Gas station without pumps

2015 August 7

Draft book cover

Filed under: Circuits course — gasstationwithoutpumps @ 12:36
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I played around last night a bit with creating a book cover, just to have a placeholder on Leanpub until I can get a proper book cover designed.

Small thumbnail (150 pixels wide, 220 high)

Full size book cover, 2250 pixels wide by 3300 high.  That's 8.5" by 11" at 300dpi. (click to get full-size image)

Full size book cover, 2250 pixels wide by 3300 high. That’s 8.5″ by 11″ at 300dpi. (click to get full-size image.)

Thumbnail for book cover, 225 pixels wide and 330 high.

Thumbnail for book cover, 225 pixels wide and 330 high.

I’ve included the images here so that people can see them (and make suggestions for improvement or totally different cover designs—this one looks too much like the “generic” product labels of the 1970s). Also, I wanted to have a URL for the tiny icon to put in my sidebar.

Ideally I’d like a design that is visually striking, and that conveys visually that the book is about electronics. It should look OK full size, but also work as a small thumbnail, since that is how Leanpub displays their books.

Book draft available online

Filed under: Circuits course — gasstationwithoutpumps @ 01:29
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In Lean publishing I said

I’ll think about it for a week, but right now I’m leaning towards doing a pre-release of my book at a very low price on Leanpub.  What do my readers think?  Anyone interested?

Well, that week lasted less than a day.  I’ve put the book up on Leanpub’s book store as

For now, everything is pretty much draft format: I have a temporary cover page, lots of marginal notes to myself about what needs changing, few exercises, and a host of things that need to be done to the book.

The book is only available in PDF format, because I’m developing it in LaTeX, and there is no good way to get LaTeX documents into EPUB and MOBI formats.  From what I’ve seen so far, there is no good way to produce books with a lot of figures and cross references in EPUB and MOBI formats, so I’m stuck with LaTeX at least for the next year.

I dithered for a while about setting a price for the book—I wanted it cheap enough that people who were interested in it would be willing to get a pre-release copy, but not free—since the people would not bother looking at it, even if they got a copy.  I settled on a minimum price of $2.99 and suggested price of $9.99, as representing a fair price for the book in its current draft form.  Those prices probably won’t stop anyone who wants to read the book from getting it, but will discourage random freebie hunters. I do plan to raise the minimum price as the book gets more nearly finished.

The Leanpub model, where purchasers get all updates to the book that are done on Leanpub, means that early purchasers get a real bargain.

I’ve not yet put up a sample chapter or table of contents for the book, but I plan to do that later this week—I’ll probably include all the front matter and two sample chapters (a lab chapter and the associated supporting theory chapter) in the sample.  I’ve not figured out which chapters to include in the sample yet. (If anyone does buy the draft book, I’d welcome suggestions about which chapters to show in the sample.)

I’ll be setting up coupons for  students who take my class to get the book for free, and I’ll make those coupons available to students who have formerly taken the class.  (I’ve not done that yet, since the next class isn’t until Spring 2016, but if there are former students reading this blog, send me e-mail and I’ll set up a coupon code you can use.)

None of the book is set in stone, but some parts are more solid than others—I’m pretty happy with how several of the chapters worked in the Spring 2015 offering of the course, but other labs need complete rewrites, changing the nature of the lab.  The cover page is definitely a placeholder—I threw it together in a couple of hours tonight, just to have something to put on the site. I started an index, but have not really gone through the book looking for what concepts need to be indexed, nor indexed all occurrences of the concepts I’ve started indexing.  A better index is pretty far down on my priority list right now, but I will take suggestions about things that really need indexing—fixing one or two entries in the index could be a good break from more intense writing.

At some point I’ll be putting up a bunch of other files with the book as a “bundle”.  The bundle will include all the gnuplot scripts and programs that I provide to my students, plus Eagle files for the prototyping PC boards.  I might also do a “teacher” bundle that includes all the gnuplot scripts and data files used for generating the figures in the books.  I don’t know whether Leanpub provides a way for purchasers of a book to later upgrade to a bundle that includes the book—but a workaround can probably found using coupons.

One of the reasons for releasing a draft on Leanpub is to get feedback from readers—particularly about things they find incorrect, poorly written, inconsistent, missing, redundant, or just confusing.  That feedback can be on the Leanpub site, by email (Leanpub provides a link), or here on the blog.  Tiny details are probably best done by e-mail, but more substantive suggestions that might be worth discussing (like pedagogical approach or order of the material) may be better done in blog comments.

2015 August 5

Lean publishing

Filed under: Circuits course — gasstationwithoutpumps @ 23:17
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Katrin Becker just pointed me to another publishing opportunity that might be a good fit for my textbook:

Are you going with a publisher or doing it yourself?
I ask, because I recently discovered It strikes me as a really good option for some kinds of publishing–especially if it is something you plan to update regularly.

I looked at Leanpub and it looks like a reasonably good deal for what I want to do.  The offer very minimal services: mainly a storefront and translation from Markdown to PDF, EPUB, and MOBI formats, but have very author-friendly terms (royalties are 90% -50¢ a sale, they take no ownership of any of the content, and you can up-stakes and move to a different publisher at any time).

They believe that they can be profitable with this very lean model, surviving on the 10% +50¢ a sale by having very little in the way of expenses: no marketing, no printing, no editing, … .  It is essentially a way for an author to self-publish e-books without having to handle the actual sales.

The authors can set both a recommended price and a minimum price—the buyer gets a slider to choose any price they want to pay above the minimum.  The author can also create coupons for discounts or even free copies (something I would want to do for students in my classes—I don’t think professors should require their own books without arranging for the students to get them at the lowest possible price with no royalty to the professor).

The advantage for readers over many other  e-book stores is that the reader gets updates to the book whenever the author makes them—Leanpub recommends their site for authors developing books, to get in contact with readers and get feedback from them.  The store even lists the authors’ estimate of what % complete the book is, so that readers can watch the progress.

The big downside for me is the use of Markdown.  It would be very, very difficult to convert my book to Markdown.  The math alone would be a nightmare.  There are some extensions to Markdown for math, but

It’d be nice if everybody could agree on the same syntax(es) to denote math fragments in Markdown; alas, as every extension to Markdown, it’s a mess. []

Leanpub does offer the capability of just publishing files created elsewhere (bypassing their conversion of Markdown to PDF, EPUB, and MOBI), so I could publish just the PDF generated by LaTeX.

I don’t think that I’d necessarily want to do my final publishing with Leanpub—I don’t have the enthusiasm to run a marketing campaign for the book—but it might be  good way to get early copies into the hands of a few readers, to provide me feedback on the drafts and to tell me whether there is a market for the book outside my classes and a handful of hobbyists. Leanpub encourages this model fairly strongly:

Serial, In-Progress and Lean Publishing

Using Leanpub, authors can start publishing their books before they are finished.

As an author, publishing your book before it’s finished lets you interact with early readers and improve your book in a number of ways. As a reader, you’ll receive all future updates of the book for free, as new content is added and as the book is otherwise improved. At the same time, you can provide the author with suggestions and even corrections.

In the twenty-first century, in-progress publishing is a great way to publish non-fiction books too. Technology books are perhaps the most obvious example of a book category that naturally fits the Lean Publishing model, since things move so quickly and early access to cutting-edge thinking is so important. []

Leanpub claims to have made about $3.5m in sales so far, with $2.9m of that going to the authors as royalties. So, though they are a small company, they might be making enough to stay in business a while longer. They have about 725 books listed on their store, about 50 of which are textbooks.  The store is really bare bones, and browsing looks like it will become difficult if they ever get enough books to matter.

I think that some of the bigger sales are from books that are textbooks for Coursera courses—the class is free, but the book for it is not, allowing the author to make some money off the Coursera course.

Leanpub also provides the ability to bundle other documents with the book (or bundle multiple books together), providing the ability to make a free or low-cost book, but charge extra for handy extras (like source files for programs).   I could bundle the Eagle files for the PC board designs, for teachers or hobbyists who want to order their own boards, for example, or gnuplot scripts and data for some of the plots in the book.

I’ll think about it for a week, but right now I’m leaning towards doing a pre-release of my book at a very low price on Leanpub.  What do my readers think?  Anyone interested?

2014 November 17

Faculty writing community

Filed under: Circuits course — gasstationwithoutpumps @ 20:35
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Eric L. Muller wrote in Developing the Faculty as a Writing Community | AAUP,

I have also come to see how many other pleasures and labors of life are enhanced by companionship and accountability. Lots of people exercise more in groups, read more books with groups, lose more weight in groups. Wouldn’t it stand to reason that many faculty members might write more in groups, too?

That was a question that the Center for Faculty Excellence (CFE) at UNC at Chapel Hill set out to explore in the summer of 2013. The CFE is the university’s pan-campus faculty development center. Together with the Institute for the Arts and Humanities in the College of Arts and Sciences, the CFE piloted the Summer Writing Group program for faculty members across the university. The response was enthusiastic.

He went on to describe what sounds like a fairly successful experiment in faculty development.  I note that it did not appear to include any engineering or science faculty, though perhaps there were one or two in the “completely interdisciplinary” groups.

It sounds like an interesting idea, and it probably would have helped me last summer while I was trying to work on my textbook for the bioengineering electronics class.  I ended up practicing all sorts of “creative procrastination” instead of writing.  I got some stuff done on the book over the summer, but not nearly as much as I had hoped at the beginning of the summer. A writing group may have helped me keep my nose to the grindstone (a metaphor I’ve always found rather gross if taken literally).  I don’t know how much I’ll get done before I have to use the book in the Spring, since I’m teaching two classes each quarter, as well as all the work of being undergrad director and program chair for the bioengineering program.

I’ve not been part of writing group since grad school, when I was in a poetry-writing group with a bunch of people twice my age or older. Having a monthly meeting did help me then, and it was important that we read each others’ work and took it seriously (not just providing rah-rah comments). I’m not sure that the UNC approach would help much, unless the other faculty were close enough in their expertise to be willing and able to read and comment on the draft chapters.

Have any of the faculty who read this blog ever participated in anything like the UNC summer writing group? Did it help you keep to a schedule? Was it important to share drafts with each other?


2014 May 30

Class-D amplifier lab done, EKG block diagrams begun

Filed under: Circuits course — gasstationwithoutpumps @ 21:08
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Yesterday’s lab ran long (as expected), because students had not gotten enough done in Tuesday’s lab.  But everyone in the lab did get a working class-D power amplifier.  Several also managed to measure the turn on and turn off times for the comparators driving the FETs, though that required some hands-on guidance in using the digital scopes (setting the trigger level to the FET threshold voltage, then looking to see how long the rise or fall was before reaching the trigger level.  As expected, everyone had chosen values that made the pFETs turn on and off quickly, but it was difficult to get the nFETs to turn off quickly.  I don’t know whether anyone managed to equal turn on and turn off times for the nFET (they turned on fairly fast), but several groups managed to keep their FETs cool.  Even those with warm FETs did not dissipate so much in them that they got dangerously hot.

I’ll be reading the design reports over the weekend, and I’ll see whether the students really understood PWM or not.  I suspect that about half the groups understood what they were doing well enough, and the other half got part of the ideas.  There should be time on Monday to review the idea of PWM and to explain again why it is a good choice for efficient power delivery, particularly for inductive loads.

Today, I returned the quiz 2s redone as homework.  Students did fairly well on them as homework (range 18.5 to 31.5 out of 36, up from 7 to 17 on the timed quiz).  The biggest difficulty was with the last problem, which asked them to design a simple amplifier, giving both a block diagram and a schematic.  A lot of students did not understand the question as I phrased it, perhaps because I had not been clear enough earlier in the quarter about what a block diagram means and how to use it.

Students have not yet internalized the idea of something having inputs and outputs, and a block diagram being a refinement of an I/O spec into I/O specs for subunits.  I may need to use that language more explicitly earlier next year. I’m thinking also that I need to add more text to the lab handouts next year and refer to them as a draft textbook rather than as lab handouts.  How many pages do I have so far?

handout pages
01-thermistor  11
02-microphone  9
03-hysteresis  11
04-electrodes  7
05a-loudspeaker  8
03b-sampling  7
06-audio-amp  6
07-pulse-monitor  11
08-pressure-sensor  8
09-power-amp  13
09-power-amp-addendum  6
10-EKG  5
total  100

One hundred pages is a bit short for a textbook, but there is a lot of explanatory material still missing (most of which I provided in class or in lab). If I worked on it diligently over the summer, I could probably create a book with most of what the students need that would be around 200 pages. Do I have the energy to turn this into a textbook? Is it worth the effort?

After going over the block diagram of the quiz problem, I helped the students develop an EKG block diagram.They did get to the realization that the unknown but potentially large DC offset from the EKG electrode half cells limits the gain that they can ask from the first stage of the EKG, and that they’ll have to high-pass filter and add more gain.  The design is similar to their pressure sensor instrumentation amp, but the gain needs to be higher (1000 to 1500, rather than 100 to 250), and the pressure sensor amplifier had to go down to DC, so did not include a high-pass filter.

I was a little worried that I may have suggested too high a lower end for the passband (0.1Hz to 40Hz).  They’ll get less baseline drift with a 0.5Hz cutoff instead of 0.1Hz.  My EKG designs have used 0.05Hz—88.4Hz and 1.0Hz–7.2Hz for the blinky EKG.  Both worked ok, but I now think that the 7.2Hz cutoff is too low (it was adequate for blinking an LED, but not for recording the waveform).  Since I did not have much problem with a 0.05Hz corner frequency, I think they’ll be ok with a 0.1Hz one.  The blinky EKG circuit has an adjustable gain (needed to make the R spike large enough to light the LED), but it is probably better to have a fixed gain.

It would be really nice if they could finish the EKG on Tuesday, since the annual undergraduate poster symposium is scheduled for the same time as the Thursday lab, and I always like to spend an hour or so looking at the posters.

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