Abstract: A wrench assembly is mounted on a drill rig so as to have some freedom of movement in three axes. The wrench assembly includes a wrench subassembly having an upper wrench and a lower wrench. Both the upper wrench and the lower wrench are provided with jaw assemblies that are adapted to grip a pipe section or to release it. One of the upper wrench and lower wrench is pivotally moveable with respect to the other to apply a twisting force to a pipe section gripped by one of the upper and lower wrenches with respect to an adjacent pipe section gripped by the other of the upper and lower wrenches. The wrench assembly also includes a generally planar support table. The wrench subassembly is attached to the support table in such a manner as to allow the wrench subassembly to pivot about an axis that is perpendicular to the plane of the support table, and in such a manner as to allow the wrench subassembly to tilt with respect to the plane of the support table.

Abstract: Various methods related to air moving devices in electronic systems are disclosed. Various electronic systems including controlled air moving devices are also disclosed. Thus, in one method of controlling an air moving device in an electronic system, the air moving device is operable to accelerate between rotational speeds at a maximum angular acceleration. The method includes limiting an angular acceleration of the air moving device to a first acceleration limit less than the maximum angular acceleration when changing the air moving device from a first rotational speed to a second rotational speed.

Abstract: Multi-winding magnetic structures and methods of making multi-winding magnetic structures are disclosed. In one embodiment, a multi-winding magnetic structure includes a core constructed of a magnetic material and a plurality of windings. The core includes a core top, a core bottom, and a plurality of columns. The core top has an exterior edge defining a shape of the core top. A central section of the core top has a substantially constant thickness that defines a thickness of the core top. The core bottom is beneath the core top and has an exterior edge defining a shape of the core bottom. A central section of the core bottom has a substantially constant thickness that defines a thickness of the core bottom. The thickness of one of the core bottom and the core top decreases from an edge of its central section to its exterior edge. The plurality of columns extends from the core bottom to the core top and the plurality of windings are wound around the columns.

Abstract: It is an object to provide a small-hole electrical discharge machining device to discharge the machining debris efficiently and to drill a small hole by electrical discharge machining at a high speed.

Abstract: A control circuit for controlling one or more power switches of a power converter includes a voltage control loop and a current control loop. The control circuit is configured to generate a current reference for the current control loop using the voltage control loop and an AC reference signal. The control circuit is configured to operate in at least a first mode in which a parameter of the voltage control loop is sampled only at every other zero crossing of the AC reference signal and the sampled parameter is used to generate the current reference for the current control loop. The power converter may be an AC-DC converter or a DC-AC converter (i.e., inverter). Alternatively, the voltage control loop may be sampled at every zero crossing of the AC reference signal, and/or more frequently during transient load conditions.

Abstract: Bridgeless boost PFC circuits and systems providing an improved method of current sensing using two current sensing resistors is envisaged. Analog switches are provided to select one of the two current sensing resistors based on the polarity of the AC line. An amplifier is provided to eliminate use of resistors with large values, thus resulting in lower power loss and efficient systems.

Abstract: Methods of making an assembly are disclosed. The assembly may include a circuit board with a top surface and a circuit component mounted on the top surface of the circuit board. The method may include positioning an inductor coil above the circuit component and the top surface of the circuit board and encapsulating the inductor coil, the circuit component and at least part of the top surface of the circuit board in a magnetic material. Assemblies according to such methods are also disclosed.

Abstract: A drum rotation machine includes a working drum mounted for rotation within an enclosure. An access door provides access to the interior of the enclosure, and the access door is moveable between a closed position and an open position. A latch assembly is mounted on the enclosure and is moveable between a locked position and an unlocked position. In the locked position, the latch assembly prevents the access door from moving from the closed position to the open position. In the unlocked position, the latch assembly allows the access door to be moved from the closed position to the open position, and engages an anti-rotation catch on the working drum to prevent rotation of the working drum.

Abstract: A method of generating an output voltage from a variable input voltage with a power factor correction (PFC) system is disclosed. The PFC system includes a first power rail and a second power rail connected in parallel between an input for receiving the input voltage and an output for outputting the output voltage. The method includes operating one or both of the first power rail and the second power rail to generate the output based, at least in part, on whether the input voltage exceeds a threshold voltage. Power supplies and PFC systems suitable for performing the method are also disclosed.

Abstract: A drilling rig assembly having a longitudinal axis and comprising a drilling rig skid and a derrick assembly having a derrick assembly pivot axis and being adapted to move relative to the drilling rig skid. The derrick assembly comprises a pair of derrick masts disposed on opposite sides of the longitudinal axis and comprising a rack, and a carriage assembly being substantially disposed between the pair of derrick masts, being adapted to move along the pair of derrick masts and comprising a pinion. The drilling rig assembly also comprises a means for moving the derrick assembly relative to the drilling rig skid, a pipe loader assembly having a pipe loader assembly pivot axis, and a means for moving the pipe loader assembly relative to the drilling rig skid. The derrick assembly pivot axis and the pipe loader assembly pivot axis are co-axial.

Abstract: Switching device controllers, drive circuits, power converters and related methods are disclosed. One example controller for a switching device includes a drive circuit for controlling the switching device and an auxiliary circuit coupled to the drive circuit. The auxiliary circuit includes an input for receiving a waveform having alternating first and second intervals. The auxiliary circuit is configured to energize the drive circuit during the first intervals and de-energize the drive circuit during the second intervals. One example method of energizing and de-energizing a drive circuit for a switching device includes receiving a waveform having alternating first and second intervals, energizing the drive circuit during the first intervals, and de-energizing the drive circuit during the second intervals.

Abstract: A method of operating an LED driver including a power converter to generate an output current for powering an LED and to provide active power factor correction is disclosed. The power converter is coupled between an input to receive a rectified AC voltage and an output for providing the output current to the LED. The method includes operating the power converter at a substantially fixed frequency in an open loop mode based on a current through the inductive element and the rectified AC voltage. LED drivers operable in accordance with the disclosed method are disclosed.

Abstract: A power system includes a plurality of DC/DC converters and a DC/AC inverter. The plurality of DC/DC converters having outputs electrically connected in parallel for supplying a DC voltage bus to an input of the DC/AC inverter. The plurality of DC/DC converters each include a maximum power point tracker (MPPT). Various DC/DC converters and DC/AC inverters suitable for use in this system and others are also disclosed.

Abstract: A method of controlling a power factor correction (PFC) converter that has a discontinuous input current includes sensing the input current, sensing an output voltage and controlling a duty cycle of at least one switch in the converter in response to the sensed input current and output voltage using a control equation for controlling the duty cycle of the switch such that an average input current to the converter is sinusoidal. Example circuits capable of performing the method are also disclosed.

Abstract: Multi-winding magnetic structures and methods of making multi-winding magnetic structures are disclosed. A multi-winding magnetic structure includes a plurality of windings (512A, 512B; 612A, 612B, 612C; 712A, 712B; 912A, 912B, 912C; 1012A, 1012B; 1112A, 1112B; 1212A, 1212B; 1412; 1512A, 1512B) and a core (402; 502; 602; 702; 902; 1202; 1402; 1502) formed of a magnetic material. The core includes a core top (408; 508; 608; 708; 908; 1208; 1408; 1508), a core bottom (410; 510; 610; 710; 910; 1210; 1410; 1510) and a plurality of columns (404A, 404B, 404C; 504A, 504B; 604A, 604B, 604C; 704A, 704B; 904A, 90413, 904C; 1204; 1404; 1504). The core top has an exterior edge (1522) defining the shape of the core top and a central section (1516) having a substantially constant thickness. The core bottom which is beneath the core top has an exterior edge (1526) defining the shape of the core bottom and a central section (1518) having a substantially constant thickness.

Abstract: Power supplies, power adapters, and related methods are disclosed. One example power supply includes an open loop DC to DC converter having an input for connecting to an input power source and an output for supplying a DC output voltage or current and an enable/disable circuit coupled to the open loop DC to DC converter. The enable/disable circuit is configured to enable and disable the open loop DC to DC converter as a function of the DC output voltage or current. One example method includes determining a DC output voltage or current from an open loop DC to DC converter and enabling and disabling the open loop DC to DC converter as a function of the determined DC output voltage or current.

Abstract: A method of operating a DC-AC inverter to produce AC power having alternating positive and negative half cycles is disclosed. The inverter includes an input connected to a DC power source, an output, a first buck converter coupled between the input and the output and a second buck converter coupled between the input and output. The method includes alternately operating the first buck converter and the second buck converter to alternately produce the positive and negative half cycles at the output.

Abstract: Multi-winding magnetic structures and methods of making multi-winding magnetic structures are disclosed. In one embodiment, a multi-winding magnetic structure includes a core constructed of a magnetic material and a plurality of windings. The core includes a core top, a core bottom, and a plurality of columns. The core top has an exterior edge defining a shape of the core top. A central section of the core top has a substantially constant thickness that defines a thickness of the core top. The core bottom is beneath the core top and has an exterior edge defining a shape of the core bottom. A central section of the core bottom has a substantially constant thickness that defines a thickness of the core bottom. The thickness of one of the core bottom and the core top decreases from an edge of its central section to its exterior edge. The plurality of columns extends from the core bottom to the core top and the plurality of windings are wound around the columns.

Abstract: A cost effective solution for power factor correction in power devices operating at two widely separated input voltages comprises two unequal power rails. One power rail is optimized for operation at high line voltage only, while the other power rail is designed only for low line voltage. When operating at high line voltage, the second rail is disabled. At low line, both power rails are enabled but by virtue of unequal boost inductors, the high line power rail handles only about 30% of the power while the low line power rail handles the remaining power. Hence, the efficiency at high line voltage is maximized. As the inductance used in the high line power rail is much higher in value, it stays in continuous conduction mode for all load conditions and hence the power factor is significantly improved.

Abstract: An isolated switching power converter includes a power isolation transformer having at least one primary winding, at least one secondary winding and a plurality of sides, a first power board mechanically coupled to a first side of the transformer, and a second power board mechanically coupled to a second side of the transformer. The first power board includes a primary side circuit electrically coupled to the at least one primary winding, and the second power board includes a secondary side circuit electrically coupled to the at least one secondary winding.