Abstract: A multiphase DC/DC power converter includes an input, an output, at least a first converter and a second converter coupled in parallel between the input and the output, an inductor coupled to the first and second converters, an output capacitor coupled between the first and second converters and the output, and a control circuit coupled to the first converter and the second converter. The first and second converters each include a power switch. The control circuit is configured to switch the power switches at a frequency with a phase shift therebetween, and to vary the frequency to regulate a voltage at the output. Additionally, the control circuit may be configured to switch power switches at a fixed frequency with substantially no phase shift therebetween during startup of a multiphase DC/DC power converter, and at a variable frequency with a defined phase shift therebetween after startup.

Abstract: A power supply includes a power circuit for converting an input voltage or current to an output voltage or current, at least one interface port for receiving signals from one or more external devices, and a control circuit coupled to the power circuit and the at least one interface port. The control circuit is adapted to operate the power circuit in response to control signals having a plurality of different control signal formats that are received by the at least one interface port.

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 single phase redundant power supply system may include a first power supply having an input coupled to a first phase voltage in a polyphase power distribution system and an output coupled to a load for supplying an amount of DC power to the load, and a second power supply having an input for coupling to a second phase voltage in the polyphase power distribution system and an output coupled to the load for supplying an amount of DC power to the load. At least the first power supply is configured to reduce phase current imbalances in the polyphase power distribution system by adjusting the amount of DC power supplied to the load by the first power supply and the amount of DC power supplied to the load by the second power supply.

Abstract: A mixing tube assembly having an inlet end and an outlet end and being adapted for use in a burner assembly. The mixing tube assembly comprises a substantially cylindrical outer wall which defines an interior open space. The mixing tube assembly also comprises a turbulator that is disposed in the interior open space defined by the substantially cylindrical outer wall. A method for mixing fuel and air in a burner assembly comprising providing a mixing tube assembly. The preferred method also comprises conveying fuel and air from the inlet end of the mixing tube assembly to the outlet end of the mixing tube assembly.

Abstract: A dryer having an inlet end, a discharge end, an exterior shell, a discharge end manifold and an inlet end manifold. The preferred dryer also comprises a primary tube adapted to convey heat transfer oil to and from the dryer, a discharge end secondary tube which is in fluid communication with the primary tube and the discharge end manifold, and an inlet end secondary tube which is in fluid communication with the inlet end manifold. The preferred dryer further comprises a plurality of tertiary tubes which are in fluid communication with the discharge end manifold and the inlet end manifold, a heat source that is adapted to heat the heat transfer oil, and a sweep gas assembly. The preferred method comprises providing such a dryer, introducing heat transfer oil into the dryer, introducing wood materials into the dryer and drying the wood materials.

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 and a controller for controlling the air moving device. The controller is configured to selectively control a rotational speed of the air moving device. The controller is configured to vary the rotational speed within a range bounded by and including a first rotational speed and a second rotational speed during a time that a target rotational speed is within the range.

Abstract: A multiphase power converter includes a plurality of subconverters and a control circuit. Each subconverter has an input circuit, an output circuit, and a magnetic core coupling the input circuit to the output circuit. The magnetic core of at least one of the plurality of subconverters has a core section that is shared by the magnetic core of another one of the plurality of subconverters. The control circuit is configured to operate the input circuits of the plurality of subconverters with different phases. The magnetic cores may be cores of a transformer, a coupled inductor, etc.

Abstract: An assembly for processing green biomass material for pelletizing into a fuel pellet includes a heating assembly, a drying assembly and a cooling assembly. The heating assembly heats a thermal fluid to a temperature within the range of 200° F. to 550° F. The drying assembly includes a rotating dryer drum that has a plurality of thermal fluid tubes therein. Material that is dried in the dryer drum is conveyed to a rotating cooling drum that has a cooling tube extending along the interior thereof. A nozzle is mounted on the end of the cooling tube to discharge cooling fluid on the material therein, and a plurality of flights are mounted on the interior of the cooling drum and arranged to direct material from the inlet to the discharge outlet as the cooling drum is rotated.

Abstract: A resonant converter apparatus includes a plurality of resonant converters connected in parallel, and a control module outputting a pulse width modulation (PWM) control signal to the resonant converters. The control module includes a voltage control loop and a circuit control loop. The voltage control loop compares the sensed output voltage with a predetermined reference voltage, and outputs a PWM control signal to one of the resonant converters so the output voltage of the one converter is equal to the predetermined reference voltage. The current control loop uses the sensed output current of the one converter as a reference current, compares the reference current with the sensed output current from each of the other resonant converters, generates a frequency adjusting variable, and calculates the individual PWM control signal for each of the other converters so the output currents of the plurality of converters are the same.

Abstract: Methods of regulating an output voltage of a switched mode power supply having a variable input voltage and a power switch include adjusting a reference voltage to adjust a duty cycle of a control signal for the power switch. The reference voltage may be adjusted as a function of the duty cycle, in response to the duty cycle of the control signal being outside a defined range and/or in the response to a temperature within the switched mode power supply being above a threshold temperature. Other methods include selecting a reference voltage from a plurality of reference voltages based on a determined input voltage and generating a control signal for the power switch as a function of the selected reference voltage to adjust the duty cycle of the control signal. Switched mode power supplies and control circuits for implementing the methods are also disclosed.

Abstract: Methods of regulating an output voltage of a switched mode power supply having a variable input voltage and a power switch include adjusting a reference voltage to adjust a duty cycle of a control signal for the power switch. The reference voltage may be adjusted as a function of the duty cycle, in response to the duty cycle of the control signal being outside a defined range and/or in the response to a temperature within the switched mode power supply being above a threshold temperature. Other methods include selecting a reference voltage from a plurality of reference voltages based on a determined input voltage and generating a control signal for the power switch as a function of the selected reference voltage to adjust the duty cycle of the control signal. Switched mode power supplies and control circuits for implementing the methods are also disclosed.

Abstract: Methods of regulating an output voltage of a switched mode power supply having a variable input voltage and a power switch include adjusting a reference voltage to adjust a duty cycle of a control signal for the power switch. The reference voltage may be adjusted as a function of the duty cycle, in response to the duty cycle of the control signal being outside a defined range and/or in the response to a temperature within the switched mode power supply being above a threshold temperature. Other methods include selecting a reference voltage from a plurality of reference voltages based on a determined input voltage and generating a control signal for the power switch as a function of the selected reference voltage to adjust the duty cycle of the control signal. Switched mode power supplies and control circuits for implementing the methods are also disclosed.

Abstract: A grid-tie inverter includes a power circuit and a control circuit coupled to the power circuit. The power circuit has an input terminal for coupling to a DC power source and an output terminal for coupling to an AC power grid. The control circuit is configured to perturb an AC output current of the power circuit a first time and detect a first change in an AC output voltage of the power circuit without shutting down the power circuit, perturb the AC output current of the power circuit a second time and detect a second change in the AC output voltage of the power circuit, and shut down the power circuit in response to detecting at least the first change in the AC output voltage and the second change in the AC output voltage. Example embodiments and related methods of controlling grid-tied inverters are also disclosed.

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 concrete plant comprising an aggregate feed bin adapted to hold and release aggregate materials, a feed conveyor adapted to receive the aggregate materials from the aggregate feed bin, a collecting belt conveyor adapted to receive the aggregate materials from the feed conveyor, a silo assembly adapted to hold and release components of concrete, a screw conveyor adapted to receive the components of concrete from the silo assembly and convey the components of concrete to the collecting belt conveyor, and a mixer adapted to receive the aggregate materials and components of concrete from the collecting belt conveyor and mix the aggregate materials and components of concrete with water. The amount of aggregate materials received by the collecting belt conveyor from the conveyor and the amount of concrete components received by the collecting belt conveyor from the conveyor are precisely and accurately controlled.

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 combination of components is provided for use in making asphalt concrete from a plurality of aggregate material streams. The combination includes an indirect dryer for heating aggregate material from a first material stream without directly exposing said first stream material to hot gases of combustion. The combination also includes a mixer for mixing aggregate material from the first material stream, aggregate material that has not been heated in the indirect dryer from a second material stream, and a binder component to produce asphalt concrete.

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: An assembly for handling drill pipes includes a basket for drill pipes arranged in rows and columns, and a support table that has a drill pipe receiver. The support table moves laterally with respect to the drill pipe basket between a plurality of column alignment positions and an external position which locates the drill pipe receiver laterally outside of the basket. The support table also moves between the plurality of column alignment positions and the external position. The drill pipe handling assembly also includes a drill pipe elevator assembly and a loader arm assembly comprising a loader arm having a pipe gripper. The loader arm moves between a table alignment position in which the pipe gripper may grab or release a drill pipe when the support table is in the external position and a drilling alignment position in which the pipe gripper may grab or release a drill pipe.