摘要:
A circuit board includes a current balancing unit that receives a number of current values from ammeters. A minimum current value between the current values is determined by the current balancing unit. Resistance of one or more variable resistors of the current balancing unit is adjusted by the current balancing unit to make the current value from one or more the ammeters serially connected to the one or more the variable resistors to be substantially equal to the minimum current value.
摘要:
A testing apparatus is for testing products on an assembly line and includes a worktable, a positioning device, and a testing member. The worktable includes a number of wheels pivotably attached to a bottom thereof, and a number of retractable feet attached to the bottom thereof. The positioning device is attached to the worktable and includes a number of clamping members to position a product to be test. The testing member is attached to the worktable and operated by a control box to move a robot arm with a testing head to test the product.
摘要:
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.
摘要:
A system and method generates a test file of a print circuit board (PCB). The system and method loads trace information of the PCB into a storage system of a test computer, searches the storage system for the trace information matching keywords received and selects traces to test from the searched results. The system and method further acquires length and test points of each selected trace, and sets test parameters of each test item. In addition, the system and method generates a test file of the PCB according to the test parameters, the length, and the test points of each selected trace.
摘要:
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 θ, the angle θ 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.
摘要:
A clamping mechanism for holding a workpiece includes an end executor, a driving member, and a contact member detachably mounted on the end executor. The end executor includes a plurality of claws arranged in matrix. The contact member includes a mounting board and a plurality of contact sleeves corresponding to the claws. The driving member is capable of driving the mounting board, moving the contact sleeves to extend the claws, and hold the workpiece.
摘要:
A computer motherboard includes a printed circuit board which includes a central processing unit (CPU) socket and a group of memory slots. The group of memory slots includes an in-line type memory slot and a surface mounted device (SMD) type memory slot. The in-line type memory slot includes a number of plated through holes. The SMD type memory slot is set between the in-line type memory slot and the CPU socket. The through holes of the in-line type memory slot are connected to the CPU socket through traces, pads of the SMD type memory slot are connected to corresponding through holes of the in-line type memory slot having the same pin definition.
摘要:
The REVERSING TRANSMISSION includes a shaft, a retainer, a spacing collar, a plurality of reversing members, two gears and two covers. The holder is sleeved on the shaft with spaced sliding notches formed thereon. The spacing collar is mounted on an outer surface of the retainer. The reversing members each includes two spaced swing plates with two reversed spiral teeth dented on two diagonal half surfaces of the two spaced swing plate. The reversing members slide into the sliding notches of the holder with two swing plates distributed at different side of the spacing collar. Each of the gears has a group of spiral teeth formed on the inner side for engaging with the group of spiral teeth of the reversing members, and cogs formed on the outer circumference surface. The covers are mounted on two opposite ends of the holder to keep the reversing member in position.
摘要:
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 moving to two slots of an insulation portion, to detach the filter.
摘要:
An apparatus for adjusting a differential probe includes a regulator arranged therein capable of adjusting a distance between two tips of the probe. The probe is supported on the apparatus. The apparatus includes a rotatable shaft and a rotatable disk. The rotatable shaft engages with the regulator of the probe. The rotatable disk is mounted surrounding the rotatable shaft and rotatable together with the rotatable shaft. An angular ruler or a radian ruler is described on an outer surface of the rotatable disk to indicate a rotation angle or a rotation radian of the rotatable shaft, therefore the distance between the two tips of the probe are accurately adjusted.