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2017 January 7

Book draft 2017 Jan 7

Filed under: Circuits course — gasstationwithoutpumps @ 17:03
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I’ll be releasing an updated version of the Applied Electronics for Bioengineers text on LeanPub today.  I’ll probably raise the minimum price next week, to reflect the improved quality, but I’ll give people a few days to get the book at the old price.  (Remember that the LeanPub model allows you to get all future editions of the book free, as long as I continue publishing through them, so there is no reason to wait until a new edition comes out.)

I’ll list the changes in two sections: changes that were made since the October 2016 release, then changes that were made in the Oct 2016 release (because I don’t seem to have posted those to the blog).

Changes since October 2016

  • Fleshed out assignment schedule and moved to Preface.
  • Rearranged several of the early chapters (without significant content change) for better ordering of assignments.
  • Added mention of Analog Discovery 2 to oscilloscope chapter, replaced some Bitscope traces with Analog Discovery~2 traces.
  • Added bonus frequency response activity to pressure sensor lab.
  • Added Lego-brick pictures for the optical-pulse-monitor lab.
  • Revised all chapters and labs from the microphone chapter to the EKG lab (the second half of the course).  Many of the changes were minor revisions (typo fixes, indexing, changing to numbered exercises, spell check).
  • Added exercises to the microphone chapter and moved some exercises from the microphone lab to the microphone chapter.
  • Moved some of the oscilloscope introduction from the microphone lab to the sampling lab.
  • Rewrote DC analysis of microphone to use function generator, rather than potentiometer, for variable voltage.
  • Added R+L figure to loudspeaker chapter, rather than referring to impedance chapter.
  • Moved inductor description to new chapter just before loudspeakers.
  • Added RMS power exercise and R-L plot exercise to loudspeaker chapter.
  • Moved some intro amplifier material from preamplifier lab to pressure-sensor lab, reflecting change in order of labs.
  • Moved some instructions about color coding wiring from preamplifier to an earlier lab.
  • Added mention of using earbuds instead of loudspeakers for preamplifier lab.
  • Redid Miller plateau oscilloscope trace using Analog Discovery 2, using smaller gate resistor to get higher speed.
  • Added cross-section of a power nFET (still needs to be redrawn)
  • Fixed clipping on several schematics (the Vdd power symbol gets clipped if at the top of the schematic—a known bug in SchemeIt).
  • Put inductive load in the single-nFET driver schematic, including flyback diode.
  • Added explanation of why the crude model for computing slew rate is so far off.
  • Removed most references to obsolete AOI514 nFETs (using NTD4858N nFETs instead).  This required gathering new data to characterize the transistors.
  • Redid the section on open-collector outputs for LM2903 comparators.
  • Added table of conductivity for NaCl solutions.
  • Added section on 4-electrode conductivity measurements.
  • Moved information about nulling ohmmeters when measuring resistance from electrode lab to loudspeaker lab.
  • Reiterated some of the EKG safety info in the EKG lab.

Changes between April 2016 and October 2016

  • Added more background to first chapter (logarithms, picture of complex plane) and started chapter numbering at 1 instead of 0.
  • Rearranged chapters for new lab order, with all the audio labs after the pressure sensor and optical pulse monitor.
  • Updated information on using lead-free solder.
  • Added a generic block diagram to lab report guidelines, and added definition of “port” to the block diagram discussion.
  • Added subsection on Thévenin equivalent of voltage divider.
  • Added section on series and parallel connections to resistance chapter, to reflect lower prerequisite expectations of course.
  • Moved some gnuplot exercises into thermistor lab from sampling and aliasing, to reflect new lab order, also moved PteroDAQ installation instructions.
  • Added picture of metal thermometer to thermistor lab.
  • Added voltmeter connection schematic to DAQ chapter.
  • Moved details of PteroDAQ out of DAQ chapter to separate appendix.
  • Added potentiometer schematic and photo to resistance chapter.
  • Split data acquisition from sampling and aliasing into separate chapters.
  • Improved figure showing aliasing and Nyquist frequency.
  • Added pictures for wire stripping and flying resistors to sampling lab.
  • Added scaffolding for oscilloscope probe exercise.
  • Hysteresis measurement changed to use function generator.
  • Moved multi-stage amplifier discussion to beginning of amplifier chapter and beefed it up.
  • Added introduction to differential amplifiers before instrumentation amps and op amps.
  • Added pH meter block diagram to beginning of amplifier chapter.
  • Moved discussion of clipping to the end of the instrumentation amplifier section.
  • Added active low-pass filters to amplifier chapter.
  • Added chapter on transimpedance amplifiers with section on log-transimpedance amplifiers and rewrote pulse-monitor lab to use logarithmic current-to-voltage conversion.
  • Added discussion of absorbance of melanin, fat, and water to blood section.
  • Moved the instrumentation amplifier internals to new chapter, before the EKG chapter.
  • Simplified the sensitivity calculation for LEDs and phototransistors, making the exercise more productive.
  • Added text to caption of microphone preamp photo.
  • Moved loudness section from the amplifier chapter to the microphone chapter.
  • Added notes at end of loudspeaker lab to improve student reporting of models.
  • Added more safety information to EKG chapter
  • Made all exercises be numbered, and changed most of the prelab questions into numbered exercises.
  • Added equipment-needed lists to the beginning of each lab.
  • Redrew several block diagrams using, and added captions to several figures to indicate what drawing tool was used.
  • Changed caption formatting to be more distinctly different from body text.
  • Cleaned up several schematics.

2016 November 22

Black Friday sale 2016

Filed under: Circuits course — gasstationwithoutpumps @ 20:29
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Although I personally celebrate Buy Nothing Day this Friday, I have bowed to the marketing wisdom of the LeanPub publishers and am having a sale on my book this weekend.  From 2016 Nov 25 until 2016 Nov 29, the coupon link

will reduce the minimum price of my book from $3.99 to $2.56, approximately a 36% discount!  (At other times, it will just offer the usual pricing.)

Once you’ve bought the book, you can download any future versions that I publish through LeanPub (and I expect to have at least one more version before classes start in January).

Note: I’ll be sending coupons for free copies to the students registered for the course some time in December, so they don’t need to spend even the $2.56 of the Black Friday discount.

2016 October 8

Release notes for book (Oct 2016)

Filed under: Circuits course — gasstationwithoutpumps @ 17:10
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I’ve just finished doing a rewrite pass over the part of the textbook needed for BME 51A, which I’ll be teaching starting in January. I’ve been working on this rewrite pass since June, so a little over 4 months. I’ll be spending the next couple of months doing a rewrite pass for the part of the book needed for BME 51B, but that should go a little quicker, as there are about half as many pages in the second “half”, and I think they are in somewhat closer to the desired form than the part I just finished.

There are still a lot of “to-do” notes in the margins of the book, even in the part I just “finished”, but they are all fairly small things, I think. This blog post will be my release notes for this version of the book, summarizing what I changed.

The biggest change was a rearrangement of the order of the labs, so that there are now two amplifier labs in the first half, and all the audio labs are in the second half.  Lots of things (like the table of equipment for labs and the schedule of lectures) needed to be revised to fit.  I still have some work to do on the lecture schedule.

I moved the sampling and aliasing lab after the thermistor lab, so that there is more time in lecture to talk about time-varying signals before the lab.

I expanded the  op-amp chapter into a more general amplifier chapter, and now discuss multi-stage amplification from the beginning, because the instrumentation amp lab for the pressure sensor is now the first amplifier lab. I also added active low-pass filters to the op-amp chapter.

I rewrote the optical pulse-monitor lab, which now calls for a more robust design using logarithmic current to voltage conversion.  I’m still experimenting with different ways of holding the phototransistor, so I may need to redo all the photographs, if I come up with a better design. The optical properties of blood section of the optoelectronics chapter now discusses melanin and fat, and the effect they can have on optical pulse monitoring.  I added a new chapter on transimpedance amplifiers, and added log-transimpedance amplifiers to the chapter. The difficult sensitivity analysis for the pulse monitor has been removed, as the log-transimpedance design does not require great care in setting the gain.

I added more coverage of expected background material, so that students who had not had physics electricity and magnetism courses could still follow along.  I found that a lot of the students didn’t remember anything from physics anyway, so I had to cover the essentials over again, and so I reduced the prerequisites for the course to calculus and high-school physics. I also added a section on logarithms.

I added a bunch more figures, bringing the numbered figures up to 145 (and several of those are multi-part figures). I also improved the typesetting of the captions, so that they are better distinguished from the main body text. Several of the block diagrams were redrawn with, and I added some new block diagrams and a bit more discussion of how to use block diagrams effectively. I cleaned up a few of the schematics also.

I added a few more exercises, added autonumbering, and converted the somewhat vague prelab assignments into numbered exercises, so that I can assign blocks of numbered exercises without worrying that students may have missed part of the prelab assignment. The oscilloscope probe exercise that caused a lot of problems last year has been rewritten with more scaffolding.

I added “equipment-needed” lists to the beginning of each lab.

I changed some of the labs that had used potentiometers to sweep voltages to use function generators with a slow triangle wave instead. This should save quite a bit of time, particularly for the hysteresis lab, where I described how to trigger on the output of a Schmitt trigger changing to record the input thresholds.

I created a new appendix for some of the PteroDAQ details, which I removed from the DAQ chapter.

I added more index terms and fixed a number of glitches in the index.  Index entries with subindexing now stay together in one column, rather than being split between columns and pages.

I’ve started boxing “important” things (and I may change to highlighting them), but choosing the right things to box will probably take another full pass over the book.

I fixed all the overfull-hbox errors through Chapter 24.


2015 December 22

Small updates to book

Filed under: Circuits course — gasstationwithoutpumps @ 13:56
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I released a couple more small updates to my book today:

  • revised Chapter 25 (Electrodes) and electrode lab
  • small additions to loudspeaker lab to remove several TODO comments
  • cleaned up many (but not all) overfull-box LaTeX errors

I’ll try to get Chapter 27 (EKGs) and the EKG lab redone by the end of 2015, completing the rewrite that I started in June 2015.  After finishing this pass, I’ll raise the minimum price on the book (probably to $3.99 from $2.99), though the book still won’t be “finished”—I’ll still have 46 TODO comments to resolve.

If anyone is waiting for me to finish the book before buying it, remember that as long as I’m publishing it with leanpub, buying a copy entitles you to all updates for free, so you might as well get it now, before I raise the price.

2015 September 1

Softcover: another self-publishing house

Filed under: Circuits course — gasstationwithoutpumps @ 22:52
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I was pointed today to another self-publishing house, Softcover, that also uses Markdown as the starting point for e-books on multiple platforms. Their approach is less turnkey than Leanpub, in that Softcover expects you to download the conversion software and run everything on your own machine.  That has advantages and disadvantages—you have to redownload software to get bug fixes, but you have more access to the software to make your own workarounds or fixes.  Softcover seems to be converting Markdown into PolyTeX, a subset of LaTeX, and you have the option of starting in PolyTeX directly (which seems like an easier conversion path from LaTeX than going all the way to Markdown).  But you don’t have the option of just providing a PDF file, so far as I can tell.

The Softcover royalty scheme for their store (straight 90%-10% split with immediate payment) is slightly more generous than Leanpub’s (90%-50¢), but they don’t have the adjustable pricing of Leanpub, and setting up the store site seems more of a hassle on Softcover.

For now, I plan to stick with Leanpub, but I’ll look into Softcover as a possibility if I decide to try to produce MOBI and EPUB formats.

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