Abstract:
A power system includes a plurality of DC/DC converters and a DC/AC inverter. The plurality of DC/DC converters having outputs electrically connected in parallel for supplying a DC voltage bus to an input of the DC/AC inverter. The plurality of DC/DC converters each include a maximum power point tracker (MPPT). Various DC/DC converters and DC/AC inverters suitable for use in this system and others are also disclosed.
Abstract:
A portable secure data file includes an encrypted data portion and a metadata portion. When a request associated with a current user of a device to access a portable secure data file is received, one or more records in the metadata portion are accessed to determine whether the current user is permitted to access the file data in the encrypted data portion. If a record indicates the user is permitted to access the file data, a content encryption key in that record is used to decrypt the encrypted data portion.
Abstract:
A method and system for executing and undoing distributed server change operations for a collection of server objects across multiple target servers in a transaction-safe manner is provided. In one embodiment, server change operations for a collection of server objects, such as files and configuration file entries, are specified in a transaction package. The target servers to which the specified change operation are directed are also identified in the transaction package. Parameter values for each of the identified target servers are specified through a parameter file in the transaction package. The transaction package is sent to the identified target servers, which execute the change operations on the target servers in a transaction-safe manner using these parameter values.
Abstract:
A method of generating an output voltage from a variable input voltage with a power factor correction (PFC) system is disclosed. The PFC system includes a first power rail and a second power rail connected in parallel between an input for receiving the input voltage and an output for outputting the output voltage. The method includes operating one or both of the first power rail and the second power rail to generate the output based, at least in part, on whether the input voltage exceeds a threshold voltage. Power supplies and PFC systems suitable for performing the method are also disclosed.
Abstract:
A power conversion system for use with a photovoltaic (PV) power source may include a DC/DC converter for converting a first DC voltage into a second DC voltage, an isolation transformer, an inverter for converting DC power to AC power, and at least one controller for controlling the DC/DC converter and the inverter. The controller may be configured to operate the DC/DC converter as a buck converter or a boost converter based, at least in part, on whether the first DC voltage is less or greater than a reference voltage. Additionally, the controller may operate the converter according to a maximum power point tracking algorithm. Further, the controller may be configured to operate the inverter to control the DC voltage at the inverter's input as a function of the AC voltage at the inverter's output. Example embodiments of power systems, DC/DC converters, DC/AC inverters and related methods are also disclosed.
Abstract:
A cost effective solution for power factor correction in power devices operating at two widely separated input voltages comprises two unequal power rails. One power rail is optimized for operation at high line voltage only, while the other power rail is designed only for low line voltage. When operating at high line voltage, the second rail is disabled. At low line, both power rails are enabled but by virtue of unequal boost inductors, the high line power rail handles only about 30% of the power while the low line power rail handles the remaining power. Hence, the efficiency at high line voltage is maximized. As the inductance used in the high line power rail is much higher in value, it stays in continuous conduction mode for all load conditions and hence the power factor is significantly improved.
Abstract:
Methods of regulating an output voltage of a multi-output isolated power converter are disclosed. One method includes allowing the output voltage to vary unregulated when the output voltage is below a threshold value and preventing the output voltage from increasing when the output voltage reaches the threshold value. Additional methods and multi-output power supplies are also disclosed.
Abstract:
One embodiment of the present invention provides a system that facilitates faster execution of code on a memory-constrained computing device that has fast on-chip RAM, wherein the fast on-chip RAM is located on a processor chip, but is not cache memory. The system operates by copying a compiled method from an object heap to the fast on-chip RAM on the memory-constrained computing device. Additionally, the system updates an execution pointer to point to the compiled method in the fast on-chip RAM, wherein the execution pointer can also point to a compiled method in the object heap or an interpreted method in the object heap.
Abstract:
A method and system for executing and undoing distributed server change operations for a collection of server objects across multiple target servers in a transaction-safe manner is provided. In one embodiment, server change operations for a collection of server objects, such as files and configuration file entries, are specified in a transaction package. The target servers to which the specified change operation are directed are also identified in the transaction package. Parameter values for each of the identified target servers are specified through a parameter file in the transaction package. The transaction package is sent to the identified target servers, which execute the change operations on the target servers in a transaction-safe manner using these parameter values.
Abstract:
A method and information processing system for wirelessly transmitting at least one of a downlink channel descriptor and an uplink channel descriptor for reception by at least one wireless device (104). The method comprises selecting at least one transmission time for transmitting a pointer that indicates a transmission time for a DCD and/or a UCD. The pointer is transmitted at a time between a first transmission and a second transmission of the at least one of downlink channel descriptor and uplink channel descriptor. The transmission time is selected to reduce a time interval for the at least one wireless device (104) to search for the at least one of the DCD and UCD. Also, a message that includes DCD information and/or UCD information associated with at least one neighboring cell can also be chosen to transmit at specifically chosen times to the at least one wireless device (104).