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Isolated probing tech for fast-switching power device testing

Keysight Technologies has developed an optically isolated differential probing family dedicated to enhancing efficiency and performance testing of fast-switching devices such as wide-bandgap GaN and SiC semiconductors. Validation of floating half-bridge and full-bridge architectures commonly used in power conversion, motor drives, and inverters requires measurement of small differential signals riding on high common-mode voltages. This measurement can be challenging due to voltage source fluctuations relative to ground, noise interference, and safety concerns.
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Protect sensitive electronics in explosive environments with new aluminum ATEX Cabinet Cooler Systems

EXAIR's ATEX Cabinet Cooler^® Systems deliver a powerful and affordable solution for keeping electrical enclosures cool in hazardous ATEX classified areas -- and they're now available in durable aluminum construction. Engineered for use in Zones 2 and 22, these coolers are UL tested, CE compliant, and meet stringent ATEX standards for purged and pressurized enclosures. With cooling capacities up to 5,600 Btu/Hr., ATEX Cabinet Coolers are ideal for preventing overheating in electrical cabinets. EXAIR offers a comprehensive lineup of systems.
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PLC handbook chock full of must-know information

Automation-Direct's Practical Guide to Program-mable Logic Controllers Handbook has been improved with tons of new need-to-know info, making it a more comprehensive guide to the world of PLCs. Besides covering the basics of PLC history, PLC hardware, and PLC software, this guide takes you deeper into the ever-changing world of PLC communication, the importance of feedback loops, cyber security, and many other areas that are a must-know for any PLC novice or seasoned automation professional.
Get this great resource today.

Haptic feedback prototyping kit from TDK

Get your customers to feel the difference your products make. TDK has released a development starter kit for fast haptics prototyping. It gives mechanical designers and engineers first impressions of the haptic feedback using PowerHap piezo actuators, shows how the mechanical integration works, and provides a reference design. Applications include automotive, displays and tablets, household appliances, vending machines, game controllers, industrial equipment, and medical devices.
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Mini ESD preset torque screwdriver

Need precision fastening with ESD protection at the smallest torque levels? Mountz has you covered. The new FG Mini ESD Preset Torque Screwdriver is built for low-torque, high-precision tasks. Its compact design makes it ideal for tight spaces and small fasteners, while delivering the same reliable control and ESD protection users have come to expect from Mountz. Two models available: FG25z (3 to 25 ozf.in, 2 to 17.7 cN-m) and FG50z (20 to 50 ozf.in, 14.1 to 35.3 cN-m).
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Laumas load cells and electronics from AutomationDirect

Automation-Direct has added Laumas precision-engineered load cells, transmitters, and accessories that deliver reliable performance in industrial weighing and force measurement applications. The FCAL series high-precision bending beam load cells are ideal for low- to mid-capacity systems. CTL series load cells are designed for both tension and compression, with excellent linearity. The CBL series low-profile compression load cells are perfect for space-limited applications. Laumas load cell transmitters are available too for precise monitoring and control. Very good pricing.
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Engineer's Toolbox: What is ground loop feedback?

Improper grounding can create problems in data logging, data acquisition, and measurement and control systems. One of the most common problems is known as ground loop feedback. Experts at CAS DataLoggers run through five ways to eliminate this problem.
Read the full article.

What is a braking resistor?

According to Automation-Direct, "Braking resistors don't actually provide braking directly -- rather, they allow a drive to stop a loaded motor faster." Why is this important? Protect your AC or DC drive system from regenerative voltage that can create an over-voltage fault on the drive -- especially with high inertial loads or rapid deceleration.
View the video.

New Digital Static Meter: Precise measurement, easy use

Static electricity isn't just a nuisance; it's a serious threat to manufacturing efficiency, product integrity, and workplace safety. Unchecked static can lead to costly downtime, product defects, material jams, and even hazardous shocks to employees. If static is interfering with your processes, EXAIR's upgraded Model 7905 Digital Static Meter offers an essential first step in identifying and eliminating the problem. With just the press of a button, this easy-to-use, handheld device pinpoints the highest voltage areas in your facility, helping you diagnose static issues before they become a problem.
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New laser cutting modulating strategy tested with Mikrotron high-speed camera

Modulating a laser beam's intensity distribution optimizes energy delivery to the process zone, resulting in better cutting speed, cut edge quality, and cut kerf geometry. Scientists in Belgium have come up with a new method that they say produces better cutting results.
Read the full article.

All-in-one embedded PLC based on Raspberry Pi 4 -- build control applications

The new PLC CPI-PS10CM4 from Contec Co. is a compact embedded programmable logic controller (PLC) that is loaded with CODESYS, the world's most widely used software PLC. This product uses Contec's original single-board computer, which is based on Raspberry Pi's latest embedded module, the Compute Module 4 (CM4). By using the wide range of peripheral devices for Raspberry Pi, such as Contec's CPI Series, you can build various control applications in a PLC language that complies with the IEC 61131-3 international standard.
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Torque sensors for fastening applications and more

Saelig Company has introduced the Sensor Technology SGR525/526 Series Torque Sensors to provide precision torque monitoring that is critical for performance and safety. The square drive design (for applications with non-cylindrical shafts) allows for seamless integration into power tools, test rigs, industrial machinery, and precision fastening applications, ensuring superior torque measurement without the need for additional adapters or modifications. The SGR525 offers torque measurement only, while the SGR526 provides torque, speed, and power measurement using a 360-pulse-per-revolution encoder. Industries include automotive, aerospace, manufacturing, and research and development.
Learn more.

Wide-angle camera optimized for larger, faster conveyor belts

Wider conveyor belts operating at higher speeds are now commonplace in modern logistics. To keep up, SVS-Vistek is offering a cost-effective alternative to multi-camera systems with its fxo901CXGE 10-GigE color camera featuring the Sony IMX901-AQR wide-aspect global shutter 16.4-megapixel CMOS sensor. Unlike standard cameras, this unit captures targets in a wide field of view while maintaining high resolutions. The 4:1 horizontal aspect ratio allows one fxo901CXGE to replace an entire multi-camera system, removing the need for image synchronization.
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Handheld thermal imager cuts diagnostic time

The FLIR TG268 is a next-generation thermal imager that provides professionals in the utility, manufacturing, electrical, automotive, and industrial sectors with a lightweight, handheld, affordable condition monitoring tool. Latest enhancements include higher temperature ranges, improved resolution, and larger data storage capacity. Go beyond the restrictions of single-spot IR thermometers to view and evaluate hot and cold spots that may signify potentially dangerous issues. Accurately measure temps from -25 to 400 C. Native thermal images improved with Super Resolution upscaling.
Learn more.

SOLIDWORKS 2025: Sheet metal design top features from an expert

Find out what's new in SOLIDWORKS 2025 when it comes to sheet metal and weldments, and learn some valuable tips and tricks along the way from TriMech. Topics covered include copying cut list properties, bend notches, tab and slot enhancements, groove beads (a new type of weld bead), performance enhancements, and more. When you're done, check out TriMech's full YouTube channel filled with educational material.
View the video.

New device offers long-distance, low-power underwater communication

The system could be used for battery-free underwater communication across kilometer-scale distances to aid monitoring of climate and coastal change.

By Adam Zewe, MIT News

MIT researchers have demonstrated the first system for ultra-low-power underwater networking and communication that can transmit signals across kilometer-scale distances.

This technique, which the researchers began developing several years ago, uses about one-millionth the power that existing underwater communication methods use. By expanding their battery-free system's communication range, the researchers have made the technology more feasible for applications such as aquaculture, coastal hurricane prediction, and climate change modeling.

"What started as a very exciting intellectual idea a few years ago -- underwater communication with a million times lower power -- is now practical and realistic. There are still a few interesting technical challenges to address, but there is a clear path from where we are now to deployment," says Fadel Adib, associate professor in the Department of Electrical Engineering and Computer Science and director of the Signal Kinetics group in the MIT Media Lab.

The new device is an array of piezoelectric transducers that enables battery-free underwater communication. [Credit: Courtesy of the researchers]

 

 

Underwater backscatter enables low-power communication by encoding data in sound waves that it reflects, or scatters, back toward a receiver. These innovations enable reflected signals to be more precisely directed at their source.

Due to this "retrodirectivity," less signal scatters in the wrong directions, allowing for more efficient and longer-range communication.

When tested in a river and an ocean, the retrodirective device exhibited a communication range that was more than 15 times farther than previous devices. However, the experiments were limited by the length of the docks available to the researchers.

To better understand the limits of underwater backscatter, the team also developed an analytical model to predict the technology's maximum range. The model, which they validated using experimental data, showed that their retrodirective system could communicate across kilometer-scale distances.

The researchers shared these findings in two papers which will be presented at this year's ACM SIGCOMM and MobiCom conferences. Adib, senior author on both papers, is joined on the SIGCOMM paper by co-lead authors Aline Eid, a former postdoc who is now an assistant professor at the University of Michigan, and Jack Rademacher, a research assistant; as well as research assistants Waleed Akbar and Purui Wang, and postdoc Ahmed Allam. The MobiCom paper is also written by co-lead authors Akbar and Allam.

Communicating with sound waves
Underwater backscatter communication devices utilize an array of nodes made from "piezoelectric" materials to receive and reflect sound waves. These materials produce an electric signal when mechanical force is applied to them.

When sound waves strike the nodes, they vibrate and convert the mechanical energy to an electric charge. The nodes use that charge to scatter some of the acoustic energy back to the source, transmitting data that a receiver decodes based on the sequence of reflections.

However, because the backscattered signal travels in all directions, only a small fraction reaches the source, reducing the signal strength and limiting the communication range.

To overcome this challenge, the researchers leveraged a 70-year-old radio device called a Van Atta array, in which symmetric pairs of antennas are connected in such a way that the array reflects energy back in the direction it came from.

However, connecting piezoelectric nodes to make a Van Atta array reduces their efficiency. The researchers avoided this problem by placing a transformer between pairs of connected nodes. The transformer, which transfers electric energy from one circuit to another, allows the nodes to reflect the maximum amount of energy back to the source.

"Both nodes are receiving and both nodes are reflecting, so it is a very interesting system. As you increase the number of elements in that system, you build an array that allows you to achieve much longer communication ranges," Eid explains.

In addition, they used a technique called cross-polarity switching to encode binary data in the reflected signal. Each node has a positive and a negative terminal (like a car battery), so when the positive terminals of two nodes are connected and the negative terminals of two nodes are connected, that reflected signal is a "bit one."

But if the researchers switch the polarity, and the negative and positive terminals are connected to each other instead, then the reflection is a "bit zero."

"Just connecting the piezoelectric nodes together is not enough. By alternating the polarities between the two nodes, we are able to transmit data back to the remote receiver," Rademacher explains.

When building the Van Atta array, the researchers found that if the connected nodes were too close, they would block each other's signals. They devised a new design with staggered nodes that enables signals to reach the array from any direction. With this scalable design, the more nodes an array has, the greater its communication range.

They tested the array in more than 1,500 experimental trials in the Charles River in Cambridge, MA, and in the Atlantic Ocean, off the coast of Falmouth, MA, in collaboration with the Woods Hole Oceanographic Institution. The device achieved communication ranges of 300 m, more than 15 times longer than they previously demonstrated.

However, they had to cut the experiments short, because they ran out of space on the dock.

Modeling the maximum
That inspired the researchers to build an analytical model to determine the theoretical and practical communication limits of this new underwater backscatter technology.

Building off their group's work on RFIDs, the team carefully crafted a model that captured the impact of system parameters, like the size of the piezoelectric nodes and the input power of the signal, on the underwater operation range of the device.

"It is not a traditional communication technology, so you need to understand how you can quantify the reflection. What are the roles of the different components in that process?" Akbar says.

For instance, the researchers needed to derive a function that captures the amount of signal reflected out of an underwater piezoelectric node with a specific size, which was among the biggest challenges of developing the model, he adds.

They used these insights to create a plug-and-play model into which a user could enter information like input power and piezoelectric node dimensions and receive an output that shows the expected range of the system.

They evaluated the model on data from their experimental trials and found that it could accurately predict the range of retrodirected acoustic signals with an average error of less than one decibel.

Using this model, they showed that an underwater backscatter array can potentially achieve kilometer-long communication ranges.

"We are creating a new ocean technology and propelling it into the realm of the things we have been doing for 6G cellular networks. For us, it is very rewarding, because we are starting to see this now very close to reality," Adib says.

The researchers plan to continue studying underwater backscatter Van Atta arrays, perhaps using boats so they could evaluate longer communication ranges. Along the way, they intend to release tools and datasets so other researchers can build on their work. At the same time, they are beginning to move toward commercialization of this technology.

Read: "Enabling Long-Range Underwater Backscatter via Van Atta Acoustic Networks" and "The Underwater Backscatter Channel: Theory, Link Budget, and Experimental Validation"

Published September 2023

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