Space Systems/loral, LLC

The Boeing Company

Switch Bulb Company, Inc.

Stanley Canter

Ronald J Lenk

John D Grainger

Robert A Wiedeman

John C Hall

Edward Hirschfield

Robert Matthew Martinelli

Winnie W Choy

Jane R Felland

Dennis Yoichi Nakasone

Aaron J Mendelsohn

Christopher F Hoeber

David P Freidhoff

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.

Power factor control for an LED bulb driver circuit

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.

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.

Canted solar array and method for using same

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.

Autonomous battery cell balancing system with integrated voltage monitoring

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

Battery cell balancing system

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.

Charge control circuit and method for charging multiple battery cells

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.

AC power system with redundant AC power sources

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.

Distributed converter and method for equalizing lithium-ion batteries

A method for operating a pulse width modulated switching power converter (,), 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 (,) and an output providing an output current, the output being coupled to battery (,) for applying a charging current I,to the battery while also supplying a current I,to a load. The method includes the steps of: (a) incrementally increasing (,, C,) 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 (,) a first magnitude of both I,and I,; (c) storing (,) the sensed magnitude; (d) sensing a second magnitude of both I,and I,; and (e) comparing (,) the stored first magnitude to the sensed second magnitude. If the stored first magnitude is determined to be less than the sensed second magnitude, the method maintains the duty cycle at a current duty cycle increment. If instead the stored first magnitude is determined to be greater than the sensed second magnitude, the method decreases the duty cycle. The step of incrementally increasing includes a step of periodically increasing the charge upon a capacitance (C,) that is coupled to a control node of the pulse width modulated switching power converter, and the step of decreasing the duty cycle includes a step of at least partially discharging the capacitance.

Solar array peak power tracker

A battery charging system that may advantageously be used to directly charge a battery of a spacecraft, for example. The battery charging system permits charging of the battery without the use of power conditioners or dedicated charging arrays. Primary and secondary solar array strings are coupled by way of a shunt regulator circuit to a power bus, such as a power bus of the spacecraft. A shunt regulator circuit is coupled to the secondary solar array string and to the power bus. Charge control relays are coupled between the secondary solar array string and the battery. A computer is coupled to the shunt regulator circuit and to the charge control relays. Current from the secondary solar array string is used to charge the battery when the charge control relays are closed. If the computer determines that the battery is fully charged, the charge control relays are commanded open and current flows to the power bus unless shunted by the shunt regulator circuit. Fine control over the battery charge is achieved by adjusting the charging time and the number of circuits of the secondary solar array string that are connected to the battery.

Low cost battery charging systems

A spacecraft power system having an increased number of battery cells that is charged to the battery's full capacity, which exceeds a predetermined maximum voltage allowed by a bus. The battery can be disconnected from the bus during charging. The battery is then partially discharged to accommodate the bus before being reconnected. This provides a reduced voltage range experienced by the bus, as the minimum battery voltage is increased by the increased number of cells. A tap is provided to supply the bus with power when the battery is disconnected from the bus, and when a solar array powering the bus fails to supply current to the bus.

Spacecraft power system

Disclosed is a method for operating a communications signal transmitter and apparatus for carrying out the method. The method includes the steps of receiving a communications signal; sensing an amount of user demand; adjusting an output of a power supply that supplies operating power to a communications signal transmitter amplifier in accordance with the sensed demand so as to increase the output of the power supply when the sensed demand increases and to decrease the output of the power supply when the sensed demand decreases; and amplifying the received communications signal with the communications signal transmitter amplifier. The step of adjusting includes the steps of setting the duty cycle of a pulse width modulated signal as a function of at least the sensed signal strength; driving a switch with the pulse width modulated signal to chop a primary DC source into an AC signal; and synchronously rectifying the AC signal with an inverse of the pulse width modulated signal to provide a DC output from the power supply for supplying the operating power to the communications signal transmitter amplifier.

Satellite communication power management system

Disclosed is a method for operating a communications signal transmitter and apparatus for carrying out the method. The method includes the steps of receiving a communications signal; sensing a signal strength of the received communications signal, the signal strength being indicative of the current user demand; adjusting an output of a power supply that supplies operating power to a communications signal transmitter amplifier in accordance with the sensed signal strength so as to increase the output of the power supply when the sensed signal strength increases and to decrease the output of the power supply when the sensed signal strength decreases; and amplifying the received communications signal with the communications signal transmitter amplifier. The step of sensing may include a step of subtracting a noise component from the received communications signal. The step of adjusting includes the steps of setting the duty cycle of a pulse width modulated signal as a function of at least the sensed signal strength; driving a switch with the pulse width modulated signal to chop a primary DC source into an AC signal; and synchronously rectifying the AC signal with an inverse of the pulse width modulated signal to provide a DC output from the power supply for supplying the operating power to the communications signal transmitter amplifier.

An electric power regulator circuit for discharge of a spacecraft battery is employed for powering a load with energy stored in the battery. In order to produce a simplification of circuitry with reduction in the total number of components, the regulator circuit has two loops which share a common inductor. In a first loop, the inductor is serially connected with a gate, in the form of a first field effect transistor (FET) connected to the battery. The second loop includes the inductor with a series connection via a diode or a second FET to a capacitor which charges to feed the load. The load is serially connected via a current monitor between terminals of the capacitor, the monitor serving to sense the presence of short circuit current. The first FET is pulse-width modulated by a modulator operating in response to voltage sensed across the capacitor. The pulse width duty factor is adjusted automatically to compensate for changes in capacitor voltage, thereby to establish an essentially constant value of voltage. The second FET is operated in complementary fashion to the first FET. The forward conduction direction of the diode is opposed to the direction of current flow through the battery to insure that there is no flow of current through the battery in the event of a short circuit.

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Hermosa Beach, CA, United States of America

Stanley Canter