Abstract: A circuit for providing a dummy load includes first to fifth resistors, a comparator, and first to fifth electronic switches. When a power good signal from a power supply is at a low level signal, the first electronic switch is turned off. The second to fourth electronic switches are turned on. The fifth electronic switch is turned off. When the power good signal from the power supply is at a high level signal, the first electronic switch is turned on. The second to fourth electronic switches are turned off. The fifth electronic switch is turned off.

Abstract: A power supply system includes a power supply unit (PSU) and a motherboard. The PSU includes a control chip. The motherboard includes a voltage regulator, a first resistor, and a second resistor. The voltage regulator includes an input terminal coupled to the PSU to receive a first voltage, and an output terminal outputting a second voltage regulated from the first voltage by the voltage regulator. The output terminal of the voltage regulator is grounded through the first resistor and the second resistor. A node between the first and second resistors functions as a feedback point and is coupled to the control chip. The control chip fine-tunes the first voltage according to a voltage fed back from the feedback point, to make the output terminal of the voltage regulator steadily output the second voltage.

Abstract: An inductor protection device includes a single chip microcomputer (SCM) and an input unit. The protection device is used for protecting an inductor in a circuit, the circuit includes a controller configured for triggering on or cutting off the circuit. The SCM sets a limiting voltage according to parameters input from the input unit, obtains a current voltage of the inductor, compares the current voltage with the limiting voltage, and sends a control signal to the controller to cut off the circuit when the current voltage is bigger than or equal to the limiting voltage.

Abstract: A control circuit for controlling a soft-start time of a DC power supply includes a digital potentiometer, a first drive circuit, and a controller. The digital potentiometer includes a first potentiometer. The first drive circuit includes a first driver, a first MOSFET, and a first charge capacitor. The first driver charges the first charge capacitor via the first potentiometer when the DC power supply is first switched on, and the first MOSFET is switched on to connect the DC power supply to the load when the first charge capacitor is fully charged. The controller regulates resistance of the first potentiometer to regulate a charge time constant of the first charge capacitor, enabling a gradual rise in voltage supplied, from approximately zero to full power, within a desired period of time.

Abstract: A power adapter includes a processing circuit converting mains power to another alternating current (AC) power or a direct current (DC) power, a first output outputting the converted AC or DC power, a sense resistor connected between the processing circuit and the first output for sampling current flowing through the first output and converting the sampled current to a sampled voltage, an amplifying circuit connected to the sense resistor for amplifying the sampled voltage, and a metallic oxide semiconductor field effect transistor (MOSFET). A gate of the MOSFET is connected to the amplifying circuit. A drain of the MOSFET is connected to the first output through a first resistor and grounded through a second resistor. A source of the MOSFET is grounded. A node between the first and second resistors is connected to the processing circuit. The amplifying circuit makes the MOSFET work in a variable resistance region.

Abstract: A motherboard includes a central processing unit (CPU), a drive, and a voltage-state display system to display a voltage mode of the CPU. The voltage-state display system includes a power management chip, a first transistor, a second transistor, a first light emitting diode (LED), and a second LED. A first phase output terminal of the power management chip is connected to the first LED through the first transistor. A second phase output terminal of the power management chip is connected to the second LED through the second transistor. The LEDs indicate the voltage mode of the CPU.

Abstract: A circuit for providing a dummy load includes first to fifth resistors, a comparator, and first to fifth electronic switches. When a power good signal from a power supply is at a low level signal, the first electronic switch is turned off. The second to fourth electronic switches are turned on. The fifth electronic switch is turned off. When the power good signal from the power supply is at a high level signal, the first electronic switch is turned on. The second to fourth electronic switches are turned off. The fifth electronic switch is turned off.

Abstract: A control circuit for controlling a soft-start time of a DC power supply includes a digital potentiometer, a first drive circuit, and a controller. The digital potentiometer includes a first potentiometer. The first drive circuit includes a first driver, a first MOSFET, and a first charge capacitor. The first driver charges the first charge capacitor via the first potentiometer when the DC power supply is first switched on, and the first MOSFET is switched on to connect the DC power supply to the load when the first charge capacitor is fully charged. The controller regulates resistance of the first potentiometer to regulate a charge time constant of the first charge capacitor, enabling a gradual rise in voltage supplied, from approximately zero to full power, within a desired period of time.

Abstract: A protection circuit includes first and second field-effect transistors (FETs), a bipolar junction transistor, first to sixth resistors, and a first capacitor. The protecting circuit is connected between a power supply unit and a fan, for powering on or powering off the fan.

Abstract: An electronic device with an overclocking mode includes a processor, a memory storing a first range and a second range, and a digital controller which includes a first register, a second register, a monitor module, a determining module, a first writing module, an implementing module, and a second writing module. The monitor module monitors a value of current of the processor. The determining module determines whether the current is within the first range. The first writing module writes the current value in the first register. The implementing module reduces a value from the current value to acquire a new current value. The second writing module writes the new current value in the second register. The processor reads the new current value, detects whether the new current value is within the second range, and keeps itself in the overclocking mode when the new current value is within the second range.

Abstract: A motherboard includes a central processing unit (CPU), a drive, and a voltage-state display system to display a voltage mode of the CPU. The voltage-state display system includes a power management chip, a first transistor, a second transistor, a first light emitting diode (LED), and a second LED. A first phase output terminal of the power management chip is connected to the first LED through the first transistor. A second phase output terminal of the power management chip is connected to the second LED through the second transistor. The LEDs indicate the voltage mode of the CPU.

Abstract: An exemplary voltage testing device includes a testing circuit and an oscillograph. The testing circuit includes a filtering unit, a rectifier unit, and a voltage dividing unit. The filtering unit receives and filters an alternating current (AC) voltage. The rectifier unit receives the filtered AC voltage and rectifies the filtered AC voltage into a first direct current (DC) voltage. The voltage dividing unit receives the first DC voltage, and dividess the first DC voltage into a second DC voltage equaling an effective value of the AC voltage, thereby the second DC voltage is tested and displayed on the oscillograph.

Abstract: A voltage adjustment circuit includes a programmable resistor, a keyboard, and a microprocessor control unit (MCU). The programmable resistor includes an input connected to a first power supply to receive a first voltage. The MCU is connected to the keyboard and the programmable resistor. A preset voltage is set through the keyboard. The MCU adjusts a resistance of the programmable resistor according to the preset voltage, such that the programmable resistor outputs a second voltage.

Abstract: A power adapter includes a processing circuit converting mains power to another alternating current (AC) power or a direct current (DC) power, a first output outputting the converted AC or DC power, a sense resistor connected between the processing circuit and the first output for sampling current flowing through the first output and converting the sampled current to a sampled voltage, an amplifying circuit connected to the sense resistor for amplifying the sampled voltage, and a metallic oxide semiconductor field effect transistor (MOSFET). A gate of the MOSFET is connected to the amplifying circuit. A drain of the MOSFET is connected to the first output through a first resistor and grounded through a second resistor. A source of the MOSFET is grounded. A node between the first and second resistors is connected to the processing circuit. The amplifying circuit makes the MOSFET work in a variable resistance region.

Abstract: A control circuit for a power supply of a memory includes a power controller, a keyboard, and a processing circuit. The power controller is connected to the power supply. The keyboard sets working mode of the power supply and a voltage output from the power supply. The processing circuit is connected to the power controller and the keyboard. The processing circuit processes instructions input from the keyboard such that the working mode of the power supply and the voltage output from the power supply can be set through the keyboard.