September 19, 2017 Volume 13 Issue 35

Electrical/Electronic News & Products

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All about slip rings: How they work and their uses

Rotary Systems has put together a really nice basic primer on slip rings -- electrical swivels that carry a current from a stationary wire into a rotating device. Common uses are for power, proximity switches, strain gauges, video, and Ethernet signal transmission. This introduction also covers how to specify, assembly types, and interface requirements. Rotary Systems also manufactures rotary unions for fluid applications.
Read the Rotary Systems article.


Digital microscope with 2,040x mag: Under $200

Inspect work products or help your little engineer at home win that science fair with the AD246S-M HDMI Digital Microscope from Andonstar Technology Co. This tri-lens unit boasts a wide magnification range (60 to 240x, 18 to 720x, 1,560 to 2,040x), very good image performance, built-in rotatable monitor, and a slew of multifunctional accessories including a remote, dimmer cable to adjust illumination, and more. A solid choice for a small investment.
Learn more.


What is 3D-MID? Molded parts with integrated electronics from HARTING

3D-MID (three-dimensional mechatronic integrated devices) technology combines electronic and mechanical functionalities into a single 3D component. It gives engineers the power and freedom to shrink components, optimize space, and provide higher overall functional density -- while offering the same or more capabilities as in larger devices. HARTING's tagline for the tech is, "Like a PCB, but 3D."
Read the full article.


World-first bendable 5K2K gaming monitor

The LG UltraGear OLED Bendable Gaming Monitor (model 45GX990A) is the world's first 5K2K-resolution bendable OLED display. The 45-in. monitor can smoothly transition from completely flat to a 900R curvature within seconds for more flexibility and control over your gaming experience. Its upgraded Dual-Mode feature allows users to switch effortlessly between resolution and refresh rate presets, and customize aspect ratio and picture size.
Learn more about this monitor and other LG releases at CES.


Rugged photoelectric sensors see up to 4 meters

Automation-Direct has added AchieVe FDM series 12-mm tubular photoelectric sensors that offer a rugged metal construction, high IP67 protection ratings, and sensing distances up to 4 m. These sensors feature selectable light-on/dark-on operation, a 10- to 30-VDC operating voltage range, potentiometer or teach-in button sensitivity adjustment, and a fast 1-kHz switching frequency. Highly visible red LED models are offered with the polarized reflective sensing style, while infrared models are available in diffuse and through-beam styles. Lots of applications. Three-year warranty.
Learn more.


Engineer's Toolbox: Critical inspection of airplane parts with a SVS-Vistek 10GigE camera

Manufacturers of aviation engine components are being impacted by Industry 4.0's emphasis on quality control, which is challenging them to rethink outdated processes and to embrace new technologies. A new system developed by researchers in Italy uses a Kuka robot, a SVS-Vistek 61-megapixel 10GigE camera, and AI to detect defects in honeycomb aerospace parts faster and with more accuracy.
Read the full article.


What's new in MATLAB and Simulink?

Release 2024b from MathWorks offers hundreds of new and updated features and functions in MATLAB and Simulink including several major updates -- including 5G Toolbox, Simulink Control Design, System Composer, and more -- that streamline the workflows of engineers and researchers working on wireless communications systems, control systems, and digital signal processing applications.
View the video.


COTS-based space-ready orbital systems

Aitech Systems' solutions can meet the growing demands for shorter development times and lower costs among satellite buses, subsystems, and payloads. Using a Space Digital Backbone (DBB) approach, which provides a flexible, scalable communication pathway for the increasing number of Internet of Things technologies being implemented into space missions, the company provides a selection of space-rated subsystems for common space platforms including: Earth observation, communications, power control, navigation, and robotics.
Learn more.


Circuit breakers have magnetic module option

SCHURTER has upgraded its 2-pole classic TA35 and TA36 thermal circuit breaker models with an additional, optional magnetic module. From now on, no additional fuse is required when using a thermal-magnetic type. Depending on the application, the magnetic modules are available either with a slow- or a fast-acting characteristic. Both models are designed for snap-in mounting and with finely graduated rated currents. A variety of colors and lighting options make the designer's choice easier.
Learn more.


All about magnetic rotary encoder

The precision and reliability offered by modern rotary encoders are essential in many product categories. These include robotics, machine tools, printing presses, motion control systems, medical equipment, aerospace, gaming and entertainment, and automotive. Learn all about magnetic rotary encoders -- and important developments in the technology's future.
Read the full Avnet article.


High-res image sensor for automotive ADAS and AD

OMNIVISION has expanded its TheiaCel™ product portfolio with a new OX12A10 12-MP high-res image sensor for automotive cameras. This sensor, with the highest resolution in its line, improves automotive safety by eliminating LED flicker regardless of lighting conditions. It is ideal for high-performance front machine vision cameras for advanced driver assistance systems (ADAS) and autonomous driving (AD).
Learn more.


Durable, full redundant angle sensors for automotive and off-highway

Novotechnik's new RSK-3200 Series angle sensors are designed for harsh automotive and off-highway applications. Measurement range is 0 to 360 degrees, and the temperature range is -40 to 125 C. This unit's built-in coupling accepts D-Shaft, with shaft customization available. The sensors are sealed to IP 67 or IP 69k depending on version. RSK-3200 Series sensors are extremely durable with MTTF of 285 years for each of the two channels! Applications include throttle control and EGR valves, transmission gear position, and accelerator position. Very competitive pricing.
Learn more.


Great design: Handle with integrated lighting/signaling

Signaling and indicator lights, switches, and buttons -- elements that hardly any machine can do without. The new JW Winco cabinet U-handle EN 6284 integrates all these functions into a single, compact element. The new U-handle is designed to enhance the operation of systems and machines. It features an integrated button and a large, colored, backlit area on the handle. These elements can be used individually or in combination, providing a versatile tool for system control and process monitoring that can be seen from across the room.
Learn more.


World's most popular 3D multisensor metrology systems get next-gen addition

Offered in two benchtop and two floor-model options to handle nearly any size part, the SmartScope M-Series systems from Optical Gaging Products usher in the next generation of enhancements in image accuracy, optics, and throughput to the world's most popular 3D multisensor video measurement platform. SmartScope M-Series features fixed optics with a 20-megapixel camera and proprietary Virtual Zoom, combined with advanced sensors, illumination, and accessories, to achieve class-leading optical measurement speeds. Lots more features.
Learn more.


SOLIDWORKS Tips: 3 easy ways to focus on your model

SOLIDWORKS Elite Applications Engineer Alin Vargatu demonstrates his top tips for focusing on your model: finding planes the easy way inside your assembly with the Q key, breadcrumbs, and a better way to use the component preview window. Very helpful. Lots more tips on the SOLIDWORKS YouTube channel.
View the video.


Tiny terahertz laser could be used for imaging, chemical detection

A new technique boosts the power output of tiny, chip-mounted terahertz lasers by 88 percent. [Image: Demin Liu/Molgraphics]

 

 

By Larry Hardesty, MIT

Terahertz radiation -- the band of the electromagnetic spectrum between microwaves and visible light -- has promising applications in medical and industrial imaging and chemical detection, among other uses.

But many of those applications depend on small, power-efficient sources of terahertz rays, and the standard method for producing them involves a bulky, power-hungry, tabletop device.

For more than 20 years, Qing Hu, a distinguished professor of electrical engineering and computer science at MIT, and his group have been working on sources of terahertz radiation that can be etched onto microchips. In the August issue of Nature Photonics, members of Hu's group and colleagues at Sandia National Laboratories and the University of Toronto describe a novel design that boosts the power output of chip-mounted terahertz lasers by 80 percent.

As the best-performing chip-mounted terahertz source yet reported, the researchers' device has been selected by NASA to provide terahertz emission for its Galactic/Extragalactic ULDB Spectroscopic Terahertz Observatory (GUSTO) mission. The mission is intended to determine the composition of the interstellar medium, or the matter that fills the space between stars, and it's using terahertz rays because they're uniquely well-suited to spectroscopic measurement of oxygen concentrations. Because the mission will deploy instrument-laden balloons to the Earth's upper atmosphere, the terahertz emitter needs to be lightweight.

The researchers' design is a new variation on a device called a quantum cascade laser with distributed feedback. "We started with this because it was the best out there," says Ali Khalatpour, a graduate student in electrical engineering and computer science and first author on the paper. "It has the optimum performance for terahertz."

Until now, however, the device has had a major drawback, which is that it naturally emits radiation in two opposed directions. Since most applications of terahertz radiation require directed light, that means that the device squanders half of its energy output. Khalatpour and his colleagues found a way to redirect 80 percent of the light that usually exits the back of the laser, so that it travels in the desired direction.

As Khalatpour explains, the researchers' design is not tied to any particular "gain medium," or combination of materials in the body of the laser.

"If we come up with a better gain medium, we can double its output power, too," Khalatpour says. "We increased power without designing a new active medium, which is pretty hard. Usually, even a 10 percent increase requires a lot of work in every aspect of the design."

Big waves
In fact, bidirectional emission, or emission of light in opposed directions, is a common feature of many laser designs. With conventional lasers, however, it's easily remedied by putting a mirror over one end of the laser.

But the wavelength of terahertz radiation is so long, and the researchers' new lasers -- known as photonic wire lasers -- are so small, that much of the electromagnetic wave traveling the laser's length actually lies outside the laser's body. A mirror at one end of the laser would reflect back a tiny fraction of the wave's total energy.

Khalatpour and his colleagues' solution to this problem exploits a peculiarity of the tiny laser's design. A quantum cascade laser consists of a long rectangular ridge called a waveguide. In the waveguide, materials are arranged so that the application of an electric field induces an electromagnetic wave along the length of the waveguide.

This wave, however, is what's called a "standing wave." If an electromagnetic wave can be thought of as a regular up-and-down squiggle, then the wave reflects back and forth in the waveguide in such a way that the crests and troughs of the reflections perfectly coincide with those of the waves moving in the opposite direction. A standing wave is essentially inert and will not radiate out of the waveguide.

So Hu's group cuts regularly spaced slits into the waveguide, which allow terahertz rays to radiate out. "Imagine that you have a pipe, and you make a hole, and the water gets out," Khalatpour says. The slits are spaced so that the waves they emit reinforce each other -- their crests coincide -- only along the axis of the waveguide. At more oblique angles from the waveguide, they cancel each other out.

Breaking symmetry
In the new work, Khalatpour and his coauthors -- Hu, John Reno of Sandia, and Nazir Kherani, a professor of materials science at the University of Toronto -- simply put reflectors behind each of the holes in the waveguide, a step that can be seamlessly incorporated into the manufacturing process that produces the waveguide itself.

The reflectors are wider than the waveguide, and they're spaced so that the radiation they reflect will reinforce the terahertz wave in one direction but cancel it out in the other. Some of the terahertz wave that lies outside the waveguide still makes it around the reflectors, but 80 percent of the energy that would have exited the waveguide in the wrong direction is now redirected the other way.

"They have a particular type of terahertz quantum cascade laser, known as a third-order distributed-feedback laser, and this right now is one of the best ways of generating a high-quality output beam, which you need to be able to use the power that you're generating, in combination with a single frequency of laser operation, which is also desirable for spectroscopy," says Ben Williams, an associate professor of electrical and computer engineering at the University of California at Los Angeles. "This has been one of the most useful and popular ways to do this for maybe the past five, six years. But one of the problems is that in all the previous structures that either Qing's group or other groups have done, the energy from the laser is going out in two directions, both the forward direction and the backward direction."

"It's very difficult to generate this terahertz power, and then once you do, you're throwing away half of it, so that's not very good," Williams says. "They've come up with a very elegant scheme to essentially force much more of the power to go in the forward direction. And it still has a good, high-quality beam, so it really opens the door to much more complicated antenna engineering to enhance the performance of these lasers."

The new work was funded by NASA, the National Science Foundation, and the U.S. Department of Energy.

Published September 2017

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