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
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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
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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
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