Abstract: A fan selection method is provided. The method determines an optimal amount of each type of fan to be used in a cabinet. The optimal amount of each type of fan is determined by an intersection between a fan performance curve and an airflow resistance curve of the cabinet. The model number and optimal amount of each type of fan is output to a user.

Abstract: A cooling system includes a first group of fans, a second group of fans, and an air conducting cover. The air conducting cover includes a first partition, a second partition, a third partition. The first partition is connected between the second partition and the third partition to define a first space, a second space and a third space. Wherein the first group of fans directs air flow to enter the first space and the second space, the second group of fans directs air flow to enter the third space.

Abstract: A card socket assembly includes a card socket and a non-conductive airflow guide member. The card socket includes a main body defining a slot, and two latches rotatably connected to opposite ends of the main body. The airflow guide member includes a main plate and an airflow guide plate. A bottom of the main plate is inserted into the slot of the card socket. Two notches are defined in a first end and a second end of the main plate opposite to the first end, to receive the latches. The airflow guide plate is formed on the first end of the main plate, and includes an airflow guide portion slanted relative to the main plate, to guide airflow away from the card socket.

Abstract: A retaining device includes a support including an uneven base; and at least one flexible latch each including a curved lower portion joining the base, an upward extending intermediate portion, and a curved transverse top. A joining edge of the upward extending intermediate portion of each of the at least one latch and the curved transverse top thereof is offset laterally with respect to a joining edge of the curved lower portion of each of the at least one latch and the base. Expansion and contraction of materials of components to be retained by the retaining device are considered in its design phase.

Abstract: An apparatus for electrical discharge machining modulation control includes an EDM module, an open-circuit voltage modulation module, a reference-voltage modulation and judgment module, a database, and a control unit. The control unit selects a reference voltage, and an open-circuit voltage corresponding to characteristics of a workpiece from the database, and generates and transmits a second control signal to the open-circuit voltage modulation module for modulating the open-circuit voltage, and a third control signal to the reference-voltage modulation and judgment module for modulating the reference voltage utilised to determine if the ignition happened. The open-circuit voltage modulation module receives a first control signal periodically transmitted from the control unit for providing the open-circuit voltage to the EDM module.

Abstract: A container data center includes a container having a raised floor defining a number of vents, a server system including a cabinet supported on the raised floor adjacent to the vents, a cooling device, an adjusting plate movably installed to the cabinet for covering or uncovering the vents, a driving member, a temperature sensor mounted to the cabinet, and a micro control unit (MCU) electrically connected to the driving member and the temperature sensor. The cooling device releases cooling air into the container under the raised floor. The temperature sensor senses the temperature in the cabinet. The MCU receives the sensed temperature and compares the sensed temperature with a preset temperature, to direct the driving member to drive the adjusting plate to move relative to the vents.

Abstract: An electronic device includes a case having a vent defining a plurality of holes. The electronic device further includes an adjusting plate movably mounted on the case and aligning with the vent, and the adjusting plate defines a plurality of holes. A plurality of vent regions are defined on the vent, at least one hollow region and at least one tangible region are defined on the adjusting plate. The adjusting plate is movable relative to the vent such that the plurality of the holes of the adjusting plate aligns with, or the adjusting plate partially blocks or totally blocks, the plurality of holes of the vent.

Abstract: A cooling system includes a first group of fans, a second group of fans, and an air conducting cover. The air conducting cover includes a first partition, a second partition, a third partition. The first partition is connected between the second partition and the third partition to define a first space, a second space and a third space. Wherein the first group of fans directs air flow to enter the first space and the second space, the second group of fans directs air flow to enter the third space.

Abstract: A cooling system is used for cooling a plurality of electronic components received in a casing. The casing defines an air outlet. The cooling system includes at least one fan received in the casing, an air tachometer, and a controller. The air tachometer is arranged adjacent to the air outlet, and is used for measuring an airflow speed of the air outlet. The controller is electrically connected to the at least one fan and the air tachometer, and used for comparing a threshold value with the airflow speed detected by the air tachometer, and controlling a rotating speed of the at least one fan based on the comparing result.

Abstract: A server rack includes a main body, a pair of rails, and a pair of air guiding members. The main body includes two opposite sidewalls, each of which include a first flange defining a number of first through holes and define an air hole. The rails define a channel communicating with the air holes in the main body. Each air guiding member covers the corresponding air hole and includes a second flange that contacts corresponding first flange and defines a number of second through holes. A portion of the second though holes in each second flange and the corresponding first through holes are inserted by fasteners and the other second through holes and the corresponding first through holes without the fasteners inserted are reserved for directing cooling air to the channel via the air guiding members and the air holes.

Abstract: A composite structural element is provided with a hollow spine member of metal or alloy, and a surrounding member of plastic material around the spine member. The spine member includes at least one lengthwise shaped member and at least one lengthwise rib. The structural element can accommodate thermal expansion or contraction to prevent itself from breaking.

Abstract: An electronic device includes a case having a vent defining a plurality of holes. The electronic device further includes an adjusting plate movably mounted on the case and aligning with the vent, and the adjusting plate defines a plurality of holes. A plurality of vent regions are defined on the vent, at least one hollow region and at least one tangible region are defined on the adjusting plate. The adjusting plate is movable relative to the vent such that the plurality of the holes of the adjusting plate aligns with, or the adjusting plate partially blocks or totally blocks, the plurality of holes of the vent.

Abstract: A self-adjusting power device for high efficiency electrical discharge machining and method thereof is disclosed. A high-voltage arc unit and a low-voltage discharge unit provide a high voltage arc pulse and a low voltage discharge pulse to an electrode respectively. The electrode machines a workpiece and feeds back a gap voltage to a discharge pulse generation unit. The discharge pulse generation unit determines whether the gap voltage is lower than a predetermined voltage or not. If yes, a discharge channel between the electrode and the workpiece is conducted, and the discharge pulse generation unit shuts down the high-voltage arc unit and the low-voltage discharge unit is still operating at ON time and shuts down at OFF time. If no, looping the determination of the discharge pulse generation unit. Therefore, discharge machining energy is accurately controlled and high efficient power saving is achieved.

Abstract: A server cabinet includes a rack and an air baffle plate. The rack defines an interior space configured for accommodating a plurality of servers therein. The rack includes a top wall, an opposite bottom wall and two sidewalls respectively connected between left sides of the top and the bottom walls and right sides of the top and the bottom walls. The servers are arranged along a bottom-to-top direction. Each of the servers is fixed between the two sidewalls. A space is defined between a topmost server and the top wall. The air baffle plate is positioned in the space for blocking an airflow on a rear side of the servers from flowing back to a front side of the servers via the space.

Abstract: A server rack includes a main body, a pair of rails, and a pair of air guiding members. The main body includes two opposite sidewalls, each of which include a first flange defining a number of first through holes and define an air hole. The rails define a channel communicating with the air holes in the main body. Each air guiding member covers the corresponding air hole and includes a second flange that contacts corresponding first flange and defines a number of second through holes. A portion of the second though holes in each second flange and the corresponding first through holes are inserted by fasteners and the other second through holes and the corresponding first through holes without the fasteners inserted are reserved for directing cooling air to the channel via the air guiding members and the air holes.

Abstract: A printed circuit board includes a layer. A layer of copper is covered on a surface of the layer. A through hole passes through the printed circuit board. A number of thermal engravings are defined in the layer around the through hole. Each thermal engraving is a groove defined in the surface of the layer, without covered with the layer of copper. The number of thermal engravings are not in contact with each other.

Abstract: A server cabinet includes a rack and an air baffle plate. The rack defines an interior space configured for accommodating a plurality of servers therein. The rack includes a top wall, an opposite bottom wall and two sidewalls respectively connected between left sides of the top and the bottom walls and right sides of the top and the bottom walls. The servers are arranged along a bottom-to-top direction. Each of the servers is fixed between the two sidewalls. A space is defined between a topmost server and the top wall. The air baffle plate is positioned in the space for blocking an airflow on a rear side of the servers from flowing back to a front side of the servers via the space.

Abstract: An electrochemical discharge machining device includes a base, a sensor disposed on the base, a shaft rotatably disposed on the base, an electrode disposed at one end of the shaft and contacting with a work piece, an isolating element disposed between the sensor and the shaft, and a control module connected to the sensor. Current flows to the electrode via the shaft to machine the work piece, and the force exerted on the electrode by the work piece is transmitted via the shaft and the isolating element to the sensor converting the force into a signal sent to the control module for raising or lowering the base to maintain contact between the electrode and the work piece. The sensor serves as a detecting mechanism to ensure appropriate contact between the electrode and the work piece.

Abstract: A common module for a double data rate-synchronous II synchronous dynamic random access memory (DDRII SDRAM) and a DDRIII SDRAM applied in a computer is provided. The common module includes a first bus, a termination circuit card, a first slot, and a second slot. The first bus transmits a plurality of signals. The termination circuit card comprises a plurality of termination resistors. The first slot is disposed on the common module and coupled to the first bus. The DDRII SDRAM is installed in the first slot. The second slot is disposed on the common module and coupled to the first bus. The DDRIII SDRAM or the termination circuit card is installed in the second slot. When the DDRII SDRAM is installed in the first slot, the termination circuit card is installed in the second slot.

Abstract: A method for detecting and compensating electrode wear of electric discharge machining (EDM) is disclosed, which comprises the steps of: defining a calibration node; calculating a wear length of a tool electrode by an edge-finding algorithm; using the calculated wear length of the tool electrode as a cut compensation for compensating a machining depth of next new tool electrode replacing the previously machined tool electrode; whereas the machining depth is obtained according to the following formula: the machining depth=designed depth of cut+predicted wear of the tool electrode for machining to desire depth?calculated wear length of the previously machined tool electrode+a through hole offset. With the aforesaid method, the wear of an used tool electrode can be detected automatically for compensating the machining depth of an unused tool electrode without ant additional equipment while achieving accurate machining.