Application Briefs

Measuring LED and Solid State Lighting Performance

Light emitting diodes (LEDs) and solid state lighting (SSL) products that incorporate LEDs pose many measurement challenges compared with other lighting elements, such as traditional tungsten and fluorescent. Advanced optical radiation measurement equipment and new techniques are often required to determine basic photo-metric and colorimetric parameters for LEDs and SSL products. Updated measurement instrumentation, calibration and performance characterization methods have allowed for improvement in the repeatability and reproducibility of measurements of average LED intensity, total luminous flux and colorimetric quantities. Lower uncertainty, detector-based standards provide a convenient transfer and monitoring from primary measurement standards.

Posted in: Application Briefs, Applications, ptb catchall, Photonics, Exterior lighting, Measurements, Light emitting diodes (LEDs), Interior lighting, Radiation

Computational Fluid Dynamics Aids Aerospace Apps

Just a few years ago, the use of computational fluid dynamics (CFD) in most aerospace companies was restricted to pure research or troubleshooting problems with existing designs. But in the past few years, newly available CFD tools are fully embedded in the mainstream mechanical design environment and hence much easier, faster and less expensive to use. The trend toward using CFD early stages in the design process has resulted in a large number of new users of this powerful analysis technique. Bell Helicopter technical specialists have developed a set of CFD best practices with the goal of guiding users in following company design guidelines and optimizing the analytical processes. The tools are based on guidelines developed for use by engineers working on propulsion systems. The guidelines are based on the application of Mentor Graphics Mechanical Analysis Division’s FloEFD suite of CFD software used by Bell Helicopter for internal flow simulations.

Posted in: Application Briefs, Motion Control, Computational fluid dynamics, Design processes, Standardization, Rotary-wing aircraft

Coded Mask Instruments Key to HETE-2 Satellite’s Gamma-Ray Burst Discoveries

Coded optic mask foil Dynamics Research Corp. (DRC) Andover, MA 978-475-9090

The High Energy Transient Explorer (HETE-2) satellite was launched into Earth orbit on October 9, 2000, and has been tracking and studying high-energy gamma-ray bursts (GRBs) from deep space. First discovered in 1967, GRBs had been difficult phenomena to observe, as they occur at random locations in the sky, last only a few seconds, and leave virtually no trace for ground-based observers. HETE-2’s ability to rapidly disseminate very precise positions of where the GRB was detected has allowed ground telescopes to catch and observe the event, leading to discoveries such as one that links GRBs with supernovas. Most of the satellite assembly occurred at Massachusetts Institute of Technology (MIT), but many subassemblies and critical components were manufactured by other institutions throughout the world.

Posted in: Application Briefs, Cameras, Data Acquisition, Architecture, Optics, Parts, Satellites

System Provides Critical Communications Among Stennis Rocket Test Team Members

Subsystem Multiplexer (Sub-MUX) Quintron Systems Santa Maria, CA 805-928-4343

NASA has awarded Quintron Systems an Indefinite-Delivery- Indefinite-Quantity (IDIQ) contract, and the first task order is for a command and control communications system that will be used at the rocket engine test stands at NASA’s Stennis Space Center in Alabama. This task order includes approximately 250 multi-channel communication key sets, of which 160 are certified for use within hazardous fuel areas.

Posted in: Application Briefs, Communications, Wireless communication systems, Collaboration and partnering, Rocket engines, Test procedures

Computational Fluid Dynamics Aids Aerospace Apps

Just a few years ago, the use of computational fluid dynamics (CFD) in most aerospace companies was restricted to pure research or troubleshooting problems with existing designs. But in the past few years, newly available CFD tools are fully embedded in the mainstream mechanical design environment and hence much easier, faster and less expensive to use.

Posted in: Application Briefs, Aerospace, Fluid Handling, Aircraft structures, Computational fluid dynamics, Design processes, Systems engineering

Position Sensors Help Cameras Focus on Mars

Hall Effect position sensors Micropac Industries Garland, TX 972-272-3571

Micropac’s hermetic Hall Effect devices are being used by Alliance Spacesystems, LLC and Malin Space Science Systems in camera mechanisms on the Mars Science Laboratory (MSL) Rover. Malin Space Science Systems’ Mast Camera (MastCam) and the Mars Hand-Lens Imager (MAHLI) will use focus, filter wheel, and cover mechanisms produced by Alliance Spacesystems. The Hall Effect position sensors are used in the focusing mechanisms on both cameras.

Posted in: Application Briefs, Sensors, Attitude control, Optics, Sensors and actuators

Devices Execute Critical Separations for Phoenix Lander

Hi-Shear separation devices Hi-Shear Technology Corp. Torrance, CA 310-326-8110

Hi-Shear separation nuts and pressure cartridges recently were used on the Phoenix Mars lander after being exposed to the cold temperatures and harsh environments of space for nine-and-a-half months. The Phoenix lander landed on Mars on May 25, 2008, and the Hi-Shear devices executed the Critical Cruise Stage Separation, Backshell Separation, and Heatshield Separation for a successful landing and operation on the surface of Mars. The spacecraft targeted the circumpolar region using a robotic arm to dig through the protective top soil layer to the water ice below, and to ultimately bring both soil and water ice to the lander platform for analysis.

Posted in: Application Briefs, Aerospace, Fastening, Robotics, Fasteners, Entry, descent, and landing, Launch vehicles, Satellites

Seven Practical Steps for Designing Networking Enclosures

The design of enclosures to house networking servers and components should be guided by one overriding concern — heat. Servers, in particular, generate a great deal of heat, so an enclosure must be capable of dissipating that heat to ensure that the components deliver their expected life.

Posted in: Application Briefs, Application Briefs

Tactile Feedback for Touch-input Devices

As products become more featurerich, manufacturers are looking at ways to improve the human-computer interface (HCI). Touchscreens, with intuitive operation and software flexibility, and screen-printed touch surfaces, with refined aesthetics and better sealing, have become extremely popular. But what these touch-input devices do not supply is tactile confirmation of (1) a button’s location and (2) pressing it. The loss of this tactile information can be detrimental to user engagement and understanding, productivity, completion of transactions, safety, and satisfaction. In some applications, the lack of tactile feedback has been enough of a problem to prevent the conversion from mechanical switches to digital controls. The solution is simple — add tactile feedback to secure the best features of touch-input devices.

Posted in: Application Briefs, Applications, ptb catchall, Photonics, Human machine interface (HMI), Displays, Performance upgrades

Powered by Lithium-Ion Batteries, NASA Spacecraft Explore Mars and the Moon

Lithium-ion batteries Yardney Technical Products Pawcatuck, CT 860-599-1100

NASA’s Phoenix Mars Lander landed safely near the planet’s north polar icecap in May. Phoenix relies on advanced lithiumion batteries from Yardney Technical Products to dig and look for water, seeking a habitable environment. The Phoenix batteries provide power at night when there is no sunlight for the solar panels to convert to electricity. They can also be used any time when a task requires more power than the primary power source can deliver.

Posted in: Application Briefs, Batteries, Lithium-ion batteries, Spacecraft

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