Category: Analog Electronics

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Analog Electronics Renewable Energy Supply Chain

EEStor not delivering

I used to read Popular Science religiously. Those great stories about the new technologies were so exciting, sometimes I had trouble sitting still. And the best part was turning to the back where you could buy some DIY kit! I remember there were “lightsabers” and “hovercrafts” and flying vehicles, all available in kit form. I have since stopped reading Popular Science, but I could very easily imagine some of those ads on the back. One might just happen to read “Batteries no longer necessary. Ultra-capacitor is the wave of the future! Cheap energy for all!”. Of course, these are in fact the headlines for an Austin based company EEStor.

So I’m going to say it. I don’t think EEStor will deliver on the hype surrounding them. Even the more recent endorsements from third party auditors, a deal with Lockheed Martin and their ongoing partnership with ZENN motors does not make me think they can produce an award winning product any more than other companies out there could. Part of me thinks there are signs that prove this (explained below) but the other part of me is secretly hoping this is one of those situations where I say something will never happen and then it immediately does. This could be called “self-reverse-psychology” or “deluding myself” or even just “being wrong”, but who cares? I just don’t see it in the cards for EEStor and I’m not the only one.

Oh sorry. I forget sometimes that the only people who fall into reading my blog are my lovely friends and hopefully a few casual browsers. EEStor is a company that claims they have and are continuing to develop an “ultra-capacitor” capable of producing capacitors with extremely high capacitance, thanks to a new dielectric material, barium titanate. But real quick, let’s look at capacitors in general for anyone who might not have the whole picture. (Maybe skip down the page if you know how capacitors work).

The simplest capacitor possible is two flat plates of metal, connected to a DC electricity source:

When you turn on the source, charge flows to either side of the plate, but cannot pass through. In this case it cannot pass through because of the air in between the plates; here, the air is the dielectric.

Ok, so now there is charge stored on either side of the plates…but what good does that do? Well, there are myriad uses for the capacitor in the world of science and otherwise; but in the most basic definition, a capacitor exists to store energy. Furthermore, the higher the capacitance of a capacitor, the more energy it can store. So how do we get that capacitance to be higher? Let’s look at the equation (real quick, I promise and then no more equations).

C = frac{varepsilon{}A}{d}

Here C is capacitance, A is the area of the plates, d is the distance between the plates, and ε is something called the permittivity of the dielectric. So to make C bigger, we either need to make A or ε much bigger or d much smaller. At first I thought EEStor was trying to only find a better dielectric (with a higher value for “ε”), which would look like this:

This shows that the charges being closer together, but in reality, it’s that the material between the plates allows the electric field to permeate through to the other side better than air. This approach of having a better dielectric is actually closer to an electrolytic type capacitor.

However, EEStor is trying to make a better ultra-capacitor. So back to the formula (last time). Ultra-capacitors try to change everything in the formula. To maintain overall size of capacitors, the area of the plates (“A”) is changed by adding material with higher surface area (Wikipedia lists a possible material as activated charcoal). This gives the charges on each plate more places to rest. Next, the distance between the plates (“d”) is reduced to be as small as possible, down to the nanometer range. This is where most ultra-capacitor manufacturers stop. They use an ultra-thin dielectric layer with a standard permittivity (“ε”) and then surround the capacitor in electrolytic fluid. This limits the overall capacitance and the material properties of the current dielectric also limits the amount of voltage (potential energy), usually to around 3V (rather there is a trade off between voltage rating and capacitance).

EEStor is trying to change all of this by using a dielectric with a much higher value. They use barium titanate, which in a powder form has a very high dielectric constant and very high tolerance to voltage. They claim to compress the material to a pure form in a very thin layer (up to 99.9994% purity, they claim), which should maintain that high dielectric constant; however, this is up for contention. If they do manage to purify the material, they will be able to put a much higher voltage across the dielectric without fear of material breakdown, which they claim is main benefit of using barium titanate. Additionally, they use many different layers of the dielectric and other plates in order to create a higher capacitance. Why, you ask? Because the work (Energy * charge) a capacitor is capable of producing is equal to

That means if you are capable of increasing the voltage rating of a capacitor (how much it can handle before the dielectric breaks down or blows up), the work goes up in a square relation to that higher voltage (doubling the voltage yields 4 times the work). You can have a much higher energy density in the device, making the operation appear to be closer to that of a battery.

Alright, so we’re finally at the point where I explain why I think that EEStor won’t deliver on their promises. First, let’s look at what they have promised:

  1. A working prototype by the end of 2008. A fully implemented device in a ZENN vehicle by the end of 2009.
  2. A Capacibattery at half the cost per kilowatt-hour and one-tenth the weight of lead-acid batteries.
  3. A selling price to start at $3,200 and fall to $2,100 in high-volume production.
  4. Weighs 400 pounds and delivers 52 kilowatt-hours.
  5. The batteries fully charge in minutes as opposed to hours.

Yikes. Those are some pretty lofty goals. I’d say the most unbelievable of these is the first one (followed closely by the third). Since they haven’t shown the slightest sign of publicity, there really is not much to go off of. In fact, as a business model, EEStor has mystique as it’s main asset. They could go public with no product and have people bid up the stock price towards the sky with absolutely no product behind the curtain. In fact, the only people who have really stuck their head out to talk about this product is the CEO of ZENN motors, Ian Clifford. And why not? Even if the EEStor product (called the EESU) is a flop, ZENN motors can play the martyr and get the free publicity. But that’s all business. What about the technical stuff? Let’s look at some safety/efficiency/production concerns that could prevent them from making a product that can be mass produced at (relatively) low prices:

  1. ESR
    • ESR stands for “Equivalent Series Resistance”. It is caused by imperfections in both the dielectric and the material that connects the capacitor to the rest of the world. The ESR is how much the imperfections impede the current flow, as the current works to align internal bonds (in both the capacitor and the connecting material). Normally, ESR will not have any effect at DC because it is assumed that there is no charging time. However, charging a battery or capacitor is more like an AC signal (albeit only half of a cycle), and the faster someone tries to charge it (in EEStor’s case, quite fast) the higher resistance will be. This will translate to heat in the capacitor and wasted energy. With the high currents being pushed through the capacitor at high rates, this becomes a safety concern first and an efficiency concern second.
  2. High Voltage
    • This is really the key to the EEStor device. If they are ever planning to have a super fast charge, it will require higher voltages, likely on the order of kV. However, the high voltages have the obvious safety concerns (ZAP!) and the not-so-obvious concerns such as skin effects. Manufacturing a safe product that will pass automotive standards will be a difficult test. Consistently turning out a reasonably priced product that will safely deliver those same voltages will be even more difficult.
  3. Piezoelectric Effect
    • Piezoelectric effect occurs when the crystal structure of a substance is stressed and then releases charge. The best piezos release charge all in the same direction based on their crystal structure. What happens when this box gets compressed, via a car crash? Will all of the charge be released at once? Will a fender bender turn into a ZENN car sponsored fricassee? (on a related, but unimportant note: If we go to all electric cars, what will happen in car chases in the future and they want to blow up the other car? Even though it doesn’t actually work, what will they shoot if there’s no gas tank? 🙂 )
  4. Material/Production Costs
    • The product we have heard about so far, with extreme purity, will require a cleanroom-like setting, a foundry-like setting, or both (comparing it to what I know about fabs). In any of these scenarios, the cost of operation far exceeds what most venture capital firms are willing and capable of supplying in terms of cash. Unless they are quickly bought by a large scale producer of batteries or similar technologies, they would not have the working capital necessary to bring their production facility to a point where they are making enough units to create economies of scale (lowering the overall cost by averaging large fixed cost over all products produced).
  5. Manufacturing issues/Large scale manufacturing
    • Aside from the material cost and the operations cost, let’s look at the obvious: making one of these units seems to be hard.  I understand that they are developing processes to create these products, but the precision required for a consistent quality product could be so cost sensitive that they will drive the final part cost way past the projected $3200 price tag.
  6. Leakage
    • Leakage would likely not be a barrier to production, but it would probably hurt them in their ability to deliver a product with the longevity needed to power cars. If the voltage across a capacibattery is supposed to be 1kV or higher, even with the best available insulators, there will be some amount of leakage (everything allows it). If the car was required to be plugged in while in a parking lot it would not be as big of an issue, but I don’t believe this is the model they are going for; they seem to want to deliver a standalone piece of equipment.
    • Another way “leakage” can happen is across the dielectric. As capacitors age, the stress on the dielectric barrier eventually starts to break down and let electrons through. If EEstor does not properly monitor for DC leakage, there could eventually be catastrophic failure of the capacitor, as more and more current moves through the dielectric; this would heat up the device to unsafe temperatures and eventually cause a meltdown or explosion (exciting, but unsafe).
  7. Efficiencies
    • Let’s say you have a “fueling station” that is actually capable of charging a ZENN car in minutes (as opposed to hours); it would likely require voltages on the order of kV as opposed to 10s or 100s of volts and currents that are on the order of amps. Let’s say for our example that we are trying to transfer 10 kW (10A * 1000V) . Even at 95% efficiency of power transfer (a very optimistic estimation), that means we would be wasting at least 500W everytime that we go to charge our capacicars.
  8. Infrastructure
    • While my friend Nate would love to point out that the energy density of these devices still won’t approach that of gasoline or ethanol, they are proposing a product that comes closer than any others have yet. However, to achieve their miraculously fast charge times and high capacity capacitors, the product will require a charging station as mentioned above that is capable of deliving a high voltage payload to the battery (hopefully at a high efficiency). This means we’ll either need to convert gas stations into power stations or create huge step up transformers for the home. Remember, US line voltages coming into a house are 120V out of your wall socket. That will take some expensive equipment to safely regulate those voltages and convert to DC (another potential efficiency problem). The costs associated with implementing such a system (either commercially or in the home) could seriously hinder any chance of public acceptance.

So for the final piece of this ultra-capacitor manifesto, let’s look at the possible scenarios we might eventually encounter with EEStor. Aside from the skeptics, there are a good deal of people who are hopeful this company will succeed and fully expect it to; this outcome is possible, but the extent to which EEStor delivers will be up for anyone’s guess. As such, I’ve included a complementary predicition of the chance each will happen (in percentage):

  1. They deliver a “product” but it is only a fraction of the promised delivery-Perhaps they have an overzealous marketing person.
    • Chance of happening: 40%
  2. They deliver a product but price it so high, there is no way to employ it in any commercial application for the next 5 years-Lockheed still might buy it. Lockheed’s interest is what got everyone so excited again back in May…but it doesn’t mean this product will be delivered or that it’s even possible.
    • Chance of happening: 55%
  3. They deliver on all of their specifications and price targets
    • Chance of happening: 5%

So go ahead EEStor, prove me wrong. I don’t want to seem like those people that said man would never fly or that there would be no need for more than 5 computers, I just wanted to write an article pointing out the difficulties that EEStor is likely to encounter and hopefully have already overcome. So EEstor, if you’re sending out samples and need a tester, I would be happy to play with one of your toys. And if you (the reader) think I missed any crucial points about ultra-capacitors or EEstor, please let me know in the comments.

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Analog Electronics Economics Politics Renewable Energy

Barack Obama Further Lays Out Renewable Energy Plan

I take a personal interest in Barack Obama‘s new plan to increase investment in renewable energy technologies, as I think and hope my long-term plan of working on renewable energies will come to fruition.


Skip to 9:38 to hear about his plans for renewable energy

I don’t seek to point out any political messages other than to focus on his determination to make renewables a viable part of the American economy, much like Thomas Friedman points out in Hot, Flat & Crowded. A green revolution or economy will help to return America as an arbiter of international issues by once again showing our leadership and innovation abilities (not to mention our economic strength). While I will point out that John McCain has also shown some initiatives for renewable energy (not to mention he does not believe that drilling for oil is the only solution), I feel that his focus on nuclear as the only true long term solution in his administration would not put enough money into the hands of people that will drive the “green revolution”. Given the possibility of recession in this country (or is it already here?), I believe that direct government investment in renewables will help to jump start the economy by driving job growth. And it won’t just come from the presidential administration either; people in the house and senate all need to push these new green energy agendas to really allow for new legislation. Great examples of this are Alice Kryzan, running for the 26th congressional district in New York and Dan Maffei who is running for the  25th district, also in New York.

Probably the point that I would like to point out most in this video is his call upon the American people to reduce their consumption AND take personal responsibility in their lives (i.e. childhood education). Sure, we could use our innovative techniques to create energy at the cost of the environment ad nauseum. But why not instead work on power saving techniques? Why not inflate your car tires to increase gas mileage, instead of pushing for faster ramp ups of offshore drilling? Why not tell people to turn off their lights, recycle their garbage, stop watering their lawns and driving gas-guzzling cars? Because it’s tough telling people that stuff. It’s not going to work at first, but it will over time, and that’s why I thought this was a good video.

I always welcome comments on renewable energy, but given the touchiness of politics, please be extra gentle when commenting. What do you think of the renewable energy plan? Is it a pipe dream? Do you think there are pieces that both candidates are missing?

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Analog Electronics Digital Electronics Engineering Learning Life Work

How to get a job as a new electrical engineer grad

I was going to call this post “A portrait of an electrical engineer as a young man (or woman)” but decided against it. I’ve got nothing on James Joyce, neither in loquaciousness nor confusing writing.

Anyway, I have been pondering what kind of employee I would hire out of school for an electrical engineering position. There are some basic skill sets that will allow just about any young engineer to succeed if they have these skills (the best situation) or at least appear they will succeed if written on their resume (not the best situation). Either way, let’s look over what a new grad should have on their utility belt before going out into the scary real world.

  1. Conceptual models of passive components — This has been one of the most helpful things I have learned since I have left school…because this kind of thinking is not taught in classrooms (at least it isn’t in the curriculum). The idea is to conceptualize what a component will do, as opposed to what the math is behind a certain component or why the physics of material in a component give it certain properties. Why does this matter? When you’re looking at a 20 page schematic of something you’ve never seen before, you don’t care what kind of dielectric is in a capacitor and how the electric field affects the impedance. Nope, you care about two things: What is the value and how does it affect the system. The first question is easy because it should be written right next to the symbolic notation. The second is different for each type of passive component you might encounter. Let’s look at the common ones
    • Resistors — The  best way I’ve found to think of resistors is like a pipe. The electrons are like water. The resistance is the opposite of how wide the pipe is (if the resistance is higher, the pipe is smaller, letting fewer electrons through in the form of current). Also, the pressure (voltage) it takes to get water (electrons, current) through a pipe (resistor) will depend on the thickness of the pipe (resistance). Well whaddaya know? V=IR!
    • Capacitors — At DC, a capacitor is essentially an open circuit (think a broken wire). If you apply charge long enough (depending on the capacitance), it can consume some of that charge; after it is charged it will once again act like an open circuit. When considering AC (varying) signals, the best way to think about a capacitor is like a variable resistor. The thing controlling how much the capacitor will resist the circuit is the frequency of the signal trying to get through the capacitor. As the frequency of the signal goes up, the resistance (here it is called “impedance”) will go down. So in the extreme case, if the frequency is super high, the capacitor will appear as though it is not there to the signal (and it will “pass right through”). Taking the opposite approach helps explain the DC case. If the signal is varying so slowly that it appears to be constant (DC), then the impedance of the capacitor will be very high (so high it appears to be a broken wire to the signal).
    • Inductors — Inductors have an opposite effect as capacitors and provide some very interesting effects when you combine them in a circuit with capacitors. In their most basic form, inductors are wires that can be formed into myriad shape but are most often seen as spirals. Inductors are “happy” when low frequency signals go through them; this means that the impedance is low at low frequencies (DC) and is high at high frequencies (AC). This makes sense to me because if the signal is going slow enough, it’s really just passing through a wire, albeit a twisty one. An interesting thing about electrons going through a wire is that when they do, they also product tiny magnetic fields around the wire (as explained by Maxwell’s Equations). When a high frequency signal tries to go through the inductor, the magnetic fields are changing very rapidly, something they intrinsically do not want. Instead it “slows” the electrons, or really increases the impedance. This “stops” higher frequency signals from passing through depending on the inductance of the inductor and the frequency of the signal applied. Looking at the how they react to different frequencies, we can see how inductors and capacitors have opposite effects at the extremes.
    • Diodes — I think of diodes as a one way mirror…except you can’t see through the one way until you get enough energy. The one way nature is useful in blocking unwanted signals, routing signals away from sensitive nodes and even limiting what part of a varying signal will “get through” the diode to the other side.
    • Transistors — I always like thinking of transistors as a variable resistor that is controlled by the gate voltage. The variable resistor doesn’t kick in until the gate voltage hits a certain threshold and sometimes the variable resistor also allows some energy to leak to one of the other terminals.
  2. C coding — Sorry to all you analog purists out there, but at some point as an engineer, you need to know how to code. Furthermore, if you’re going to learn how to code, my personal preference for languages to start with is C. Not too many other languages have been around for as long nor are they as closely tied to hardware (C is good for writing low level drivers that interpret what circuits are saying so they can talk to computers). I’m not saying higher level languages don’t have their place, but I think that C is a much better place to start because many other languages (C++, JAVA, Verilog, etc) have similar structure and can quickly be learned if you know C. Even though the learning curve is higher for C, I think it is worth it in the end and would love to see some college programs migrate back towards these kinds of languages, especially as embedded systems seem to be everywhere these days.
  3. How an op amp works — I set the op amp apart from the passives because it is an active component (duh) and because I think that it’s so much more versatile that it’s important to set it apart conceptually. I’ve always had the most luck anthropomorphizing op amps and figuring out what state they “want” to be in. Combining how you conceptually think about op amps and passives together can help to conceptualize more difficult components, such as active filters and analog to digital converters.
  4. The ability to translate an example — A skill that nearly every engineering class is teaching, with good reason. Ask yourself: are homework problems ever THAT much different from the examples in the book? No. Because they want you to recognize a technique or a idiosyncrasy in a problem, look at the accepted solution and then apply it to your current situation. Amazingly, this is one of the most useful skills learned in the classroom. Everyday engineering involves using example solutions from vendors, research done in white papers/publications and using even your old textbooks to find the most effective, and more importantly, the quickest solution to a problem.
  5. High level system design — This is similar to the first point, but the important skill here is viewing the entire picture. If you are concentrating on the gain of a single amplification stage, you may not notice that it is being used to scale a signal before it goes into an analog-to-digital converter. If you see a component or a node is grounded periodically, but ignore it, you may find out that it changes the entire nature of a circuit. The ability to separate the minutiae from the overarching purpose of a circuit is necessary to quickly diagnose circuits for repair or replication in design.
  6. Basic laws — It is amazing to me how much depth is needed in electrical engineering as opposed to breadth. You don’t need to know all of the equations in the back of your textbook. You need to know 5-10; but you need to know them so well that you could recite them and derive other things from them in your sleep. A good example would be Kirchoff’s laws. Sure, they are two (relatively) simple laws about the currents in a node and the voltage around a loop, but done millions of times and you have a fun little program called SPICE.
  7. Budgeting — There are many important budgets to consider when designing a new project. In a simple op amp circuit, there are many sources of error and inefficiencies. Determining and optimizing an error budget will ensure the most accurate output possible. Finding and determining areas that burn power unnecessarily must be discovered and then power saving techniques must be implemented. The cost is another consideration that is usually left to non-engineering, but is an important consideration in many different projects. Finding cost effective solutions to a problem (including the cost of an engineer’s time) is a skill that will make you friends in management and will help you find practical solutions to many problems.
  8. Math — Ah yes, an oldy but goody. Similar to the passive components, having a conceptual notion of what math is required and how it can be applied to real life situation is more important than the details. Often knowing that an integral function is needed is as important as knowing how to do it. And similar to the basic laws, you don’t need to know the most exotic types of math out there. I have encountered very few situations where I need to take the third derivative of a complicated natural log function; however, I have needed to convert units every single day I have been an engineer. I have needed simple arithmetic, but I’ve needed to do it quickly and correctly. Sure, you get to use a calculator in the real world, but you better learn how to use that quickly too, because your customers don’t want to wait for you to get out your calculator, let alone learn how it works.

Each of these skills could be useful in some capacity for a new electrical engineer grad. There are many different flavors of engineering and the skills listed above are really modeled off what would be good for an analog system engineer (who develop commercial or industrial products). However, a future chip designer and even a digital hardware engineer all could benefit from having the skills listed, as it is sometimes more important to be open to new opportunities (especially given the possibility of recession and potential shifting of job markets).

Did I miss anything? Do you think there are other skills that are necessary for young electrical engineers? What about general skills that could apply to all young engineers?

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Analog Electronics Economics Supply Chain

DC powered home

Either my readership has extended to people at multinational corporations or the idea is intrinsically viable enough to actually work! Either way, I’m happy.

Junko Yoshida of EE Times reports that Sharp Corp and TDK corp have both displayed home mock-ups that include DC modules running of of solar cells and do not require any AC/DC or DC/AC conversion (thereby saving power wasted on the conversion process). This is reminiscent of when I asked if DC can power an entire home. They cite instances of using DC power to directly use in LED home lighting, flatscreens and various other commercial products.

Looks like the idea is catching on, I can’t wait until it becomes possible for everyone!

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Analog Electronics Blogging Health Learning Life Music Politics

Why start a namesake site?

Tonight, I’m using every bit of my being not to post something political (watching the VP debate). The tension in this country is so thick you can cut it up and serve it. Anyway, instead I will post a question (to myself).

Why did I start ChrisGammell.com?

I’ve written before about why I started a blog, but never why I decided to make it a namesake site (using my real name, all over the place). The main reason is branding. Pure, simple and maybe a little bit selfish. It’s actually a lot of work to get people to know your name. It’d be much easier to start a blog titled “AnalogElectricalEngineering.com” or something like that. That would be great for the average Analog Electrical Engineer, but not so much for Chris Gammell. In that case, I would have to work extra hard to let people know who I am and what I do. So why else? I like trying to be an individual (even if it complete individuality may not be possible). I love the idea that people are reading my ideas. I like the attention, sure, but moreso, I like contributing to society, even a little bit. Perhaps it’s a characteristic of Generation Y, but I enjoy it and I’ll spend some late nights to help out if I can. Yet another reason is that I enjoy challenging myself to learn knew things. True, I feel a little guilty blogging about things I’m not a master of, but if I spend some time researching, I can usually point readers in the right direction, even if I’m not completely sure. The best point is where I define a problem for myself online and then figure it out and get to post it later.

It’s a risk, for sure. First off, if I publish some bogus articles, people will know it. Moderators, readers, editors, professionals, everyone is really a critic on the internet. But I’m ok with that because when someone corrects me (hopefully in a civil manner) it’s an opportunity to learn. Plus my ego isn’t so big that I think I know everything (or anything). Beyond the simple idea of being wrong, I’m also giving direct access to a lot of information about myself and my life, even if it is my professional life. I justify the lack of anonymity by thinking about having people coming back and reading my ideas because they recognize my name. If I can inspire some confidence in my ideas, then I’m doing alright. Finally, I take great care to not reflect badly upon those that know me, nor those that are associated with me. In my thus-far short career as an analog engineer, I’ve found that referring other people is a power that should be respected. Not only should you be careful who you refer to others but also how you interact with others so they will someday refer you.

Short and simple, I started a namesake site because of my ego. I keep it going because I love the direction it’s taken me in. I love that blogging is helping me define myself outside of my job, even if it is similar to my job (which I also love).

Why do you blog (or not blog)? Respond in the comments, please!

Categories
Analog Electronics Digital Electronics Engineering Renewable Energy

Power Saving Techniques

Two things will make people want to use less power: not giving them much to start with and making it prohibitively expensive. Both of these scenarios seem to be dovetailing right now with the shrinking of many devices and energy becoming an ever more expensive and sought after.

Sure, there are people out there trying to create and harvest more energy. Either through more drilling, more wars, more acquisitions or new technologies. But eventually, people start to question why we are using so much energy in the first place. Instead of running device batteries into the ground quickly, why not draw less current? Instead of putting a bigger more expensive battery on a device in the first place, why not come up with new techniques to conserve power? Instead of paying high prices for energy and polluting the environment, why not conserve energy in our devices so that we don’t need as much energy overall?

Here are some of the methods that designers use in increasing numbers to reduce power consumption

  1. New chips — The basic idea is the same for any chip: Try and have the same or better performance of today’s chips with incrementally less power.  Most often, the best way to do so is to reduce the number of electrons it takes to store a value or drive another circuit (or whatever your task may be). However, there is a lower limit to how few electrons are required to complete a task (one, duh). How do we get less electrons doing these tasks?
    • Smaller geometries — Moore’s law tells us that process technologies will allow a doubling of technological ability every 18 months. This could even be a faster rate than previously thought, according to one of my favorite futurists, Ray Kurzweil. As fabrication facilities race to leapfrog one another to the next smallest process technology, they also help to reduce the number of electrons running through a device. If you look at the path of an electron along a trace on a microchip or op amp, it resembles a “tunnel” that electrons flow through. As process technologies get smaller and smaller (32 nm, anyone?) there is less room for electrons to flow through and thus, less power is used.
    • New materials — If you have less electrons flowing through a semiconductor, that means the total current flowing through the semiconductor is lower (current is defined as the number of electrons [measured in charge] flowing past a point for a period of time i.e. Coulombs per second). While less current can also mean less noise (fewer electrons bumping into other molecules and heating them up), it also means that if there is more resistance in a connection between two points, it will be harder for the electrons to travel that distance. As such, semiconductors are now made with new doping compounds (the molecules they force into silicon) or they forgo the silicon and try entirely new materials (Gallium Arsenide is a good example). These new materials allow for more efficient transistors and lower power consumption in devices.
    • New architectures — National Semiconductor has been pushing a new, more consistent power metric called “PowerWise“; it is targeted towards the mobile market and the “green revolution”. While this is a bit of a marketing move, it also helps to highlight their most efficient products across the different product types (LDOs vs Switching Regulators vs Op amps, etc).  Some of these newer, higher effeciency products use new architectures, as in the case of some of the switching regulators
    • Lower supply voltages — This one affects me on a more regular basis. Sure, the lower potential across a junction will drive less current in the off state (Iq) and will have less noise due to lower potentials; but this also throws a wrench in the works if you’re trying to find parts that will drive some significant currents or have any kind of large allowable input voltage ranges to a circuit without bootstrapping the supplies.
  2. PWM — Pulse Width Modulation (or PWM) is an easy way to reduce power in LED lighting situations. The idea is based off the fact that the human eye cannot determine the continuity of a light signal if it is below a certain frequency; instead, pulsing an LED on and off quickly will translate to the human eye as a lower intensity than an LED lit continuously. This idea is used regularly in portable electronics to dim the “backlight” of a laptop screen, cell phone, GPS device, etc. The duty cycle is the time that a device is powered divided by the total time it is on; usually it is given as a percentage. So if an LED is lit for 1 seconds and then off for 3 seconds (1 second on divided by 4 seconds total), the duty cycle is 25. In that example, the LED would appear to be one quarter as bright as a fully powered LED, but will also save a little less than 75% of the power normally required. The power saved can never be the entire difference between the normal case and the PWM case because some amount of power is required in order to switch between the on and off states.
  3. Microcontroller/Code Improvements — One of my favorite new blogs, written by Rick Zarr of National Semiconductor, has two great posts about the energy content of software. In it, he points out some of the ways that software can intelligently shut down portions of the code in order to reduce redundant processes and save on processing power. However, the points that I really like are the ones  he makes about making the simplest possible solution that will still get the job done well. This could mean cutting out some software libraries that were easier to just include in a project or learning how to properly construct a software project. Other techniques could be a combination of better coding and PWM: putting a device to “sleep” for a set period of time only to have it wake up at set intervals to see if it is needed.
  4. Going Analog — One last great point that Rick makes in his first post about energy saving techniques in software actually relates more to hardware. Instead of using a DSP, an ADC and some coded FIR filters, why not pull the filter back into the analog domain? Sure, it’s a little more difficult at the beginning but there won’t be any quantization errors (the error that comes from approximating a real signal with a digital signal). Analog engineers can do the same task with an active filter as digital engineers can do with a digital filter for many simpler applications. With the lower part count and the lower strain on the system of not converting a signal from analog to digital and back again, designers can save some significant power.

The final solution to our energy problems will be a combination of power saving techniques and new renewable energy sources. With some of the above techniques, designers will be able to use smaller batteries that allow longer usage times and have less of an impact on the environment. Please feel free to leave comments or any other power saving techniques you have heard of in the comments!

Categories
Analog Electronics Economics Engineering Politics

Possibility of Recession

I’m sure it’s one of the first times I’ve ever thought this, but right now I’m really glad I didn’t go into finance for a career. OK, that’s untrue, even though the money is good for them, I’ve always recognized that the lifestyle stinks. But holy moly, those guys (and gals) are probably not having a great time right now, even if they’ve socked away money before this month.

As any part-time pessimist would do in rough economic times, I’ve been thinking about work and how I could be affected by an extended recession. I’m not too worried that a possible economic downturn will have me out on the street tomorrow, but of course I wonder what might happen in the near- to mid-future. Furthermore, being the perpetual optimist, I am trying to see how a recession could be good not only for engineers, but also for engineers (and others) in Generation Y. So for now, forget about golden parachutes, let’s think about silver linings:

  1. Hard times — You know what people who were around in the depression era love talking about? Hard times. You know why? Because they made it, that’s why. So listen up! They weren’t handed jobs and houses and pre-packaged suburban Lego™-kit lives. They put up with some sucky times and earned a lot of what they got. Fast forward 80 years and you have Generation Y, the helicopter parent driven careers with high salaries and lower skill levels than many engineers leaving school 20 years ago. I’m not saying I’m not grateful for the opportunities I’ve had and the work I’ve been allowed to do, I’m just saying that a wake up call could help our generation in some subtle ways. Who knows, maybe in 80 years we’ll be the ones telling the young whippersnappers how good they have it.
  2. Weak dollar — I hear a good deal on NPR about how the credit crunch is the most worrisome aspect of a flailing economy and I agree it can really hurt companies if they do not have access to capital. Poor cash flow through one business can affect the next and the next and so on because companies are not capable of buying the products they need to get their job done. However, something a lot of economists are failing to mention is how the bailout and the economy in general is pushing the dollar to new all time lows. For engineers, with jobs being outsourced daily, this can be somewhat good. It has been cost effective to send manufacturing jobs overseas and even some design jobs, but that has been because of discrepancies in currency (no thanks to the Chinese government). If the value of the dollar drops off, it’s unlikely that textile mills will be popping up in Cleveland like they do in Malaysia or India. But maybe a few more manufacturing jobs will stick around. And maybe a manager or two will think twice about the equivalent cost of sending a design job overseas where they might have to spend some extra time fighting the language barrier.
  3. More start-ups — Somewhere along the way, bright young entrepreneurs who can’t get jobs at their local global conglomerate because of a hiring freeze end up saying “Hey, I can start a company! I’m already not making money, it wouldn’t be any different!” Don’t believe me? Google started in 1998. It flourished through the entire tech bubble mess. Yeah, there’s an example for you. Hard times, especially when it’s hard to get loans or credit, make the environment particularly well suited to software start-ups, where fixed costs (factory equipment, raw material, Swingline staplers) are much lower than they would be for a widget making facility.
  4. Repair — Some of the best lessons I’ve ever learned in electronics was trying to fix something that was already broken. I’m trying to fix a broken piano right now and it’s already been an enlightening experience. In the spirit of all things renewable, why not fix the gadgets we have instead of creating new ones we don’t need (“Oh look, this refrigerator has GPS!”). As the world goes more digital and parts get smaller, there’s less troubleshooting and more “throw out that board, put in a new one”. But even having younger engineers analyze failures on a system level can have a positive effect on their understanding of said systems.

I would love to tell you that everything is hunky dory and that the economy will have a continually positive growth rate forever. But seriously, that’s politicians’ jobs to lie about that. I’m just saying that in the event of a recession, people deal. I’m not planning on going all grapes of wrath and trying my hand at farming in the dust bowl, but I feel (perhaps overly) confident that I’m flexible enough to weather any economic storm brewing on the horizon. Do you think you are? Let me know in the comments.

Categories
Analog Electronics Learning Life Politics Supply Chain Work

The Great North

This blog started when I moved back to Cleveland. Really, it was a little bit sooner, but it got going full time once I was settled in back in May. Since I’ve been back, I’ve actually really enjoyed it. There are some things I miss about Austin (where I used to live), but I am happy with my decision, most notably because of my job. I feel like I am part of the minority that is moving back North, that others in my generation are more likely to head south at the first opportunity.

Is there any reason to live in the north anymore?

Let’s go over the sour points first:

  1. It’s cold — No brainer on that one, it definitely snows more in Ohio than in Texas, but you do get the benefit of some winter sports (skiing, tubing, professional snowman making) and the picturesque nature of seeing snow on Christmas or at other times (this wears off after about two weeks). Unfortunately, the cold lasts longer than most people would like in Ohio. Back in Texas I was wearing shorts and tubing down the river by March.
  2. Gas/Heating —  This year might be the best example of expensive heating, but it has yet to play out. Oil prices are falling right now but could easily rise again in time for winter. There are some other (corny) ways to heat your house, so oil prices do not have the final say in how much we’ll be paying per month for oil north of the Mason-Dixon line. On the bright side, we’re paying WAY less for electricity than the south during the summer months.
  3. Young people — There’s kind of an avalanche effect to people migrating out of one city or into another. The more people that move somewhere, the “hotter” the scene becomes and more people want to move there. Cleveland still has a pretty vibrant night life, but it pales in comparison to Austin and some other larger cities.
  4. Urban Development — Suburbs happen. Sprawl happens. The longer a city has been around (such as those  in the north), the more people want to spread out and get their own space. This is slowly happening in the south (Dallas, anyone?), but Austin is still relatively compact. With newer, smaller, growing southern cities, urban planning can help to compact things and make them more accessible. If you are moving to a city in the north, it’s likely that a lot of the urban development is already done (though not completely).
  5. Jobs — We hear about the manufacturing jobs lost in Mid-West every time you turn on NPR. But there are also less large corporations in the north, due to some of the above listed reasons and less amiable tax laws than parts of the south.

But there is a lot of bright spots in Cleveland, even in the winter!

  1. Water — Necessary for life, right? Well some people didn’t really think about that when they were setting up new cities and towns in the southwest (I’d reference all of Arizona first). The Mid-West though? We’ve got tons of it! The great lakes are a great resource, whether for shipping, recreation, fishing or even lighting on fire (go Cleveland!). It definitely makes the summer months that much better and makes the winter months that much more bearable. Polar bear club, anyone?
  2. Infrastructure — Even though we may be a sprawling metropolis with many different cities, I will say that Cleveland has the benefit of a well developed system of roads. If you are so inclined, you can also take an AmTrak train to more destinations than you can from Austin (more track = more destinations…but to be fair you can get to most any city if you sit on a train long enough).
  3. Proximity — This was another nice deciding factor, both in where I went to school and why I wanted to move back. I can easily drive home to Buffalo in 3 hours, can drive to Columbus in 2.5, can drive to Detroit in 2.5 if I’m feeling feisty and can get to Chicago or DC in about 6. This compared with Austin having a 3 hour drive to the next biggest city (that I didn’t want to visit anyway) and a 12 hour drive to get out of the state.
  4. Airport — Similar to above, sometimes you just want to get out of town. If you can’t drive, you might as well fly. And if you’re going to fly, you might as well fly out of a hub. Even though continental decided to cut back their flights out of Cleveland, we have a great place to fly out of to get to some warmer destinations in those bleak winter months.
  5. Home Prices/Cost of Living — Thanks in part to our bozo friends in the finance industry and the overzealous DIYer house crowd, the housing market isn’t doing too hot right now. However, if you’re looking for a house, this is a great time! House prices and general food prices make for a much lower cost of living than many parts of the country, especially those with similar populations to Cleveland. Sometimes this is offset by lower taxes, but your consumption rate can be a little higher without incurring as much cost.
  6. Renewable energy — There is a lot of wind out on Lake Erie. This primes the region for becoming one of the premier renewable energy markets as we move forward with attempting our energy independence. The Great Lakes Institute for Energy Innovation is a start up at Case Western that could really help to move this forward.

I’m still really glad that I moved back to Cleveland. I only dealt with winter from Feb – April last year, so we’ll see how I handle an entire Cleveland winter. I’m not saying I’ll live in the Great North forever, but that for now, it fits me just right. Keep warm!

Categories
Analog Electronics Life Music

Breaking my Wurlitzer 200A

“Hmm, I should really get a sound sample for the before and after on my piano. I’m so confident I can get this thing to work that I want some evidence how broken it was prior to my genius fixing of this machine.”

POP. ZAP. HUMMMMMMMMMMMMMMMMMMMMMMM.

“EEP,” thinks Chris.

HMMMMMMMMMMMMMMMMMMMMMMMMMMMM….

So it seems that I may have broken the amplifier on my Wurlitzer 200A. This after I took my sweet ol’ time getting all the replacement parts in from Mouser. After they finally arrived, I scheduled a time to work on the piano on the weekend to try and fit into my relatively busy schedule.

First inspection of the board shows that this piano has definitely had work done on it before. There are multiple places where the solder joints have been over done with solder (too much globbed up in one place). The resistors and capacitors also do not appear to be the originals, though they still appear to be pretty old and could be the originals.

So what do I think happened? In my onomatopoeic description at the beginning of this article, you may have guessed that there was a short to ground (the “ZAP”). This happened because I was dumb enough to try turning on the piano when it was not bolted to the chassis. The circuit board likely shorted from one of the high potential points to the chassis, which is grounded. In the process, high amounts of current either caused a part to fail catastrophically through material failure (a PN junction having too many carriers “break through”) or thermally (an electrolytic capacitor exploding due to high temperature).

I have a very primitive multimeter intended for use on power lines and such, so it could only tell me the there is 2 volts DC at the speaker output. This is definitely not healthy for the speaker nor the system and leads me to believe the output coupling capacitor may have broken. I will update more once I borrow my friend’s advanced multimeter.

Categories
Analog Electronics Learning Life Work

What is an engineer?

I’ve been having what some would call an identity crisis. How, you ask? I’ve been working on digital electronics.

*GASP*!

I found out that in the early 90s and even earlier, analog engineers routinely switched from working in the analog domain to the digital domain…because it was paying really great. Not only that, most analog engineers had the expertise to do what most early digital engineers were doing (basically stringing together a lot of digital gates in DIP packages). It wasn’t until later that digital engineers started acting more as programmers and VHDL/Verilog experts.

So why do I bring this up? Because I’ve been thinking about the versatility required from engineers in general, not just analog or digital engineers. Routinely engineers are asked to switch modes or tasks or careers in order to get a job done. It’s not that other professions are never asked this; it’s just that the chameleon-like requirement placed on engineers seems to define the profession. Allow me to explain.

What is an engineer?

An engineer puts theories into practice using available devices and elements. They create new products and pass on knowledge through design iterations and trial and error. Their work should be directly applicable to the real world (sometimes in the form of an end-product, sometimes not) and hopefully able to be reproduced successfully in the same form for multiple parties (mass manufacturing). Engineers are often rooted in math and science but require a wide range of skill-sets in order to properly construct an end product.

I think it is important to note that an engineer is different from a scientist, although the line can often be blurred (especially when looking back at the inventors of the early 20th century). In modern times a scientist is usually tasked with pushing the barrier and finding new theories and concepts. This means that the concept will not necessarily be available in product form right away (although this is not always the case), as the product form must be iterated upon and improved for production.

Another interesting point is how the above definition manifests itself in higher education. When I was in school, the focus was definitely on making engineering scientists, that is engineers who are taught to research new methodologies and concepts with the final product in mind. There was much less focus on using existing products (i.e. discrete transistors) to create something new or to solve a problem. I do not think that it is a huge problem, as some of my classmates went on to work on their Master’s degrees or to work in research labs. The rest of us trying to break into industry were a little more strapped on what is expected from an engineer. Let’s go over what some of these things might be.

  1. Flexibility — This could be a theme of this article. Engineers have to be flexible and think on their feet. Again, I’m not saying scientists and other professions do not have to do this, only that it is required for many engineers. I went into my first job (working in a fab) as an electrical engineer student and ended up looking at chemical reactions and doing process engineering. The company I worked for didn’t want an electrical engineer, they wanted and engineer, someone they could teach their methods to and who could pick up the nuances as quickly as possible. I think it’s also important to note that they didn’t just hire engineers, they also hired scientists (don’t worry, I like scientists).
  2. Science and math knowledge — No surprise here, you have to know the basics in order to really get going in the field. However, I think that the interesting thing is that the basics is usually the majority of what you need. I used Ohm’s Law more often in practice than I use the knowledge of how to do the third integral of a sphere.
  3. Design re-use and not trying to re-invent the wheel — This was actually the reason I wanted to write this post, to point out that engineers often enter the field thinking they will be designing every piece of a system from the ground up. First off, this is irresponsible. The industries would never have standards if every engineering firm was trying to redesign a buck-boost converter everyday. Instead, engineers use optimized solutions available from vendors. Not only does it help standardize, it saves time.
  4. KISS — This directly relates to the above point. You have to keep it simple, because there are only 24 hours in a day. I have claimed to be a system designer before (or at least will be). To design a full system, you have to look at the simplest and fastest solutions because they are often the best and most elegant solutions. Not only that, if you don’t do it as fast and simple as possible, someone else will, and then you’ll lose out on a customer, contract, etc.
  5. Learning is pain — Even though continual learning is one of the main reasons I got into engineering, it’s not always fun. It’s not a great feeling when someone asks you to do something and then you have to slink away because you have no clue how to do it. Hopefully you’re slinking to go learn about it and not running away, but that is dependent on the person. The point is, learning is a difficult process and we really learn the most when we’re in situations that stretch us to the limits. In my experience, I always learned more in classes where I worked to get a C than in the ones where I breezed by and got an A.

Engineering is a field I entered because of the myriad things I could work on throughout my career. I did not switch to the digital domain for the money. I switched to digital work because I was asked to and it has been really interesting so far. Programmable logic is something I’ve worked on in the past and something I’m sure will become more prevalent in the workplace as design requirements become more stringent and timetables get shorter. If you are an engineering student or an aspiring engineer reading this article, I would highly suggest the profession (just make sure you note the above points). If you’re an experience engineer, please feel free to leave your experience in the comments. Thanks for reading.