Eeweb Pulse - Issue 33, 2012

Interview with Dermot O’Shea - Joint Managing Director; Navagating the Antenna Challenges of Miniaturized Telematics; Switching FETs and Dead Time; Transistors to Turbines; RTZ - Return to Zero Comic
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PULSE EEWeb Issue 33 February 14, 2012 Dermot O’Shea Taoglas Electrical Engineering Community It’s all about students hobbyists connections. EEWeb Electrical Engineering Community discussions industry experts engineers technical documents white papers links Contact Us For Advertising Opportunities reference designs resources [email protected] power 1.800.574.2791application notes lighting community microcontroller wireless sensor The user-to-user forum is for everyone, from design engineers to hobbyists, to discuss technology, products, designs and more. Join the discussions that match your interest or offer your expertise to others. Digi-Key is an authorized distributor for all supplier partners. New products added daily. © 2011 Digi-Key Corporation, 701 Brooks Ave. South, Thief River Falls, MN 56701, USA Join the discussion now at: TA B L E O F C O N T E N T S Dermot O’Shea Taoglas Limited Interview with Dermot O’Shea - Joint Managing Director 4 8 10 11 15 20 TABLE OF CONTENTS Navagating the Antenna Challenges of Miniaturized Telematics BY DERMOT O’SHEA How Taoglas faced the challenges of implementing their high performance antenna system into a miniature device. Featured Products Switching FETs and Dead Time BY PAUL CLARKE WITH EBM-PAPST Paul Clarke explains why we shouldn’t fear “dead time” when switching FETs. Transistors to Turbines BY BILLIE JOHNSON WITH WOWE The story of how one outreach volunteer helped install a wind turbine on a middle school campus and the positive impact it had on its curriculum. RTZ - Return to Zero Comic EEWeb | Electrical Engineering Community Visit 3 DermotTaoglas O’SheaLimited How did you get into electronics/engineering and when did you start? I began by studying physics and mathematics at University College Dublin, and went on to get graduate degrees in a wide range of disciplines from Dublin Business School, Griffith College Dublin and Waterford Institute of Technology. My degrees are in the areas of enterprise development, business studies, computing and computer hardware design. Dermot O’Shea - Joint Managing Director INTERVIEW FEATURED INTERVIEW After completion of my studies and working in the logistics industry, I decided to travel the world for a little bit, then came back here to Ireland to work in the electronics industry. I later went to Taiwan and met another Irish guy there named Ronan Quinlan. We were of similar minds in terms of wanting to set up our own business, and he had some experience with electroceramic materials, an area that was just taking off. Electroceramic patch antennas are a very efficient material for GPS antennas. In Taiwan there were some very unique ceramic materials that were revolutionary for efficient antennas. We have a number of antennas made of ceramic that have unique properties; The PA25a and the PA700 are multiband PCB surface mounted 3G and 4G antenna solutions that provide very high efficiencies to customers requiring high performance from an embedded antenna without the need to design a custom solution. Another antenna, the “Athena” combines a GPS ceramic patch EEWeb | Electrical Engineering Community Visit 4 INTERVIEW antenna, low noise amplifier (LNA), and Front-End SAW filter in one SMT body, eliminating the requirement for cables and connectors. It is another ceramic antenna that is used by M2M manufacturers in automotive, telematics, tracking and remote monitoring. I wasn’t really an expert when it came to antennas; we didn’t really learn about them in university. But despite that, we decided to go into the antenna business with the goal of providing wireless antenna solutions for mobile and remote devices that use Global Positioning System (GPS) and Global System for Mobile communications (GSM) frequencies to communicate. We started the company in 2004, and since then I’ve become much more knowledgeable with regard to antenna technology and have learned mostly all of what I know now while in the industry. How many products do you have today? We have over 1,000 part numbers in our system now. Every day we do something different for a customer, and we are growing progressively larger with our product totals increasing all the time. Right now, we have about 90 products on our current project list, and average about 10 to 15 customer projects per week. From each of those projects also comes a new product number, so we are continuing to steadily grow. We not only make GPS antennas— we also supply a range of cellular external, embedded and base station antenna solutions. Can you tell us more about your antenna designs? With our product developments, we’re always looking to do something better. So we’re constantly trying to incorporate different topologies and new materials. Like I mentioned before, ceramics is something that we began with, and is a technology which is very strong at the moment. Some of our leading antennas are developed with customized raw electroceramic materials inside for more proficient use. For custom designs, nearly half the time we spend during the development process is towards conducting research. We look at and think about things like how much space we have, the target performance for the device, certification required, what types of antenna topologies we have and what designs would suit them. Right now we’re working on an active 4G antenna. We have already developed 3Gs, but we are constantly looking to improve our designs. And like I said before, those designs are primarily for mobile and remote devices that use GPS and GSM frequencies to communicate. Compared to when you started Taoglas Limited, what are your capabilities today regarding characterization and testing? Today we have an office in Ireland, Taiwan and the United States, each of which contains a lab with characterization and testing capabilities. We are now trying to expand to Mexico, in an effort to attract customers from the Latin American market. We already have some basic equipment there, but in the other three locations we have full test chambers. This allows us to not only perform all of the necessary antenna testing, but also the active device over the air (OTA) testing. When we started, we really had none of these capabilities. But as we’ve developed and sold more products, our ability to have these sorts of commodities has increased. You know, we’re very much focused on sales and resultant positive change. The equipment we own, we paid for ourselves. All of the start up funding was used for product development. We work really hard to do everything we can with what we have, and are constantly trying to improve our products and efficiency. Are your customers typically very explicit with their custom design specifications regarding things like gain, sensitivity and direction? As you can imagine, it really depends on the design and the customer. The more specific designs are usually for higher device performance, or a customer requires a specific spec like gain in a certain direction. When the design is up to us, we do our best to educate our customers about the product so they can be as comfortable as possible with what they should expect. We’re doing better to convince customers to discuss their product designs with us first, because if we can talk to a particular customer at the beginning of the design, we can better determine if we’re the right fit to develop that specific product. FEATURED INTERVIEW EEWeb | Electrical Engineering Community Visit 5 INTERVIEW Do you ever help customers design certain antennas without manufacturing it for them? That’s not really part of our business. But we do give our customers all of the product options, and sometimes the best solution is for us to not develop the product after assisting with the design. Generally though, when we design antennas for customers, we aren’t only planning to provide them with the one antenna as a one off project. We are seeking to forge partnerships and want to be the antenna provider of choice for all the requirements of the customer. This not only benefits our own sales and processes but it means the customer can avail of unrivalled support and our resources for design and development are at their disposal. Do you integrate impedance matching circuitry in your antenna designs, or provide direction for users on what to use on their system? Again, it depends on the customer and design. We provide guidance for customers on how to perform specific integrations themselves, and provide information on what to use on their system. Many customers specifically request these sorts of services, and we are glad to perform them. Do you perform simulations with your antennas, or is your testing all done in the lab? Simulation is the first stage. The effectiveness of antenna simulation has definitely improved to become very powerful. The next stage is prototyping, followed by the lab and chamber optimization. We try to start the more traditional way and move on to the lab and test efficiency, which leads to what we call the active device stage. This stage involves more concrete testing, for example connecting the antenna to the device inside the best return loss and efficiency and looking at the effects of the device PCB and battery for example. We would never go ahead to make an antenna from simulation only, it is only a guideline and a design tool. Where do you see Taoglas Limited heading in the next few years? We really want to increase and improve our services. There is a large demand for our services, and we can help our customers overcome the challenges they face when designing these devices. Many of them are under a lot of pressure and don’t have enough time to overcome these issues themselves, and we can really be of some major assistance. We recently announced that we are a Sprint M2M Collaboration Center Partner and a Verizon LTE Innovation Centre partner. Sprint’s collaboration center is a roll-upyour-sleeves workshop where partners and enterprises work sideby-side to develop commercially viable offerings based on M2M technology as well as prepare M2M devices for certification on the Sprint Network. We help Sprint’s M2M customers prepare for over the air (OTA) transmit and receive sensitivity (TRP/TIS) and antenna performance testing. With Verizon we are providing 4G antenna and RF testing and design expertise to Verizon’s M2M LTE device manufacturers. ■ FEATURED INTERVIEW For custom designs, nearly half the time we spend during the development process is towards conducting research. chamber and make a call from the base station simulator to see how the sensivity is in the “pure” unnoisy environment. The reason for this testing is because no matter how well the antenna is designed, the active device will always alter it in some way. These simulation and testing methods have not only been very successful for us, but have worked very well for our customers too. During the simulation process, what kinds of modifications are you able to make with the antennas? The simulation process is only a model and can not be used when you have a cable and connector for example. So you are modifying the radiating element seeking the EEWeb | Electrical Engineering Community Visit 6 Avago Technologies Motion Control Products New Encoder for the Worst Case Environments Avago Technologies new AEAT-6600 Hall E ect Magnetic Encoder delivers optimal solutions for Robotic, Industrial and Medical systems designers. • World’s highest resolution • 16-bit absolute positiion through SSI • Programmable Magnetic Rotary Encoder IC • 16-pin TSSOP package • Power down mode For more information and to request a free sample go to: N PROJECT Delphi is a global supplier of electronics and technologies for automotive and commercial vehicles. The company delivers real-world innovations that make automotive products smarter and safer as well as more powerful and efficient. When Delphi was looking to make a new miniaturized telematics device, it needed an antenna partner that would not only deliver the best cellular and GPS performance, but would also help to get product certification and network approvals first time. Some miniature wireless devices are installed underneath the glove compartment of a car in front of the passenger’s knee and need to be small enough to fit compactly into the diagnostics port in the vehicle. Delphi’s new wireless device had two challenges; EEWeb | Electrical Engineering Community avigating the Antenna Challenges of Miniaturized Telematics Devices devices before so, we were familiar with the territory,” said Dermot O’Shea, director, Taoglas. “This device however, presented us with a new challenge.” Taoglas worked closely with the Delphi engineering team to figure out the requirements for the device and then custom-built a quad-band cellular antenna, the PCS.01 and a custom-tuned GPS active patch antenna module, the AP .25H.07.0040A.dn. “It was difficult to get high performance inside the device because it was so small,” commented O’Shea. “When you get down to that size, the small ground plane leads to efficiency challenges. In order to ensure top antenna performance, we collaborated with the Delphi team to optimize the whole device as a send and receive system to minimize the loss from FEATURED PROJECT By Dermot O’Shea it was less than half the size of a cell phone, but required AT&T network certification, which is based on a cell phone-sized products. Added to this, the device had stacked PCB boards, which act as a large capacitor and bring down antenna performance and efficiency. Delphi needed an antenna provider for the small telematics device that could meet the challenges and deliver high antenna efficiency in these harsh conditions. Delphi chose Taoglas the M2M antenna provider, because of its antenna expertise, understanding of U.S. network certification processes and because Taoglas could design an antenna and optimize the whole system for TIS and TRP testing (receive and transmit sensitivity). “We had integrated antennas in similar cellular miniaturized wireless Visit 8 PROJECT an RF aspect. Devices of this kind present an added challenge with tacked boards, which have a huge impact on the antenna. It’s probably the most difficult environment to place an antenna when you consider all the M2M products in the market today.” The PCS.01 was successfully integrated into the telematics wireless device and passed AT&T network certification first time. “It was a fantastic project to work on,” said O’Shea “It presented us with many challenges, but we met them head-on and engineered a top-class antenna. Bring on the next antenna challenge.” ■ Figure 1: Toaglas GSM Antenna design. FEATURED PROJECT EEWeb | Electrical Engineering Community Visit 9 F E AT U R E D P R O D U C T S USB 16-bit 5MHz Oscilloscope Saelig Company, Inc. has introduced PS4262, a 2 channel, 5 MHz 16-bitresolution oscilloscope that includes a built-in low-distortion signal generator. PS4262 is a full-featured oscilloscope, with a function/arbitrary waveform generator that includes a sweep function to facilitate rapid frequency response analysis. It also offers advances scope capabilities such as: spectrum analysis, mask limit testing, math functions, reference waveforms, advanced digital triggering, serial decoding, automatic measurements, and color persistence display. Its performance rivals many more expensive dedicated audio and dynamic signal analyzers. Careful front-end design and shielding has minimized noise, crosstalk, and harmonic distortion to yield a precision 16-bit data acquisition tool. For more information, please click here. FEATURED PRODUCTS VDD SDI SDO SCLK CE SERMODE GND The MAX31722/MAX31723 digital thermometers and thermostats with an SPI™/3-wire interface provide temperature readings that indicate the device temperature. No additional components are required; the devices are truly temperature-to-digital converters. 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By elimination of the synchronization circuitry, some nonideal artifacts such as images and discrete clock spurs remain stationary on the AD9737A/AD9739A between power-up cycles, thus allowing for possible system calibration. AC linearity and noise performance remain the same between the AD9739 and the AD9737A/AD9739A.For more information, please click here. LVDS DDR RECEIVER LVDS DDR RECEIVER DB0[13:0] DB1[13:0] 4-TO-1 DATA ASSEMBLER DATA CONTROLLER DACCLK EEWeb | Electrical Engineering Community Visit 10 Switching FETs & Dead Time Paul Clarke Electronics Design Engineer I was looking through some old notes this week and stumbled upon the day I learned about dead time. No, this is not that fatal moment we all try to ignore; it’s a period of time where switching FETs on and off in either a Half or Full bridge is critical. So what is it, and why is the switching of FETs so important? When digital meets analogue circuits, it is always fun getting the results you want and Half and Full bridges are no exception. Although I’ll be looking at these particular circuits, it’s fair to say the same ideas will also be useful for switching any device, such as turning a FET on and off, with accurate timing and control. Below, I have set out the basics of one side of a bridge, but with some components removed so we can look at the key features alone. (Figure 1) The circuit works by generating a square wave from the HI and LO outputs in the opposite phase. This, in theory, means that only one device is on at a time and that point ‘A’ will go between 0 volts and +V. You will see that there are two resistors connected to the gates of the FETs. These are specified by the datasheet as required. They +V HI LO COM 4R7 4R7 A I 0 Volts Figure 1: Driver IC Circuit limit the current that flows between the driver IC and the FETs gate. The gate in these devices contains a small capacitor that is just part of the function of the FET. So when the gate voltage ( Vgs ) swings between 0 and, say 15 volts, this capacitor needs to charge up. Then it needs to discharge when the gate goes back to 0 volts. The driver ICs can switch rather high instantaneous currents, EEWeb | Electrical Engineering Community Visit 11 TECHNICAL ARTICLE but the resistor is there to limit this. I’ve also added zenor diodes, which is good practice as this protects the gate voltage from going over the switching level (in this case 15 volts) or generating a negative voltage below -0.5. Lastly, I have added an inductor (I) which is not really a fitted device, but will represent the PCB inductance between the bottom FET and the 0 volt reference of the driver IC (in this example the driver side is connected separately to the bottom of the FET, but is not always available in ICs of this type). So what we should see if nothing is connected at ‘A’ is only a transition of voltage and no current passing from top to bottom. However, we have two RC circuits formed by the capacitor in the FETs and the series resistors that are affecting the gates of the FETs. What we see is one device slowly switching on as the other slowly switches off. At a mid point, the FETs are both partly switched on and current will flow. In the circuit I was testing at the time, I had 400Vdc across the bridge and was getting 30 amps through the FETs for around 1nS—not good. This causes more issues than simply a large current surge and EMC. The large current in the PCB and my invisible inductor causes a voltage to appear at the source of the bottom FET. This lifts the COM connection, and in this device has the effect of starting to switch the FET off again (Vgs reduces). You will also notice ringing noise in the circuit as the inductance starts to resonate. to 22R. Then to get a really quick switch off time I use a bypass diode that allows the driver IC to quickly ground the gate of the FET. In some cases you may still want a small resistor, for example, 1R in series with this diode if the gate currents are large, but the diode alone will normally do the job. In my circuit this reduced the current to less than 1 amp at the crossover and was acceptable at the time. TECHNICAL ARTICLE Dead Time Figure 3: Dead Time 22R This period of time, as I said, is called the “dead time” and allows for the reduction of this short circuit effect that happens in these circuits. However, times have evolved and dead time control is now built into driver ICs and even microcontrollers. It would not be too hard to see that in the above circuit, if the HI and LO signals have a short pause between transitions allowing control of the timing of the gates and the switching of the FETs. Dead time is not symmetrical, and this can be seen in modern dead time control devices. The circuit above will have different current surges when going from high to low and low to high. So the new devices use a pre and post-timer that can be separately configured. Below you can see a typical timing arrangement for this taken from a Microchip controller. It’s easy to see the original signal (PWM Generator) that feeds the dead time control circuit. With a time set to zero, Figure 2: New FET gate circuit The old way of fixing this is to generate some dead time when the devices are both switched off enough, preventing large current surges. This was done by changing the circuit that feeds the FET. First, we want to slow down the charging of the FET when switching it on by increasing the resistance—in this case from 4R7 EEWeb | Electrical Engineering Community Visit 12 TECHNICAL ARTICLE TECHNICAL ARTICLE PWM Generator PWMxHy PWMxLy Dead time = 0 PWMxHy PWMxLy Non-zero dead time Time selected by DTSxA bit (A or B) Figure 4: Pre and Post Timing Time selected by DTSxl bit (A or B) the high and low sides switch together. Then adjusting these pre and post-times allows for asymmetric dead times. This allows for more efficient control and will allow you to reduce losses in circuit designs. You are also reducing noise that can affect your EMC results. Dead time and controlling FET gate switching can make significant improvements and modern devices are allowing increasingly better control. About the Author Paul Clarke is a digital electronics engineer with strong software skills in assembly and C for embedded systems. At ebm-papst, he develops embedded electronics for thermal management control solutions for the air movement industry. He is responsible for the entire development cycle, from working with customers on requirement specifications to circuit and PCB design, developing the software, release of drawings, and production support. ■ EEWeb Electrical Engineering Community Join Today EEWeb | Electrical Engineering Community Visit 13 Get the Datasheet and Order Samples 6A Digital Synchronous Step-Down DC/DC Converter with Auto Compensation ZL2101 The ZL2101 is a 6A digital converter with auto compensation and integrated power management that combines an integrated synchronous step-down DC/DC converter with key power management functions in a small package, resulting in a flexible and integrated solution. The ZL2101 can provide an output voltage from 0.54V to 5.5V (with margin) from an input voltage between 4.5V and 14V. Internal low rDS(ON) synchronous power MOSFETs enable the ZL2101 to deliver continuous loads up to 6A with high efficiency. An internal Schottky bootstrap diode reduces discrete component count. The ZL2101 also supports phase spreading to reduce system input capacitance. Power management features such as digital soft-start delay and ramp, sequencing, tracking, and margining can be configured by simple pin-strapping or through an on-chip serial port. The ZL2101 uses the PMBus™ protocol for communication with a host controller and the Digital-DC bus for interoperability between other Zilker Labs devices. Features • Integrated MOSFET Switches • 6A Continuous Output Current • ±1% Output Voltage Accuracy • Auto Compensation • Snapshot™ Parametric Capture • I2C/SMBus Interface, PMBus Compatible • Internal Non-Volatile Memory (NVM) Applications • Telecom, Networking, Storage equipment • Test and Measurement Equipment • Industrial Control Equipment • 5V and 12V Distributed Power Systems Related Literature • AN2010 “Thermal and Layout Guidelines for Digital-DC™ Products” • AN2033 “Zilker Labs PMBus Command Set - DDC Products” • AN2035 “Compensation Using CompZL™” 100 90 80 70 60 50 40 0.0 VIN = 12V fSW = 200kHz L = 6µH 1.0 2.0 3.0 IOUT (A) 4.0 5.0 6.0 VOUT = 3.3V EFFICIENCY (%) FIGURE 1. ZL2101 EFFICIENCY January 23, 2012 FN7730.0 Intersil (and design) is a registered trademark of Intersil Americas Inc. Copyright Intersil Americas Inc. 2012 All Rights Reserved. All other trademarks mentioned are the property of their respective owners. Transitors to Turbines: Outreach with Substance Vcc Vcc Vcc Vout Vin Vin Vout Vin Vout Physical Design Engineer Billie Johnson Introduction Many tech companies sponsor outreach initiatives ranging from robotics programs to science and engineering fairs to one-time field trips. Motives for such sponsorships vary as widely as the examples of outreach. Companies may be leveraging the PR value of such programs, utilizing a tax break, or have a genuine interest in planting seeds for the future tech workforce. Kids—our next generation of scientists and engineers— can reap the benefits. Sometimes the volunteer efforts of individual engineers, technicians and other STEM (Science, Technology, Engineering, and Math) proponents can be just as valuable at a grassroots level as a sweeping corporate endorsement. And, for the volunteer, opportunities exist to dive into the depths of technical content or simply lead students through a few basics. This story traces how my involvement in a middle school math program led to the installation of a residential wind turbine on the school’s campus and the integration of technically rich renewable energy education into its curriculum. Background I spend my days nestled in a cubicle laying out milliongate ASICs for ON Semiconductor. I love the visual aspect of my job in getting to see what the IO, memories, IP and roadways of a chip will look like before it is manufactured, but it’s good for me to think outside of the cubicle. It’s even better to get outside of it once in a while. My favorite hobby loosely tied to my engineering career is coaching a middle school math club, MATHCOUNTS®, at the Pocatello Community Charter School (PCCS). My job as an engineer established an immediate credibility with the students, parents and educators at PCCS when I first began working with their MATHCOUNTS club 11 years ago. Unfortunately, I soon found out I had the classroom management skills of a brick. I didn’t have a handle on different learning styles or the intricacies of leading project-based explorations. When I think I’ve got a grasp of what works with kids, I have conversations with their teachers that have me revamping lessons and teaching strategies. To apply a term from our industry, this school is on the “bleeding edge” of educational reform. Like engineers are always EEWeb | Electrical Engineering Community Visit 15 TECHNICAL ARTICLE improving flows, methodologies and design techniques, teachers are continuously improving teaching methods based on research regarding the best possible practices. PCCS follows an Expeditionary Learning curriculum model. My math club has become much more successful as I familiarized myself with Expeditionary Learning and incorporated more real-world examples in our practices. The Allure of Wind Power A few years ago, just as we were wrapping up our MATHCOUNTS season, the Women of Wind Energy (WoWE) sponsored an ad in an IEEE newsletter for scholarships to an annual WINDPOWER conference. In the same week, the nearby Idaho National Laboratory (INL) helped install a wind turbine on a high school campus in southern Idaho. Both of these piqued my interest and prompted some hearty internet research. I uncovered a Department of Energy initiative called Wind for Schools and learned that a few of the flagship members of WoWE had ties to this program. The more I learned about the program and WoWE’s commitment to wind energy education, the more clear it became that PCCS was a perfect candidate and that I had an entire network out there that could help. The program was running in six states at the time and provided a model for installing a residential wind turbine (2.7kW) and sensor on school campuses. Web-based software is included, which allows students to see what their own turbine is doing and cprovides a comparison to turbines at other schools across the country. I wrote a few grants, made a few phone calls, and (fast-forward 18 months ) PCCS was the first entity in the city of Pocatello, Idaho to tackle the permitting process needed to install a residential wind turbine. They also have a 1.1kW solar panel to make two authentic real-world projects to draw upon for loads of math and science investigations. Installation Process The PCCS student council was invited to help assemble the turbine and see all that happens on installation day. The kids attached the blades to the rotor, transported the entire blade assembly to the base of the tower, and threaded the bolts of the tower’s base. An engineering student from Boise State University (BSU), who received scholarship funding also through the Wind for Schools program, was on site guiding the kids through everything along with engineers from BSU and INL. TECHNICAL ARTICLE Figure 1: Students assemble a wind turbine at Pocatello Community Charter School EEWeb | Electrical Engineering Community Visit 16 TECHNICAL ARTICLE The entire process was captured in a slideshow and is available on YouTube. The students who helped with the installation are now in high school, but each year that the middle school classes embark upon their renewable energy expedition, teachers show the video to demonstrate how their wind turbine came to be. The staff and administration at the school deserve all of the credit for leveraging education opportunities available with an on-site wind turbine. They have assembled the content and developed hands-on projects that augment their school’s renewable energy nicely. Part of their course work has the students build their own miniature wind turbines and test them with box fans. I have an opportunity each year to listen to the kids explain their blade designs and configurations when they present their experiments and findings. It’s easy to imagine many of these young people working alongside me in a decade or so. ON Semiconductor Associations I used to be able to kick off each MATHCOUNTS season talking about how chips I’ve worked on are in cell phones, printers, medical devices, and top-secret military and aerospace applications. Cell phones are “so yesterday”, and I’ve found that just hearing about applications isn’t good enough anymore for these kids. They expect to see and experience it. While my main goal is to enhance their performance and comprehension in our math club, I naturally like to give as many plugs as I can for a career in engineering. It’s difficult to get them excited about electrical engineering through ASICs alone because they just aren’t flashy – all of the excitement happens beneath the lid. Circuit boards are nebulous and confusing for 6-8th graders, but the wind turbine in their backyard and the solar panel on the front of their school offer great visuals and a segue way for what my company and I do. All students at the school, from kindergarten through 8th grade, understand basic information about wind energy and solar power. They know how wind is created, how sunlight is converted to electricity, the main parts of a turbine, and how the turbine utilizes wind to create electricity. The 7th and 8th graders tackle a more in-depth study on renewable energy, so they have an even more robust foundation of knowledge. Now, instead of kicking off MATHCOUNTS season just talking, I ask them to tell me what they know about their school’s turbine and wind energy. After they have exuberantly and beautifully covered just about everything, they enjoy hearing about how the factory in their own community designs and manufactures chips that appear throughout the process of harnessing renewable energies. I use illustrations (1) to demonstrate where ON Semiconductor technology can be found in a grid system, including their own school’s smart meter. I explain that the inverter is actually contained within the nacelle of their turbine, but that most systems have a standalone one. My personal cool factor gets a little boost when they learn that ON Semiconductor develops power management components that control, convert, protect and monitor the supply of power in systems just like theirs. My most humorous and enlightening experience came when explaining the RF sensors atop the turbine that communicate wind speeds and energy data. Naturally, TECHNICAL ARTICLE Figure 2: Students build miniature wind turbines EEWeb | Electrical Engineering Community Visit 17 TECHNICAL ARTICLE one of the kids asked what “RF” stands for. I attempted a little side-splitting engineer humor and replied, “Real Fast.” Of course, since none of them knew it was really “Radio Frequency”, there was no laughter amidst my pre-teen audience (I know a few of them will use that line in one of their classes later in life and score a few extra points with their professor). It’s normal for a little chatter to surface while they work their weekly problems, and shortly after that I overheard one of the kids tell his buddy, “Yeah, whatever. I’m already done because I’m RF. That’s ‘Real Fast,’ which obviously you are not.” It cracks me up when they engage in math smack talk, but it’s even better when they articulate technical puns at this age. Conclusion Many companies, including mine, are committed to educational outreach initiatives. It can be tricky, both at the corporate and personal levels, to support opportunities that have the most bang for the buck, so to speak. When outreach addresses teaching standards, it is even more valuable in the eyes of teachers and administrators. Experiences like field trips or robotics programs are indisputably valuable, but when all kids get to see and understand examples of engineering every day on their campus, they have an authentic ownership and investment in learning about their wind turbine. Our wind turbine project has led to one child excitedly telling me about how her family was stuck at a railroad crossing when utility scale wind turbine blades went through town. She seized upon this captive audience and informed the car load about how the cranes will work with them when they arrive at the construction site. Another boy talked about his family’s frustration during a round of weekend disc golf when the wind kept diverting their discs, but he knew it meant good things for his school’s net metering. Wind energy in particular is visually captivating, new to the mainstream scene, and popular. Also, at its most rudimentary level, its mechanical work-to-electrical energy concepts are the same for a classroom kit or a utility scale turbine. It has been a great vessel for math and science education. I encourage you to explore any outreach opportunities through your company or in your community. It’s fun, good for our profession, and great for the soul. TECHNICAL ARTICLE Grid-connected Systems Meter AC Inverter Wind Turbine Load Figure 3: ON Semiconductor technologies in wind energy systems EEWeb | Electrical Engineering Community ON Semiconductor Applications Visit 18 TECHNICAL ARTICLE Acknowledgements The Wind for Schools program and Idaho’s Wind Application Center representatives at Boise State University were instrumental throughout permitting and construction. The Idaho National Laboratory (INL) and the Center for Advanced Energy Studies (CAES) created and hosted a database to allow turbine data sharing for all Wind for Schools projects nationwide. Members of the Women of Wind Energy from across the country contributed wind turbine calendars, children’s books, educational materials and consultation. With increasing cuts to education funding, this project would not have been possible without the monetary and labor donations of local and state businesses, parents, teachers, and members of the Pocatello community. The wind turbine kits used at the Pocatello Community Charter School were purchased through KidWind® and are available to anyone who wants to play with the power of the wind. References (1) wind/small_wind_guide.pdf. About the Author Billie Johnson is a Physical Design Engineer at ON Semiconductor. Her work experience spans test, design, technical marketing and layout, and she holds a B.S. in Engineering and an MBA from Idaho State University in Pocatello, Idaho. She has participated in numerous K-12 math and engineering outreach programs throughout her career including MATHCOUNTS ®,FIRST®LEGO® League (FLL®) , Wind for Schools and Introduce a Girl to Engineering Day. ■ TECHNICAL ARTICLE EEWeb | Electrical Engineering Community Visit 19 RETURN TO ZERO RETURN TO ZERO EEWeb | Electrical Engineering Community Visit 20 RETURN TO ZERO RETURN TO ZERO ACOUSTICS & SENSORS PRODUCTS Speakers Buzzers Piezo Elements Back-up Alarms Horns Sirens/Bells Beacons Microphones Sensors BeStar INDUSTRIES Automotive Durables Medical Industrial Mobile Fire / Safety Security Consumer Leisure ® Teamwork • Technology • Invention • Listen • Hear Preferred acoustic component supplier to OEMs worldwide | [email protected] | 520.439.9204 EEWeb | Electrical Engineering Community Visit QS9000 • TS/ISO16949 • IS O 14001 • IS O 13485 • IS O 9001 21