Abstract: A bipolar junction transistor (BJT) may be used in a power stage DC-to-DC converter, such as a converter in LED-based light bulbs. The power stage may be operated by a controller to maintain a desired current output to the LED load. The controller may operate the power stage by monitoring a start and end of a reverse recovery time of the BJT. Information regarding the start and end of the reverse recovery time may be used in the control of the power stage to improve efficiency of the power stage.

Abstract: A bipolar junction transistor (BJT) may be used in a power stage DC-to-DC converter, such as a converter in LED-based light bulbs. The power stage may be operated by a controller to maintain a desired current output to the LED load. A resistor may be coupled to the BJT through a switch at the emitter of the BJT. The switch may regulate operation of the BJT by allowing current flow to ground through the resistor. The controller may perform measurements of the resistor to allow higher accuracy determinations of the current through the BJT and thus improve regulation of current to the LED load.

Abstract: A system and method for controlling access to web services resources. A system may include a storage medium configured to store instructions and one or more processors configured to access the storage medium. The instructions may be executable by at least one of the processors to implement a web services access control system (ACS) configured to receive requests. Each request specifies an access operation to be performed with respect to a corresponding resource. Each of the requests is associated with a corresponding principal. For each received request, the ACS may be further configured to determine whether an access control entry exists that is associated with both the resource and principal associated with the request and that specifies an access type sufficient to perform the access operation. If no such entry exists, the ACS may deny the request.

Abstract: A novel insecticidal chitinase protein from fern Tectaria sp., a process for preparation of the insecticidal protein and nucleic acid sequence encoding for said insecticidal protein and its application for insect control purposes.

Abstract: A system and method for controlling access to web services resources. A system may include a storage medium configured to store instructions and one or more processors configured to access the storage medium. The instructions may be executable by at least one of the processors to implement a web services access control system (ACS) configured to receive requests. Each request specifies an access operation to be performed with respect to a corresponding resource. Each of the requests is associated with a corresponding principal. For each received request, the ACS may be further configured to determine whether an access control entry exists that is associated with both the resource and principal associated with the request and that specifies an access type sufficient to perform the access operation. If no such entry exists, the ACS may deny the request.

Abstract: A low power analog-to-digital converter configured to sense sensor signals may include a loop filter and a feedback digital-to-analog converter. The loop filter may have a loop filter input configured to receive an input current signal from a sensor and generate an output signal responsive to the input current signal. The feedback digital-to-analog converter may have a feedback output configured to generate a current-mode or charge-mode feedback output signal responsive to the output signal, the feedback output coupled to the loop filter input in order to combine the input current signal and the feedback output signal at the input.

Abstract: Identifying state inconsistency in edge-based software defined networks is disclosed. A verification server may receive controller network configuration data from a controller of an edge-based software defined network (SDN) and end-host network configuration data from at least one end-host of the SDN. The verification server may parse the controller network configuration data into a network state representation and the end-host network configuration data into the network state representation. The network state representation of the controller network configuration data and the end-host network configuration data may be compared to identify state inconsistency in the SDN. Responsive to identifying the state inconsistency, an alert and/or a report may be generated and transmitted to an administrator user interface.

Abstract: Identifying state inconsistency in edge-based software defined networks is disclosed. A verification server may receive controller network configuration data from a controller of an edge-based software defined network (SDN) and end-host network configuration data from at least one end-host of the SDN. The verification server may parse the controller network configuration data into a network state representation and the end-host network configuration data into the network state representation. The network state representation of the controller network configuration data and the end-host network configuration data may be compared to identify state inconsistency in the SDN. Responsive to identifying the state inconsistency, an alert and/or a report may be generated and transmitted to an administrator user interface.

Abstract: An electronic lighting system and method described herein control energy provided to an electronic lighting device, such as one or more light-emitting diodes (LEDs) and/or compact fluorescent lamps (CFLs), of the electronic lighting system. A triac-based dimmer phase cuts a line voltage provided to the electronic lighting system. A controller of the electronic lighting system utilizes a probing system to overcome idiosyncrasies of the triac-based dimmer to allow the controller to probe and sense the line voltage. To reduce energy consumption, rather than probing each cycle of the output voltage of the triac-based dimmer, the controller periodically or intermittently probes the output voltage of the triac-based dimmer.

Abstract: A power distribution system and method includes a controller that is configured to control a switching power converter. In at least one embodiment, the controller includes a compensation current control circuit to control a compensation current that reduces and, in at least one embodiment, approximately eliminates variations in current drawn by the controller during a particular operational time period. In at least one embodiment, the power distribution system is a lamp that includes the controller, a switching power converter, and one or more light sources, such as light emitting diodes.

Abstract: A controller may be configured to generate a control signal to activate and deactivate a switch of a switching power converter in order to control a switching period and a peak current of the switching power converter to maintain a regulated current of the switching power converter at a desired current level such that: if the switching period decreases below a minimum switching period, the controller increases the switching period by a ringing period of a voltage of the switch and increases the peak current to compensate for the increase of the switching period in order to maintain the regulated current, and if the peak current increases above a maximum peak current, the controller decreases the switching period by a ringing period of the voltage of the switch and decreases the peak current to compensate for the decrease of the switching period in order to maintain the regulated current.

Abstract: An LED lighting device includes an auxiliary power supply that supplies power to a control circuit of the LED lighting device that receives an input from a terminal of a light-emitting diode (LED) string of the lighting device that has a substantially lower voltage than the line voltage to which the lighting device is connected. The terminal may be within the LED string, or may be an end of the string. A linear regulator may be operated from the voltage drop across a number of the LEDs in the string so that the energy wasted by the auxiliary power supply is minimized. In other designs, the auxiliary power supply may be intermittently connected in series with the LED string only when needed. The intermittent connection can be used to forward bias a portion of the LED string when the voltage supplied to the LED string is low, increasing overall brightness.

Abstract: A system and method include a controller that reduces power dissipated by a switch, such as a source-controlled field effect transistor, when an estimated amount of power dissipated by the switch exceeds a predetermined threshold. Reducing the power dissipated by the switch prevents damage to the switch due to overheating. The controller determines the estimated amount of power dissipated by the switch using actual drain-to-source current and drain voltage data. In at least one embodiment, the controller includes a fail-safe, estimated power dissipation determination path that activates when the drain voltage data fails a reliability test. Additionally, in at least one embodiment, the controller includes a model of thermal characteristics of the switch. In at least one embodiment, the controller utilizes real-time estimated power dissipation by the switch and the model to determine when the estimated power dissipated by the switch exceeds a power dissipation protection threshold.

Abstract: A power control system includes a switching power converter and a controller. The controller is configured to detect an over-current condition of an inductor current in the switching power converter using at least one non-inductor-current signal. In at least one embodiment, the switching power converter does not have a resistor or resistor network to sense the inductor current. In at least one embodiment, the controller indirectly determines a state of the inductor current using at least one non-inductor-current signal. Potentially damaging inductor current values that are, for example, greater than a normal maximum value or at a value that causes a discontinuous conduction mode system to operate in continuous conduction mode represent exemplary inductor over-current conditions addressed by one embodiment of the power control system.

Abstract: A controller may be configured to generate a control signal to activate and deactivate a switch of a switching power converter in order to control a switching period and a peak current of the switching power converter to maintain a regulated current of the switching power converter at a desired current level such that: if the switching period decreases below a minimum switching period, the controller increases the switching period by a ringing period of a voltage of the switch and increases the peak current to compensate for the increase of the switching period in order to maintain the regulated current, and if the peak current increases above a maximum peak current, the controller decreases the switching period by a ringing period of the voltage of the switch and decreases the peak current to compensate for the decrease of the switching period in order to maintain the regulated current.

Abstract: In at least one embodiment, a system and method provide current compensation in a lighting system by controlling a lamp current to prevent a current through a triac-based dimmer from undershooting a holding current value. In at least one embodiment, at least one of the lamps includes a controller that controls circuitry in the lamp to draw more lamp current for a period of time than needed to illuminate a brightness of the lamp at a level corresponding to particular phase-cut angle of the supply voltage. By drawing more current than needed, the controller increases the dimmer current during the period of time to prevent the dimmer current from falling below the holding current value. In at least one embodiment, the period of time corresponds to a compensating pulse of the lamp current at a time when the dimmer current would otherwise fall below the holding current value.

Abstract: An LED lighting device includes an auxiliary power supply that supplies power to a control circuit of the LED lighting device that receives an input from a terminal of a light-emitting diode (LED) string of the lighting device that has a substantially lower voltage than the line voltage to which the lighting device is connected. The terminal may be within the LED string, or may be an end of the string. A linear regulator may be operated from the voltage drop across a number of the LEDs in the string so that the energy wasted by the auxiliary power supply is minimized. In other designs, the auxiliary power supply may be intermittently connected in series with the LED string only when needed. The intermittent connection can be used to forward bias a portion of the LED string when the voltage supplied to the LED string is low, increasing overall brightness.

Abstract: Provided are a semiconductor circuit and a method of operating the same. The semiconductor circuit includes a first pulse generating circuit enabled to a rising edge of a clock signal and configured to generate a first read pulse, a second pulse generating circuit enabled to a rising edge of the clock signal and configured to generate a second read pulse independent of the first read pulse, a dynamic pull-down stage configured to develop a voltage level of a first dynamic node based at least on data values of an input signal and the first and second read pulses, and a dynamic pull-up stage configured to develop a voltage level of a second dynamic node based at least on data values of the input signal and the first and second read pulses.

Abstract: An LED lighting device includes an auxiliary power supply that supplies power to a control circuit of the LED lighting device that receives an input from a terminal of a light-emitting diode (LED) string of the lighting device that has a substantially lower voltage than the line voltage to which the lighting device is connected. The terminal may be within the LED string, or may be an end of the string. A linear regulator may be operated from the voltage drop across a number of the LEDs in the string so that the energy wasted by the auxiliary power supply is minimized. In other designs, the auxiliary power supply may be intermittently connected in series with the LED string only when needed. The intermittent connection can be used to forward bias a portion of the LED string when the voltage supplied to the LED string is low, increasing overall brightness.

Abstract: A low power analog-to-digital converter configured to sense sensor signals may include a loop filter and a feedback digital-to-analog converter. The loop filter may have a loop filter input configured to receive an input current signal from a sensor and generate an output signal responsive to the input current signal. The feedback digital-to-analog converter may have a feedback output configured to generate a current-mode or charge-mode feedback output signal responsive to the output signal, the feedback output coupled to the loop filter input in order to combine the input current signal and the feedback output signal at the input.