Abstract: A power supply is coupled to an input voltage source. The power supply includes a plurality of converters. Each converter has an input for receiving an input voltage and an output for providing an output voltage. The inputs are connected in series and the outputs are connected in parallel to provide an output voltage. The power supply further includes an output regulating controller coupled to one of the plurality of converters for regulating the output voltage. The power supply further includes one or more input regulating controllers correspondingly coupled to the remaining one or more converters of the plurality of converters for regulating one or more input voltages.

Abstract: A power supply having an input and an output, includes a power converter coupled between the input and output of the power supply including at least one switch that is controlled by comparing a sensed voltage, the sensed voltage corresponding to a current flowing through the switch, to a reference voltage. A controller, in response to a change detected in a switching frequency of the switch, reduces audible noise generated by the power supply by at least one of: adjusting the reference voltage; adjusting the current sense voltage; or adjusting a resistance used to generate the sensed voltage.

Abstract: A low input-current harmonic three-phase boost rectifier includes an input stage for receiving a three-phase input voltage in relation to a neutral node and an output stage adapted to couple to at least one load. The rectifier further includes one or more switching converter stages, each having a plurality of switches coupled to the neutral node, the plurality of switches operating with a fixed duty cycle, the fixed duty cycle being a substantially 50% duty cycle. The rectifier further includes one or more controllers adapted to vary the switching frequency of the plurality of switches based on at least one of a condition of the at least one load or the input voltage and includes one or more decoupling stages, each including one or more inductive elements adapted to inductively decouple the output stage from at least one of the one or more switching converter stages.

Abstract: A power supply having an input and an output, includes a power converter coupled between the input and output of the power supply including at least one switch that is controlled by comparing a sensed voltage, the sensed voltage corresponding to a current flowing through the switch, to a reference voltage. A controller, in response to a change detected in a switching frequency of the switch, reduces audible noise generated by the power supply by at least one of: adjusting the reference voltage; adjusting the current sense voltage; or adjusting a resistance used to generate the sensed voltage.

Abstract: A low input-current harmonic three-phase boost rectifier includes an input stage for receiving a three-phase input voltage in relation to a neutral node and an output stage adapted to couple to at least one load. The rectifier further includes one or more switching converter stages, each having a plurality of switches coupled to the neutral node, the plurality of switches operating with a fixed duty cycle, the fixed duty cycle being a substantially 50% duty cycle. The rectifier further includes one or more controllers adapted to vary the switching frequency of the plurality of switches based on at least one of a condition of the at least one load or the input voltage and includes one or more decoupling stages, each including one or more inductive elements adapted to inductively decouple the output stage from at least one of the one or more switching converter stages.

Abstract: A load current balancing circuit that operates with a direct current (DC) power supply includes at least one transformer having a first inductive element adapted to couple in series with a first load and a second inductive element adapted to couple in series with a second load. The first load is parallel to the second load. The load balancing circuit further includes at least one switch adapted to operate at one or more switching frequencies associated with at least one driving signal. The switch is configured to periodically interrupt respective current flows through the first inductive element and second inductive element substantially simultaneously.

Abstract: A load current balancing circuit that operates with a direct current (DC) power supply includes at least one transformer having a first inductive element adapted to couple in series with a first load and a second inductive element adapted to couple in series with a second load. The first load is parallel to the second load. The load balancing circuit further includes at least one switch adapted to operate at one or more switching frequencies associated with at least one driving signal. The switch is configured to periodically interrupt respective current flows through the first inductive element and second inductive element substantially simultaneously.

Abstract: A power supply is coupled to an input voltage source. The power supply includes a plurality of converters. Each converter has an input for receiving an input voltage and an output for providing an output voltage. The inputs are connected in series and the outputs are connected in parallel to provide an output voltage. The power supply further includes an output regulating controller coupled to one of the plurality of converters for regulating the output voltage. The power supply further includes one or more input regulating controllers correspondingly coupled to the remaining one or more converters of the plurality of converters for regulating one or more input voltages.

Abstract: A variable inductor comprises one or more magnetic cores providing magnetic flux paths. An inductor coil is wound around one or more inductor sections of the one or more magnetic cores. An inductor magnetic flux flows through one or more closed flux paths along the inductor sections of the magnetic core. A control coil is wound around one or more control sections of the one or more magnetic cores. A control magnetic flux flows through one or more closed flux paths along the control sections of the magnetic core. Under this arrangement, the inductor magnetic flux substantially does not flow through the control sections of the magnetic core and the control magnetic flux substantially does not flow through the inductor sections of the magnetic core. The closed flux paths associated with the inductor magnetic flux and the closed flux paths associated with the control magnetic flux share one or more common sections of the magnetic core not including the control sections and inductor sections.

Abstract: A PFC circuit comprises a first converter and a second converter and a multi-port electromagnetic device. The first converter has a first inductive element and the second converter has a second inductive element. The multi-port electromagnetic device comprises a first magnetic core having a first closed flux path and a second magnetic core having a second closed flux path, with the first closed flux path being independent of the second closed flux path. The first inductive element of the first boost circuit comprises a first winding that electromagnetically couples the first magnetic core to the second magnetic core and the second inductive element of the second boost circuit comprises a second winding that electromagnetically couples the first magnetic core to the second magnetic core independent of the electromagnetic coupling of the first winding such that current application in one windings does not induce a substantial voltage in the other.

Abstract: A ballast according to the present invention operates in an ignition state, a warm-up state, and a steady state for igniting and powering a lamp. The ballast comprises an igniter that ignites the lamp during the ignition state and a switching power inverter, for example, a full bridge DC-AC inverter implemented with MOSFET switching transistors, that powers the lamp during the warm-up and steady states. The switching power inverter, which drives the igniter, operates at a first switching frequency during the ignition state and operates at a second switching frequency during the steady state. Preferably, the first switching frequency, which in one exemplary embodiment is in the kHz range, is higher than the second switching frequency.

Abstract: A ballast according to the present invention operates in an ignition state, a warm-up state, and a steady state for igniting and powering a lamp. The ballast comprises an igniter that ignites the lamp during the ignition state and a switching power inverter, for example, a full bridge DC-AC inverter implemented with MOSFET switching transistors, that powers the lamp during the warm-up and steady states. The switching power inverter, which drives the igniter, operates at a first switching frequency during the ignition state and operates at a second switching frequency during the steady state. Preferably, the first switching frequency, which in one exemplary embodiment is in the kHz range, is higher than the second switching frequency.

Abstract: A PFC circuit comprises a first converter and a second converter and a multi-port electromagnetic device. The first converter has a first inductive element and the second converter has a second inductive element. The multi-port electromagnetic device. comprises a first magnetic core having a first closed flux path and a second magnetic core having a second closed flux path, with the first closed flux path being independent of the second closed flux path. The first inductive element of the first boost circuit comprises a first winding that electromagnetically couples the first magnetic core to the second magnetic core and the second inductive element of the second boost circuit comprises a second winding that electromagnetically couples the first magnetic core to the second magnetic core independent of the electromagnetic coupling of the first winding such that current application in one windings does not induce a substantial voltage in the other.

Abstract: A multi-port electromagnetic device comprises a first magnetic core having a first closed flux path and a second magnetic core having a second closed flux path, with the first closed flux path being independent from the second closed flux path. At least one first winding electromagnetically couples the first magnetic core to the second magnetic core, and at least one second winding electromagnetically couples the first magnetic core to the second magnetic core independent of the electromagnetic coupling of the at least one first winding such that current application in one of the first or second windings does not induce a magnetic flux in the other one of the first or second windings.

Abstract: The present invention relates to a current control circuit for controlling inrush current through an energy storage capacitor of a power supply having an input voltage. A semiconductor device is coupled in series to the energy storage capacitor; and a control circuit produces a constant current through the semiconductor device during an inrush current period when the energy storage capacitor is charged by the input voltage to reach an energy storage capacitor voltage that causes the semiconductor device to act as a short switch.

Abstract: A non-isolated power conversion system has an input stage and an output stage. A plurality of cascaded switching power converter stages are coupled between the input stage and the output stage. Each of the plurality of switching power converter stages has at least one switch that is activated in accordance with a duty cycle associated with a switching cycle. At least one energy storage device temporarily stores energy that is proportional to the duty cycle during the switching cycle for delivery to the output stage.

Abstract: The present invention includes multiple power converters for driving one or more loads via an input power source, AC or DC. A first switching power converter has first one or more windings coupled to an input power source, and a second switching power converter having second one or more windings coupled to one or more loads. A magnetic device comprising a single integrated magnetic core couples the first one or more windings to the second one or more windings for reducing switching loss.

Abstract: A soft-switched boost converter includes an active snubber to provide soft switching of all semiconductor components. Specifically, the current (“turn-off current”) in the rectifier is switched off at a controlled rate, the main switch is closed under zero-voltage switching (ZVS) condition, and the auxiliary switch in the active snubber is opened under zero-current switching (ZCS) condition. As a result, switching losses are reduced with beneficial effects on conversion efficiency and EMC performance.

Abstract: The invention features novel RNase P molecules and nucleic acids encoding the same. Methods for discovery of antimicrobial compounds are also featured.

Abstract: A soft-switched, full-bridge pulse-width-modulated (FB PWM) converter and its variations provide zero-voltage-switching (ZVS) conditions for the turn-on of the bridge switches over a wide range of input voltage and output load. The FB PWM converters of this invention achieve ZVS with a substantially reduced duty cycle loss and circulating current, which optimizes the conversion efficiency. The ZVS of the primary switches is achieved by employing an auxiliary circuit comprising an inductor and transformer to store energy for ZVS turn-on of the bridge switches.