Special Coverage

Lightweight, Flexible Thermal Protection System for Fire Protection
High-Precision Electric Gate for Time-of-Flight Ion Mass Spectrometers
Polyimide Wire Insulation Repair System
Distributed Propulsion Concepts and Superparamagnetic Energy Harvesting Hummingbird Engine
Wet Active Chevron Nozzle for Controllable Jet Noise Reduction
Magnetic Relief Valve
Active Aircraft Pylon Noise Control System
Unmanned Aerial Systems Traffic Management

Transforming Gaussian Beams into Uniform, Rectangular Intensity Distributions

The majority of laser types in current use produce output beams with circular or elliptical crosssections, with either Gaussian or near- Gaussian intensity profiles. This Gaussian intensity distribution is acceptable, and often beneficial for many applications in which the laser beam is being focused to a small spot. However, there are also many different uses for which a uniform intensity distribution (often referred to as a “flattop”) would be more optimal. For example, in materials processing tasks, a uniform intensity distribution ensures that the entire laser illuminated area is processed evenly. It is also valuable in situations where the laser light is used essentially for illumination. This is because uniform illumination makes identical features that all appear to have the same brightness, regardless of where they are located in the illuminated field, simplifying the image processing task and increasing contrast and resolution. These same benefits apply over a wide range of other applications that can be broadly classed as “illumination,” from machine vision, through flow cytometry, inspection, and even some medical uses.

Posted in: Articles, Features, Photonics


Designing Optical Systems With Off-The-Shelf Products

Utilization of COTS (commercial off-the-shelf) products is now almost a bylaw of government and military design projects and is becoming of increasing interest in commercial designs, as well. Optical systems are no exception; the use of stock optics can provide tremendous advantages in terms of reduced cost and development effort. The key is finding the most appropriate way of employing stock optics in a custom design.

Posted in: Articles, Applications, ptb catchall, Photonics


Coordinated Circuit Protection for LED Lighting

By Matt Williams, TE Circuit Protection, Menlo Park, CA As lighting technologies transition from power-hungry incandescents to coldcathode fluorescent lamps (CCFLs), and now to light-emitting diodes (LEDs), it is clear that while end-users are willing to pay more for greener light there is an inherent expectation that longer life and improved reliability will be the net benefit of that investment.

Posted in: Articles, Lighting, Powering & Controlling LEDs


The Cold Hard Facts

Contemporary LED Lighting Offers Superb Performance, Energy Efficiency, and Maintenance Savings in Cold Storage Applications By Michael Schratz, Dialight, Farmingdale, NJ Highly regarded for their maintenance-free, energy-efficient operation, and environmental friendliness in a wide range of industrial applications, light-emitting diode (LED) lighting solutions are quickly becoming a sought-after alternative to high-intensity discharge (HID) and fluorescent lighting in cold storage applications. By their very nature of operational form and function, LEDs effectively overcome virtually all of the most vexing challenges surrounding cold storage lighting for both refrigeration and deep-freeze environments to provide an ultralong-life lighting solution with an ROI payback period of as little as two years.

Posted in: Articles, Lighting, Manufacturing & Prototyping


Speech Recognition Interfaces Improve Flight Safety

NASA Technology “Alpha, Golf, November, Echo, Zulu.” “Sierra, Alpha, Golf, Echo, Sierra.” “Lima, Hotel, Yankee.” It looks like some strange word game, but the combinations of words above actually communicate the first three points of a flight plan from Albany, New York to Florence, South Carolina. Spoken by air traffic controllers and pilots, the aviation industry’s standard International Civil Aviation Organization phonetic alphabet uses words to represent letters. The first letter of each word in the series is combined to spell waypoints, or reference points, used in flight navigation. The first waypoint above is AGNEZ (alpha for A, golf for G, etc.). The second is SAGES, and the third is LHY.

Posted in: Articles, Aeronautics


Event-Driven Processor Programming

Almost since computers were invented, interrupts have been a common programming method to deal with real-time tasks. An interrupt causes a processor to stop the running task, and to execute an interrupt handler instead. The interrupt handler determines the cause of the interrupt, responds to the interrupt, whereupon control is restored to the original task. A simple example is an interrupt from a UART (a serial port) stating that a character has been received, and the interrupt handler will take the character from the UART and store it in a queue in memory for use by the main task.

Posted in: Articles, Articles


Extensible Processing Platforms: Giving Designers the Best of Both Worlds

Creating a new field programmable gate array is no small feat. FPGA vendors spend tens-of-thousands of man-hours simply researching markets to determine the feature set a given device will require and the silicon process that they will use to manufacture the device. This starts years before they embark on the ever more difficult task of actually designing the IC and the software to allow users to program it.

Posted in: Articles, Articles


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