Abstract: In an embodiment, a sub-surface wireless charger includes a transmitter coil and a controller. The controller is configured to generate a protective pulse having a first energy, determine a characteristic of the transmitter coil based on the generated protective pulse, determine whether it is safe to begin wireless charging based on the determined characteristic, and when the controller determines that it is safe to begin wireless charging, generate an operating pulse having a second energy, where the second energy is higher than the first energy.

Abstract: A DC-DC converter is composed a transformer; a cutoff switch connected between one of terminals of a primary winding of the transformer and one of terminals of a power source; a driving switch connected between the other of the terminals of the primary winding and the other of the terminals of the power source; and a control unit that alternately repeats turning on the cutoff switch and the driving switch, and turning off the cutoff switch and the driving switch.

Abstract: In an apparatus for selectively coupling a load to a grid power source and an inverter that is fed electric power by an alternate power source, a node is coupled to the load. A grid sensor senses the grid power source. A grid relay selectively couples grid power to the node. An inverter relay also selectively couples the inverter to node. A controller closes the grid relay and the inverter relay when grid power is available. The controller opens the grid relay when grid power is not available. The controller opens the inverter relay when grid power is not available and when feedback indicates that the grid relay is closed.

Abstract: A system that efficiently captures and utilizes the maximum generation capacity of an alternate energy source is disclosed. A first power converter is provided between the alternate energy source and a load. The first power converter is selected such that the capacity of the power converter is less than the generation capacity of the alternate energy source. A second power converter is selected such that the capacity of the second converter is at least equal to the difference between the capacity of the alternate energy source and the first power converter. A battery is provided to store the additional energy generated by the alternate energy source, and the second power converter is connected between the output of the alternate energy source and the battery. The power output from the first power converter is utilized to control operation of the second power converter.

Abstract: Systems, apparatuses, and methods for a modular inverter system having a system controller module that includes several electronic switches that may be controlled to couple various nodes in the system controller module to various circuits coupled to input/output terminals at the modular inverter system to realize various modes of operation. Such modes of operation may include powering a local load (e.g., a house) with locally generated power as well as charging a local battery stack and selling excess power to a utility company that provides a grid tie-in. Such control may be automated based on monitoring various control signals or may be manually invoked by a system operator.

Abstract: Control circuits and techniques are provided for use with DC-DC converters. The circuits and techniques may, in some implementations, be used with LED driver systems. In some embodiments control circuits are provided that rely on multiple different feedback paths to adjust a duty cycle of a DC-DC converter. In some embodiments, control circuits are provided that switch between multiple capacitors to provide as duty cycle control signal for use with a DC-DC converter.

Abstract: A calculation processing sub-unit controls a frequency control sub-unit and a DC-AC inverter circuit to repeat a first period and a second period. The first period continues for at least two cycles, each cycle including a first sub-period during which the current is maintained in one polarity and a second sub-period during which the current is maintained in an opposite polarity. The second sub-period is shorter than and subsequent to the first sub-period. The second period, during which the current is maintained in a constant polarity, is as long as or longer than the first sub-period. The calculation processing sub-unit controls a PWM control sub-unit and a voltage step-down circuit to maintain an absolute value of the current at a first current value during at least part of the first period, and at a second current value, greater than the first current value, during the second period.

Abstract: An inverter system includes inverting circuitry for inverting an input DC signal into a square wave or quasi-square wave AC signal across a resistance, and a controller for causing the inverting circuitry to invert the input DC signal into the AC signal. The DC signal is a DC voltage having a value that ranges from 24-32 volts DC. The AC signal is an AC voltage having a value that ranges from 115-230 volts AC RMS.

Abstract: Embodiments of the present invention may provide a circuit. The circuit may include a primary side, a secondary side, and an isolated energy transfer device electrically isolating the primary side and the secondary side. The primary side may include a first energy storage device coupled to a power source, a control system coupled to the first energy storage device for power, a second energy storage device, and a coupling system, coupled to the control system, to selectively couple the second energy storage device to the power source in a first phase and to selectively couple the second energy storage device to the primary side of the isolated energy transfer device during a second phase.

Abstract: In one embodiment, each of a plurality of sites may produce surplus power. All or a fraction of the surplus power may be supplied to the power grid according to an agreement between the user of a site and an electric utility. A computer of the utility is in communication with a computer at each of a plurality of sites having a local power source. Terms of power provision that include an amount of power to be provided during a specified time of day is communicated between a site and the utility.

Abstract: A power converter system includes a power converter system including: a DC-to-AC power converter; a first output configured to be coupled to a power grid; a first input configured to be coupled to the power grid; second outputs each configured to be coupled to a corresponding AC load; a power-grid switch coupled to the converter and to the first output; load switches coupled to the converter, the second outputs, and the first input; and a controller coupled to the load switches and to the first output and configured to determine whether energy from the power grid satisfies at least one criterion, the controller being further configured to control the power-grid switch and the load switches to couple the converter to the first output and to couple the first input to the second outputs if the at least one criterion is satisfied and otherwise to control the power-grid switch and the load switches to isolate the converter from the first output and to couple the converter to at least one of the second outputs.

Abstract: A control circuit for a washing machine that avoids contact bounce short circuit failures is provided. A washing machine that utilizes an induction motor including a starting winding used to start rotation of the motor at the beginning of a cycle. Such washing machines require that the motor be operated in both directions during different cycles. To enable such operation, a mechanical timer uses a pair of single pole, double throw switches in a switching assembly to reverse the L1 and neutral connections to the starter winding. To avoid the contact shorting problem, the control wiring runs either the L1 or neutral side of the voltage source, or both, through the centrifugal switch to open the input contact(s) once the motor has reached its operating speed. Then, if the switching assembly has L1 and N contacts touching at the same time, it will not result in a dead short.

Abstract: A power converter system includes a power converter system including: a DC-to-AC power converter; a first output configured to be coupled to a power grid; a first input configured to be coupled to the power grid; second outputs each configured to be coupled to a corresponding AC load; a power-grid switch coupled to the converter and to the first output; load switches coupled to the converter, the second outputs, and the first input; and a controller coupled to the load switches and to the first output and configured to determine whether energy from the power grid satisfies at least one criterion, the controller being further configured to control the power-grid switch and the load switches to couple the converter to the first output and to couple the first input to the second outputs if the at least one criterion is satisfied and otherwise to control the power-grid switch and the load switches to isolate the converter from the first output and to couple the converter to at least one of the second outputs.

Abstract: A power converter capable of improving converter's efficiency and achieving zero-voltage-switching is provided, in which a first series circuit is connected in parallel with a direct current (DC) power supply and has a first inductor, a first primary winding, first and second switching elements connected in series. A second series circuit is connected in parallel with the DC power supply and has third and fourth switching elements, a first capacitor, a second primary winding and a second inductor connected in series. A second capacitor is connected between a first node between the first primary winding and the first switching element in the first series circuit and a second node between the fourth switching element and the second primary winding in the second series circuit. A third node between the first and second switching elements is connected to a fourth node within the second series circuit.

Abstract: A thermal protection circuit arranged in an integrated circuit for protecting a power delivery is disclosed. The thermal protection circuit for protecting a power delivery circuit includes a first thermal sensing circuit exhibiting a negative temperature coefficient characteristic for sensing a temperature of the power delivery circuit and providing a first voltage, a second thermal sensing circuit exhibiting a positive temperature coefficient characteristic for transforming the temperature of the power delivery circuit to a second voltage, an amplifier electrically connected to the first voltage and the second voltage for providing a control signal, wherein the amplifier is a function of a voltage difference between the first voltage and the second voltage, and a switch electrically connected to an output of the amplifier for limiting a maximum current passing there through in response to the control signal.

Abstract: The present invention provides smooth conversion of electric power between an AC line operating at a first voltage and a DC line operating at a second voltage bearing a fixed ratio to the first voltage. In one embodiment, polyphase AC is converted to rippled DC. In one embodiment, switched DC is converted to AC of one or more phases. The electric power converter of the invention uses a single electrical winding can be thought of as derived from the formerly well-known, and now largely forgotten, synchronous converter by locking the rotor, discarding the field winding and its power supply, replacing the AC slip ring contacts with hardwired connections, and replacing the DC commutator taps, bars and brushes with rectifying taps. Thus, the new power converter may be referred to as a single-winding static synchronous converter.

Abstract: A power converter is provided with a split primary current fed push pull topology. An inductor connects the primary windings. Controllable switches provide alternate circuits from the dc source inputs through each of the primary windings and the inductor. Clamping diodes connect the ends of the inductor to the dc source inputs opposite to those provided by the controllable switches. The clamping makes cross conduction unnecessary. Separate duty cycle control is provided in each primary circuit.