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 voltage measuring circuit includes a voltage measuring port, a voltage reference unit, a first voltage comparing unit and a light emitting diode. The voltage measuring port is for receiving an external voltage to be measured. The voltage reference unit includes a port providing a reference voltage. The first voltage comparing unit includes a reference port connected to the voltage reference unit, a measuring port connected to the voltage measuring port, and an output port for outputting a high/low level voltage when the external voltage is lower/higher than the reference voltage. The light emitting diode includes a cathode connected to the output port of the first voltage comparing unit and an anode connected to an external voltage port.

Abstract: A protection circuit includes a coding chip, a digital-to-analog converter (DAC), and a control circuit. The coding chip receives parallel voltage identification definition (PVID) signals or serial voltage identification definition (SVID) signals from a central processing unit (CPU), and converts the PVID signals or the SVID signals to voltage identification definition (VID) signals. The DAC receives the VID signals from the coding chip, and converts the VID signals to an analog voltage. The control circuit receives the analog voltage from the DAC and a voltage received by the CPU, and compares the analog voltage from the DAC with the voltage received by the CPU. When the voltage received by the CPU is greater than the analog voltage from the DAC, the control circuit disconnects the CPU from a first power supply.

Abstract: A voltage stabilizing circuit including an input port, an output port, a transistor, a diode, a three-terminal voltage regulating reference source, a first resistor, and a second resistor. The transistor has a collector terminal and an emitter terminal connected to the input port and the output port, respectively. The diode has an anode connected to the input port and a base terminal of the transistor. The three-terminal voltage regulating reference source has an anode connected to ground, a cathode connected to the input port and a cathode of the diode, and a reference terminal The first resistor is connected between the cathode of the diode and the reference terminal of the three-terminal voltage regulating reference source. The second resistor is connected between ground and the reference terminal of the three-terminal voltage regulating reference source.

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: A voltage detection circuit used to detect a voltage source includes a Zener diode, a thyristor, a first resistor, a second resistor, a first light-emitting diode (LED), and a second LED. A cathode of the Zener diode is connected to the voltage source. An anode of the Zener diode is connected to a control terminal of the thyristor through a first resistor. An anode of the thyristor is connected to the voltage source through a second resistor. The anode of the thyristor is connected to an anode of the first LED. A cathode of the thyristor is connected to a cathode of the first LED. The cathode of the thyristor is connected to an anode of the second LED, and a cathode of the second LED is grounded.

Abstract: A socket connector packaging includes a main body and a cover. The main body includes a first sidewall and a pivot positioned on the first sidewall. The cover includes a second sidewall, a coupling portion and a stop portion. The coupling portion and the stop portion are positioned on the second sidewall and opposite to each other. The pivot is placed over the coupling portion, thereby making the cover to be rotatable relative to the main body through the pivot. The stop portion is configured for preventing the cover from further rotating when the pivot contacts with the stop portion.

Abstract: An input system for a host computer includes an input module, a processing unit, and a receiver unit. The input module outputs a first data signal including a key signal corresponding to a key matrix unit, a sensing signal corresponding to a touch sensor, and an operation signals corresponding to first and second buttons. The processing unit is configured to identify the button signal, the sensing signal, and the operation signal, and transmits operation information about the host computer to the receiver unit to be operated by a host computer.

Abstract: A wireless input module includes a wireless keyboard and a mouse. The wireless keyboard includes a processor, and a wireless module, the wireless module is electronically connected to the processor. The mouse is electronically connected to the processor. The processor is operable to receive input signals from the wireless keyboard and the mouse and allow the wireless module to transmit the input signals to an external host.

Abstract: A customizable alarm system includes a graphic user interface (GUI), a central processing unit (CPU) to set a predetermined range of a first electronic element through the GUI, an embedded controller (EC) to store the predetermined range of the first electronic element, and an audio chip. The EC obtains an actual value of the first electronic element, and determines whether the actual value of the first electronic element is within the predetermined range. The EC generates an audio code in response to the actual value not being within the predetermined range. The audio chip receives the audio code, and chooses a corresponding audio file from a plurality of audio files stored in the audio chip. A speaker plays the audio file.

Abstract: A layout method for the creation of a differential pair for the transmission of signals generates a differential pair between a differential signal sender and a differential signal receiver in a layout of a PCB. Differential signals are transmitted via two wires. A plurality of vertical lines are created on the differential pair. Junctions of the vertical lines and the two wires are defined as pairs of points. A first length between one terminal of the differential signal sender and one point of each pair of points and a second length between the other terminal of the differential signal sender and the other point of each pair of points are calculated. If any difference between the first length and the second length does not fall within an allowable range, the lengths of the two wires are adjusted.

Abstract: An electrical connector assembly includes a male connector and a female connector connectable to the male connector. The male connector includes a male insulating housing and a number of first terminals assembled in the male insulating housing. a protrusion extends up from the top surface of the male insulating housing. The protrusion forms an ejecting surface at a rear side of the protrusion. The female connector includes a female insulating housing and a number of second terminals assembled to the female insulating housing for connecting with the first terminals. a fastening hole is defined in the top surface of the female insulating housing to hold the protrusion therein. The ejecting surface of the protrusion of the male connector is substantially arc-shaped or inclined.

Abstract: A temperature monitoring circuit includes a negative temperature coefficient (NTC) resistor, a zener diode, an alarm, a silicon controlled rectifier. A first terminal of the NTC resistor is connected to a power supply through a first resistor. A second terminal of the NTC resistor is grounded. A cathode of the zener diode is connected to a node between the NTC resistor and the first resistor. An anode is grounded through a second resistor. A first terminal of the alarm is connected to the cathode of the zener diode, and is grounded through a third and fourth resistors in series. A cathode of the silicon controlled rectifier is connected to the anode of the zener diode. An anode of the silicon controlled rectifier is connected to a second terminal of the alarm. A control terminal of the silicon controlled rectifier is connected to a node between the third and fourth resistors.

Abstract: A driver device includes a circuit board, a number of sockets, a number of driver chips, a control switch, and a signal output element. The sockets are positioned on the circuit board. Each driver chip is received in and electrically connected to a corresponding socket. The control switch includes a number of switches. An input of each switch is electrically connected to a corresponding socket. An output of each switch is electrically connected to the computer motherboard through the signal output element.

Abstract: An auto-shut off circuit includes a relay, a voltage conversion device, a first diode, a second diode, a third diode, a capacitor, a first transistor, and a second transistor. The relay includes a coil and a switch. The auto-shut off circuit disconnects an electronic device from a power supply when the electronic device is not at a working state.

Abstract: A measuring system executable by a computer for measuring a PCB is provided. A layout information obtaining module obtains layout information of the PCB. A parameter setting interface display module display a parameter setting interface on a display screen. A measuring parameter setting module determines customized parameters in response to an operator's operation on a parameter setting button provided by the parameter setting interface. A measurement analyzing module obtains the customized parameters and measures the widths of the selected traces, determines whether the measured widths matches with the width parameters. A measuring result obtaining module obtains a measuring result provided by the measurement analyzing module, and identifying the traces of which the measured widths do not match with the width parameters associated therewith. A related method is also provided.

Abstract: A circuit is for checking the voltage of a battery. The circuit includes a regulator component, a pnp type transistor, an npn transistor, a diode, and an alarm. The circuit activates an alarm when the voltage of the battery is less than a preset value.

Abstract: A fan speed control circuit for controlling the rotation speed of a fan motor unit. The speed control circuit includes a resistor, a voltage stabilizing unit, a transistor and a thermal resistor. The resistor is connected to a power source of the fan motor unit, the voltage stabilizing unit is connected between the resistor and ground. The collector of the transistor is connected to the fan motor unit, the base is connected to a node between the resistor and the voltage stabilizing unit. The thermal resistor is connected between an emitter of the transistor and ground.

Abstract: The temperature control circuit, to keep a temperature of an enclosed space within a temperature range, comprises a cooling unit to keep the temperature of the enclosed space below a maximum temperature of the temperature range, a heating unit to keep the temperature of the enclosed space above the minimum temperature of the temperature range, and an indicating unit to indicate whether the temperature is within the temperature range.

Abstract: A socket connector includes a main body, a fastener for locking an electric element on the main body, and a cover. The fastener includes a fixed plate defining a through hole. The fixed plate includes two opposite inner sidewalls. A first slide rail protrudes inward from one inner sidewall, and a second slide rail protrudes inward from the other inner sidewall. The cover includes two blocks. Each of the blocks includes an L-shaped main portion and a stop portion connected to L-shaped main portion. The L-shaped main portion and the stop portion of each block cooperatively define a slide groove. The first rail and the second rail slide into the slide grooves, respectively, and are stopped by the corresponding stop portions, such that the cover is detachably positioned on the fixed plate.