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Intro to reed switches, magnets, magnetic fields

This brief introductory video on the DigiKey site offers tips for engineers designing with reed switches. Dr. Stephen Day, Ph.D. from Coto Technology gives a solid overview on reed switches -- complete with real-world application examples -- and a detailed explanation of how they react to magnetic fields.
View the video.

Bi-color LEDs to light up your designs

Created with engineers and OEMs in mind, SpectraBright Series SMD RGB and Bi-Color LEDs from Visual Communi-cations Company (VCC) deliver efficiency, design flexibility, and control for devices in a range of industries, including mil-aero, automated guided vehicles, EV charging stations, industrial, telecom, IoT/smart home, and medical. These 50,000-hr bi-color and RGB options save money and space on the HMI, communicating two or three operating modes in a single component.
Learn more.

All about slip rings: How they work and their uses

Rotary Systems has put together a really nice basic primer on slip rings -- electrical collectors 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 overview.

Seifert thermoelectric coolers from AutomationDirect

Automation-Direct has added new high-quality and efficient stainless steel Seifert 340 BTU/H thermoelectric coolers with 120-V and 230-V power options. Thermoelectric coolers from Seifert use the Peltier Effect to create a temperature difference between the internal and ambient heat sinks, making internal air cooler while dissipating heat into the external environment. Fans assist the convective heat transfer from the heat sinks, which are optimized for maximum flow.
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EMI shielding honeycomb air vent panel design

Learn from the engineering experts at Parker how honeycomb air vent panels are used to help cool electronics with airflow while maintaining electromagnetic interference (EMI) shielding. Topics include: design features, cell size and thickness, platings and coatings, and a stacked design called OMNI CELL construction. These vents can be incorporated into enclosures where EMI radiation and susceptibility is a concern or where heat dissipation is necessary. Lots of good info.
Read the Parker blog.

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 replaces the traditional printed circuit board and opens up many new opportunities. It takes injection-molded parts and uses laser-direct structuring to etch areas of conductor structures, which are filled with a copper plating process to create very precise electronic circuits. HARTING, the technology's developer, says it's "Like a PCB, but 3D." Tons of possibilities.
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Loss-free conversion of 3D/CAD data

CT CoreTech-nologie has further developed its state-of-the-art CAD converter 3D_Evolution and is now introducing native interfaces for reading Solidedge and writing Nx and Solidworks files. It supports a wide range of formats such as Catia, Nx, Creo, Solidworks, Solidedge, Inventor, Step, and Jt, facilitating smooth interoperability between different systems and collaboration for engineers and designers in development environments with different CAD systems.
Learn more.

Top 5 reasons for solder joint failure

Solder joint reliability is often a pain point in the design of an electronic system. According to Tyler Ferris at ANSYS, a wide variety of factors affect joint reliability, and any one of them can drastically reduce joint lifetime. Properly identifying and mitigating potential causes during the design and manufacturing process can prevent costly and difficult-to-solve problems later in a product lifecycle.
Read this informative ANSYS blog.

Advanced overtemp detection for EV battery packs

Littelfuse has introduced TTape, a ground-breaking over-temperature detection platform designed to transform the management of Li-ion battery systems. TTape helps vehicle systems monitor and manage premature cell aging effectively while reducing the risks associated with thermal runaway incidents. This solution is ideally suited for a wide range of applications, including automotive EV/HEVs, commercial vehicles, and energy storage systems.
Learn more.

Benchtop ionizer for hands-free static elimination

EXAIR's Varistat Benchtop Ionizer is the latest solution for neutralizing static on charged surfaces in industrial settings. Using ionizing technology, the Varistat provides a hands-free solution that requires no compressed air. Easily mounted on benchtops or machines, it is manually adjustable and perfect for processes needing comprehensive coverage such as part assembly, web cleaning, printing, and more.
Learn more.

LED light bars from AutomationDirect

Automation-Direct adds CCEA TRACK-ALPHA-PRO series LED light bars to expand their offering of industrial LED fixtures. Their rugged industrial-grade anodized aluminum construction makes TRACKALPHA-PRO ideal for use with medium to large-size industrial machine tools and for use in wet environments. These 120 VAC-rated, high-power LED lights provide intense, uniform lighting, with up to a 4,600-lumen output (100 lumens per watt). They come with a standard bracket mount that allows for angle adjustments. Optional TACLIP mounts (sold separately) provide for extra sturdy, vibration-resistant installations.
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World's first metalens fisheye camera

2Pi Optics has begun commercial-ization of the first fisheye camera based on the company's proprietary metalens technology -- a breakthrough for electronics design engineers and product managers striving to miniaturize the tiny digital cameras used in advanced driver-assistance systems (ADAS), AR/VR, UAVs, robotics, and other industrial applications. This camera can operate at different wavelengths -- from visible, to near IR, to longer IR -- and is claimed to "outperform conventional refractive, wide-FOV optics in all areas: size, weight, performance, and cost."
Learn more.

Orbex offers two fiber optic rotary joint solutions

Orbex Group announces its 700 Series of fiber optic rotary joint (FORJ) assemblies, supporting either single or multi-mode operation ideal for high-speed digital transmission over long distances. Wavelengths available are 1,310 or 1,550 nm. Applications include marine cable reels, wind turbines, robotics, and high-def video transmission. Both options feature an outer diameter of 7 mm for installation in tight spaces. Construction includes a stainless steel housing.
Learn more.

Mini tunnel magneto-resistance effect sensors

Littelfuse has released its highly anticipated 54100 and 54140 mini Tunnel Magneto-Resistance (TMR) effect sensors, offering unmatched sensitivity and power efficiency. The key differentiator is their remarkable sensitivity and 100x improvement in power efficiency compared to Hall Effect sensors. They are well suited for applications in position and limit sensing, RPM measurement, brushless DC motor commutation, and more in various markets including appliances, home and building automation, and the industrial sectors.
Learn more.

Panasonic solar and EV components available from Newark

Newark has added Panasonic Industry's solar inverters and EV charging system components to their power portfolio. These best-in-class products help designers meet the growing global demand for sustainable and renewable energy mobility systems. Offerings include film capacitors, power inductors, anti-surge thick film chip resistors, graphite thermal interface materials, power relays, capacitors, and wireless modules.
Learn more.

More than illuminating: Researchers steer the flow of electrical current with spinning light

Light can generate an electrical current in semiconductor materials. This is how solar cells generate electricity from sunlight and how smart phone cameras can take photographs. To collect the generated electrical current, called photocurrent, an electric voltage is needed to force the current to flow in only one direction.

In new research, scientists at the University of Minnesota used a first-of-its-kind device to demonstrate a way to control the direction of the photocurrent without deploying an electric voltage. The new study was recently published in the scientific journal Nature Communications.

The study reveals that control is effected by the direction in which the particles of light, called photons, are spinning -- clockwise or counterclockwise. The photocurrent generated by the spinning light is also spin-polarized, which means there are more electrons with spin in one direction than in the other. This new device holds significant potential for use in the next generation of microelectronics using electron spin as the fundamental unit of information. It could also be used for energy-efficient optical communication in data centers.

"The observed effect is very strong and robust in our devices, even at room temperature and in open air," said Mo Li, a University of Minnesota electrical and computer engineering associate professor and a lead author of the study. "Therefore, the device we demonstrate has great potential for being implemented in next-generation computation and communication systems."

Optical spin and topological insulators
Light is a form of electromagnetic wave. The way the electric field oscillates, either in a straight line or rotating, is called polarization. (Your polarized sunglasses block part of the unpleasant reflected light that is polarized along a straight line.) In circularly polarized light, the electric field can spin in the clockwise or counterclockwise direction. In such a state, the particle of light (photon) is said to have positive or negative optical spin angular momentum. This optical spin is analogous to the spin of electrons, and endows magnetic properties to materials.

Recently, a new category of materials, called topological insulators (TI), was discovered to have an intriguing property not found in common semiconductor materials. Imagine a road on which red cars only drive on the left lane, and blue cars only in the right lane. Similarly, on the surface of a TI, the electrons with their spins pointing one way always flow in one direction. This effect is called spin-momentum locking -- the spin of the electrons is locked in the direction they travel.

This image shows a false-colored electron microscope image of the University of Minnesota device. The blue area marks the topological insulator on top of the optical waveguide in red. [Credit: University of Minnesota]

 

 

Interestingly, shining a circularly polarized light on a TI can free electrons from its inside to flow on its surface in a selective way, for example, clockwise light for spin-up electrons and counterclockwise for spin-down electrons. Because of this effect, the generated photocurrent on the surface of the TI material spontaneously flows in one direction, requiring no electric voltage. This particular feature is significant for controlling the direction of a photocurrent. Because most of the electrons in this current have their spins pointing in a single direction, this current is spin-polarized.

Controlling direction and polarization
To fabricate their unique device that can change the direction of a photocurrent without the use of an electric voltage, the University's research team integrated a thin film of a TI material, bismuth selenide, on an optical waveguide made of silicon. Light flows through the waveguide (a tiny wire measuring 1.5 microns wide and 0.22 micron high) just like electrical current flows through a copper wire. Because light is tightly squeezed in the waveguide, it tends to be circularly polarized along a direction normal to the direction in which it flows. This is akin to the spin-momentum locking effect of the electrons in a TI material.

The scientists supposed that integrating a TI material with the optical waveguide will induce strong coupling between the light in the waveguide and the electrons in the TI material, both having the same, intriguing spin-momentum locking effect. The coupling will result in a unique optoelectronic effect: light flowing along one direction in the waveguide generates an electrical current flowing in the same direction with electron spin polarized. Reversing the light direction reverses both the direction of the current and its spin polarization. And this is exactly what the team observed in their devices. Other possible causes of the observed effect, such as heat generated by the light, have been ruled out through careful experiments.

Future prospects
The outcome of the research is exciting for the researchers. It bears enormous potential for possible applications.

"Our devices generate a spin-polarized current flowing on the surface of a topological insulator. They can be used as a current source for spintronic devices, which use electron spin to transmit and process information with very low energy cost," said Li He, a University of Minnesota physics graduate student and an author of the paper.

"Our research bridges two important fields of nanotechnology: spintronics and nanophotonics. It is fully integrated with a silicon photonic circuit that can be manufactured on a large scale and has already been widely used in optical communication in data centers," he added.

This research was funded by the Center for Spintronic Materials, Interfaces and Novel Architectures (C-SPIN) at the University of Minnesota, a Semiconductor Research Corporation program sponsored by the Microelectronics Advanced Research Corp. (MARCO) and the Defense Advanced Research Projects Agency (DARPA), and the National Science Foundation (NSF).

Source: University of Minnesota College of Science and Engineering

Published February 2018

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