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.

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, one example electronic system includes an air moving device, a sensor for monitoring an operating parameter of the electronic system and generating a signal representative of the operating parameter, and a controller for controlling the air moving device. The controller is configured to selectively control a rotational speed of the air moving device, to receive the signal representative of the operating parameter, and to delay changing the rotational speed of the air moving device in response to the signal representative of the operating parameter.

Abstract: A discharge chute for a material reducing machine having a discharge opening includes a plurality of adjacent chute segments and a linkage system. The plurality of adjacent chute segments includes a rear chute segment, an intermediate chute segment and a front chute segment, each of which is pivotally connected to an adjacent chute segment. The linkage system includes a plurality of links that interconnect the adjacent chute segments, and an actuator that is adapted to cause the discharge chute to be steered to the left by pivoting the intermediate chute segment to the left with respect to the adjacent rear chute segment, and to cause the discharge chute to be steered to the right by pivoting the intermediate chute segment to the right with respect to the adjacent rear chute segment.

Abstract: Multi-level power converters are disclosed. In one embodiment, a multi-level power converter includes an input for receiving an input voltage and a converter output for providing a variable output voltage. The multi-level power converter includes a plurality of switching circuits. Each switching circuit is connected to the input in parallel with each other switching circuit. Each switching circuit includes an output. Each switching circuit is selectively operable to couple its output to the input voltage or a reference voltage. The multi-level power converter includes a parallel multi-winding autotransformer (PMA). The PMA includes a plurality of windings and a magnetic core having a plurality of magnetically connected columns. Each winding is positioned around a different one of the columns and has a beginning and an end. The output of each switching circuit is coupled to the beginning of a different winding. The end of each winding is connected to the converter output in parallel with each other winding.

Abstract: A dryer performance optimization system comprising a dryer having an inner wall and being adapted to rotate at variable speeds and a variable frequency drive being adapted to vary the rotational speed of the dryer. The preferred system also comprises a baghouse having an inlet end being adapted to receive exhaust gas from the dryer and an outlet end and a controller being adapted to control the temperature of the exhaust gas from the dryer. A method for controlling the temperature of exhaust gas in a baghouse comprising providing a dryer performance optimization system as described herein and varying the temperature of the exhaust gas from the dryer by varying the rotational speed of the dryer.

Abstract: A multi-stage power converter includes a pre-regulator circuit configured to provide a regulated output voltage, at least one DC/DC converter, and a control circuit coupled to the pre-regulator circuit and the DC/DC converter. The DC/DC converter is configured to provide an output voltage and an output current to a load. The DC/DC converter includes an input, an output, and at least one power switch. The input of the DC/DC converter is coupled to the pre-regulator circuit. The control circuit is configured to regulate the output voltage of the DC/DC converter and vary the regulated output voltage of the pre-regulator circuit as a function of the output current of the DC/DC converter.

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: A power conversion system for use with a photovoltaic (PV) power source may include a DC/DC converter for converting a first DC voltage into a second DC voltage, an isolation transformer, an inverter for converting DC power to AC power, and at least one controller for controlling the DC/DC converter and the inverter. The controller may be configured to operate the DC/DC converter as a buck converter or a boost converter based, at least in part, on whether the first DC voltage is less or greater than a reference voltage. Additionally, the controller may operate the converter according to a maximum power point tracking algorithm. Further, the controller may be configured to operate the inverter to control the DC voltage at the inverter's input as a function of the AC voltage at the inverter's output. Example embodiments of power systems, DC/DC converters, DC/AC inverters and related methods are also disclosed.

Abstract: A filter for a power supply includes at least two inputs, at least two outputs, and a common mode choke coupled between the at least two inputs and the at least two outputs. Each input includes a pair of input terminals and each output includes a pair of output terminals. The common mode choke includes a magnetic core and at least four windings extending about the magnetic core. Each winding is coupled between one of the input terminals and one of the output terminals. The filter may further include X-capacitors coupled between the at least two inputs and the at least two outputs. Also disclosed are power supply systems including one or more power supplies and a filter coupled to the power supplies.

Abstract: A power system includes a DC power source having a maximum output voltage, a DC/AC inverter having an input coupled via a connection to the DC power source and an output for supplying AC power to a load, and a control circuit for controlling the DC/AC inverter. The control circuit is configured to maintain a DC voltage at the input of the DC/AC inverter above a threshold voltage to inhibit arcing as a result of a break in the connection between the DC power source and the DC/AC inverter. The threshold voltage is substantially equal to the maximum output voltage of the DC power source less a minimum arcing voltage for the connection between the DC power source and the DC/AC inverter.

Abstract: A power supply includes an input terminal, an output terminal, a DC voltage regulator coupled between the input terminal and the output terminal to provide a substantially constant DC output voltage at the output terminal, a voltage divider coupled between the output terminal and ground (e.g., earth ground or another suitable reference potential), the voltage divider including at least a first resistance, a second resistance and a first node between the first resistance and the second resistance, the first node coupled to the DC voltage regulator to provide a feedback voltage to the DC voltage regulator for regulating the DC output voltage, and an adjustable shunt regulator coupled between the output terminal and the first node.

Abstract: A method of optimizing a gain adjustment value Kadj for a digital controller in an isolated switched mode power supply. The power supply includes an opto-coupler having a current transfer ratio (CTRX) within a range defined by a minimum current transfer ratio (CTRMIN) and a maximum current transfer ratio (CTRMAX). The method includes determining the CTRX of the opto-coupler, determining an optimal gain adjustment value KadjX based on the determined CTRX of the opto-coupler, and storing the optimal gain adjustment value KadjX in the digital controller. The method can be performed by the digital controller or by a programming device external to the power supply.

Abstract: A system includes a soft DC power source having an output terminal, a DC load, a disconnect switch coupled between the output terminal of the DC power source and the DC load, and a capacitor coupled between a power side of the disconnect switch and a reference potential. The capacitor inhibits a rise in voltage across the disconnect switch as the disconnect switch is opening to inhibit arcing in the switch. Further, a disconnect switch assembly includes a pair of input terminals for coupling to a DC power source, a pair of output terminals for coupling to a DC load, a disconnect switch coupled between one of the input terminals and one of the output terminals, and a capacitor coupled between the pair of input terminals.

Abstract: A material reducing machine includes a rotor assembly having a plurality of short cutting tools and a plurality of long cutting tools. The short cutting tools are arranged in rows which extend across the length of the rotor assembly, which rows are spaced around the periphery of the rotor assembly. Each of the short cutting tools has a cutting bit with a leading edge that is spaced outwardly from the periphery of the rotor assembly by a short cutter distance. The long cutting tools are also arranged in rows which extend across the length of the rotor assembly, which rows are spaced around the periphery of the rotor assembly. Each of the long cutting tools has a cutting bit with a leading edge that is spaced outwardly from the periphery of the rotor assembly by a long cutter distance that is greater than the short cutter distance of each of the short cutting tools. A breaker assembly includes a plurality of shear blocks, each of which is spaced so as to be aligned with a short cutting tool.

Abstract: A material reduction machine includes a frame, a drum housing mounted to the frame, and a drum that is mounted for rotation within the drum housing. The drum includes a circumferential wall and a knife that is mounted on the drum. The machine includes a plurality of interchangeable belly bands, each of which is adapted to be removably attached to the frame so as to form a portion of the drum housing and to provide an inner surface that forms a belly band arc portion that is concentric with and of a larger diameter than the circumferential wall of the drum. A first interchangeable bellyband has a smooth inner surface, and a second interchangeable belly band has a plurality of flow interrupters spaced along its inner surface.

Abstract: A transformer assembly includes a first circuit board, a transformer electrically coupled to the first circuit board, and a terminal block moveably connected to the transformer and moveable relative to the transformer in at least a first direction. The terminal block includes a terminal. The transformer includes a magnetic core and a winding having a winding wire extending from the winding. The winding wire is electrically coupled to the terminal of the terminal block. The transformer assembly further includes a second circuit board electrically coupled to the terminal of the terminal block. Example embodiments and related methods of manufacturing a transformer assembly are also disclosed.

Abstract: A cost effective solution for construction of high frequency, double ended, isolated, push pull, center tapped power transformers operating in continuous/discontinuous mode with minimized winding proximity losses comprises at least two identical sets of windings with identical coupling coefficients. Each set of windings consists of at least one primary winding and at least one secondary winding tightly coupled to each other. Both the sets of windings are loosely coupled to each other with a magnetic field isolating separator.

Abstract: A material reducing machine includes a frame and a drum rotor which is mounted for rotation with respect to the frame. The drum rotor includes a generally cylindrical peripheral wall with a tool mounted thereon. The tool has a leading edge that defines an arc as the drum rotor is rotated, which arc is spaced outwardly from the peripheral wall and is parallel thereto. The machine includes a material input device for conveying material to be reduced towards the drum rotor, and an outlet for reduced material. A breaker bar assembly is located adjacent to the drum rotor. The breaker bar assembly includes a back plate with a plurality of breaker bars mounted thereon. The breaker bar assembly is located so that material which is carried by the tool of the drum rotor is directed against the breaker bar assembly.

Abstract: An angled endgate assembly adapted to produce an edge on an asphalt mat. The preferred angled endgate assembly comprises a frame that is adapted to be attached to an item of asphalt paving equipment. The preferred angled endgate assembly also comprises an edger assembly that is attached to the frame and has an asphalt contacting surface. The preferred asphalt contacting surface tapers from a minimal compaction portion to a maximum compaction portion. The preferred angled endgate further comprises a means for moving the edger assembly relative to the frame. The method of the invention comprises providing an angled endgate assembly adapted to produce an edge on an asphalt mat. The method also comprises compacting the edge of the asphalt mat.

Abstract: A driver circuit for one or more LEDs includes a power circuit having an output terminal, a capacitor coupled to the output terminal and a switch, and a control circuit coupled to the power circuit for controlling the power circuit. The control circuit is configured to operate the switch for coupling a resistance in series with the capacitor in response to detecting an open circuit condition at the output terminal. Additionally, or alternatively, the driver circuit may include a switched mode power supply, and the control circuit may be configured to switch operation of the switched mode power supply from a current control mode to a voltage control mode, and reduce a current setting for the current control mode, in response to detecting an open circuit condition at the output terminal.