Power Management

Device Accommodating Volume Expansion and Contraction for Water-Ice Phase Change Material Heat Sinks

This innovation enables the use of water as a phase change material for thermal energy storage. Lyndon B. Johnson Space Center, Houston, Texas This invention accommodates the volume expansion and contraction of water ice as it freezes and thaws, thus enabling the use of water as a phase change material (PCM) for thermal energy storage. Due to the relatively large volume expansion of water upon freezing, and the relatively large bulk modulus of elasticity of ice, it is imperative to accommodate the volume expansion in order to prevent rupture of the containment vessel. In addition to accommodating the volume expansion associated with the phase change from liquid water to solid ice, this invention is usable at temperatures as low as –150 °C, thus enabling the ice to be super-cooled for additional sensible thermal storage capacity. Finally, this invention operates independent of gravity, enabling its use in space applications.

Posted in: Briefs, TSP, Electronics & Computers, Power Management, Thermal management, Containers, Foams


High-Power, Solid-State Power Amplifier System

Marshall Space Flight Center, Alabama The purpose of the invention was to increase the operational power levels of solid-state power amplifiers using state-ofthe- art power amplifier design and combining methodology. Using 1-kW RF modules and proper RF combining techniques, a system was built that generated 16 kW of RF power for use in electric plasma propulsion. The 1-kW units were fault-protected against excessive power, excessive current, and high VSWR, since the RF power devices are extremely sensitive to variations in their operating conditions.

Posted in: Briefs, Electronics & Computers, Power Management, Amplifiers


H2O/NaCl-Based Radio Frequency Power Load

Marshall Space Flight Center, Alabama The purpose of the invention was to increase the operational power levels of power loads as well as improve the overall reliability and safety of existing systems. Using water (H2O), table salt (NaCl) or some other form of salt, and a matching network, an RF power load can be built to absorb transmitted power levels in the 10s or 100s of kilowatts, where the water absorbs the power. The only byproduct is the barely detectable heating of the water bath.

Posted in: Briefs, Electronics & Computers, Power Management, Radio equipment, Electric power


NASA Flywheel for iPad

John H. Glenn Research Center, Cleveland, Ohio NASA Flywheel is an augmented reality application intended to highlight NASA Glenn’s research efforts in the area of flywheel energy storage systems. The app utilizes a printed optical target, available on the GRC Flywheel Program brochure and through the NASA Glenn Web portal, to present users with 3D views of flywheel hardware and space applications. Additional video and imagery are also included in the application package. The software has been compiled and bundled as an iOS app for the iPad, and is intended for release through the Apple App Store.

Posted in: Briefs, TSP, Electronics & Computers, Power Management, Computer software and hardware, Imaging and visualization, Flywheels


Three-Dimensional Photovoltaics Array for Laser-Based Power Transfer

Potential applications include situations in which there is a need to create electrical power at a remote location. Goddard Space Flight Center, Greenbelt, Maryland A standard solar array is a flat panel configured of many individual solar cells, wired in series or parallel, depending on their junction configuration and material. Since the solar flux is constant depending on the distance from the Sun, the maximum energy conversion for a given solar panel depends upon the capability to absorb as many spectral peaks as possible (different materials) across the total solar spectrum. If the radiative source is a man-made device such as a laser, parked in a different orbit or on Earth, then the impinging intensity is narrow spectrally, coherent and accurately pointed, and capable of very high intensities. Thus, the materials can be tailored to match the incoming radiation for maximum absorption.

Posted in: Briefs, TSP, Electronics & Computers, Power Management, Solar energy


Nanowire-Based Piezoelectric Power Generation

Energy scavenging is appealing for powering sensors, and for charging cellphones and small consumer electronics. Ames Research Center, Moffett Field, California Sensors have improved in terms of size, capability, and power consumption, but their deployment in remote areas is limited by battery power supplies. Using piezoelectric (PE) materials for energy scavenging is a possible way to remedy the situation. The technology developed in this work converts existing sources of nonpolluting energy (mechanical strain) from nature into electricity. The quantity of energy produced is not massive, but it can be easily generated from free sources such as vibration and electromagnetic waves.

Posted in: Briefs, Electronics & Computers, Power Management, Electric power, Nanomaterials


Reducing Power-On/Off Glitches in Precision DACs

Voltage glitches are common in a signal chain path, especially when the system is being powered up or down. Depending on the peak amplitude and glitch duration, the end result in the system output can be catastrophic. One example is an industrial motor control system where a digital-to-analog converter (DAC) drives the motor drivers to control motor spin. If the glitch amplitude is higher than the motor driver’s sensitivity threshold, the motor could be spinning without control in any direction when the system is powered up/down.

Posted in: Briefs, Power Management, Motors & Drives, Engine control systems


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