Abstract: A fly-back type switched current regulator includes a primary transformer winding coupled to receive a rectified DC signal derived from an AC signal. The drain of a power transistor is coupled to the primary winding, with the source of the power transistor coupled to an input of a comparison circuit and a primary transformer winding sense resistor. A control terminal of the power transistor is coupled to an output of the comparison circuit. A capacitor stores a variable reference signal for application at a first capacitor terminal to another input of the differential circuit. The variable reference signal is compared to a winding current signal generated by the sense resistor by the comparison circuit. An injection circuit applies an AC signal derived from the rectified DC signal to a second terminal of the capacitor so as to modulate the stored variable reference signal. The regulator is coupled to drive LEDs.

Abstract: A fly-back type switched current regulator includes a primary transformer winding coupled to receive a rectified DC signal derived from an AC signal. The drain of a power transistor is coupled to the primary winding, with the source of the power transistor coupled to an input of a comparison circuit and a primary transformer winding sense resistor. A control terminal of the power transistor is coupled to an output of the comparison circuit. A capacitor stores a variable reference signal for application at a first capacitor terminal to another input of the differential circuit. The variable reference signal is compared to a winding current signal generated by the sense resistor by the comparison circuit. An injection circuit applies an AC signal derived from the rectified DC signal to a second terminal of the capacitor so as to modulate the stored variable reference signal. The regulator is coupled to drive LEDs.

Abstract: A fly-back type switched current regulator includes a primary transformer winding coupled to receive a rectified DC signal derived from an AC signal. The drain of a power transistor is coupled to the primary winding, with the source of the power transistor coupled to an input of a comparison circuit and a primary transformer winding sense resistor. A control terminal of the power transistor is coupled to an output of the comparison circuit. A capacitor stores a variable reference signal for application at a first capacitor terminal to another input of the differential circuit. The variable reference signal is compared to a winding current signal generated by the sense resistor by the comparison circuit. An injection circuit applies an AC signal derived from the rectified DC signal to a second terminal of the capacitor so as to modulate the stored variable reference signal. The regulator is coupled to drive LEDs.

Abstract: An AC/DC power converter is coupled between a fluorescent ballast circuit and a set of light emitting diodes (LEDs) forming an LED lamp. The power converter converts an AC output from the ballast circuit to a DC current applied to drive operation of the LEDs. The power converter transforms and rectifies the AC output from the ballast circuit to generate a DC output current. An open load protection circuit is coupled to protect the ballast circuit when the LED lamp is not connected. Current control is provided by a transistor having a source/drain conduction path coupled to shunt the DC output current in response to a control signal having a duty cycle generated as a function of a zero-crossing of the AC output and a sensed value of the DC output current applied to the LED lamp.

Abstract: A process for organizing a series of discussion replies is disclosed, including monitoring a discussion thread for a series of single replies, each subsequent reply in the series responding to an immediately preceding reply. Once the system determines the existence of the series of single replies, the series of single replies is arranged into a single horizontally-aligned block, the block being vertically separated from other replies to the discussion comment that are not in the series of single replies. Thus, the horizontal-space used by the discussion thread is minimized and readability of the discussion thread improved.

Abstract: An AC/DC power converter is coupled between a fluorescent ballast circuit and a set of light emitting diodes (LEDs) forming an LED lamp. The power converter converts an AC output from the ballast circuit to a DC current applied to drive operation of the LEDs. The power converter transforms and rectifies the AC output from the ballast circuit to generate a DC output current. An open load protection circuit is coupled to protect the ballast circuit when the LED lamp is not connected. Current control is provided by a transistor having a source/drain conduction path coupled to shunt the DC output current in response to a control signal having a duty cycle generated as a function of a zero-crossing of the AC output and a sensed value of the DC output current applied to the LED lamp.

Abstract: A line-powered LED driver is operable to provide primary-side regulation of output current supplied to LED circuitry. The circuit includes a feedback loop coupled to a power converter, wherein the feedback loop adds scaled input current to scaled input voltage to produce a control signal. The power converter is responsive to the control signal to adjust input current drawn by the power converter in response to changes in line voltage to provide constant input power. The power converter produces output power for supplying constant output current at the LEDs. The feedback loop may use a reference voltage derived from the LED circuitry so that the output power may be regulated to provide constant LED current for varying LED voltages. When compared to secondary-side current feedback schemes, the LED driver provides increased efficiency and reliability at a reduced cost by implementing primary-side regulation of the output current.

Abstract: A fly-back type switched current regulator includes a primary transformer winding coupled to receive a rectified DC signal derived from an AC signal. The drain of a power transistor is coupled to the primary winding, with the source of the power transistor coupled to an input of a comparison circuit and a primary transformer winding sense resistor. A control terminal of the power transistor is coupled to an output of the comparison circuit. A capacitor stores a variable reference signal for application at a first capacitor terminal to another input of the differential circuit. The variable reference signal is compared to a winding current signal generated by the sense resistor by the comparison circuit. An injection circuit applies an AC signal derived from the rectified DC signal to a second terminal of the capacitor so as to modulate the stored variable reference signal. The regulator is coupled to drive LEDs.

Abstract: A system and method for providing a constant current source driver for a light emitting diode string. The converter includes a current sensor that derives feedback signal corresponding to a peak current through the light emitting diode string. The feedback signal is used by a controller to vary a duty cycle of the controller to regulate the average current. The controller is operable to regulate the average current as the number of light emitting diodes is increased and/or decreased.

Abstract: A line-powered LED driver is operable to provide primary-side regulation of output current supplied to LED circuitry. The circuit includes a feedback loop coupled to a power converter, wherein the feedback loop adds scaled input current to scaled input voltage to produce a control signal. The power converter is responsive to the control signal to adjust input current drawn by the power converter in response to changes in line voltage to provide constant input power. The power converter produces output power for supplying constant output current at the LEDs. The feedback loop may use a reference voltage derived from the LED circuitry so that the output power may be regulated to provide constant LED current for varying LED voltages. When compared to secondary-side current feedback schemes, the LED driver provides increased efficiency and reliability at a reduced cost by implementing primary-side regulation of the output current.

Abstract: A thyristor power control circuit reduces EMI and maintains a holding current in the thyristor to prevent flickering at a load. The power control circuit includes a thyristor configured to receive an input AC voltage, and responsive to a gate pulse generates a modified AC voltage. A rectifier receives the modified AC voltage and generates a rectified DC voltage. A power converter coupled to the rectifier receives the rectified DC voltage and generates a controlled output current. A damping circuit coupled to an output terminal of the rectifier includes a damping resistor for maintaining the holding current in the thyristor during an ON period of the thyristor. The damping circuit includes a first capacitor coupled in series to the damping resistor and a diode coupled in parallel to the damping resistor. The diode enables the first capacitor to discharge without causing power loss at the damping resistor.

Abstract: A system and method for providing a constant current source driver for a light emitting diode string. The converter includes a current sensor that derives feedback signal corresponding to a peak current through the light emitting diode string. The feedback signal is used by a controller to vary a duty cycle of the controller to regulate the average current. The controller is operable to regulate the average current as the number of light emitting diodes is increased and/or decreased.

Abstract: A thyristor power control circuit reduces EMI and maintains a holding current in the thyristor to prevent flickering at a load. The power control circuit includes a thyristor configured to receive an input AC voltage, and responsive to a gate pulse generates a modified AC voltage. A rectifier receives the modified AC voltage and generates a rectified DC voltage. A power converter coupled to the rectifier receives the rectified DC voltage and generates a controlled output current. A damping circuit coupled to an output terminal of the rectifier includes a damping resistor for maintaining the holding current in the thyristor during an ON period of the thyristor. The damping circuit includes a first capacitor coupled in series to the damping resistor and a diode coupled in parallel to the damping resistor. The diode enables the first capacitor to discharge without causing power loss at the damping resistor.

Abstract: A relatively compact, lightweight outflow valve assembly includes suitable redundancy features that allow the valve assembly to meet regulatory requirements for certain postulated single point failures. The valve assembly includes a valve body that is constructed at least partially of a non-metallic material and has an outer surface and an inner surface that defines a flow passage having at least two flow ports. A sleeve is disposed within the valve body flow passage that is constructed at least partially of a metallic material. The sleeve has a flow passage formed therein that is in fluid communication with the valve body flow passage flow ports. A valve element is disposed within the sleeve flow passage and is moveable between at least an open position and a closed position. A plurality of brackets is mounted on the valve body outer surface and is coupled to the sleeve. When the valve assembly is installed in an aircraft, the plurality of brackets further couples the sleeve to the aircraft fuselage.

Abstract: The present invention enables a three-pane page flow editor optimized for viewing and editing a page flow. It provides a visual representation of nodes and the connections among them, enabling the ability to read and edit connections between nodes in a local area of the page flow without the overlaps between lines and crossovers once the page flow grows complex in real applications. In addition, a declarative validation rule editor is operable to create and manage a plurality of declarative validation rules of the page flow and their associated messages at design time which can be used by the page flow runtime to keep the user from entering and/or submitting bad or invalid data into the page flow. This description is not intended to be a complete description of, or limit the scope of, the invention. Other features, aspects, and objects of the invention can be obtained from a review of the specification, the figures, and the claims.

Abstract: The present invention enables a three-pane page flow editor optimized for viewing and editing a page flow. It provides a visual representation of nodes/actions and the connections among them, enabling the ability to read and edit connections between nodes in a local area of the page flow without the overlaps between lines and crossovers once the page flow grows complex in real applications. In addition, it detects and resolves mismatches between annotations of a plurality of action outputs—representing data that an action can provide to a page, and a plurality of page inputs—representing data required by a page in the page flow. This description is not intended to be a complete description of, or limit the scope of, the invention. Other features, aspects, and objects of the invention can be obtained from a review of the specification, the figures, and the claims.

Abstract: A process for the isolation of substantially pure ascorbyl-6-fatty acid ester from the products obtained by the sulphuric acid-catalyzed esterification of ascorbic acid with fatty acids comprises extracting with diethyl ketone such reaction products from the mixture remaining after the esterification reaction, hydrolysing the sulphate ester by-products in the diethyl ketone extract, removing the generated sulphuric acid from the product of this hydrolysis, isomerizing the ascorbyl-5-fatty acid ester by-product to the desired ascorbyl-6-fatty acid ester by acid catalysis in a non-polar aprotic organic solvent, and recovering the accumulated ascorbyl-6-fatty acid ester.

Abstract: A system and method comprising, sharing information between a plurality of participants in a collaboration; and exposing a set of functions that enable a participant in the plurality of participants to share the information, the set of functions comprising: first functions to facilitate establishing a context in which to interact with the plurality of participants; and second functions to facilitate storing and retrieving one or more values from a shared state, wherein the shared state is accessible within the context.

Abstract: A system and method for providing an interactive group chat involving a plurality of participants and a business process, comprising initiating the business process to coordinate the plurality of participants; determining the plurality of participants based on dynamic evaluation of a role, wherein the role is based on presence information for the plurality of participants; joining each one of the plurality of participants into the group chat; and distributing a message from one of the plurality of participants to the others.

Abstract: A method for allowing a collaboration process to perform actions on behalf of a client process, comprising: receiving a message from the client process; impersonating a user for the purposes of performing an action on behalf of the user; performing the action with the same privilege(s) of the user; and wherein the client process and the collaboration process are part of a collaboration.