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Articles from 2013 In February

Prospective Engineers Get a 'Good Feeling'

Prospective Engineers Get a 'Good Feeling'

It's not every day that we come across a music video extolling the virtues of engineering salaries, but we have one today, and it comes from the most unlikely of sources.

The football program at the Missouri University of Science and Technology has produced a video targeting high school players who want to study engineering. Instead of listing graduates who have made it to the National Football League, the program's coaches use the unusual video to emphasize the high starting salaries of engineering graduates.

To a backdrop of the song "Good Feeling" by the rapper Flo Rida, the video explains that the university's graduates have an average starting salary of $60,000 a year. Then a scrolling screen breaks down the average for each engineering discipline: $83,201 for petroleum engineering, $55,533 for aerospace, $57,108 for electrical, $57,910 for mechanical, $59,513 for nuclear, and so on.

"It's really for the parents," David Brown, former Missouri S&T football coach and one of the video's creators, told us. "When you have that big investment in college, you want your student to get an education, but you also want them to have a degree that will mean something financially and professionally."

For many of us, the video serves as a reminder that an engineering degree is a great way to start a career, despite the grumbling about salaries we may hear around the office. Each year, engineering students dominate virtually every list of highest-paid graduates. And those students don't necessarily have to depend on costly graduate degrees (or ultra-costly medical or law school educations) to draw those salaries.

The video also serves as a pleasant rejection of pop culture stereotypes in a couple of important ways. In the world of athletic recruiting, high school students are often approached by big, prestigious schools as athletes first and students second. Some are even discouraged from enrolling in curricula (such as engineering) that might require intense study. Here, however, that's not the case. Brown said the school holds its practices at 6:30 a.m. to accommodate class and lab schedules.

Moreover, Missouri S&T's approach flies in the face of the tiresome nerd image that we see too often on television. Seventy percent of the school's football players are engineering majors, including many on athletic scholarships.

At a time when politicians are finding it necessary to push science, technology, engineering, and mathematics initiatives and NCAA programs are too often getting out of control and embarrassing themselves, Missouri S&T's video is a nice reminder that it doesn't have to be that way. Here, the student-athlete model lives on. And students don't have to be pushed into engineering -- they are drawn instead by the real-world benefits of the degree.

"We tell our recruits, 'If you're interested in engineering, you can always go to a school with a bigger stadium, but that's going to fade in your memory,'" Brown said. "'But the degree you'll get from here is going to be profitable for a long time to come.'"

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Motion Control is Key to OSU's Futuristic Electric Car

Motion Control is Key to OSU's Futuristic Electric Car

It's half the size of your average passenger car, corners like it's on rails, and is capable of being folded to fit into a parking spot. Meet the future for the urban electric car, if Ohio State University (OSU) researchers have anything to say about it.

A team led by Junmin Wang, assistant professor of mechanical engineering and director of the Vehicle Systems and Control Laboratory at OSU, has been working on a new design for an electric vehicle -- created by repurposing a gasoline-engine utility vehicle -- since 2009, Wang told Design News.

The key to the vehicle's design is that each of its wheels turn independently, courtesy of dedicated, battery-operated motors that allow the car more capability and maneuverability than the electric cars on the market. Those vehicles depend on one motor to provide torque to all the wheels, he told us.

"They have more freedom in terms of control," Wang said of the wheels on OSU's experimental vehicle. "In a typical electrical vehicle, the torque transmitting from the wheels cannot be arbitrarily assigned. For this one, we can do this because they are not mechanically coupled."

This makes the car more nimble in terms of turning and performing lateral and yaw motions. It also makes the car safer when it turns sharp corners and stops suddenly, given its more stable and precise movements.

Researchers performed tests with the vehicle at the Transportation Research Center in East Liberty, Ohio, in which the car was able to follow a driver's desired path within four inches. They also tested its maneuverability on slippery road conditions in a university parking lot on a snowy day. In that test, the car's accuracy of movement was up to eight inches, and it did not fishtail on the slippery surface, thanks to independent control of each side of the car.

Wang said the vehicle -- which weighs 800 kilograms (about 1750 pounds), or about half the weight of the average passenger car -- could be the ideal electric car for urban environments because of its maneuverability, and another feature that makes it handy, especially in cities with limited parking spots: "It is architecturally flexible, so it could be folded to fit into a smaller parking space," he said. "Because it's small and compact, it's promising in urban areas to use for commuting and driving. I think it's a promising future platform."

The original project that spawned the car -- which called for OSU researchers to improve the motion control and stability of electric car designs -- stemmed from a grant from the Office of Naval Research. Last year, OSU received funding from the National Science Foundation to continue the work for another five years, Wang said.

Researchers will aim to improve the operational energy efficiency of the vehicle in the next phase of their work by studying how the vehicle carries loads. Data collected will then be incorporated into the vehicle's driving- and energy-management strategies.

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MathWorks Expands Functionality, Making Development Easier

MathWorks Expands Functionality, Making Development Easier

It seems that the number of people using apps is growing at a much faster rate than the number of the people writing code. MathWorks software developers have noticed this trend and have redesigned their platforms to meet the needs of app developers.

The update to the MATLAB, Stateflow, and Simulink platforms (dubbed R2012b) is meant to shrink the gap between apps and computer coding. MathWorks hopes this will close the gap between computer programming and the practical world.

The update will help users of previous versions in many ways, and the new layout is easier for new users to grasp. Tool strips replace menus and toolbars in the desktop, making it easier to access more commonly used functions. The new desktop also includes an app gallery where users can access premade MATLAB programs instead of writing code. This will help streamline the procedures for common tasks.

If you do want to write some code, you can write and package your own app and share it in the app gallery. MATLAB's file exchange lets you share and download many new apps for free. With the rise of tablet and smartphone applications, writing software compatible with human interaction is necessary for success.

Like Ford's assembly line, model-based design could cut development time in half by managing the interaction between all internal systems simultaneously. Making model-based design even faster with MathWorks software required a more integrative setup for running MATLAB, Simulink, and Stateflow smoothly together. Managing and completing projects is easier and faster, thanks to refined navigation, searching, browsing, filtering, and organizing.

Not only is the software better organized, but added features offer new ways of accomplishing goals. Simulink can assist projects involving Arduino, BeagleBoard, Pandaboard, and Lego Mindstorms NXT. It connects to source control software easier and faster, and new smart signal routing finds the optimal path for signals. New editors, editor tabs, and simulators will help in testing and finalizing designs.

Stateflow has new state transition tables and a similar editor to Simulink, and it uses MATLAB as an action language.

MATLAB now includes functions for delay differential equations and improved Bessel functions. New import tools allow you to use data from any spreadsheet, including XLSM and XLTM. The new Command Window helps correct invalid functions or variables. The new tabs allow for management of multiple documentation windows, and MAC OS users will see a full-screen desktop feature.

R2012b includes support for code programmers using the new SimMechanics, Communication Systems Toolbox, and HDL Coder. With projects like Intel's 48-core chip in the making and core density continuing to increase, parallel computing will become only more useful and necessary to exploit new capabilities. The update also brings better tools to support this technique. Neural Network Toolbox, Phase Array System Toolbox, and SimEvents are included in the R2012b update. Those are just a few of the 74 MathWorks programs available for updates. If you need help running any product, a new documentation holds all necessary references.

MathWorks update not only helps with app development, but it also provides a platform to create the embedded systems integrated in smart devices. Engineers have to manage loads on sensory information to create smart tools, but they must have a place to simulate and optimize performance to ensure smart automated systems are secure and assistance is readily available at any level. The more cohesive and efficient Stateflow, Simulink, and MATLAB deliver this.

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Energy Efficiency Drives Motor Control Design Trends

Energy Efficiency Drives Motor Control Design Trends

Today more than ever, energy efficiency dominates many product developments. From auto and truck engines to air conditioning, refrigeration, household appliances (large or small), and beyond, component space is at a premium. Fewer parts are a plus, and cool running, long-life power is a must.

Fuel efficiency in autos is probably the most prominent energy example, with demand from consumers as well as federal mandates giving it top priority. New cars average 24.5mpg, but that's a far cry from the 54.5 average mandated for 2025. It's also well below the 35.5 required by a much closer deadline of 2016.

Whatever the end product, there is no magic bullet; efficiency must be gleaned from many sources. In automotive and other industries, years of product development point toward a series of observations. For one thing, low-cost power electronics have made sensorless control of brushless DC (BLDC) motors with integrated controllers a viable option for numerous applications. This leads to several interrelated trends and challenges for both design engineers and manufacturers:

  • Increased interest in sensorless BLDCs to deliver component power
  • Frequent reliance on off-the-shelf generic control algorithms provided by numerous semiconductor manufacturers
  • Lack of advanced-level control engineering expertise to address canned algorithm limitations and, more importantly, provide rapid, cost-effective custom designs
  • Emergence of outside specialists and new model-based development techniques for sensorless BLDC motor controls.

Pluses and pitfalls of sensorless controls for BLDCs
The search for efficient energy and cool, long-running power finds a powerful ally in sensorless control technology. For example, a control recently designed for an engine pump motor could result in a 5 percent fuel savings. At $3.50 to $4 per gallon, that adds up to a tidy sum for any car, pickup, or SUV owner, and it would amount to a rather large sum for the operator of a fleet of long-haul semi-trailer trucks.

Sensorless controls are also highly reliable, in large part because sensors aren't needed for feedback. This adds complexity to the controller, however, as sensorless BLDC motors depend on a closed-loop algorithm for operation. Therein lies the rub.

Many semiconductor manufacturers offer canned control algorithms. The tendency for some design engineers is to view them as a means to jump-start development and get to market quicker while reducing costs. Fact is, they usually have the opposite effect. Promoted as plug-and-play (assuming all hardware components are available), they may be acceptable in some applications, but they typically fall far short of expectations for several reasons.

Video: Robotic Droplets Will Assemble Satellites

Video: Robotic Droplets Will Assemble Satellites

Researchers at the University of Colorado at Boulder are developing small, swarming robots -- dubbed by the team as "droplets" -- that will be able to accomplish a variety of tasks. Possible uses include building a space station or a satellite, self-assembling into a piece of hardware after being launched into space, or cleaning up an oil spill on Earth.

Swarm robotics is a fast-changing, quickly growing area of robotics research and development. We've reported on a swarm of "hedgehog" robots being developed by Stanford University to explore space, and swarms that can play Beethoven, or repair coral reefs. We've also reported on the robotic self-assembling pebbles developed in Daniela Rus' Distributed Robotics Laboratory at MIT, where the leader of the University of Colorado team, Assistant Professor of Computer Science Nikolaus Correll, did post-doc work.

The University of Colorado team has built a swarm 20 strong. The droplets form a "liquid that thinks" when they swarm together, said Correll in a press release. He plans to use the swarm of robots to demonstrate pattern recognition, sensor-based motion, and adaptive shape change, as examples of swarm-intelligent and self-assembly behaviors. These behaviors could then be transferred to much larger swarms that could carry out more complex tasks in water- or air-based environments.

The computer science research team also includes research associate Dustin Reishus and professional research assistant Nick Farrow. Together, the team has designed a basic robotic building block.

The platform will eventually be reproduced in large quantities for developing increasingly complex systems. Correll hopes to create a design methodology that will allow the swarm of robots to work as an aggregate in more complex behaviors. These might include assembling parts of an aircraft or a large space telescope.

In a video that describes the team's research (watch it below), Reishus says 10 of the droplets are now working and some of the software is written, but the robots aren't solving any useful tasks yet. "We are still just testing each individual robot, getting the very low-level communication between two robots working."

Reishus says that, after the droplets are completed, the team will have a platform that can be used for conducting various experiments with swarm robotics, whatever those might be.

Those experiments will probably be thought up by students working in a lab Correll has set up. There, students can use basic, inexpensive tools to explore and develop new applications for the robots. He expects that this will help accelerate the pace of development. The lab's research focuses on intelligent distributed systems, including sensing, actuation, computation and communication.

Aside from robotic swarms, researchers are working on large-scale, outdoor robot teams and smart materials.

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Slideshow: Fisker Says 'Plug-In Hybrids Make More Sense Than Pure Electrics'

Fisker Automotive co-founder Henrik Fisker describes the Karma as a "sedan with a coupe-like appearance."" Design highlights include a long hood

The worldwide auto industry is taking the wrong path to environmental friendliness, Fisker Automotive co-founder Henrik Fisker told an audience at the recent Chicago Auto Show. "Every big car company is making one little electric car, mostly for satisfying its overall fleet average," Fisker explained to attendees at a luncheon sponsored by the Economic Club of Chicago. "But my prediction is we will have too many pure electric cars. Whereas, if you look at plug-in hybrids, there are a lot fewer of them and a lot more buyers."

Fisker, whose company builds the plug-in hybrid Karma and the forthcoming Atlantic, said consumers want stylish vehicles that can be easily identified as eco-friendly, but they also want the vehicles to be practical. Today's battery-electric vehicles (BEVs) don't currently fit well in either of those categories, he said. "We don't think it's wise to have a giant battery," Fisker said of BEVs. "You're carrying around this giant battery, and it costs a lot of money for your daily commute. And when you really want to go far, you can't do it anyway."

Click on the image below for a closer look at the Fisker Karma and Fisker Atlantic.

Fisker chided the automotive press for not taking care to distinguish between plug-in hybrids and pure electric cars. The result, he said, is that the low demand for pure electrics is being interpreted as a bad sign for plug-in hybrids. "A lot of people -- journalists, as well -- are putting this all in one big bowl and saying there's not a lot of demand," he told the audience. "Well, right, there's not a lot of demand for pure electric cars. But hybrids are on the rise and plug-in hybrids will be the next big step."

Fisker's comments are consistent with those of industry analysts who have said they expect plug-in hybrid sales to rise, while pure electrics will fall over the next few years. A recent study from KPMG International, for example, contended that consumer interest in plug-in hybrids jumped by 15 percentage points in 2012 alone, while pure electrics fell by five points during that period.

The inspiration for Fisker's $100,000-plus Karma came to him while watching actor Leonardo DeCaprio drive to the Academy Awards in a Prius a few years ago, Fisker said. Seeing a wealthy actor making an environmental statement by driving a Prius made him realize that there could be a market for those who want eco-friendly luxury. As a result, Fisker made it a mission to build a vehicle that would be easily recognized as a hybrid but would offer more style than a Prius. "With our car, we were very set on the idea that when you pass it by, it should not resemble a Mercedes or BMW," Fisker explained. "It should look like a completely different type of vehicle, which it does."

The Karma, which Fisker said can range from $100,000 to $125,000, accomplished that by employing solar roofs, reclaimed wood, 22-inch alloy wheels, and diamond-dust paint, in addition to the hybrid electric powertrain.

Fisker added that the company's engineers considered alternatives to a gasoline-burning engine, which is used by the Karma as a range extender and will be employed in the Atlantic. "We thought about other forms of energy, whether ethanol or diesel," he said. "But we wanted the consumer to have convenience. If they run out of electricity, there will always be a gas station. There are still more gas stations in the US than diesel (stations)."

Thus far, the biggest challenge has been the cost of starting a car company and dealing with a seemingly endless roster of regulations, he said. After investing more than a billion dollars, the company has sold only about 2,000 Karmas to date. "If you want to start a chain of 1,000 restaurants, you could start with one little restaurant and a couple hundred thousand dollars," Fisker explained. "But that just doesn't work in the car industry. You need hundreds of millions of dollars. The barrier to entry is huge."

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Extending the Reach of an Application Processor Using Customizable Silicon

Extending the Reach of an Application Processor Using Customizable Silicon

Chip designers must balance many factors when bringing a new application processor to market, including how much memory and which peripherals, interfaces, and hardware-based accelerators to integrate. Each new feature expands the number of applications and markets that can utilize the device. However, every additional feature also increases cost, size, and power consumption, limiting the types of applications to which the processor is suited.

A processor that supports application-specific interfaces and functionality clearly holds a higher value than one that doesn't. The interfaces required for industrial applications, however, can be different than those used in consumer electronics or automotive systems. Certain applications also need specific features. Given the long lead time to design and bring a processor to market, it can be difficult to anticipate which features the market will demand and be willing to pay for. Product requirements can also change over time, and so OEMs need to be able to introduce new features quickly to address new market opportunities. For example, consider the rapid adoption of touchscreen technology in mobile devices. This technology, introduced to smartphones in 2007, took less than 12 months to become standard across the industry. Silicon manufacturers that could not provide this functionality to their customers lost hard-earned market share.

One way to meet the challenge of offering the right mix of standard and application-specific features is to augment an application processor's functionality with a companion device. Rather than increase the cost of a processor across all applications, only those applications that need the added functionality will have to pay for it.

The benefits for silicon vendors to offer a companion device to complement an application processor include:

  • Test market response to new functionality before committing to investment in an ASIC.
  • Leverage an existing architecture into new market segments that might not have the volumes to justify spinning a separate processor.
  • Optimize an architecture for low power and low cost by removing features that can be added back in using a companion chip.
  • Recover from mistakes in feature specification by being able to make critical features available without delaying release of the application processor.
  • Enable marketing to continue to provide input late into the design process.

Silicon manufacturers can implement a companion device using a number of technologies. ASIC-based designs, given their heavy upfront investment and long lead time, are really only suitable for implementing commodity features, not for strategically bringing new and product-differentiating features to market. Even ASSPs, with their software configurability, still require OEMs to pre-define exactly the right mix of capabilities to be useful.

Some functionality can be implemented in software. However, such an approach requires substantial processing resources on the application processor. Software offers less performance and increases system cost and power consumption, compared to a hardware-based approach. For some tasks, a hardware approach may be unavoidable.

Functionality can also be implemented in traditional programmable logic. However, SRAM-based logic comes at a high cost and continuously consumes power. SRAM-based programmable logic is also volatile in nature, requiring memory resources to store the FPGA configuration. Hence, the FPGA must be configured at startup. Furthermore, the power consumption of most SRAM-based programmable logic precludes its adoption in mobile applications.

Rock Always Wins in Lawnmower Battle

Rock Always Wins in Lawnmower Battle

Many years ago, I purchased a lawnmower from a reputable national chain. I expected it to have a long life, yet shortly after the one-year warrantee ran out, I hit a large rock that was sticking up in the lawn. The mower began to vibrate severely. Obviously, something had gone terribly wrong.

I stopped the lawnmower and turned it upside down. I rotated the shaft by hand, and I could see that the shaft was bent. When I removed the blade I could also see there were no shear pins nor any other way for the blade to take the shock without transmitting it to the whole mower. Once it hit the rock, the shaft took all of the impact. I was now stuck with an almost-new mower that had a bent shaft. I was facing the option of either rebuilding the engine or buying another mower.

I live in a rural farming community where it is common to fix the oldest and most decrepit machinery -- it's part of our lifestyle. I remembered having seen a house nearby that had a bunch of old lawnmowers sitting out for sale. The house also had a sign posted advertising lawnmower repair. So I took the mower to the gentleman who ran the mower shop and asked if he could repair my mower's shaft. He took the mower and turned it over. He grabbed a pipe and put it on the bent shaft. He pushed the pipe in just the right direction, and he pushed with just the right amount of pressure. He was able to straighten the shaft. Just like that it was fixed.

The original problem was still there, however. There was no give if the blade hit a fixed and hard object -- which was bound to happen again. So I modified the shaft-to-blade adapter so that the blade would spin on the adapter if I hit another object. Voila, a solution. I used the lawnmower with great success for another 24 years.

This entry was submitted by Ray Mainer and edited by Jennifer Campbell.

Tell us your experiences with Monkey-designed products. Send stories to Jennifer Campbell for Made by Monkeys.

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Video: Researchers Use Spray-Coating Technique to Develop Cheaper Solar Cells

Video: Researchers Use Spray-Coating Technique to Develop Cheaper Solar Cells

Researchers in the UK have come up with a way to fabricate solar cells that involves a process similar to spray painting and lowers the price of manufacturing the cells, potentially making them more accessible.

Originally, the idea to apply an active polymer material to photovoltaic devices involved a process called spin-casting that is similar to how a potter's wheel works, David Lidzey, a professor in the University of Sheffield's Department of Physics and Astronomy and one of the leads on the project, told Design News. However, that method was not scalable to a large area, so -- inspired by project partners -- the research team last year devised a new way to apply the material via a spray-coater system that's similar to common spray painting. Lidzey told us:

The idea of using a spray-coater was suggested to us by a group of industrialists we were collaborating with. They pointed out that this technique is already used to put down other films at industrial scale, and would be very interesting to adapt to put down the active layer of organic photovoltaic devices.

The system works using a piezoelectric ceramic element that vibrates a high frequency, onto which a solution of semiconductor ink is fed onto the surface. The vibrations break the solution up into fine droplets that are then carried to the surface of a cell by a jet of nitrogen carrier gas. Lidzey said:

At present, most research groups around the world use spin-coating to deposit thin films for organic electronic applications. The spray-coat technique is, we feel, better than this as it is less wasteful of expensive organic semiconductor inks, and can in principle be scaled up to very large size -- something that would be difficult by spin-coating.

The benefit of this method is that spray-coating is a low-waste process already used widely in industries such as graphic arts and automotive to produce thin-film coatings. To apply this process to creating organic solar cells that use polymer rather than silicon as an active material -- a nascent but evolving industry -- could make the production of cells less expensive and also be applied to other fabrication processes.

Lidzey said:

Organic photovoltaics do however hold out significant promise as the technology requires a lower energy input compared to other solar cells -- e.g., crystalline silicon -- where expensive infrastructure and high temperature processes are often required. Organic materials require less energy input into their synthesis, and spray-coating is an energy-efficient manufacture process. This means that organic solar-cells may have much lower embodied energy than other solar-cell technologies.

There are some drawbacks to the organic cells, Lidzey pointed out, which currently have lower efficiency and much lower operational lifetimes. However, "these are issues that many groups around the world are currently addressing."

In addition to creating solar cells, the spray-coating method could also one day be used to apply a photovoltaic material to car roofs and glass windows, giving those surfaces the ability to store and generate energy, researchers said.

Lidzey and his team will continue to experiment with spray-coating to scale up the devices being fabricated, since they are currently on the small side. "We would also like to further improve device efficiency, and find ways of using spray-coating to control the nanostructure of the thin films and thereby make further gains in device efficiency," he said.

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New Approaches to High-Efficiency Current Sensing

New Approaches to High-Efficiency Current Sensing

Recent advancements in integrated Hall-effect current sensor technology provide an alternative current sensing solution that reduces power loss, achieves most cost targets, and occupies a much smaller volume on the application printed circuit board.

Current sensing with a sense resistor and amplifier
Conventional current sensing techniques insert a sense resistor in series with the conductor carrying the current being measured. An amplifier is also required, so that when current flows through the resistor, the voltage developed can be used to measure the input current. The value (usually ranging from 1 to 100 mΩ) of the sense resistor depends on the maximum target current that is to be sensed. Smaller sense resistor values develop a lower signal-voltage when current is applied.

The resistor-amplifier sensing circuit is implemented as a shunt circuit, either on the low side (near ground potential) or on the high side (near supply potential) of the load that carries the applied current.

High-side current sensing allows the detection of short-circuit conditions to ground potential, and is largely immune to ground potential disturbances. Ground potential disturbances become a greater concern when multiple low-side current sense resistors are connected in parallel (to reduce power loss), because this can cause parasitic ground-loops.

The disadvantage of high-side sensing is that depending on the high-side voltage, the amplifier circuitry must be able to operate with high common-mode input voltage signals, making the design more complex and the solution more expensive. Low-side sensing relaxes the common-mode input requirements for the amplifier circuitry, but it is also more susceptible to disturbances in system ground potential, and is unable to detect short-circuit conditions from supply to ground potential.

In sense resistor implementations, measurement accuracy is largely limited by the temperature coefficient, TC, of the sense resistor and the input offset error, VOSI, of the amplifier.

A smaller value sense-resistor usually results in degraded accuracy performance, since the amplifier's input offset error now constitutes a larger percentage of the applied signal at the amplifier input. The use of a larger value sense resistor, while beneficial for output accuracy, results in higher power dissipation. As a result, the sense resistor value for a design is usually chosen based on a design trade-off between sensing accuracy and power dissipation.

Consider that a typical current sense resistor value for low-side applications is on the order of 20 mΩ. For a 30A continuous current-sense application, the power dissipation from resistive losses would be:

PD = I2R = (30)2 x 0.02 = 18W