Abstract: A computer system includes a display, a motherboard and a power circuit. The display includes a video interface. The motherboard includes a super input-output (SIO) chip. The power circuit includes a first switch unit, a second switch unit, a third switch unit, and an oscillator. When the display is powered on, the video interface outputs a high level signal, the first switch unit is turned on, a power supply powers the oscillator through the first switch unit. The oscillator operates and outputs a high level signal, the second switch unit is turned on, a power-on signal pin of the SIO chip receives a low level signal, and the motherboard is turned on.

Abstract: A power control device includes a multiple socket-outlet, a power plug and a power supply control circuit. The control circuit includes a power output unit, a first relay and a second relay, a first capacitor, a mechanical switch, an electronic switch and a connector connected to the host of a computer to receive a first voltage. The mechanical switch is turned on to supply power to the multiple socket-outlet, the first relay is closed, the power output unit outputs a working voltage for charging the first capacitor, the electronic switch is turned on, the second relay is closed. If the connector is turned off, the electronic switch is turned off, and the second relay is turned off so that the the multiple socket-outlet is closed.

Abstract: A clip for a basic input/output system (BIOS) chip includes a main body, two clipping elements, and two resilient members. The main body includes a number of connecting pins mounted on the main body, and a number of signal pins mounted on the main body electrically connected to the connecting pins and configured to couple with a programming device. The clipping elements are rotatably mounted to opposite ends of the main body and configured to latch the BIOS chip. The resilient members are mounted between the clipping members and the main body.

Abstract: A user verification method executed in an electronic device stores iris information of a user in a storage device of the electronic device. In response to a user request to access the electronic device, iris information of the user is captured. The captured iris information is compared with the stored iris information. If the captured iris information matches the stored iris information, the user is allowed to access the electronic device.

Abstract: In an alarm control method executed in an electronic device, voice commands are set using a voice capturing device and stored into a storage device. The voice commands are set for controlling an alarm of the electronic device. In event the alarm rings, real-time audio data is captured using the voice capturing device. The voice commands are read from the storage device, and the voice commands are compared with the audio data to determine that at least one voice command matches the audio data. The alarm is controlled according to a matched voice command.

Abstract: A buzzer circuit is connected to a drive circuit. The buzzer circuit includes a buzzer and a control unit. The control unit includes an electronic switch, a first resistor, a second resistor, and a constant voltage component. A control end of the electronic switch is connected to a power pin of the buzzer through the first resistor, and is grounded through the constant voltage component. A first end of the electronic switch is connected to a grounded pin of the buzzer. A second end of the electronic switch is grounded through the second resistor. When the buzzer receives a high level drive signal, the electronic switch is turned on. A voltage between the control end and the second end of the electronic switch is constant, the constant voltage component provides a constant voltage to the second resistor, and a current of the second resistor is constant.

Abstract: A power on circuit is connected between a video graphics array (VGA) connector of a display and a super input output (SIO) chip of a motherboard. The power on circuit includes first to fourth electronic switches and a timer. When a power button of the display is pressed, a serial data line pin of the VGA connector outputs a high level signal to turn on the first electronic switch, the second electronic switch is turned on, the fourth electronic switch is turned on, and the timer outputs a periodic pulse signal. When the pulse signal outputted from the timer is at a high level, the third electronic switch is turned on, the SIO chip receives a low level signal from the fourth and third electronic switches, and the motherboard is turned on.

Abstract: A method for unlocking a display screen of an electronic device includes activating the display screen which is locked of the electronic device when receiving a communication signal from a key, and generating an unlocked icon on the display screen. A request is sent to the key for generating first audio information after the unlocked icon is pressed, and the first audio information of an unlock code is received from the key. When the first audio information is the same as second audio information generated by a decryption algorithm stored in the storage device of the electronic device, the display screen of the electronic device is unlocked.

Abstract: Method of adjusting a brightness of a display device of an electronic device includes obtaining data of a facial feature of a user of the electronic device. The brightness of the display device is adjusted when the brightness of the display device is not suitable for the user, which is determined by comparing the obtained data with preset data of the facial feature.

Abstract: A fastening apparatus for fixing a circuit board includes a bracket. The bracket includes a main plate, two extending plates extending perpendicularly from opposite ends of the main plate, two fixing tabs extending perpendicularly from distal ends of the two extending plates, and two fastening tabs. The main plate and the two extending plates clamp the circuit board, and the two fastening tabs couple the circuit board to the bracket.

Abstract: A buzzer circuit includes an amplifier U, a first electronic switch and a second electronic switch, a first resistor and a second resistor, and a buzzer. The buzzer circuit is coupled to a drive circuit for receiving a drive signal. The first electronic is turned on and when the power pin of the buzzer receives a high level drive signal, the second electronic switch is turned on, and the buzzer buzzes steadily.

Abstract: A buzzer circuit includes a control unit, a constant current unit, and a buzzer. The buzzer circuit is coupled to a drive circuit. The buzzer includes a power pin and a ground pin. The constant current unit includes a constant voltage component and a first resistor. When the power pin of the buzzer receives a high level drive signal, the constant voltage component provides a constant voltage, controlled by the control unit, to the first resistor, and the ground pin is coupled to ground through the first resistor, and the buzzer buzzes steadily.

Abstract: A controlling circuit for a fan includes three comparators, a capacitor, and a thermistor. When the temperature around the thermistor changes, the resistance of the thermistor changes. The comparators control the charging and discharging time of the capacitor, thereby generating a corresponding pulse width modulation signal to the fan according to the temperature, to adjust the speed of the fan.

Abstract: An indicator light control circuit includes a basic input output system (BIOS) integrated circuit (IC), a microcontroller, a signal control unit, an electronic switch, and an indicator light. The microcontroller includes a general purpose input output (GPIO) pin. When different operating options of the indicator light are set into and by the BIOS IC, the BIOS IC controls the GPIO pin of the microcontroller to output command signals, such as a low voltage signal, a high voltage signal and pulse signals, then the signal control unit generates and outputs signals according to the command signals. Thus, the electronic switch is operated to turn on or turn off or to pulse when controlling the operation of the indicator light(s).

Abstract: An all-in-one (AIO) computer with a fixed and simple connection includes a panel, a motherboard, and a connector. The connector includes a male connector and a female connector. The male connector is mounted on the motherboard and the female connector is mounted on the panel. The panel communicates with the motherboard through the connector.

Abstract: An interface detection circuit is used for detecting whether an interface of an electronic device is in good contact with an interface of a connection device. The interface detection circuit includes a pressure sensing module, a signal processing module, and a warning module. The pressure sensing module detects whether the pins of the interface of the electronic device is suffered pressure and transmits the detecting results to the signal processing module. The signal processing module magnifies and calculates the detecting results. The signal processing module outputs a control signal to the warning module. The warning module alerts the user whether the two interfaces make good contact with each other.

Abstract: An alternating current (AC) power cable includes discharge electrodes, a relay, and an electromagnetic coil with two windings. The relay includes an induction coil with two ends. The two ends of the induction coil are respectively connected to two ends of the electromagnetic coil. The discharge electrodes include a first discharge electrode and a second discharge electrode. The first discharge electrode is connected to the neutral wire of the AC power cable. The second discharge electrode is connected to the relay. When the AC power cable has residual charge, current is induced by the electromagnetic in the induction coil. The induction coil converts the current to magnetic force to close the relay. The residual charge is transmitted to the discharge electrodes through the relay.

Abstract: An all in one (AIO) computer implemented as a personal computer (PC) or a display includes a high definition multimedia interface, a speaker, and a speaker control circuit. The speaker control circuit includes an earphone interface circuit, a main controller, a signal processing unit, and a signal control circuit. The earphone interface circuit detects whether an earphone is inserted into the AIO computer. When the earphone interface circuit detects the earphone is connected to the AIO computer, if the AIO computer is implemented as the PC, the main controller sends a first muting signal. If the AIO computer is implemented as the display, the main controller sends a second muting signal, and the signal control circuit controls and mutes the speaker according to the first muting signal and the second muting signal.

Abstract: A linear voltage stabilizing circuit includes a main stabilizing unit, a first resistor, a second resistor, and a sub-stabilizing unit. The main stabilizing unit includes a first transistor connected between a signal input terminal and a signal output terminal, and a first comparator controlling the first transistor. The first and the second resistor are connected between the signal input terminal and ground. The voltage between the first resistor and the second resistor is equal to a first reference voltage. The sub-stabilizing unit includes a third resistor, a fourth resistor, a second transistor connected between the signal input terminal and the first transistor, and a second comparator. The third and fourth resistor are connected between the second comparator and ground. The node of the third and fourth resistor is connected to the node between the first and the second resistor. The second comparator controls the second transistor turn on or off.

Abstract: An indicating circuit for indicating the rotation speed of a fan includes a rotation speed indicating module connected to the fan and receiving rotation speed signals from the fan. The indicating circuit includes a switch and a light emitting element. If the received signal is a high level signal, the switch is turned on, and the light emitting element emits light. If the reeived signal is a low level signal, the switch is turned off, and the light emitting element does not emit light.