Electrical/Electronics

Integrated Solar Array Power Management System

Marshall Space Flight Center, Alabama

When solar cells are electrically connected to form solar arrays, they are organized into strings. Each string represents a specific number of cells connected in series to produce a specific voltage. The strings are then connected in parallel to add their currents to meet the array power requirement. This requires that the strings have the same voltage. Blocking diodes are used to take out strings with voltage that is too low, resulting in loss of power. When the arrays are mounted to a non-coplanar surface such as a spacecraft body or inflatable structure, many strings will have voltages lower than the rated voltage. This regulator manages the voltage of each string individually so that its power may be used, regardless of its voltage. It does this by converting each string’s energy into a series of high-voltage pulses that charges a reservoir capacitor to one of a set of common voltages used by the spacecraft bus. This allows for use of all of the illuminated strings in producing well-regulated power at pre-programmed voltages.

Posted in: Briefs, Power Management, Energy, Energy Storage, Architecture, Capacitors, Voltage regulators, Architecture, Capacitors, Voltage regulators, Solar energy, Spacecraft
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High-Energy-Density Solid-State Li-Ion Battery with Enhanced Safety

John H. Glenn Research Center, Cleveland, Ohio

High-energy-density and safe rechargeable batteries are required for NASA’s future exploration missions. Lithium-ion (Li-ion) batteries are attractive energy storage systems due to their relatively high energy and power densities. However, the unfavorable side reactions between the electrodes and the liquid electrolyte adversely impact performance. These interfacial reactions are in the form of either anodic oxidation of the electrolyte, or dissolution of the cathode into the electrolyte. As a result, the practical capacity and cycle life of the battery are limited. More importantly, the reactions at the cathode-electrolyte interface pose a serious threat to safety due to the electrolyte decomposition and formation of gaseous products within the cell. In addition, growth of lithium dendrite on the anode can cause cell short circuit and lead to fire or even explosion in the presence of liquid electrolyte.

Posted in: Briefs, Thermal Management, Energy, Energy Storage, Battery cell chemistry, Lithium-ion batteries, Battery cell chemistry, Lithium-ion batteries, Safety testing and procedures, Spacecraft
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Neural Network Chip Can Perform Powerful Artificial-Intelligence Tasks

In recent years, some of the most exciting advances in artificial intelligence have come courtesy of convolutional neural networks, large virtual networks of simple information-processing units, which are loosely modeled on the anatomy of the human brain. Neural networks are typically implemented using graphics processing units (GPUs), special-purpose graphics chips found in all computing devices with screens. A mobile GPU, of the type found in a cell phone, might have almost 200 cores, or processing units, making it well suited to simulating a network of distributed processors.

Posted in: Articles, Electronics & Computers
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Iron Studded BNNTs Could Replace Semiconductors in Wearable Tech

The road to more versatile wearable technology is dotted with iron. Specifically, quantum dots of iron arranged on boron nitride nanotubes (BNNTs). The new material is the subject of a study conducted by Yoke Khin Yap, a professor of physics at Michigan Technological University. Yap says the iron-studded BNNTs are pushing the boundaries of electronics hardware. The transistors modulating electron flow need an upgrade.

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Stable "Superoxide" Opens the Door to a New Class of Batteries

While lithium-ion batteries have transformed our everyday lives, researchers are currently trying to find new chemistries that could offer even better energy possibilities. One of these chemistries, lithium-air, could promise greater energy density but has certain drawbacks as well. Thanks to research at the U.S. Department of Energy's (DOE's) Argonne National Laboratory, however, one of those drawbacks may have been overcome.

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Device-Level Software Platform

The new Wubby (Palo Alto, CA) platform simplifies the development of IoT and Smart Home devices by providing a programming environment that supports Python code execution in the microcontroller of the device. At the core of the Wubby (pronounced Wha-bee) platform is the Wubby VM, accompanied by Wubby IDE, a platform agnostic development environment for configuration, debugging and simulation of everyday objects; Wubby Cloud, which is a collection of protocols and web services for application deployment and backend device management; and Wubby Client, which is the main tool for user interaction with everyday objects including managing them and installing/updating new apps. Click here to learn more.

Posted in: Products, Electronics & Computers
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Board Mount AC-DC Power Supplies

TDK Corporation (National City, CA) has announced the introduction of the TDK-Lambda KWS-A board mount AC-DC power supplies. Capable of starting up at -40°C, the convection cooled units will operate in ambient temperatures of up to 85oC and are rated for full load over a -10 to 45/55°C range (model dependent). The encapsulated series offers four power levels and four output voltages - 5V, 12V, 15V and 24V. The 5W and 10W models measure 38.1 x 25.4 x 21.5mm, the 15W 50.8 x 25.4 x 24mm and the 25W models 63.5 x 25.4 x 29mm. The KWS-A series accepts an input voltage of 85 to 265Vac, 47 - 440Hz, and requires no external fuses or electrolytic capacitors. Click here to learn more.

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Compact Broadband Amplifiers

Rohde & Schwarz (Munich, Germany) has expanded its R&S BBA150 broadband amplifier family with the D series to cover the frequency range from 690 MHz to 3.2 GHz and power levels up to 800 W. Both frequency bands, from 1.2 GHz to 1.4 GHz and 2.7 GHz to 3.2 GHz, as are necessary for automotive radar pulse tests with high field strength, are integrated in only one amplifier. With a frequency range starting at 690 MHz, the amplifiers meet the requirements of the LTE, GSM700, UMTS and WLAN mobile communications standards. The high power levels are required for compliance tests in EMC labs. To learn more, click here.

Posted in: Products, Electronics & Computers
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PC/104 Single Board Computers

Sundance Multiprocessor Technology Ltd. (Chesham, UK) announced that it has integrated Xilinx’s new SDSoC development environment on to its EMC2-Z7030 single board computer (SBC). Sundance’s EMC2 range is a family of industrial-grade and deployment-ready SBC’s that feature a Xilinx Zynq SoC with integrated dual-core ARM-A9 CPUs coupled to 1Gb of DDR3 memory, four-lanes of PCI-Express and re-programmable logic with Kintex-7 FPGA technology. The EMC2 range is designed to the latest, yet long-established, PC/104 form factor of 90mm by 96mm, called OneBank. The Xilinx SDSoC development environment has a full, system-optimizing C/C++ compiler. Click here to learn more.

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CMOS-Compatible Ohmic Contact RF MEMS Switch

Radio frequency (RF) microelectromechanical system (MEMS) switches have advantages over their solid-state counterparts. However, ohmic contact MEMS devices face several significant limitations, preventing entry into the mass market. These limitations are cost, reliability, packaging, and integration.

Posted in: Briefs, Electronics, Electronics & Computers, Microelectricmechanical device, Microelectromechanical devices, Radio equipment, Switches, Microelectricmechanical device, Microelectromechanical devices, Radio equipment, Switches
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