delay circuit is connected to the I/O chip and the south bridge chip. The delay circuit delays the indicating signal before sending the indicating signal to the south bridge chip.

Abstract: A power supply control circuit for a motherboard of a computer is provided. The power supply control circuit includes a south bridge chip and a voltage output control circuit connected to the south bridge chip. The south bridge chip includes a control pin and a detecting pin. The voltage output control circuit has a voltage input terminal and a voltage output terminal. The voltage output control circuit includes a transistor connected to the voltage input terminal and also connected to the voltage output terminal via a switch component. The voltage output terminal is connected to the detecting pin of the south bridge chip via a super I/O chip. The transistor is capable of controlling the switch component to transmit a high level voltage to the super I/O chip when the computer is shut down. A method is also provided.

Abstract: A power supply circuit for IEEE 1394 interface includes an IEEE 1394 interface control chip, an interface circuit, and a power circuit. The IEEE 1394 interface control chip outputs transmission protocol signals. The interface circuit is electrically connected to the IEEE 1394 interface control chip by a number of differential signal transmission lines. The interface circuit receives the transmission protocol signals and exchanges data with a peripheral device according to the received transmission protocol signals. The power circuit has a voltage decreasing circuit and provides working voltage to the interface circuit. The voltage decreasing circuit receives a DC voltage and converts the received DC voltage to the working voltage.

Abstract: A circuit is used to process video signal from a video sensor. The video signal includes video content signal and synchronization signals. The circuit includes a status register, a data register, and a processor. The status register provides a sampling clock signal to the data register and the video sensor. The sampling clock signal is synchronized with the synchronization signals to sample the video signal. The status register stores the synchronization signals. The data register storing the video content signal. The processor is coupled to the status register and the data register. The processor reads the video content signal from the data register according to the synchronization signals in the status register.

Abstract: A power supply circuit includes a first power circuit having a first power output terminal and a first ground output terminal, a second power circuit having a second power output terminal and a second ground output terminal, and a SATA control chip having a first input terminal, a second input terminal, a third input terminal, and a fourth input terminal. The first power circuit comprises a first filter circuit. The second power circuit comprises a second filter circuit. The first power output terminal, first ground output terminal, second power output terminal, and second ground output terminal are electrically coupled to the SATA control chip via the first input terminal, second input terminal, third input terminal, and fourth input terminal respectively. The first and second power circuits provide power to the SATA control chip via the first and second filter circuits respectively.

Abstract: A power supply circuit includes a pulse width modulation (PWM) signal generator, a current adjustment unit, a drive unit, and a feedback unit. The PWM signal generator outputs a PWM voltage signal to the drive unit. The drive unit outputs a first control signal to control the current adjustment unit to work, and outputs a first direct current signal and a direct voltage signal. The current adjustment unit outputs a second direct current signal. A working current of the electrical device comes from the first and second direct current signals. The feedback unit generates a feedback voltage signal according to the direct voltage signal, and transmits the feedback voltage signal to the PWM signal generator to adjust the PWM voltage signal.

Abstract: A power supply circuit for a south bridge chip includes a voltage sampling circuit, a control circuit, and an I/O controller. The voltage sampling circuit comprises an input terminal capable of receiving a first voltage, and an output terminal capable of outputting a control signal. The control circuit is capable of receiving the control signal from the voltage sampling circuit and outputting a power good signal when a high voltage level control signal is received. The I/O controller is capable of receiving the power good signal from the control circuit, adjusting time sequence for the power good signal to synchronize with the first voltage, and outputting the adjusted power good signal to provide power for the south bridge chip.

Abstract: A power supply circuit includes a first resistor and a first capacitor. One end of the first resistor is connected to a system power. The other end of the first resistor is connected to the anode of the first capacitor. The cathode of the first capacitor is connected to a digital analog converter A (DACA) VDD pin of a north bridge on a motherboard. The system power provides a stable power signal for the DACA VDD of the north bridge via the first resistor and the first capacitor. Thereby the display no longer ripples when the resolution of the display is adjusted to a certain value.

Abstract: A dual voltage switching circuit includes a first resistor and two transistors. Each transistor has a first terminal, a second terminal, and a third terminal. The first terminals are connected to a control terminal of a computer. The second terminals are connected to a standby power supply of the computer. The third terminals are connected to a power-on terminal of the computer via the first resistor. When the first terminals receive a low level signal from the control terminal, the first and second transistors are on, and the power-on terminal receives a voltage form the standby power supply via the first resistor.

Abstract: A power supply circuit for a motherboard includes a VRM, a first NMOS transistor, a second NMOS transistor, a first capacitor, a first induction coil, and a delay circuit. A gate of the first NMOS transistor is connected to a UGATE pin of the VRM. A source of the first NMOS transistor is connected to a BOOT pin of the VRM via the first capacitor and a PHASE pin of the VRM, and connected to an MCH on the motherboard via the first induction coil. A drain of the first NMOS transistor is connected to a system power. A gate of the second NMOS transistor is connected to an LGATE pin of the VRM. A source of the second NMOS transistor is grounded. A drain of the second NMOS transistor is connected to the source of the first NMOS transistor and the delay circuit.

Abstract: A power supply circuit for south bridge chip includes a voltage conversion chip, a control circuit, and a voltage increasing circuit coupled electrically to the voltage conversion chip and the control circuit. The voltage conversion chip is configured for ouputting a driving signal. The control circuit is configured for receiving the driving signal and a first voltage, and converting the first voltage to a second voltage according to the driving signal. The voltage increasing circuit is configured for increasing voltage level of the second voltage, wherein the second voltage is supplied to the south bridge chip via the voltage increasing circuit.

Abstract: A power supply circuit includes a PWM controller capable of providing pulse signals to a CPU, and an I/O controller electrically coupled to the PWM controller and the CPU respectively. The I/O controller is capable of receiving voltage selection signals from the CPU and outputting a control signal to the PWM controller. The PWM controller is capable of adjusting pulse signals provided to the CPU according to the control signal.

Abstract: A motherboard power on circuit includes a switch connector, an impedance circuit, and a super I/O chip. The impedance circuit includes a first resistor, a second resistor, and a capacitor. A terminal of the first resistor is connected to the power on terminal of the switch connector. The other terminal of the first resistor is connected to the power on terminal of the super I/O chip, a terminal of the second resistor, and a terminal of the capacitor. The other terminals of the second resistor and the capacitor are connected to a power source and ground respectively.

Abstract: An output circuit for audio codec chip includes a noise eliminating circuit electrically coupled to the audio codec chip for eliminating noise signals. The noise eliminating circuit includes a first switch and a second switch. When the audio codec chip output signals jump from low voltage level to high voltage level, the noise signals are grounded via the first and second switches respectively.

Abstract: A power supply circuit includes a PWM controller, which is capable of providing pulse signals to the CPU, a temperature feedback circuit coupled to the PWM controller, and a temperature sensor. The temperature sensor is coupled to the temperature feedback circuit, the temperature sensor is located adjacent the CPU, and capable of detects a temperature of the CPU. The PWM controller is capable of adjusting the pulse signals to maintain the pulse signals stably when the temperature sensor detects the temperature of the CPU rising.

Abstract: A power supply control circuit for a motherboard of a computer is provided. The power supply control circuit includes a south bridge chip and a voltage output control circuit connected to the south bridge chip. The south bridge chip includes a control pin and a detecting pin. The voltage output control circuit has a voltage input terminal and a voltage output terminal. The voltage output control circuit includes a transistor connected to the voltage input terminal and also connected to the voltage output terminal via a switch component. The voltage output terminal is connected to the detecting pin of the south bridge chip via a super I/O chip. The transistor is capable of controlling the switch component to transmit a high level voltage to the super I/O chip when the computer is shut down. A method is also provided.

Abstract: A power supply circuit for a south bridge chip includes a voltage sampling circuit, a control circuit, and an I/O controller. The voltage sampling circuit comprises an input terminal capable of receiving a first voltage, and an output terminal capable of outputting a control signal. The control circuit is capable of receiving the control signal from the voltage sampling circuit and outputting a power good signal when a high voltage level control signal is received. The I/O controller is capable of receiving the power good signal from the control circuit, adjusting time sequence for the power good signal to synchronize with the first voltage, and outputting the adjusted power good signal to provide power for the south bridge chip.