Abstract: A printed circuit board includes a power layer, a ground layer, a signal layer, and a backboard. The backboard is arranged below the signal layer opposite to the ground layer. A number of vias are formed from the backboard through the signal layer, and then connected to the ground layer.

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 fan rotation speed test device connected to a computer includes an information processing chip, an indicating unit, and an interface. The interface is compatible with a memory socket on a mainboard of the computer. The computer transfers control instructions to the information processing chip via the interface. After receiving the control instructions, the information processing chip outputs PWM signals by executing programs therein to modulate the rotation speed of a fan. The information processing chip collects rotation speed signals of the fan, then judges if the rotation speed of the fan is according to a predetermined standard by executing arithmetic programs. The information processing chip outputs test result signals to the indicating unit for display.

Abstract: A linear voltage regulator circuit includes first and second voltage input terminals to receive a first or second external voltage, a voltage output terminal, a voltage regulator unit, a voltage switch unit, and a voltage detecting unit. The voltage regulator unit selectively receives the first or second external voltage controlled by the voltage switch unit. The voltage detecting unit outputs a first control signal to control the voltage switch unit to output the first external voltage to the voltage regulator unit, in response to an output voltage of the voltage output terminal being less than or equal to a predetermined value. The voltage detecting unit outputs a second control signal to control the voltage switch unit to output the second external voltage to the voltage regulator unit in response to the output voltage being greater than the predetermined value.

Abstract: A fan speed control circuit includes a voltage input terminal, a thyristor, a thermistor, and first and second switches. The terminal is grounded through a first resistor and the thermistor, connected to an anode of the thyristor, and connected to a second terminal of the second switch through a second resistor. A node between the resistor and the thermistor is connected to a control terminal of the first switch. A second terminal of the first switch is grounded. A first terminal of the first switch is connected to a control terminal of the thyristor through a third resistor. A fourth resistor is connected between the anode and control terminal of the thyristor. A control terminal of the second switch is connected to the control terminal of the thyristor. A first terminal of the second switch is connected to a cathode of the thyristor and a voltage pin of a fan.

Abstract: A fan control circuit includes an integrated circuit (IC), a thermistor, and a transistor. A first input of the IC is connected to a fan power supply. A second input of the IC is connected to a stand-by power supply. A base of the transistor is grounded through the thermistor. An emitter of the transistor is connected to an output of the IC. A collector of the transistor is connected to a fan.

Abstract: A system and method validates design of an electronic product using a computing device. The method establishes design failure data and product failure data of the electronic product in a database. When the design of the electronic product is finished, the method determines whether the design is eligible by examining design modules of the design according to the design failure data in the database. When the design is eligible, the method determines whether the validation of actual samples of the electronic device is successful by validating actual samples of the electronic product according to the product failure data in the database. If the validation of the actual samples is successful, the method acquires abnormal data of executing the actual samples, and updates failure data converted from the abnormal data into the database, if the abnormal data has been acquired.

Abstract: An electrical connector assembly includes a male connector and a female connector for connectable to the male connector. The male connector includes a male insulating housing and a number of first terminals assembled on the male insulating housing. An anti-mistake insertion bulge extends from the top surface of the male insulating housing. 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. An anti-mistake insertion gap is defined in the top surface of the female insulating housing. Two cutouts are defined in two opposite sidewalls bounding the anti-mistake insertion gap to hold the anti-mistake insertion bulge.

Abstract: A fan control system includes a temperature detecting circuit and a rotation rate control circuit. The detecting circuit includes a first amplifier, a second amplifier, and a thermistor. The rotation rate control circuit includes a first terminal, a second terminal, and a third terminal. The detecting circuit detects temperature and outputs a voltage signal. The rotation rate control circuit receives the voltage signal and controls the rotation rate of the fan according to the voltage signal.

Abstract: A fan control system includes a temperature detecting circuit and a rotation rate control circuit. The detecting circuit includes a first amplifier, a second amplifier, and a thermistor. The rotation rate control circuit includes a first terminal, a second terminal, and a third terminal. The detecting circuit detects temperature and outputs a voltage signal. The rotation rate control circuit receives the voltage signal and controls the rotation rate of the fan according to the voltage signal.

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.

Abstract: A voltage testing circuit includes a voltage input terminal, an LED, a first reference resistor, a transistor, a current-limiting resistor, a second reference resistor, and a 3-terminal adjustable regulator. The transistor includes an emitter, a base connected to the voltage input terminal through the first reference resistor, and a collector connected to the voltage input terminal. The current-limiting resistor is connected between the emitter and an anode of the LED. The second reference resistor is connected between the voltage input terminal and ground. The 3-terminal adjustable regulator includes a positive terminal grounded, a negative terminal connected to a cathode of the LED, and a controlling terminal connected to the voltage input terminal through the second reference resistor. The LED emits light according to voltage of the voltage input terminal.

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: 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: A connecting device for connecting pins of a DIP chip to a test device comprises two each of half frames, columns of testing pins, connecting screws, fixing screws, and four holding plates. The two columns of testing pins are arranged respectively on the two half frames parallel to the lengthways direction of the half frame. The distance between two adjacent testing pins in the same column is equal to that between the two adjacent pins in the same column of the DIP chip. The two connecting screws screw into the half frames perpendicular to the lengthways direction of the half frame. Two of the holding plates extend down from each of the half frames and are aligned with short sides of the corresponding half frame. The fixing screws fix the two holding plates on the same half frame along a direction parallel to the lengthways direction of the half frame.

Abstract: A computer includes a display assembly, a base, a stand, and a keyboard. The base includes a supporting board and an engaging board. The stand is located on the base supporting the display assembly. The keyboard includes a main body and an extension board extending from the main body. The main body has a key area. The extension board is fixed to the engaging board to help stabilize the display assembly.

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 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: 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 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.