Jul 28, 2011

Important: Renewables Conquer Nuclear in the US

Earlier this month I talked about a closing line from Empires of Light by Jill Jonnes. She wrote in one of her final passages that “electrical power made possible the important and the frivolous, the noble and the idiotic”. I thought it would be fun to look at the ways people use and abuse electric power these days by going back through the news each month and picking out stories that met those criteria. My original intent was to do all four in one entry, but now I think doing that would make the post too long. Instead, I figure I will finish out the month with the “awards”. Over the next four days, I will post the stories I chose for July. Let’s get started. 



The inaugural title of “Important” goes to a story published on Domestic Fuel stating thatrenewable energy sources have overtaken nuclear power as a contributor to thenational energy consumption according to the July “Monthly Energy Review” published by the U.S. Energy Information Administration on the 5th. In other words, renewables now provide more energy to the nation per month than nuclear power plants. As the chart below shows, they contributed 0.806 quadrillion BTUs in April of this year. Just in case you were unaware, BTU stands for British Thermal Unit. It’s used to represent national energy savings in the United States because it is sort of an all-encompassing unit for comparing energy sources like coal, natural gas, and crude oil by measuring the amount of heat each can produce. For this reason, when the Department of Energy (DOE) sets standards for various consumer products, they are required to report the potential energy savings in BTUs rather than kilowatt hours (kWh).

 Figure 1. Energy Consumption in the US in April, EIA Monthly Energy Review 07/11

So why do I consider this story important? Well, one of my big research interests is power conversion in renewable energy systems. I have it in my plans to build a few systems of my own just to learn a bit more and document some results. However, what really impressed me about this was not so much that renewables were able to take over nuclear energy, because frankly nuclear power never really gained a lot of traction in the US after the Three Mile Island and Chernobyl incidents in ’79 and ’86 respectively, but how close they were to overtaking crude oil as well. Cynics may be quick to point out that we would need a 50% increase in renewable production to equal the contribution of crude oil, and to that I would say you are missing the point. The fact is that renewables are still a vast, untapped resource.

The integration of renewable energy sources has been slow in the US for political and environmental reasons, but in the past two years alone there has been a huge increase in their availability. According to the report, the amount of energy contributed by solar power has increased 104.8% since the first quarter of 2010. Similarly, wind energy production has increased by 40.3%, keeping the US on pace to remain the world leaders in that category. In total, renewable sources now constitute 11.73% of the total energy consumed in the US. I don’t know about you, but I am amazed to already see the day that clean sources contribute 1/10th of our entire energy demand given how anemic our efforts have been. Even with doubling its production in one year, solar energy only contributes about 1% of the total US energy consumption. When you think about the fact that enough energy from the sun hits the Earth in one hour to power the entire planet for a year, it seems sad to think that is all we can do. Fortunately, it’s not the best we can do…not even close.

I encourage anyone interested to skim the report (it is 214 pages) and check out some of the graphs the EIA published, they are pretty revealing. You can find the report here.

Jul 27, 2011

Touchstone Semiconductor Demo Board

Silicon Valley is rich in electronics history. Nearly every major semiconductor player these days is based out there or got their start among the California hills. Today, numerous startups are rooting themselves to the valley in order to be the next big IC manufacturer. In a time when nearly everything runs on computers, it’s easy to see why.

One of the newest startups to join the fray is Touchstone Semiconductor, an analog IC manufacturer out of Milipitas, CA formed just last year (2010). They have only a few circuits available right now, but seem to be making a name for themselves in the marketplace. Their big marketing ploy is that they second source Maxim parts. Maxim is famous, or infamous, among design engineers for having a large selection of excellent parts that no one can ever get. In actuality, this is more of a problem for orders in the tens of thousands rather than a couple of hundred, or in the case of a hobbyist a one-off. Second sourcing means that they are licensed by Maxim to reproduce some of their designs in Touchstone Semi’s fabrication plants (or “fabs”).

Recently, Touchstone Semi decided to give away some of their development boards through Dangerous Prototypes, who make kits and run a really good electronics blog. I managed to enter in time to win one of the boards, which you can see below. 


If you remember my entry on comparators, then you will understand what it means when I say there are two independent circuits on the board acting as comparators with built-in reference voltages. On one side is the TS9001-1 (click to head to the support site) and on the other the TS9001-2. There is a difference between the two, but this isn’t the entry to really get into that sort of thing. What I will say is that these comparators take advantage of hysteresis when toggling between high and low states. Hysteresis is another concept I will explore in future blogs – I know I say that a lot –  but what is worth knowing now is that hysteresis makes the circuit react much quicker than one without it. In my blog on comparators, I showed how the output of the circuit did not change exactly from the low state to the high state the instant the input voltage was greater than the reference voltage. Instead we saw a gradual rise in the output over a range of a few hundred millivolts. With hysteresis in place the change would be nearly instantaneous.


The only thing I can really think to do with these boards at the moment is run them through a few tests and use the results for my blog on hysteresis. It has also occurred to me that they could be used to generate a PWM signal in voltage-mode feedback DC-DC converters, should I ever choose to prototype a few designs. I am pretty happy to have the chance to mess around with them a little though, and I will definitely be looking more into Touchstone Semi’s products in the future. Check them out if you are interested in their story.


Jul 22, 2011

Solder Smoke Fan

Some time back, I started experimenting with liquid flux to practice lead-free soldering. I got a face full of fumes that instantly cleared up my sinuses every time I tried to use it, which worried me a little since you are supposed to avoid breathing in those fumes. The package says the flux contains products known to cause cancer in California, but, hey, I’m not in California.

To get around the problem I figured I would use a desk fan I used in college to blow away the smoke, but it ended up being too powerful and cooled down my soldering iron to the point that I couldn’t melt the solder properly. After some thought I decided to build a solder smoke fan to blow away the flux fumes using an old stereo system heatsink fan I kept for just such an occasion.

The circuit idea is pretty simple. I used a 555 timer (will do a blog on this in the future) to generate a PWM signal (have done a blog on this), which I used to control the speed of the fan. The 555 timer can accept input voltages from 5V up to 18V so I figured I would use a 9V battery to power the fan, though the fan is capable of accepting up to 12V at 80 milliamps. After some early testing I figured out the fan takes about 50 milliamps at 9V with 100% duty cycle. Since the 555 timer can provide up to 200 milliamps, I chose to run the fan directly off the chip. This blog entry will focus more on the exterior build because I haven’t talked about 555 timers yet. In fact, the only thing I will say about the circuit is that I used a potentiometer (variable resistor) connected to a knob to vary the duty cycle of the drive signal for the fan, thus controlling the speed. Check out my blog entry on PWM if you don’t remember some of these terms.

When I was building the RGB cube way back in August of 2010, I tried a few different acrylic enclosures to see what they would look like. Among the rejects was a hockey puck display box typically used for storing signed pucks. I thought it would be perfect to house my fan so I used a 2” diameter hole saw to drill a hole in either side of the display. That way, air can flow in from the back of the fan and out of the front to dissipate the smoke. The fan I was using had four screw terminals in its four corners so I planned on using machine screws to hold the fan in place and ultimately to put the entire assembly together. You can see a shot of all the hardware I used in Figure 2. I was also going to leave it clear for a see-through facade.

Figure 1. Pile of Shattered Dreams
A lot of these initial plans ended up working out, but there were quite a few epic fails. Check out Figure 1 to see how many different displays I went through before I got something I could work with (about 4). The good thing is the display comes in two pieces that fit together so if you buy 2 of them u actually have 4 chances to get 2 good pieces out of the lot.  

I had initially planned on putting the 9V battery inside the enclosure itself, but, by the time I started to put all the pieces to together for one last test fit, the battery was too big for the bottom of the case. Making things fit right turned out to be my biggest problem throughout the build because I would constantly have to file out bigger holes or cut new ones. In the end, I bought some 9V battery holders (see Figure 2) and secured one to the bottom of the case using some small screws from the pack of switches I got at Radio Shack. I also elevated the fan using some standoffs – I think they were about an inch and a half. You can find all the materials I used to build the enclosure in my BOM at the end of this post. 

 Figure 2. Assorted hardware used in building the fan enclosure

I ended up changing my mind on the transparent housing scheme because there were too many noticeable scratches on the acrylic once I finished cutting out all the holes. I sanded down the face until it was smooth then painted the entire enclosure flat black to match the fan, shown in Figure 3. A knob I picked up from Electronics Goldmine (see my Hobbyist Links page) completed the exterior build.

 Figure 3. Painted hockey puck displays after drilling all the holes

Figures 4 and 5 just show some pictures of the near-final project. Even with the 9V battery removed I still had some trouble getting the circuit board to fit in correctly, but with a little hot glue it all seemed to work out. 

 Figure 4. One side of the enclosure assembly


Figure 5. Nearly finalized fan assembly with PWM circuit attached

Figure 6 is my final project, and yes it is running in the picture. A quick solder test showed that it actually worked really well. I was able to solder wires, blow away the smoke, and not lose any significant temperature on the soldering iron. I am actually glad that the battery didn’t fit and I had to elevate the fan because I think it’s a more natural position for getting rid of the smoke. Several of the connections I solder are held in place by helping hands or something similar so having a bit of reach with fan turned out to be pretty useful.




All-in-all I would say this project was a success, though not without several failures. I will do more on the circuitry I used when I talk about 555 timers, because it’s a pretty standard topology for that particular IC so look for that in the future. Comments, as usual, are always welcome.


Bill of Materials
ITEM QTY UNIT PRICE ($) PRICE ($)      LOCATION
9V Battery Holder 1 2.59 2.59 Willy's Electronics
Hockey Puck Display Cube 1 2.99 2.99 The Container Store
12VDC Fan 1 12.50 12.50 PC Hub
1/8" Potentiometer Knob 1 0.40 0.40 Electronics Goldmine
SPST Heavy Duty Slide Switch 1 1.57 1.57 Radio Shack
PCB Standoffs 4 0.08 0.32 Electronics Goldmine
Set of Machine Screws 1 6.21 6.21 Home Depot





TOTAL PROJECT COST

$26.58

Jul 17, 2011

Weekend Mod #2

For awhile my workbench has been overly crowded with spools of wire, tools, and test cables. In the past few days I have made some mods to clean up my work area in an attempt to get more organized. Since I haven’t had much time to write any entries about theoretical concepts, I thought I would just do a post about some of the smaller stuff I have been doing. In the next few days I will put up some of the projects I have finished recently. It hit me a weeks back that only real project I have ever posted is my RGB cube I threw together almost a year ago. So, I think it’s probably time to rack up some more entries in that category.



One of the first mods I took on was to create a wire spool holder above my main work area so that it would elevate the wire off my bench while giving me easy access to my hook-up wire during prototyping. This is a pretty simple mod that can be done in a few minutes if you have the right materials.



First on the list is a ¾” wooden dowel. I got one from Michaels for a few dollars. The only other item necessary is a set of curtain hanger wall attachments, which you can find in any hardware store (Home Deport, Lowes, etc.). In my case, I wanted to mod my bench without drilling into the wood so I used some double-sided stick-on poster board tape (see the pic above) to secure the rod holders. If you don’t care about drilling into the wood, adding a few wood screws for support should work nicely. After getting all the materials together, simply secure one end of the rod, slide the spools on and secure the other side. In just a few minutes my bench was much cleaner. 


Wooden Dowels and Curtain Attachments
 

Granted, this isn’t the most complicated mod I have ever done, but my focus lately has been on building up some equipment that will be useful for working on projects in the future. Look for my solder smoke fan build in the next few days and for other projects down the road.


 Finished Wire Spool Rack

Jul 12, 2011

Top 50 Employers for Electronics Design Engineers

Looks like its two for one day here on To the Rails! I swear I spoil you sometimes. 

For my second post tonight I just wanted to put up this graphic I came across in an article on Electronics Design just yesterday. If you checked out my updated links pages. you saw that I added Electronics Design News (EDN) to my list. Well, Electronics Design is a sister site to EDN and they publish nearly identical material -- to the point that I am not sure why there are two sites. Anyway, this article ranked the top 50 employers of electronics design engineers in the world. Take a minute and peruse the results. Think them over. Come to your own conclusions. 

Now throw those out and read what I have to say:

1.    I was horrified to see Apple ranked as #1. I hate Apple.....a lot. They are no friends to the hobbyist community and they have managed to build up this mystique that drives me insane. However, these are personal feelings and the reality is that Cupertino is gaining ground in nearly every facet of electronics design. The news that they are moving into making their own ICs (see Apple A5) has to have boosted the hiring of analog and digital IC designers in the last few years. It could also be they need slave labor to build that ridiculous "Mothership". Let my people go!


2.   That Texas Instruments was so low last year (60) is somewhat surprising. As the largest distributor of analog ICs in the world, and the recent acquisition of National Semiconductor doing nothing to slow that down, I would have thought they were at the top of the list. Instead, their meteoric rise of 25 spots over one year still only puts them at 35 overall.


3.    Interesting fact, I personally have job application rejection letters from five of these companies (I’ve only ever applied to five of them).


4.    It’s good to see Microchip making a move up. I really like their 16, 18, and 24 series of peripheral interface controller (PIC) microcontrollers. I have talked to some of their sales representatives before and even those guys are pretty sharp.


5.    I actually met Dr. James Truchard -- the CEO of National Instruments -- just two years ago. I was designing a data acquisition system in LabVIEW for some graduate students as part of an undergraduate research project at Virginia Tech when he came in for a lab tour. Supposedly the goal was to see how LabVIEW was being utilized in an academic setting (so hopefully we managed to score some funding in the process). I shook his hand and talked to him for a few minutes. He seemed like a really cool guy so I am glad to see them so high on the list (28), though they have fallen a bit from last year (8).