Electronics & Computers

CCSDS Telemetry Decoder VHDL Core

Costly ground support equipment can be eliminated. Goddard Space Flight Center, Greenbelt, Maryland A flexible Telemetry Decoder Core (TDC) has been designed to decode Consultative Committee for Space Data Systems (CCSDS) encoded telemetry data. The TDC can be used to eliminate costly ground support equipment by placing the telemetry decoding functions in an inexpensive, commercially available field programmable gate array (FPGA) integrated circuit instead of special-purpose printed circuit boards. The TDC can also be used in the design of telemetry systems by enabling end-toend simulation of these systems’ upfront simulation before any hardware is built. The TDC was developed for the Global Precipitation Measurement (GPM) project and because of its success on that project, it will be used to verify telemetry on the Magnetospheric Multiscale (MMS) project.

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Thermal Response of a High-Power Switch to Short Pulses

Simulations are used to calculate temperature changes that occur inside semiconductor switch modules, where measurement is not possible. Army Research Laboratory, Aberdeen Proving Ground, Maryland Semiconductor switch modules composed of Super Gate Turn-Off Thyristors (SGTOs) have been evaluated. The switches are intended to handle kiloamplevel currents and may dissipate peak powers measured in megawatts. Recent experiments measured the response of a switch module composed of eight SGTOs to single-short, high-current pulses. Simulations of those experiments were performed to calculate the temperature changes that occur inside the devices, where measurement is not possible. Worst-case operating conditions in which the switches handle several pulses within the space of 4 or 5 seconds (s) also were simulated. Modeling and simulation were performed with SolidWorks 3D modeling software and SolidWorks Simulation computational fluid dynamics software from Dassault Systèmes.

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Battery Fault Detection with Saturating Transformers

This monitoring system for high-power battery health could be useful for electric cars and the aerospace industry. Lyndon B. Johnson Space Center, Houston, Texas A monitoring network has been created that can be added to a battery consisting of many parallel cells. This network allows the health of individual cells, as measured by the current that they produce under load, to be monitored. If one or more cells are producing less current than the others, the network allows the discrepant cell(s) to be sensed and located.

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Digitally Controlled, 12-V Precision Current Source for Extreme-Temperature Operation

NASA’s Jet Propulsion Laboratory, Pasadena, California Many control applications require precision, high-voltage-capable stimulus current drivers for sensor excitation. In particular, a requirement for a stimulus driver that can be primarily integrated into a motor feedback signal conditioning ASIC (application specific integrated circuit) for Martian environments is satisfied by this development.

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Scandate Cathode for High-Power, Long-Life Electric Space Propulsion

Applications include electron beam-stimulated lasers for high-power video projection systems and new-generation CT-scan x-ray imaging systems. John H. Glenn Research Center, Cleveland, Ohio Scandate cathodes are able to produce about 20 times the emission of conventional all-tungsten cathodes at the same temperature. Conversely, they operate at about 200 °C lower temperature for the same emission. Scandate cathodes have been studied since at least the 1960s. Between then and 2002, numerous approaches were investigated. All cathodes either did not work or degraded within a few thousand hours. The current nanoparticle approach appears to have overcome previous shortcomings.

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Hybrid Force/Stress Amplified Piezoelectric Energy Harvesting Transducer System

This design converts mechanical energy in the environment to electrical energy to power a device. Langley Research Center, Hampton, VA This innovation uses an active materials-based force-amplified mechanism and advanced piezoelectric materials for more efficient energy harvesting from mechanical shock and vibration. The harvested energy is stored in rechargeable batteries. The hybrid force/stress amplified transducer/actuator offers tens to hundreds of times higher electrical power output, up to ten times higher electromechanical energy conversion efficiency, and several orders of magnitude higher energy storage efficiency than conventional flex-tensional or multilayer stack transducers at the stress less than the fracture stress of the materials used in each element.

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Improved Battery Health Monitoring

Applications include electric vehicles, medical devices, robotics, power systems, and underwater unmanned vehicles. Neil A. Armstrong Flight Research Center, Edwards, California Battery health monitoring is an emerging technology field that seeks to predict the remaining useful life (RUL) of battery systems before they run out of charge. Such predictive measures require interpretation of large amounts of battery status data within a Bayesian prognostic framework.

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