Abstract: A topology for an isolated, bi-directional, DC-DC converter, that provides step-up and step-down functionality, with a reduced transformer turns ratio, allows a simplified transformer design with reduced cost and increased efficiency. This topology also has a very small level of re-circulating current, relative to other topologies regarding cost and performance.

Abstract: A high current transformer winding made from a flat conductor having opposing ends that are shaped (e.g. a lateral protrusion), such that when a middle portion of the conductor is wound around a transformer core, one or both opposing ends protrude to allow operative connection to a power source.

Abstract: A topology for an isolated, bi-directional, DC-DC converter, that provides step-up and step-down functionality, with a reduced transformer turns ratio, allows a simplified transformer design with reduced cost and increased efficiency. This topology also has a very small level of re-circulating current, relative to other topologies regarding cost and performance.

Abstract: A voltage converter system includes a first DC-AC voltage converter that converts a first DC voltage signal to a first AC voltage signal. A DC link converts the first AC voltage signal to a second DC voltage signal. A second DC-AC voltage converter converts the second DC voltage signal to a second AC voltage signal. In another configuration a DC-AC voltage converter converts a DC voltage signal to a first AC voltage signal. An AC-AC voltage converter converts the first AC voltage signal to a second, lower-frequency AC voltage signal. In yet another configuration a first voltage converter portion converts a DC voltage signal to pulses of DC voltage. A second voltage converter portion converts the pulses of DC voltage to a relatively low-frequency AC voltage signal. The voltage converter system is selectably configurable as a DC-AC voltage converter or an AC-DC voltage converter.

Abstract: An isolated step-up converter having first and second stages is described herein. The second stage can provide either DC or AC output based on the various topologies described. Resonance inductors and capacitors are used and tuned to a commutation frequency in some embodiments. Capacitors and inductors are also used in the first stage.

Abstract: An isolated step-up converter having first and second stages is described herein. The second stage can provide either DC or AC output based on the various topologies described. Resonance inductors and capacitors are used and tuned to a commutation frequency in some embodiments. Capacitors and inductors are also used in the first stage.

Abstract: A voltage converter system includes a first DC-AC voltage converter that converts a first DC voltage signal to a first AC voltage signal. A DC link converts the first AC voltage signal to a second DC voltage signal. A second DC-AC voltage converter converts the second DC voltage signal to a second AC voltage signal. In another configuration a DC-AC voltage converter converts a DC voltage signal to a first AC voltage signal. An AC-AC voltage converter converts the first AC voltage signal to a second, lower-frequency AC voltage signal. In yet another configuration a first voltage converter portion converts a DC voltage signal to pulses of DC voltage. A second voltage converter portion converts the pulses of DC voltage to a relatively low-frequency AC voltage signal. The voltage converter system is selectably configurable as a DC-AC voltage converter or an AC-DC voltage converter.

Abstract: A voltage converter system includes a first DC-AC voltage converter that converts a first DC voltage signal to a first AC voltage signal. A DC link converts the first AC voltage signal to a second DC voltage signal. A second DC-AC voltage converter converts the second DC voltage signal to a second AC voltage signal. In another configuration a DC-AC voltage converter converts a DC voltage signal to a first AC voltage signal. An AC-AC voltage converter converts the first AC voltage signal to a second, lower-frequency AC voltage signal. In yet another configuration a first voltage converter portion converts a DC voltage signal to pulses of DC voltage. A second voltage converter portion converts the pulses of DC voltage to a relatively low-frequency AC voltage signal. The voltage converter system is selectably configurable as a DC-AC voltage converter or an AC-DC voltage converter.

Abstract: A snubber circuit for a switching converter. A power source has a first rail and a second rail. A snubber transformer has a primary winding and a secondary winding, a first end of each of the primary and secondary windings being coupled together to form a transformer common point and a second end of the primary winding being connected to a half-bridge switching converter. A first capacitor is connected between the first rail and the transformer common point. A second capacitor is connected between the second rail and the transformer common point. A first diode is connected between the secondary winding and the first rail. A second diode is connected between the secondary winding and the second rail. The snubber circuit suppresses voltage transients and recovers energy from said voltage transients. In one embodiment the switching converter is a half-bridge configuration with zero current switching in a multi-level topology.

Abstract: An engine starting assist system. A battery is selectably coupled to an ultracapacitor with a contactor. In addition, a controller is configured to perform at least one of: monitor the condition of the battery, monitor the condition of the ultracapacitor, control the flow of energy between the battery and the ultracapacitor by selective actuation of the contactor, receive a start input control. The controller issues a start output control to a starter solenoid of the engine, such that energy stored in the ultracapacitor may be used to at least one of charge the battery and provide cranking current to a starter of the engine in conjunction with the battery.

Abstract: A snubber circuit for a switching converter. A power source has a first rail and a second rail. A snubber transformer has a primary winding and a secondary winding, a first end of each of the primary and secondary windings being coupled together to form a transformer common point and a second end of the primary winding being connected to a half-bridge switching converter. A first capacitor is connected between the first rail and the transformer common point. A second capacitor is connected between the second rail and the transformer common point. A first diode is connected between the secondary winding and the first rail. A second diode is connected between the secondary winding and the second rail. The snubber circuit suppresses voltage transients and recovers energy from said voltage transients. In one embodiment the switching converter is a half-bridge configuration with zero current switching in a multi-level topology.

Abstract: An engine starting assist system. A battery is selectably coupled to an ultracapacitor with a contactor. In addition, a controller is configured to perform at least one of: monitor the condition of the battery, monitor the condition of the ultracapacitor, control the flow of energy between the battery and the ultracapacitor by selective actuation of the contactor, receive a start input control. The controller issues a start output control to a starter solenoid of the engine, such that energy stored in the ultracapacitor may be used to at least one of charge the battery and provide cranking current to a starter of the engine in conjunction with the battery.

Abstract: A high-frequency DC-DC converter. The high-frequency DC-DC converter comprises a resonant power stage and a controller to operate the resonant power stage. The resonant power stage is controlled by the controller with at least one of a variable frequency mode and a pulse width modulation mode to convert an input DC voltage to one of a higher output DC voltage and a lower output DC voltage.

Abstract: A battery isolator for an electrical system having a first battery, a second battery and a charging source continuously coupled to one of the first and second batteries. The battery isolator comprises an inductor having a first terminal and a second terminal, a first switch connected between a positive terminal of the first battery and the first terminal of the inductor, and a second switch connected between a second terminal of the inductor and a positive terminal of the second battery. The first and second switches are selectively actuated in a predetermined manner, such that the battery isolator can be used to charge one of the first battery and the second battery. At least one of the first and second switches may be selectively actuated to prevent one of the first and second batteries from substantially discharging the other battery when a charging source is not present.

Abstract: A high-frequency transformer. The transformer comprises a high-voltage winding. A first bus bar is positioned proximate the high voltage winding and extends to a first portion of a plurality of power switching devices. The first bus bar is electrically coupled to the first portion of the power switching devices. A second bus bar is positioned proximate the high voltage winding and extends to a second portion of the power switching devices. The second bus bar is electrically coupled to both the high voltage winding and the second portion of the power switching devices. A third bus bar extends between the first and second bus bars and is electrically coupled to the first bus bar, second bus bar, and the high voltage winding. The second and third bus bars form a low voltage winding that electrically cooperates with the high voltage winding to form the high-frequency transformer.

Abstract: A system for controlling the excitation of an alternator field coil. The system comprises a capacitor forming a charge reservoir, a first and a second selectively operable switch connected to opposing ends of a field coil of the alternator, a first catch diode, and a second catch diode. At least one of the first and second switches are operated at a variable duty cycle and the capacitor both absorbs energy from the field coil and supplies energy to the field coil to regulate the magnetic field of the field coil, effective to regulate the output voltage of the alternator and rapidly compensate for changes in at least one load connected to the alternator.

Abstract: A high-frequency transformer. The transformer comprises a high-voltage winding. A first bus bar is positioned proximate the high voltage winding and extends to a first portion of a plurality of power switching devices. The first bus bar is electrically coupled to the first portion of the power switching devices. A second bus bar is positioned proximate the high voltage winding and extends to a second portion of the power switching devices. The second bus bar is electrically coupled to both the high voltage winding and the second portion of the power switching devices. A third bus bar extends between the first and second bus bars and is electrically coupled to the first bus bar, second bus bar, and the high voltage winding. The second and third bus bars form a low voltage winding that electrically cooperates with the high voltage winding to form the high-frequency transformer.

Abstract: A power management system for a vehicle. The system may be flexibly configured using various arrangements of DC to AC inverters, DC to DC converters AC to DC converters, DC to AC converters and AC to AC converters, one or more batteries, and a control portion to provide an AC bus, a primary DC bus and a secondary DC bus. The control portion monitors the status of the buses, inverters and converters and controls the operation of the inverters and converters to supply and regulate the power supplied by the buses. The inverters and converters may be bidirectional, allowing power to be transferred between buses.

Abstract: A system for controlling the excitation of an alternator field coil. The system comprises a capacitor forming a charge reservoir, a first and a second selectively operable switch connected to opposing ends of a field coil of the alternator, a first catch diode, and a second catch diode. At least one of the first and second switches are operated at a variable duty cycle and the capacitor both absorbs energy from the field coil and supplies energy to the field coil to regulate the magnetic field of the field coil, effective to regulate the output voltage of the alternator and rapidly compensate for changes in at least one load connected to the alternator.

Abstract: A high-frequency DC-DC converter. The high-frequency DC-DC converter comprises a resonant power stage and a controller to operate the resonant power stage. The resonant power stage is controlled by the controller with at least one of a variable frequency mode and a pulse width modulation mode to convert an input DC voltage to one of a higher output DC voltage and a lower output DC voltage.