Abstract: A light-emitting diode (LED) bulb has a shell and a base attached to the shell. An LED is within the shell. A driver circuit provides current to the LED. The driver circuit has a power factor control circuit that includes a tracking circuit configured to produce a tracking signal indicative of the voltage of the supply line. The power factor control circuit also includes a switch-mode power supply (SMPS) controller having an input pin and an output pin. The tracking circuit is connected to the input pin. Based on the signal at the input pin, the SMPS controller is configured to change a frequency of an output signal on the output pin.

Abstract: An LED bulb is described. The LED bulb comprises a shell, a plurality of LEDs within the shell, a driver circuit connected to the plurality of LEDs, and a base connected to the shell. The driver circuit comprises a first input to receive AC voltage, a second input to receive AC voltage, a neutral input, a power supply circuit connected to the plurality of LEDs, and a brightness control circuit. The brightness control circuit is connected to the first input, the second input, and the power supply circuit. The brightness control circuit is configured to output a modified AC voltage to the power supply circuit. The modified AC voltage is created by blocking a portion of a cycle of AC received by the first or second input. The blocked portion is based on whether the first input, the second input, or the first and second inputs are both hot.

Abstract: A light-emitting diode (LED) bulb has a shell and a base attached to the shell. An LED is within the shell. A driver circuit provides current to the LED. The driver circuit has a power factor control circuit that includes a tracking circuit configured to produce a tracking signal indicative of the voltage of the supply line. The power factor control circuit also includes a switch-mode power supply (SMPS) controller having an input pin and an output pin. The tracking circuit is connected to the input pin. Based on the signal at the input pin, the SMPS controller is configured to change a frequency of an output signal on the output pin.

Abstract: A light-emitting diode (LED) bulb for use with a leading-edge dimmer includes a shell and an LED contained within the shell. A base is attached to the bulb for connecting the LED bulb to an electrical socket. A driver circuit is configured to provide current to the LED. The driver circuit has an input filter circuit that includes a first inductor. In response to the input filter receiving a switched AC voltage from a leading-edge dimmer set to dim at 50%, the first inductor is configured to saturate. In response to an undimmed AC voltage from the leading-edge dimmer, the first inductor is configured to not saturate. The input filter also includes a bridge rectifier connected to the first inductor.

Abstract: A light-emitting diode (LED) bulb has a shell and a base attached to the shell. An LED is within the shell. A driver circuit provides current to the LED. The driver circuit has a power factor control circuit that includes a tracking circuit configured to produce a tracking signal indicative of the voltage of the supply line. The power factor control circuit also includes a switch-mode power supply (SMPS) controller having an input pin and an output pin. The tracking circuit is connected to the input pin. Based on the signal at the input pin, the SMPS controller is configured to change a duty cycle of an output signal on the output pin.

Abstract: A method and apparatus for deploying a fixed and canted solar array of a satellite. The solar array is rotated in a first plane and about a first axis from a stowed position to a first position, rotated about a second axis orthogonal to the first axis from the first position to a deployed position determined by a deployment orbit of the satellite, and locked in the deployed position to prevent further motion of the solar array relative to a satellite body for the operational life of the satellite.

Abstract: A light-emitting diode (LED) bulb has a shell and a base attached to the shell. An LED is within the shell. A driver circuit provides current to the LED. The driver circuit has a power factor control circuit that includes a tracking circuit configured to produce a tracking signal indicative of the voltage of the supply line. The power factor control circuit also includes a switch-mode power supply (SMPS) controller having an input pin and an output pin. The tracking circuit is connected to the input pin. Based on the signal at the input pin, the SMPS controller is configured to change a duty cycle of an output signal on the output pin.

Abstract: A light-emitting diode (LED) bulb has a shell and a base attached to the shell. An LED is within the shell. A driver circuit provides current to the LED. The driver circuit has a power factor control circuit that includes a tracking circuit configured to produce a tracking signal indicative of the voltage of the supply line. The power factor control circuit also includes a switch-mode power supply (SMPS) controller having an input pin and an output pin. The tracking circuit is connected to the input pin. Based on the signal at the input pin, the SMPS controller is configured to change a duty cycle of an output signal on the output pin.

Abstract: A light-emitting diode (LED) bulb has a shell and a base attached to the shell. An LED is within the shell. A driver circuit provides current to the LED. The driver circuit has a power factor control circuit that includes a tracking circuit configured to produce a tracking signal indicative of the voltage of the supply line. The power factor control circuit also includes a switch-mode power supply (SMPS) controller having an input pin and an output pin. The tracking circuit is connected to the input pin. Based on the signal at the input pin, the SMPS controller is configured to change a duty cycle of an output signal on the output pin.

Abstract: A method and apparatus for deploying a fixed and canted solar array of a satellite. The solar array is rotated in a first plane and about a first axis from a stowed position to a first position, rotated about a second axis orthogonal to the first axis from the first position to a deployed position determined by a deployment orbit of the satellite, and locked in the deployed position to prevent further motion of the solar array relative to a satellite body for the operational life of the satellite.

Abstract: In accordance with at least one embodiment of the present invention, a power system includes a plurality of solar panels in a solar array, with each solar panel configured to receive illumination and produce a panel power output signal for a corresponding power converter. The power converters are configured to produce corresponding converted power output signals as a function of an operating point of the solar panels to provide an array power output signal.

Abstract: An autonomous lithium-ion cell balancing system with integrated voltage monitoring includes a lithium-ion battery having a plurality of cells, a cell balancing circuit and a cell balancing control circuit. The heart of the cell balancing circuit is a plurality of gated cell balancing converters that are connected with the battery cells and a common share bus. Each gated lithium-ion cell balancing converter receives and input drive voltage and an input sample voltage and transfers energy from highly charged lithium-ion cells to the less charged lithium-ion cells, forcing all cells to have the same energy level. Further, the gated cell balancing converter provides a telemetry output voltage analog to an input cell voltage, eliminating the need for a separate cell voltage monitor.

Abstract: An autonomous lithium-ion cell balancing system with integrated voltage monitoring includes a lithium-ion battery having a plurality of cells, a cell balancing circuit and a cell balancing control circuit. The heart of the cell balancing circuit is a plurality of gated cell balancing converters that are connected with the battery cells and a common share bus. Each gated lithium-ion cell balancing converter receives and input drive voltage and an input sample voltage and transfers energy from highly charged lithium-ion cells to the less charged lithium-ion cells, forcing all cells to have the same energy level. Further, the gated cell balancing converter provides a telemetry output voltage analog to an input cell voltage, eliminating the need for a separate cell voltage monitor.

Abstract: A battery cell balancing system (12) for a battery (30) having a plurality of cells (32) is provided. The system (12) includes a power supply (38) and a plurality of transformer/rectifier circuits (34) electrically coupled to the cells (32). Preferential charging occurs for a cell with the lowest state of charge. At least one current limiting device (36) is electrically coupled to the transformer/rectifier circuits (34) and the power supply (38). The current limiting device (36) buffers a source voltage from a reflected voltage of at least one of the plurality of cells (32). A method of performing the same is also provided.

Abstract: An electrical system has a battery circuit that includes a plurality of battery blocks. Each of the battery blocks has a plurality of parallel strings of battery cells connected thereto. A plurality of virtual cells is formed during charging by parallel coupling one cell from each string in parallel using diode.

Abstract: An electrical system has a battery circuit that includes a plurality of battery blocks. Each of the battery blocks has a plurality of parallel strings of battery cells connected thereto. A plurality of virtual cells is formed during charging by parallel coupling one cell from each string in parallel using diode.

Abstract: A battery cell balancing system (12) for a battery (30) having a plurality of cells (32) is provided. The system (12) includes a power supply (38) and a plurality of transformer/rectifier circuits (34) electrically coupled to the cells (32). Preferential charging occurs for a cell with the lowest state of charge. At least one current limiting device (36) is electrically coupled to the transformer/rectifier circuits (34) and the power supply (38). The current limiting device (36) buffers a source voltage from a reflected voltage of at least one of the plurality of cells (32). A method of performing the same is also provided.

Abstract: A redundant AC power system has at least two AC power sources, each of which includes an AC voltage supply connected to the primary winding of a source transformer. The source transformers have secondary windings with two outputs and a grounded center tap. There is a steering diode in series with each output. The redundant AC power sources supply power to one or more load systems. The output sides of the respective diodes for the two AC power sources are connected to the respective inputs of the primary winding of a load transformer with a pair of load-transformer primary inputs and a load-transformer primary center tap connectable to ground. A switch controllably connects the center tap of the load transformer to ground. A load is connected to the secondary winding of the load transformer.

Abstract: A system and method for charging a lithium-ion battery in which the battery is charged by a bulk charger at a high rate until one or more of the cells reaches a predetermined series threshold voltage. When a predetermined cell threshold voltage is reached, the controller provides instructions as to whether to reduce or terminate the cell charging by the bulk charger. At this point in time, the redundant power supplies begin charging each cell individually through balancing switches. The balancing switches will turn off as their respective cells reach a predetermined cell threshold voltage. Ultimately, each cell will be fully charged to an identical high charge state.

Abstract: A method for operating a pulse width modulated switching power converter (1), and a pulse width modulated switching power converter that is constructed to operate in accordance with the method. The power converter has an input coupled to an output of a solar array (10) and an output providing an output current, the output being coupled to battery (14) for applying a charging current ICHARGE to the battery while also supplying a current ILOAD to a load. The method includes the steps of: (a) incrementally increasing (18, C1) a duty cycle of the pulse width modulated switching power converter so as to incrementally increase a magnitude of the output current of the switching power converter; (b) sensing (14a) a first magnitude of both ICHARGE and ILOAD; (c) storing (20) the sensed magnitude; (d) sensing a second magnitude of both ICHARGE and ILOAD; and (e) comparing (22) the stored first magnitude to the sensed second magnitude.