Abstract: In a method for transmitting data between a host computer and a slave device, the host computer connects to a slave device through a data communication port. The slave device is equipped with a power supply that includes at least one capacitor. The power supply is charged through the host computer using the capacitor when the host computer is powered on. The method controls the host computer sends data to the slave device, and controls the capacitor to discharge to provide power to the slave device for a period of time when the host computer is powered off, and stores the data packet into the slave device during the period of time. The method further retrieves the data from the storage device when the host computer is powered on, and resends the data to the slave device through the data communication port.

Abstract: An enclosure of an electronic device includes a plate. The plate defines a number of through holes. A number of shields extend from the plate corresponding to the through holes. Each shield extends outwards from the outer surface of the plate, surrounding and partly covering a corresponding through hole. The enclosure with the shields can shield the electronic device from EMI.

Abstract: A computing device reads a printed circuit board (PCB) layout file from a storage device. The PCB layout file includes arrangement information of signal lines, power lines, and power through-holes arranged on a PCB. Furthermore, the computing device sets a reference distance between a selected power through-hole and a neighboring signal line, and searches for one or more line segments of one or more signal lines where the a distance between each of the one or more line segment and the selected power through-hole is less than the reference distance.

Abstract: A printed circuit board includes a signal layer and a reference layer. The signal layer is covered with copper foil. A circuit topology for multiple loads is set on the signal layer. The circuit topology includes a driving terminal, a first signal receiving terminal, and a second signal receiving terminal. The driving terminal is connected to a node through a first transmission line. The node is connected to the first and second signal receiving terminals respectively through a second and a third transmission lines. A difference between lengths of the second and third transmission lines is greater than a product of a transmission speed and a rise time of signals from the driving terminal. The reference layer is covered with copper foil, and arranged under the signal layer. A region without copper foil is formed on the reference layer, under the second transmission line.

Abstract: A circuit topology for multiple loads includes a driving terminal, first and second signal receiving terminals, and a capacitor. The driving terminal is connected to a node through a first transmission line. The node is connected to the first and second signal receiving terminals through second and third transmission lines. The second transmission line is longer than the third transmission line, and a difference between lengths of the second and third transmission lines is greater than a product of a transmission speed and a rise time of signals from the driving terminal. A first terminal of the capacitor is connected to the third transmission line. A second terminal of the capacitor is grounded. A distance between the capacitor and the second signal receiving terminal is less than a distance between the capacitor and the node.

Abstract: A signal transmission apparatus includes two circuit layers. First and second ground sheets are arranged in the two circuit layers respectively. A third ground sheet is arranged between the two circuit layers. A differential pair includes a transmission line arranged between the first and third ground sheets and a transmission line arranged between the second and third ground sheets. The first to third ground sheets have same electric potential. Projections of the first and second ground sheets on the third ground sheet superpose a border of the third ground sheet. The third ground sheet is formed by extending the border along a signal transmission direction. A vertical distance between the first and second transmission lines is twice as each of a vertical distance from the first ground sheet to the first transmission line and a vertical distance from the second ground sheet to the second transmission line.

Abstract: A printed circuit board (PCB) includes two layers, two signal transmission traces, and a vertical interconnect access (via). The signal transmission traces are respectively arranged on the layers. The signal transmission traces are electrically connected to each other through the via. A centerline of the via with a vertical line of the layers form an acute angle ?, the angle ? is less than cos?1[(Lv2?Lt2)/(Lv2+Lt2)]. Wherein Lt is loss of the two signal transmitting traces in a unit length, and Lv is loss of the via in a unit length.

Abstract: In a method for testing integrity of signals transmitted from hard disk interfaces using a computing device, the computing device connects to an oscilloscope and a mechanical arm that is equipped with a test fixture. The mechanical arm controls the test fixture to make contact with one of the hard disk interfaces to be tested. The method adjusts an intensity grade of the signals through the hard disk interface, and controls the hard disk interface to produce a signal corresponding to the adjusted intensity grade. The test fixture obtains the signal from the hard disk interface, and the oscilloscope measures one or more test parameters of the signal. The method analyzes values of the test parameters to find an optimal signal, determines an intensity grade of the optimal signal as a driving parameter of the hard disk interface, and generates a test report of the hard disk interfaces.

Abstract: Parameters of a radio frequency filter can be changed by changing structure of each component of the filter. Material of each component, diameters of each of magnetic cylinders, density of each of conductive coils, thickness of a dielectric layer, and thickness of an insulation tube can be changed. When any component needs to be replaced, each cover is rotated, with connection partitions move to two slots of an insulation portion, to detach the filter.

Abstract: A printed circuit board includes a first to a fifth connector pads, a first to an eighth coupling capacitor pads, a first to a tenth transmission lines, a first via and a second via, a first to a fourth sharing pads, and a voltage converting circuit. The printed circuit board is operable to selectively support different types of connectors.

Abstract: In an electronic device and method of protecting software, a software program of the electronic device is invoked. The media access control (MAC) address of the electronic device and a serial number of a hard disk drive that stores the software program in the electronic device are searched. The MAC address and the serial number are compared with MAC addresses and serial numbers included in the software program, to determinate whether it is licensed to run the software program in the electronic device. Usage logs of the software program are further obtained to determine whether running of the software program in the electronic device is expired.

Abstract: In a method for testing serial attached SCSI (SAS) ports of a server using a computing device, the computing device connects to an oscilloscope and a mechanical arm that is equipped with a test fixture having a probe. The mechanical arm controls the probe to be plugged into one of the SAS ports. The method adjusts an intensity grade of the SAS signals through the SAS port, and controls the SAS port to generate a SAS signal corresponding to the intensity grade. The test fixture obtains the SAS signal from the SAS port, and the oscilloscope measures test parameters of the SAS signal. The method analyzes values of the test parameters to find an optimal SAS signal, determines an intensity grade of the optimal SAS signal as a driving parameter of the SAS port, and accordingly generates a test report of the SAS ports.

Abstract: A robot arm includes a circular rack, an elongated first mounting member attached to the rack, and a second mounting member attached to the first mounting member. The first mounting member extends in a radius direction of the rack and moves in a circular trace along the rack. The second mounting member slides relative to the first mounting member along the radius direction, thereby defining a polar coordinate system in a plane defined by the rack to allow the second mounting member to flexibly locate at any desired positions in the plane.

Abstract: In a method for analyzing integrality of serial attached SCSI (SAS) signals using a computing device, the computing device connects to a signal measuring device and an electronic device. A group of test parameters, an intensity grade of a SAS signal, and a total number are set for evaluating integrality of the SAS signal. The intensity grade of the SAS signal is adjusted through an SAS interface of the electronic device. The signal measuring device measures test parameters of the SAS signal, and a test number is recorded when the test parameters of the SAS are measured. The method analyzes the integrality of the SAS signal to find an optimal SAS signal when the test number equals the total number, and determines an intensity grade of the optimal SAS signal as a driving parameter of the SAS interface.

Abstract: A computing device and a method reads design standards of signal transmission lines in a printed circuit board (PCB) layout file, and determines a minimum reference length of line segments of the signal transmission lines from the design standards. The device and method then selects a signal transmission line from a circuit board, and computes an actual length of each line segment of the selected signal transmission line. If each actual length is more than or equal to the minimum reference length, the device and method determines length design of the selected signal transmission line satisfies the design standards. Otherwise, if any actual length is less than the minimum reference length, the device and method determines the length design of the signal transmission line does not satisfy the design standards.

Abstract: A printed circuit board includes first and second layout layers, first and second components, and a pair of connecting portions. The first layout layer includes a pair of first conducting portions connected to a control chip. The second layout layer includes pairs of second to fourth conducting portions. The connecting portions connect the first and third conducting portions together. When an electronic device is connected to the second conducting portions, and the first and second components are connected to the third and fourth conducting portions to form a first route, signals generated by the control chip are transmitted to the electronic device through the first route. When the electronic device is connected to the fourth conducting portions, and the first and second components are connected to the second and third conducting portions to form a second route, the signals are transmitted to the electronic device through the second route.

Abstract: In a method for checking layout of a printed circuit board (PCB) using an electronic device, a signal line is selected from a layout diagram of the PCB. The method searches for signal lines which have an acute angle when deviating from a straight line in the layout diagram of the PCB. The method further locates attribute data of the searched signal lines in the layout diagram of the PCB, and displays the attribute data of the searched signal lines on a display device of the electronic device.

Abstract: A serial advanced technology attachment (SATA) DIMM includes a board body. A control chip is arranged on the board body. An extending board extends from an end of the board body. A first edge connector is set on the extending board. A second edge connector is set on a bottom side of the board body. The first edge connector includes a number of signal pins connected to the control chip, and a number of ground pins.

Abstract: In a method for inspecting the layout of a printed circuit board (PCB), a component to be checked is determined from an electronic layout diagram of the PCB, and a power transmission line which may be serving that component is selected. The layout diagram is checked to determine whether the component is connected to the power transmission line, and further checked to determine whether more than one ground pins of the component is connected to the power transmission line. Vias that are shared by two or more ground pins of the component are determined if more than one ground pin is connected to the power transmission line. Shared vias are marked on the layout diagram.

Abstract: Parameters of a radio frequency filter can be changed by changing structure of each component of the filter. Material of each component, diameters of each of magnetic cylinders, density of each of conductive coils, thickness of a dielectric layer, and thickness of an insulation tube can be changed. When any component needs to be replaced, each cover is rotated, with connection partitions move to two slots of a resisting portion, to detach the filter.