Gas station without pumps

2018 November 17

Another book cover design

Filed under: Circuits course — gasstationwithoutpumps @ 20:47
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A former student (a Danish exchange student) sent me an SVG file with a couple of book cover designs.  I liked them better than what I came up with, but found them a little too grey (like some of the old Springer monograph series), so I redid one of them in brighter colors:

This design avoids the border symmetry that Bob Therriault rightly criticized and looks a little better than the flat background I was using.

Because it is an inkscape svg file, it is moderately easy for me to modify (my previous designs were done in Photoshop Elements, which is both harder and easier to work with, depending what you are trying to do.  I may want to redo the EKG trace from the original data, as he was working with just the low-resolution image I had posted, so the Inkscape object is a bit cruder than I’d like.

What do people think of this design?  What can/should I do to improve it? Colors? Fonts?



New book cover draft 2

Filed under: Circuits course — gasstationwithoutpumps @ 15:30
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Based on comments by gflint, I tried changing the colorway for my new cover:

new blue cover

The new colorway looks a little less generic, but it is still a boring cover.

I’m still looking for suggestions for a better book cover.

I also got one more to-do note removed from the book today, by beefing up the soldering instructions a bit and drawing a new figure:

Cross section of a good solder joint for through-hole soldering.

I drew a crude sketch on a whiteboard, then edited an SVG file to produce the image. I’m getting a little better at creating SVG files (thanks to the practice for the FET image), but it is still a slow process—not as slow for me as trying to draw with a tool like Inkscape, though.

2018 November 16

New book cover draft

Filed under: Circuits course — gasstationwithoutpumps @ 18:11
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I did a slight redesign of the cover of my book with the tentative new title.  I’m not a graphics designer, so all I’ve come up with is a rather generic book cover:

Tentative new book cover

I’m open to ideas for better cover designs.

Other than the cover, I’ve been making decent progress on the book—I even got PteroDAQ recompiled for the FRDM-KL25Z board and Arduino boards, which I haven’t bothered with for a couple of years, as we’ve been using just Teensy LC boards in the class.  ( had to make some tiny fixes to the PteroDAQ code, but nothing that took more than a couple of minutes.

I’ve got 4 to-do notes left in the book, only one of which is important (including some theory of soldering).  The other three are all optional material which needs to be cleaned up a bit or thrown out.  I think I’m still on track for a release by Nov 30.

2018 November 12

Note that

Filed under: Circuits course — gasstationwithoutpumps @ 21:04
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I’ve been making pretty good progress on my book: I have only 9 to-do notes left in the margins of the book (and one of those is in the solution set, not the book itself).  I had well over 100 such notes at the beginning of the summer, and almost 100 at the beginning of fall, so it feels good to have cleared so many. I think I’m on track to hit my self-imposed November 30 deadline for the next release.

The book is now up to 573 pages with 294 distinct images (only 242 numbered figures, but some have multiple parts so there are 83 subfigures).  The solution set is another 118 pages with another 76 images (though a few of them are identical to ones in the book).

Because most of the remaining 9 to-do notes are ones I’ve been putting off because I’ve dreaded doing them, I started on doing some global corrections that did not have associated to-do notes.

For example, tonight I removed about 200 words by removing “Note that” from the book and the solution set.  I looked at each instance, and every time I saw that I could remove “Note that” and capitalize the next word to make the writing better.  I also removed another approximately 50 occurrences of “Note:”, though a handful of those required some modification to the sentence.

I should probably also scan the book for overuse of parentheses (another of my bad writing habits), but that scan will be harder to do, as there are many legitimate parentheses in the math formulas.

I probably need to dedicate a day or two towards the end of this month just to running the spelling checker.  The book is broken up into about 60 LaTeX files, and I have to run the spell check separately on each.  Some are fairly trivial, like the top-level one that has just


but others are quite long: about 30,000 words in solutions.tex and 16,000 in lab-report-guidelines.tex.

2018 October 28

Redrawing figure in SVG

Filed under: Circuits course — gasstationwithoutpumps @ 20:18
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There is a figure in my book of the cross-section of a power nFET.  Originally, I used a figure from wikimedia:, but I wanted a color version, so I colorized it myself in Inkscape.  Unfortunately, the original SVG was poorly done—it looked like an inkscape conversion of a raster image to paths, which did not result in paths enclosing fillable areas with clean strokes around them, but separate paths filled with black for each stroke.  This made colorizing the image quite difficult.  I did (eventually) manage to make a colorized version, but I’ve never been happy with it.  The file is huge for an SVG file (over 81kB) and difficult to edit.  I’ve been wanting to do it right for some time, and I finally got around to it today.

What I did was to print out the version I’ve been using as a full-page image, then used a ruler to figure out how big each part was.  I then entered SVG code by hand to remake the image. I included comments to describe what each part did and used styles for the different materials, so editing is now easy.  I also made sure that the image is now symmetric and that all the rounded corners have smooth joins to the straight lines (the “q” command in the path “d” attribute makes that fairly easy. The new svg file is only 3425 bytes, even with the comments, and the pdf created from it is only 8kB, instead of 28kB.  Those size changes are not very important (the PDF for the book, after all, is now 25MB, up from 23.7MB last spring), but the image looks better now also. does not let me upload svg files, but you can see the PDF produced from it by inkscape at only lets me upload raster images for display, so I used inkscape to convert the hand-written SVG file to PNG just for this blog. The black line on the right edge seems to have been chopped off in the conversion, though the PDF conversion gets it right.

Here is the PNG generated by inkscape from the SVG file.

I tried uploading the SVG file to Wikimedia Commons, so it could be used on the Wikipedia Power MOSFET page, in place of the black-and-white image, but the uploaded file got rendered as a badly wrong black-and-white PNG file (with all colors converted to black), which is totally useless. I don’t have time to figure out how to tell it to do the conversion correctly, so I just asked them to delete the image again.

Here is the source code for the svg file, which I’m releasing with CC-BY-SA 4.0 (the original on WIkipedia that it was based on was released by Cyril Buttay as CC-BY-SA 3.0).

.label {font: italic 8px sans-serif;}
.super {font: italic 6px sans-serif; }
.arrow {stroke:black; fill:none; stroke-width:1; marker-end:url(#head) }
.wire {stroke:black; fill:none; stroke-width:1;}
.metal {stroke:black; fill:blue; stroke-width:1;}
.Nplus {stroke:black; fill:deeppink; stroke-width:1;}
.Nminus {stroke:black; fill:lightpink; stroke-width:1;}
.Pplus {stroke:black; fill:lightcyan; stroke-width:1;}
.poly {stroke:black; fill:tomato; stroke-width:1;}
.channel{stroke:none; fill:springgreen; stroke-width:1;}

<!-- Drawing the nFET cross-section in layers -->

<!-- the Nminus layer that is the bulk of the FET -->


<!-- the drain including metal layer -->


<!-- the Nplus layer for the drain -->


<!-- left source -->




<!-- right source -->



<!-- gate -->


<!-- channel -->


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