Abstract: A three-dimensional wound core open dry-type transformer coil structure and a winding method therefor. The three-dimensional wound core open dry-type transformer coil structure comprises a three-dimensional wound core, an insulating cylinder disposed outside the three-dimensional wound core, and a coil winding wound onto the insulating cylinder. The coil winding is formed by winding insulating wires; comb-shaped supporting bars are uniformly disposed outside the insulating cylinder; the insulating wires are wound between racks of the comb-shaped supporting bars; coil taps are connected to the coil winding; the coil taps are led out onto a surface of the coil winding; a head end of the coil winding and a part of the coil winding leading out the coil taps are wound into a forward and reverse hybrid coil; and the remaining parts are wound into a fully forward coil.

Abstract: A transformer three-dimensional wound core low-voltage lead structure is provided comprising a three-dimensional wound core formed of three rectangular single frames, and three phase windings. The wound core comprises three core posts and an upper yoke and a lower yoke, the upper and lower yokes being triangular structures. The three phase windings are arranged on the three core posts, each phase winding comprising an internal low-voltage and high-voltage winding. The head end and the tail end of each phase low-voltage winding are respectively connected to a lead-out line, and the lead-out lines are located in a triangular structure region of the upper and lower yoke, and a low-voltage bushing step-up module is provided above the wound core, three low-voltage bushings are provided on the low-voltage bushing step-up module, and the three low-voltage bushings are connected to the lead-out line of the corresponding low-voltage winding.

Abstract: A stereoscopic transformer wound core having isosceles triangle yokes is provided, comprising three core limbs and six yokes. The three core limbs and the six yokes are formed by the assembly of three rectangular single frames. The sizes and shapes of two of the rectangular single frames are completely identical, and the length of the yoke of the remaining rectangular single frame is greater than that of the yokes of the other two rectangular single frames, the three rectangular single frames have an equal height, two adjacent rectangular single frames are assembled to form core limbs with the cross section being a polygon externally connected to a whole circle. The stereoscopic transformer wound core can decrease the transformer transportation width, lower the transportation difficulty, reduce costs, and provide the shortest path for tapping a coil to a tapping switch through a lead, thereby greatly simplifying the lead arrangement.

Abstract: The present disclosure relates to an apparatus and method for driving a switch, such as a power switch. A driver comprises a voltage sensor to sense a drive voltage, and an electrical source to provide a drive signal having a drive value. The driver is adapted to adjust the drive value based on the drive voltage to limit a switch-current flowing through the switch.

Abstract: A synthetic grinding stone used for the polishing of a silicon wafer is composed of a structure containing cerium oxide fine particles as abrasive grains, a resin as a binder, a salt as a filler and a nano diamond as an additive. This synthetic grinding stone is characterized in that the purity of the cerium oxide is not less than 60% by weight, the content of the salt as a filler is not less than 1% but not more than 20%, the volume content of the nano diamond as an additive is not less than 0.1% but less than 20% relative to the total volume of the structure, and the porosity as the volume fraction relative to the total volume of the structure is less than 30%.

Abstract: A precision machining method enabling grinding with high accuracy is provided. The method includes a first step of producing an intermediate ground workpiece by roughly grinding a workpiece (a) with a diamond grinding wheel (b), and a second step of producing a final ground workpiece by grinding the intermediate ground workpiece with a grinding wheel for CMG. In the first step, feed of the rotator (6b) and the base (3) is controlled in multiple stages with different feed speeds according to control based on the amount of movement, and in the second step, movement of the rotator (6b) and the base (3) is controlled with a constant pressure or in multiple stages having different constant pressures.

Abstract: A precision machining apparatus is structured such that a feed-screw mechanism and an actuator are mounted on a second mount which supports a rotating device that rotates a wheel, and grinding is performed while appropriately adjusting the amount of movement of the second mount in a rough grinding stage through an ultra-precision grinding stage. A posture control device is interposed between a first mount and a rotating device that rotates a grinding target body. The thickness and evenness of the grinding target body are measured by an optical probe and the measurement results are sent to a computer. A feedback command is then sent to the posture control device to reduce the difference between target values and the measurement values and posture control is performed accordingly.

Abstract: A precision machining apparatus is structured such that a feed-screw mechanism and an actuator are mounted on a second mount which supports a rotating device that rotates a wheel, and grinding is performed while appropriately adjusting the amount of movement of the second mount in a rough grinding stage through an ultra-precision grinding stage. A posture control device is interposed between a first mount and a rotating device that rotates a grinding target body. The thickness and evenness of the grinding target body are measured by an optical probe and the measurement results are sent to a computer. A feedback command is then sent to the posture control device to reduce the difference between target values and the measurement values and posture control is performed accordingly.

Abstract: Disclosed is a synthetic grinding stone used for polishing of silicon wafer, which is composed of a structure comprising cerium oxide fine particles as abrasive grain, a resin as a binder, a salt as a filler and a nano diamond as an additive. This synthetic grinding stone is characterized in that the purity of the cerium oxide is not less than 60% by weight, the content of the salt as a filler is not less than 1% but not more than 20%, the volume content of the nano diamond as an additive is not less than 0.1% but less than 20% relative to the total volume of the structure, and the porosity as the volume fraction relative to the total volume of the structure is less than 30%.

Abstract: A precision machining method enabling grinding with high accuracy is provided. The method includes a first step of producing an intermediate ground workpiece by roughly grinding a workpiece (a) with a diamond grinding wheel (b), and a second step of producing a final ground workpiece by grinding the intermediate ground workpiece with a grinding wheel for CMG. In the first step, feed of the rotator (6b) and the base (3) is controlled in multiple stages with different feed speeds according to control based on the amount of movement, and in the second step, movement of the rotator (6b) and the base (3) is controlled with a constant pressure or in multiple stages having different constant pressures.

Abstract: A precision machining apparatus and a precision machining method capable of carrying out grinding with accuracy by performing switching control, for example, on a device for rotating a grinding wheel according to grinding stages through the amount of movement and constant pressure changed stepwise. To a second pedestal 3 supporting a rotary device 6b for rotating a grinding wheel b, an actuator 5 and a feed screw mechanism 4 constituted by at least a feed screw 41 and a nut 42 are attached. In a rough grinding stage, the movement of the rotary device 6b and the second pedestal 3 is adjusted through a predetermined amount of movement of the nut 42. In a super-precision grinding stage, the movement of the rotary device 6b and the second pedestal 3 is adjusted by pressure control using stepwise a plurality of pneumatic actuators 5a, 5b differing in pressure performance. An attitude control device 7 is interposed between a first pedestal 2 and a rotary device 6a for rotating an object a to be ground.

Abstract: An attitude control device and a precision machining apparatus capable of accurately controlling the attitude of an object mounted on the attitude control device according to grinding stages. The attitude control device is constituted by a first flat-plate member 21 and a second flat-plate member 22 disposed in parallel with the first flat-plate while being spaced apart from the same by a distance L. A spherical member 3 is interposed between the first and second flat-plate members 21, 22 while fitting its portions in recesses 21a, 22a respectively formed in the first and second flat-plate members 21, 22. A first actuator 4a expandable in a Z-axis direction perpendicular to a plane defined by an X-axis and a Y-axis is interposed between the flat-plate members. Second actuators 4b, 4b expandable in a suitable direction in the plane defined by the X-axis and the Y-axis are connected to the second flat-plate member 22.

Abstract: An attitude control device and a precision machining apparatus capable of accurately controlling the attitude of an object mounted on the attitude control device according to grinding stages. The attitude control device is constituted by a first flat-plate member 21 and a second flat-plate member 22 disposed in parallel with the first flat-plate while being spaced apart from the same by a distance L. A spherical member 3 is interposed between the first and second flat-plate members 21, 22 while fitting its portions in recesses 21a, 22a respectively formed in the first and second flat-plate members 21, 22. A first actuator 4a expandable in a Z-axis direction perpendicular to a plane defined by an X-axis and a Y-axis is interposed between the flat-plate members. Second actuators 4b, 4b expandable in a suitable direction in the plane defined by the X-axis and the Y-axis are connected to the second flat-plate member 22.

Abstract: A precision machining apparatus and a precision machining method capable of carrying out grinding with accuracy by performing switching control, for example, on a device for rotating a grinding wheel according to grinding stages through the amount of movement and constant pressure changed stepwise. To a second pedestal 3 supporting a rotary device 6b for rotating a grinding wheel b, an actuator 5 and a feed screw mechanism 4 constituted by at least a feed screw 41 and a nut 42 are attached. In a rough grinding stage, the movement of the rotary device 6b and the second pedestal 3 is adjusted through a predetermined amount of movement of the nut 42. In a super-precision grinding stage, the movement of the rotary device 6b and the second pedestal 3 is adjusted by pressure control using stepwise a plurality of pneumatic actuators 5a, 5b differing in pressure performance. An attitude control device 7 is interposed between a first pedestal 2 and a rotary device 6a for rotating an object a to be ground.