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Articles from 2003 In August


Fasteners that stand against corrosive environments

Fasteners that stand against corrosive environments

Read this PDF article here.

A Hollywood Thriller

A Hollywood Thriller

One of the biggest dramas in tinsel town today isn't showing on the Big Screen. Rather, it is revolving around how movies of the future will make it to the Big Screen.



Film studios and theater owners are clashing over digital cinema, and the big question is: "Who will pay?"

First, a little history: Back in 1999, when four theaters presented the first digital showing of a movie-Star Wars: Episode I-the technology held great promise. There were predictions that digital projection would rapidly fan out to theaters everywhere. But that didn't happen. Of the world's some 100,000 theaters, only 160 to date have implemented the technology.

"I thought that we had crossed the threshold and that we would be on a more aggressive deployment timetable now," says Doug Darrow, Business Manager for Texas Instrument's DLP (Digital Light Projection) Cinema Products. TI supplies the DLP chips that go into digital theater projectors, as well as hundreds of thousands of other business and home entertainment products (www.dlp.com/#Scene_1).

In the battle to bring digital technology to the theater, interested parties are lining up pretty much the way you might expect: Technology providers like TI insist that their products are proven, and that it's a question of cost and who will pay. Theater owners concerned over the estimated $150K cost per digital projector and who will bear it, insist that the technology is not yet ready for prime time. (Costs are expected to fall, but only as volume increases.) Movie studios, who stand to benefit most from the cost savings in converting from film to digital files (an estimated $1 billion annually)-are focusing on developing specs for the technology and keeping mum about who will ultimately foot the bill.

The reaction from movie goers themselves is mixed, though the truly visually discerning, like EDN editor and EE Brian Dipert, don't like their Jar Jar jaggy (www.e-insite.net/ednmag).

What's happening in Hollywood should be a cautionary tale for engineers and technology marketers alike: Even a technology worthy of an Academy Award will have an incredibly tough time making it to the Big Screen if the people who get the most value from it aren't willing to pay for it.

I only hope Hollywood doesn't try to pass along the costs to you and me.

[email protected]

Electrifying design

Electrifying design


Saving Space: "To make room for the battery pack, we had to moe all the action to the rear wheel," says Vectrix VP of Technology Peter Hughes, posing here with a prototype of the company's new electric scooter.

Newport, RI- If engineers at Vectrix Corp. had any doubts about the industry's reaction to its new electric scooter technology slated to debut in early 2004, those doubts were dispelled recently when they took their vehicle to a Peugeot test track in France. There, they laid their scooter's reputation on the line in a drag race of sorts against a top-of-the-line gas-powered competitor.

"In a one-kilometer race, they couldn't catch our scooter," recalls Peter Hughes, vice president of technology for Vectrix Corp. (www.vetrixusa.com). "They ran the race repeatedly and our scooter kept winning. They were stunned." If that weren't enough, Vectrix then took its product to Germany and demonstrated it for a major motorcycle manufacturer.

"The chief engineer there took off on our scooter and we didn't see him for 45 minutes," Hughes notes. "When he came back, he stuck his finger in my chest and said, 'You have designed a weapon.'" Weapon, indeed. If observers are correct, the battery-powered Vectrix scooter could turn out to be a weapon in the battle for the hearts, minds, and pocketbooks of European consumers looking for a better way to commute to work. If the scooter is successful, however, its success will be attributable to more than just being in the right place at the right time. Vectrix's effort to breathe life into the scooter involves a determined seven-year engineering effort.

Two-Wheel 'Challenge'

Although scooters comprise a small market and are not well understood in the U.S., their popularity in Europe is growing rapidly.

Still, Vectrix's up-and-coming status in the scooter arena carries a distinctive irony. Coming from the U.S., where most consumers don't know what a scooter is, and where electric vehicles failed miserably in the 1990s, the identification of a major opportunity in the scooter market had to be considered unlikely at best.

Vectrix's founders did see the light, however, during a meeting at Lockheed Martin Corp.'s Marietta, GA-facility during 1997. There, Vectrix's founder Andrew MacGowan struck up a deal with Lockheed: He would provide business assistance to Lockheed if the aerospace company would lend technical and engineering expertise to MacGowan's as-yet-undefined entrepreneurial effort.


Parts Count: Engineers eliminated the traditional belt drive by employing a single-stage planetary gear that rotates with the rear wheel.

During a two-day brainstorming meeting in Marietta that followed, two dozen Lockheed engineers helped nail down a technical concept in the relatively untapped area of two-wheel electric vehicles.

Once the decision was made, the three-man engineering team from Vectrix faced the complex task of designing a vehicle that could compete with its gas-powered cousins.

Most important was the issue of range. "The challenge was to come up with a two-wheeled vehicle that performs the same as 250-cc gas-powered vehicles in speed and acceleration," Hughes says. "We also wanted it to weigh the same and not cost any more than the competitors in that class."

Hughes and his team knew that others had tried to do the same, but had failed. The failures, however, had generally been at the very low end of the market (50-cc scooters) that started out as gasoline-powered products, and were subsequently reengineered as EVs. Most of the resulting scooters lacked the power to compete with gas-powered competitors.

Vectrix decided to deal with that issue by immediately opting for higher voltage and higher power. Instead of operating in the 36 to 48V range, as previous electric scooters had, Vectrix engineers employed a 125V-dc battery bus. As a result, their peak power number jumped from about 2 kW to around 20 kW. The company's engineers also opted for about 180 lbs of on-board 30 Amp-hour nickel-metal hydride batteries from Gold Peak Batteries (Hong Kong) to give them the power they needed. The downside of that decision, however, was that the vehicle, targeted between 360-420 lbs, now had a serious weight problem.


Stop-And-Go: To determine a scooter performance requirements, Vectrix engineers studied typical patterns associated with urban commuting. What they discovered -- not surpisingly -- is that city drivers spend a lot of their time starting and stoping and drive relatively short distances at a constant speed. Thorugh DSP-based motor control, engineers were able to tminimize energy consumption (right), thereby increasing the travel range of the scooter on a single battery charge.

To deal with that, engineers went to work on reducing the weight of the scooter's frame. By teaming with engineers at the Alcoa Aluminum Technical Center in Pittsburgh, Vectrix engineers designed a patented aluminum frame, the bottom half of which carries the battery pack. The aluminum frame's castings attach to the bike's suspension and to extruded aluminum swing arms that connect a rear-mounted drive to the rest of the frame. "To make space for the batteries within the frame, we had to move all the 'action' into the rear wheel," says Hughes.

Indeed, by designing the frame and drive system in that way, Vectrix engineers say that they made the scooter lighter and more energy efficient. The reason: The scooter employs a direct drive that eliminates the need for a drive belt, which would ordinarily run between an engine sprocket and the rear wheel.

Vectrix engineers say they eliminated the traditional belt drive by employing a single-stage planetary gear box from Getrag Corp. (Newton, NC) that actually rotates with the rear wheel. Instead of transferring power through mechanical linkages, the motor resides on the aluminum swing arm and is splined to the planetary gear box. To make the pieces work in unison, Mechanical Engineer Dan Baldwin performed extensive finite element analysis on the frame and worked closely with the Alcoa Technical Center.


High Energy: Engineers investigated a variety of battery technologies, selecting NiMH for its high energy density and proven reliability.

The resulting frame achieves its weight reductions by employing variable thicknesses that dip down to as low as just 1.5 mm at the belly pan, which carries the batteries. Baldwin says that by going to aluminum, the engineering team reduced the frame's weight to 25 lbs, compared to 85 lbs for a typical tubular steel frame used on similarly-sized gas-powered scooters.

Digital Soul

Achieving the high accelerations and speeds needed to compete with conventional scooters, however, was another matter. The use of a lightweight frame helped, engineers say, but by itself wasn't enough to provide the performance they wanted.

To meet the performance goals, the scooter's powertrain employs brushless dc motors that peak at 27 hp. Engineers say that the dc motors, supplied by Parker Hannifin's SBC Division (Milan, Italy) and by Kollmorgen (Radford, VA), inherently provide instant torque. In addition, the direct rear-wheel drive configuration also gives an acceleration boost, because there's no torque wind-up or backlash, nor a need to wait for fuel to pass through a carburetor.

Engineers also boosted the scooter's range by employing an intelligent drive system that "looks" at the surrounding conditions and optimizes the phase angle advance of the motor to get the most efficient operation out of it. To accomplish that, the drive system employs a digital signal processor (DSP) from Texas Instruments (Dallas, TX) that looks at the command signal from the scooter's throttle and compares it to the position of an encoder on the motor's shaft. From that input, the DSP "decides" (via a look-up table) how to control the system's insulated gate bipolar transistors (IGBTs). By doing so, it generates a pulsewidth-modulated signal that makes the dc motor operate as if it is running off a three-phase ac electrical supply.

"With this design, we can control the voltage and the current, and get the motor to do exactly what we want," Hughes explains. "That's why we say the DSP is the heart and soul of this system."

Cultural change

Vectrix engineers claim that the resulting scooter offers a 0-50 km/hour acceleration of time of just 3.6 seconds, compared to 5.0 seconds for a typical four-stroke, 250-cc gas scooter. It also offers a 110-km range, which is ten more kilometers than the company's original goal. Its weight is about 200 kg, compared to approximately 170 kg for a typical gas scooter.

What's more, the scooter is considered to be a zero-emissions vehicle, which is inducing some countries, such as England, to consider offering financial stipends to consumers who buy the product.

Despite the relatively high cost of a 180-lb nickel-metal hydride battery pack, Vectrix engineers also say they managed to minimize their product's cost through the use of the integrated aluminum castings, which enabled a dramatic reduction in the overall parts count. Their scooter, they say, consists of about 250 parts, whereas a typical gasoline-powered scooter has about ten times that many. The result, the company says, is that its assembly is far less labor intensive than that of a gasoline-powered competitor. The reduction in labor will yield a scooter that costs the same as a gas-powered 250-cc equivalent, the company says.

Late this year, Vectrix plans to roll out eight pre-production vehicles that will incorporate fully-functioning lights, seats, and body panels - elements that have been left to the very last stages of design. By next spring, Vectrix engineers plan to move to full production. Their goal is to target the 125-cc-and-over European scooter market, which exceeds annual sales of more than a million units per year. Ultimately, they hope to look to the enormous potential market in Asia.

Observers believe that the technology's only possible Achilles heel might be its reliance on a cultural change. "Instead of pulling into the petrol station to put a carcinogen in the tank, users will have to adapt to a regime of charging the bike for a couple of hours every few days," notes one observer. "That's really its only disadvantage."

Vectrix executives say that their scooter shows that electric vehicles have a place in the market, as long as they stay within their sweet spot. "The auto industry has proven that even if you invest a billion dollars, it doesn't ensure success," MacGowan says. "We invested a fraction of that, and look what we've done in the two-wheel world."

Electronics

Electronics

Resistors

Enhanced pulse and overload

The PWC series of resistors is available in sizes 0805, 1206, 2010, and 2512, with respective power ratings of 0.125, 0.33, 0.75, and 1.5W. The ratings are up to 50% higher than standard thick-film chip resistors, the company says. Working voltages of the larger sizes (400V in the 2010 and 500V in the 2512) are double conventional limits. The products have no special heat sink requirements. TT electronics; www.ttelectronics.com Enter 584

Tilt sensor

Ideal for down-hole logging

High-precision T435 inertial tilt inclinometers are reportedly rugged enough for harsh outdoor environments. The closed-loop, gravity-referenced sensors are available in a variety of ranges, with solder pin terminations. Applications include borehole mapping, dam and rock shifts, satellite dish alignment, weapons sighting, tilting train control, and civil engineering analysis. Schaevitz Sensors, www.schaevitz.co.uk Enter 585

VME modules

Processors share local memory

A four-processor, high-performance VME board has two expansion module sites: the velocity interface mezzanine and PCI mezzanine card. The board has four MPC7410 PowerPC processors providing as much as 16 gigaFLOPS of floating-point signal processing power. Boards have built-in front-panel 10/100 Ethernet and RS232 interfaces. Applications include radar, sonar, signal intelligence, and image processing. Pentek Inc. www.pentek.com Enter 586

High-performance sockets

IC guide with fingers included

ZIF 10 GHz bandwidth sockets are designed to guide the IC into exact position Sockets support very dense BGA devices using elastomer contactors. They are mechanically mounted to the PCB and have a smaller footprint than other sockets. The socket body and heat sink screw are aluminum to help heat-sinking. One example, the VF-BGA356L Intel(R) Xscale(TM) processor, is used in handheld applications. Ironwood Electronics www.ironwoodelectronics.com Enter 587

Automotive sensors

Multi-operational, compact

Specialized for automotive applications, MST system sensor chips offer safety and reliability in airbags, seatbelt tensioners, and antilock brakes. Sensors about the size of pinheads provide information on pressure, temperature, emissions, and other physical variables. Intelligent control systems and stability programs are two of the newest automobile designs that use MSTs. Bosch Rexroth Co. www.boschrexroth-us.com Enter 588

3-mm PCB LEDs

Red, green, or yellow

A series of right-angle, 3-mm PCB LEDs is reportedly ideal for automated positioning machinery where precise alignment of status indicators is required. Available in bi-level, tri-level, and quad-level, the LEDs withstand sock, vibration, frequent switching, and environmental extremes, the company says. Lasting 20 times longer than incandescent lamps, LEDs have an average life of 100,000+ hours. LEDtronics Inc., www.ledtronics.com Enter 589

Chip sets

Improved thermal characteristics

Two synchronous buck MOSFET chip sets are designed to increase battery life and reduce device on-resistance. The sets minimize conduction loss, reduce gate charge, and reduce gate-to-drain charge. Reportedly ideal for Vcore power in the Intel(R) Centrino(TM) processor, IRF7821 and IRF7832 improve efficiency over the load range. IRF7821 features a 40% reduction in gate charge, while the IRF7832 improves device on-resistance by 25%, the company says. International Rectifier www.irf.com Enter 590

Circuit breakers

Replace fuses in blocks

These circuit breakers are designed to reduce downtime by replacing the fuses in DIN-rail terminal blocks. The 1180 Series plugs into standard blocks and protects plant equipment at 250V ac or 65V ac. Breakers can be reset immediately after faulting and prevent use of the wrong replacement fuse. The units are 8 mm wide and reportedly avoid nuisance tripping during harmless, short surges, such as in-rush current. E-T-A Circuit Breakers www.etacbe.com Enter 591

Crimp splices

Shrinks above 150F

PolyCrimp heat-shrinkable crimp splices join two wires in a butt splice configuration using a one-piece, adhesive-lined sleeve with a seamless crimp barrel. Rated for 66V ac, crimps shrink at about 2:1 and insulate the butt, while protecting from environmental factors. Crimps are color coded for wire size, from 22 to 10 AWG, in 3 sizes. Applications include automotive aftermarket, marine, traffic control, pair, and maintenance. Tyco Electronics Power Componentswww.circuitprotection.com Enter 592

Ultrasonic sensors

For bottling, small containers

Quick setup and consistent performance are considered two benefits of the S18U Series compact ultrasonic sensor. These products feature push-button programming, diagnostic status LEDs, and a factory-adjusted ultrasonic beam. Available in straight or right-angle, the 18-mm barrel design offers many mounting options. The sensors are made of ABS plastic and rated IP67 and NEMA 6P. Banner Engineering Corp. www.bannerengineering.com Enter 593

Cable assemblies

Ideal for industrial, medical uses

Polarization-maintaining cable assemblies are made of single-mode fiber that preserves the polarization of light as it travels. They are precisely aligned to mechanical or optical planes. Ideal for telecommunications switching and multiplexing, PM assemblies are also used in industrial and medical applications. PM fiber can be terminated in industry standard connectors. Molex Inc., www.molex.com Enter 594

Machine vision system

15 digital input lines

The LabVIEW-based, NI CVS-1454 compact vision system makes cameras smarter and handles multiple camera inputs, according to the manufacturer. Three IEEE 1394 ports allow connection of various imaging sensors. Two on-board software versions - NI Vision Builder for automated inspection and LabVIEW - offer developers flexibility to switch between the two and migrate data. National Instruments, www.ni.com Enter 595

Sensor input module

Decrease device count

The 1762-IR4 4-channel resistance temperature detector module connects the company's model 1200 controller to platinum, nickel, nickel-iron, and copper RTDs. The product eliminates the need for expensive thermocouple transmitters, the company reports. This module reads temperatures in C or F, with resolution to tenths of degrees. The sensor range is -200 to 850C. Applications include industrial and process control, pharmaceutical, petrochemical, and transportation. Allen-Bradley www.rockwellautomation.com Enter 596

Inductive sensors

Ideal for in-die sensing

Unlike many designs using steel endcaps, the SteelFace(TM) inductive sensor body is milled from one piece of solid stainless steel. Impact and abrasion resistant, SteelFace sensors withstand up to 500 psi of dynamic pressure and are available in ferrous-only and nonferrous-only models. Typical applications are aluminum machining, sensing tool pallets, and cutting tools and fixtures while ignoring the bulk of aluminum chips. These items are available in 8-, 12-, 18-, and 30-mm sizes, and withstand wash-down applications to 1,200 psi. Balluff Inc. www.balluff.com Enter 597

Stainless steel cordsets

For food industry applications

The picofast cordset includes a 316 stainless steel M8 coupling nut for mating with standard M8 quick disconnects. Cordsets are designed for washdown applications in food industries or where caustic chemicals are used. Hex nuts are made with no knurl for easy cleaning. The product is rated to IP68 and withstands 1,200 psi wash pressure in water, detergents, and surfactants. TURCK Inc. www.turck.com Enter 598

Sensors Have to Toughen Up

Sensors Have to Toughen Up

Sensors are the backbone of much of design. Here, one expert gives his view of the latest trends and efforts to make sensors hardy enough for the factory floor.

What's the hot topic in sensors today? Robustness. There is a big push to make sensors that can withstand enormous amounts of EMI/RFI.

How do you make sensors more robust? One way is to add filtering capability to get rid of stray signals. We've gone from single-layer to multi-layer boards to include shields and filters so that, for example, a two-way radio near the center won't trigger a sensor.

Doesn't that take up more space and cost more? It does take more space-that's why we go up to four layers-but there is no extra cost to the customer. We use surface-mount technology and our own ASICS to help with board space.

Are there environmental demands that are pushing the industry toward more robust sensors? Absolutely, especially-again-on the factory floor. One example is that sensors have to be able to withstand high-pressure washdowns. NEMA (National Electrical Manufacturers Association) standards require resistance to water, but there is more than water on the factory floor. We test with caustic acids, bases, coolants, and oils because that more closely simulates a factory environment.

Are there any industries that are more demanding than others when it comes to environmental concerns? Naturally, the food industry is most demanding because of their environment. High-pressure washdown with temperature changes make for difficult conditions. We developed our harsh-duty line of sensors for that reason.

Considering how important sensors are in machines, do engineers really understand them? They understand their importance, but they don't think about them early enough in the design process. They don't think enough about the application and the mounting. Engineers think sensors are simple devices, and they don't go to sensor seminars. They go to seminars on what they consider to be more high-technology subjects.

What's the biggest thing engineers need to know about sensors? There are many things, but an important one is to know about the mounting because that can affect how well the sensor works. Too often, it's the mechanical designer who designs where the sensor mounts, but the E/E specifies the sensor. They have to talk to each other.

Is wireless the next big thing in sensors? People certainly are talking about it. Applications could include pressure and temperature transmitters, where there are long runs of cable. But for wireless to take off, battery technology will have to improve.

What's Turck's next big thing? The self-compensating sensor for automotive factories. One sensor will give a maximum range based on how you mount it to metal. Metal around a sensor affects its sensing capability. This sensor compensates for that.

Robb Black has 16 years of experience in sensor technology, including work with inductive and capacitive sensors, ultrasonics, flow, pressure, level detection, rotary, encoders, linear-displacement transducers, and frequency-identification systems.

Exciting Dots

Exciting Dots

Researchers from the National Institute of Standards and Technology (NIST) and the National Renewable Energy Laboratory (NREL) have reported a way to measure the amount of laser light needed to shift the electrons in a type of quantum dot between two discrete states-a low energy, ground state and a higher energy, excited state. Quantum dots may be able to serve as the ones and zeros in a quantum computer, once physicists have the ability to turn them "on" and "off". NIST's and NREL's new technique measures the dipole moment directly by enclosing the dots in a cavity, a dimming laser light pulse passing over them repeatedly. This in turn helps measure the dipole moment, indicating how easy the dots are to excite. For details, go to http://nist.gov.

Security at your fingertip

Security at your fingertip

The National Notary Association (NNA) has incorporated TouchChip(R) biometric technology from STMicroelectronics (www.st.com) into its electronic identity-capturing database. A capacitive sensor based on active capacitive pixel-sensing technology, TouchChip allows a fingerprint to be quickly and securely captured and stored in less than a second. In addition to handwritten electronic signatures, the NNA's electronic notary logbook-Enjoa(TM)-can also record thumbprints and digital photos from notaries to ensure proper process and eliminate fraud.

Going flat

Going flat

Motorola (www.motorola.com) is making advances in its carbon nanotechnology research. The technology (termed "nano emissive display" or NED) enables manufacturers to create large flat- panel displays that exceed the image quality characteristics of plasma and LCD screens at a reduced cost. It's feasible that NED could contribute to a wall-mounted television with a 50-inch or larger diagonal, but remain just 1 inch in depth. NED utilizes carbon atom nanotubes, less than one nanometer in diameter.

Look out, protein

Look out, protein

Sandia National Laboratories (www.sandia.gov) has designed a microdevice that can easily collect and release proteins in aqueous solution in less than one second. The device is a series of gold-coated lines, each line apart by a thickness of one-third of a human hair. It separates proteins from the solution and from each other by electrically heating the metal lines which warms a 4 nm-thick polymer film. The film then changes from a hydrophilic to a hydrophobic state, which enables the film to absorb proteins passing over it. The proteins now separated from the water molecules, are released in a natural cleansing action in the hydrophilic state.

Electric Wallpaper?

Electric Wallpaper?

Researchers at General Electric (www.ge.com) have announced "a major breakthrough in a new lighting technology." Based on organic light-emitting diodes (OLEDs), the solid-state lighting technology uses thin sheets of plastic-like material that emit light when powered by electricity. It could be made in an inexpensive, roll-to-roll manufacturing process. The goal: sheets of paper-thin lighting devices that can be applied like wallpaper.