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: A power management system with DC/AC converter for providing power to electrical heating, ventilating and air-conditioning system, having a first electrical power interface (EPI) and a second EPI. Optional DC/DC converter having a third EPI and a fourth EPI, the third EPI being electrically coupled to the second EPI. A switching arrangement of the system has a common connection, the common connection being configured to be coupled to an electromagnetic machine, a first connection selectively electrically coupled to the common electrical connection, the first electrical connection further being electrically coupled to the second EPI and the third EPI, and a second electrical connection selectively electrically coupled to the common electrical connection, the second electrical connection further being electrically coupled to the fourth EPI. The first EPI, the second EPI, the third EPI, the fourth EPI and the common electrical connection are configurable as electrical power inputs and outputs.

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: A process for monitoring the status of a battery. Steps of the process include measuring a battery current and comparing the battery current to a predetermined threshold. A battery status is determined as one of charging, discharging and quiescent. For a battery charging status determination, the charging state of charge of the battery is computed. For battery discharge status determination, the discharge current is compared to a predetermined threshold. Based upon the discharge current comparison, a basis for the discharge current is selected from one of a plurality of predetermined discharge conditions and the discharging state of charge of the battery is computed for the select discharge condition. For a quiescent status, the quiescent state of charge of the battery is computed. The computed state of charge of the battery is provided in a quantitative form.

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: A process for monitoring the status of a battery. Steps of the process include measuring a battery current and comparing the battery current to a predetermined threshold. A battery status is determined as one of charging, discharging and quiescent. For a battery charging status determination, the charging state of charge of the battery is computed. For battery discharge status determination, the discharge current is compared to a predetermined threshold. Based upon the discharge current comparison, a basis for the discharge current is selected from one of a plurality of predetermined discharge conditions and the discharging state of charge of the battery is computed for the select discharge condition. For a quiescent status, the quiescent state of charge of the battery is computed. The computed state of charge of the battery is provided in a quantitative form.

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 system for cooling an environmentally sealed enclosure. The system includes an air channel extending generally vertically from a top surface of the enclosure to a bottom surface of the enclosure, at least one interior heat sink forming a barrier between the air channel and an interior portion of the enclosure, a fan disposed in the air channel and adapted to force air to flow through the air channel, and a plenum proximate the air channel to duct exhaust air away from the enclosure, wherein air flowing through the air channel cools the enclosure. A method employs the system.

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: An electrical system control for a vehicle having a charging source, a first battery connected in series with a second battery to form a primary power supply that is connected to the charging source, and a third battery forming a secondary power supply. The system comprises a first bidirectional battery equalizer connected to the charging source and further connected to the second battery, a second bidirectional battery equalizer connected to the charging source and further connected to the third battery, and a controller adapted to monitor the state of at least one of the charging source and the first, second and third batteries. The controller also controls the operation of at least one of the first and second bidirectional battery equalizers in a predetermined manner, effective to control the charge and discharge of at least one of the first, second and third batteries.

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.