Abstract: A power supply circuit for supplying power to a central processing unit (CPU) of a computer includes a pulse width modulation (PWM) controller, a control circuit, a switch circuit, a first current protection circuit, a second current protection circuit, a first power circuit, and a second power circuit. When the computer is turned on, a first current protection threshold is set by the PWM controller through the first current protection circuit. When the computer is in a standby mode, a second current protection threshold is set by the PWM controller through the second current protection circuit.

Abstract: A power supply circuit applied to a central processing unit (CPU) of a computer includes a pulse width modulation (PWM) controller, a control circuit, a first switch circuit, a second switch circuit, a first compensation circuit, a second compensation circuit, a first power circuit, and a second power circuit. When the computer is turned on, the PWM controller regulates duty cycles of pulse signals and outputs the regulated pulse signals to the first and second power circuits according to a first compensation signal, to provide a stable voltage to the CPU. When the computer is in a standby mode, the PWM controller regulates duty cycles of pulse signals and outputs the regulated pulse signals to the first power circuit according to a second compensation signal, to provide a stable voltage to the CPU.

Abstract: A discharge circuit includes a pulse width modulator (PWM) chip, a first and second electronic switch, and a resistor. The first electronic switch receives a voltage creep from the PWM chip. When the voltage creep is less than a voltage making the first electronic switch to turned on, the voltage creep is discharged through the resistor and the second electronic switch.

Abstract: A discharge circuit for a power supply unit includes a pulse width modulator (PWM) chip, a first and second electronic switch, and a resistor. The first electronic switch receives a power good signal from the power supply unit. When a system power terminal outputs a voltage later than a stand-by power terminal, a voltage creep outputted by the PWM chip is discharged through the resistor and the second electronic switch.

Abstract: A sequence circuit includes a power output terminal, first to third power input terminals, first to sixth resistors, first to tenth filed effect transistors (FETs), first to third inductors, a first capacitor, a second capacitor, and first to third drivers. The sequence circuit ensures that different voltages work in a correct sequence.

Abstract: Power supply circuit comprises an under voltage protection module and a voltage conversion module electrically connected to the under voltage protection module. The under voltage protection module is electrically connected to a first power supply and a second power supply. The voltage conversion module is connected to the first power supply. When a voltage of the first power supply is in a normal range, the under voltage protection module offers the second power supply to power the voltage conversion module. The voltage conversion module converts the voltage of the first power supply into an operational voltage, and outputs the operational voltage. When the voltage of the first power supply is less than a threshold voltage, the under voltage protection module does not offer the second power supply to the voltage conversion module, and the voltage conversion module does not operate.

Abstract: A power supply circuit for a central processing unit (CPU) includes a comparing circuit, first to third switch circuits, first and second compensation circuits, a pulse width modulation (PWM) controller, a first power circuit connected to a first output pin of the PWM controller, and a second power circuit connected to a second output pin of the PWM controller. When a motherboard operates normally, the comparing circuit outputs a first control signal to control the first and third switch circuits to be turned on. The second switch circuit is turned off. The first compensation circuit provides a compensation signal to the PWM controller. When the motherboard is powered off, the comparing circuit outputs a second control signal to control the first and third switch circuits to be turned off. The second switch circuit is turned on. The second compensation circuit provides a compensation signal to the PWM controller.

Abstract: A protection circuit includes a voltage conversion unit, a voltage clamping unit, and a power supply. The voltage conversion unit converts a first voltage from the power supply into a second voltage and outputs the second voltage to an electronic element. The voltage clamping unit stops the power supply from operating if the second voltage is greater than a rated voltage of the electronic element.

Abstract: A power supply circuit preventing any overvoltage to an electronic element includes a voltage conversion unit and a voltage clamping unit. The voltage conversion unit converts voltage of a power supply into an operation voltage of the electronic element, and outputs the converted voltage through an output terminal of the voltage conversion unit. When the voltage output from the output terminal of the voltage conversion unit is more than the operation voltage of the electronic element, the voltage clamping unit effectively clamps the voltage output from the output terminal of the voltage conversion unit down to the operation voltage of the electronic element.

Abstract: A connector detection circuit is used for detecting whether a first connector of an electronic device is in sufficient connection with a second connector of a connection device. The connector detection circuit includes a pressure sensing module, a switch unit, and an indicator. The pressure sensing module is located under the pins of the first connector, to sense whether there is pressure applied on each pin of the first connector by a corresponding pin of the second connector, and to output sensed results. The switch unit is connected to the pressure sensing module to receive the sensed results, and is connected to the indicator to control the indicator to indicate whether the first connector and the second connector have a sufficient connection with each other according to the sensed results.

Abstract: A phase detection circuit includes first to third power input modules, first to third power input terminals, an alarm module, first to fifth electronic switches, and a power management module. The power input modules are used to convert pulse signals from a multi-phase power supply into direct current voltages and output the direct current voltages to the first to third electronic switches. When the multi-phase power supply operates abnormally, no direct current voltages are output to the first to third electronic switches and the alarm module alarms.

Abstract: A load-testing circuit is used for simulating maximum standard load currents for different types of USB ports. The load-testing circuit includes a first electronic switch, a second electronic switch, and a current selection module including a plurality of current branch circuits. When one of the current branch circuits is activated, a voltage at a third terminal of the first electronic switch is supplied to a first terminal of the second electronic switch through the activated current branch circuit to turn on the second electronic switch. A current of the third terminal of the first electronic switch is approximately equal to a current of the activated current branch circuit.

Abstract: A fan control circuit includes a hardware controller, a rectifier circuit, first to third electronic switches, and a fan. When the hardware controller outputs a pulse width modulation (PWM) signal to the rectifier circuit and the fan, the rectifier circuit transforms the PWM signal into a direct current (DC) voltage and outputs the DC voltage to the first electronic switch. The first electronic switch is turned on, and the second and third electronic switches are turned off. A rotation speed of the fan is controlled by the PWM signal received from the hardware controller. When the hardware controller does not output the PWM signal, the first electronic switch is turned off, the second and third electronic switches are turned on, a DC power supply supplies power to the fan through the third electronic switch, and the fan rotates at full speed.

Abstract: A protection circuit for a central processing unit (CPU) includes a power circuit, two comparators, a number of resistors, a thermistor, and an electronic switch. A non-inverting input terminal of the comparator is coupled to a first power terminal. An inverting input terminal of the comparator is connected to ground through the thermistor. An output terminal of the comparator is coupled to the electronic switch. When an operation temperature of the CPU exceeds a predefined temperature, the comparator enables the electronic switch to be turned on, to reduce an operation frequency of the CPU.

Abstract: In a method for automatically processing product change notice (PCN) of electronic products using a computing device, the computing device connects to a PCN database and a product design management (PDM) database through a network. PCN information of the electronic products are collected from suppliers and stored in the PCN database. A bill of materials (BOM) of each electronic product is created in the PDM database. PCN information of the electronic products is searched from the PCN database at a regular time interval. The BOM of a corresponding electronic product is searched from the PDM database according to a product ID obtained from the PCN information, and the product information of the electronic product is updated in the BOM. The PCN information of the electronic product is displayed on an electronic bulletin board to monitor the PCN information of the electronic product.

Abstract: In a method for recording system event logs of a computing device, the computing device includes a storage device and a baseboard management controller (BMC). The computing device generates an inquiring command to inquire an actual number of the system event logs that are recorded in a flash memory of the BMC. When the actual number of the system event logs is equal to the maximum number of the system event logs, the system event logs are copied from the flash memory and saved to the storage device, and the system event logs are deleted from the flash memory. The inquiring command is resent to the BMC to continue recording the system event logs in the flash memory if the computing device has not completed a stability performance test on the computing device.

Abstract: A protection circuit includes a voltage conversion unit, a voltage clamping unit, and a power supply. The voltage conversion unit converts a first voltage from the power supply into a second voltage and outputs the second voltage to an electronic element. The voltage clamping unit stops the power supply from operating if the second voltage is greater than a rated voltage of the electronic element.

Abstract: A sequence circuit includes first through third signal terminals, first through ninth resistors, and first through fifth electronic switches. The sequence circuit receives a first signal through the first signal terminal. The sequence circuit receives a second signal through the second signal terminal. The sequence circuit outputs a third signal through the third signal terminal. The sequence circuit is used to ensure the sequence of the first through third signals.

Abstract: Energy saving circuit of a computer is connected between a power supply and a motherboard. The energy saving circuit includes six electronic switches and a switch. When the computer is in the stand-by state, and the switch is pressed, the motherboard of the computer receives a standby voltage and the motherboard maintains the stand-by state. The energy-saving circuit can shut off the standby voltage by pressing the switch when the computer is powered off to save energy.

Abstract: A handheld device includes a backlight driving unit and a power supply circuit for powering the backlight driving unit. The power supply circuit includes a power management unit, a battery, a first electronic switch, a second electronic switch, and a control unit. When a voltage of a second terminal of the second electronic switch is less than a reference voltage of the control unit, the control unit turns on the first electronic switch and turns off the second electronic switch. The backlight driving unit is powered by the battery through the first electronic switch. When the voltage of the second terminal of the second electronic switch is more than the reference voltage of the control unit, the control unit turns off the first electronic switch and turns on the second electronic switch. The backlight driving unit is powered by the PMU through the second electronic switch.