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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

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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

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2016’s Best Practices for NPI and NPD Success

Smart companies know that well disciplined new product introduction (NPI) processes are critical to success. Yet, even these companies can suffer from NPI failure when important projects, policies, and guidelines are haphazardly managed as clumsy manual processes.

Posted in: White Papers, Electronics, Electronics & Computers

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High-Performance MEMS IMU Solutions for Demanding Applications

For MEMS IMU applications where the inertial profile is complex and highly dynamic, there are a number of attributes to consider when evaluating capabilities. Evaluating these attributes early in the design cycle provides an advantage over chasing open-ended deliverables, like "as accurate as possible."

Posted in: White Papers, Electronics, Data Acquisition, Sensors

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GSPS DACs Enable Ultra-Wide Bandwidth Applications

To meet the increasing capacity demand of mobile customers, the emerging E-band market requires wider bandwidth capabilities compared to traditional microwave backhaul wireless architectures. Due to increased capacity, 2-GHz E-band systems will be needed in the near future. This white paper covers the demands of current E-band point-to-point systems, and how Analog Devices’ high-speed digital-to-analog converters (DACs) provide the necessary bandwidth and sampling frequencies to support them.

Posted in: White Papers, Electronics, Data Acquisition, Sensors

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Case Study: Vance & Hines Wireless Fuel Management System for Motorcycles

Vance & Hines has represented the gold standard for aftermarket motorcycle parts and accessories since 1979. The company's new Fuelpak FP3 is a cost-effective fuel management system that links with a user's smartphone to provide a more dynamic interface. "The smartphone integration gives us the ability to not only fix performance issues, but also enhance the rider experience," said Larry Hinds, manufacturing manager at Vance & Hines. "That meant the FP3 would utilize Bluetooth technology and more robust, complex PCBs."

Posted in: White Papers, Electronics

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CMOS-Compatible Ohmic Contact RF MEMS Switch

Lyndon B. Johnson Space Center, Houston, Texas 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

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