Useful Information for Electronics Students and Engineers

revised Jan. 8, 2016

On this page I will post spreadsheets, software, various computer files, and other information that electronic engineering students and engineers may find useful.

Sources for Electronic Test Equipment  By popular demand, here is a list of some very good sources for electronic test equipment and manuals.  This link has a wide variety of electronics information for students and engineers alike.  Material is always being added to the site so check back often.   This is a link to a circuit simulator that works in the browser.

Note: I am in the process of scanning many pages of interesting hand notes I have developed over several decades and will be posting those here.  Once I get them all posted I will reorganize this page to make it easy to find related notes.  Initially, things are going to be in random order.  The following list will be growing during 2009.

Hall Network:   This is an interesting passive RC notch filter that is tunable via a single potentiometer. See the following link for an article I wrote concerning the Hall Network that was published Jan. 31, 2012 in the online version of Electronic Design. .  This is a deep link and may get moved from time to time.  If the link does not work then go to and do a search for "hall network".  A precursor to the article was hall_network.pdf .  I am keeping it here for the time being since others have linked to it but it now includes the above link to the complete article.  You might find the original submission, Design and Applications of the Hall Network , a little easier for printing.
Hall Network Symbolic Analysis   This is a scan of a symbolic analysis I did of the Hall Network back in 1979.  I worked on it during lunch where I worked for several weeks before I got it all right. This is a huge picture that full size is around 34" x 22". Although tiny it can be printed in landscape mode on a single 8.5" x 11" sheet and is still perfectly readable.  The analysis might be a little hard to following since there is no guidance other than the circled numbers for the main steps.  Guidance notes are in the above article.  This is an example of perseverance -- it is often that math explodes like this but ultimately becomes very simple.  There are a few errors where I wrote 's' that should have been 'w'.  My thanks to coworker, Kristin O'Connor, who skillfully used Photoshop to stitch the individual sub scans of this into one perfect document.  Coming soon -- a spreadsheet to explore the circuit design and frequency response.

Frequency Filter Notes  These are a collection of various hand notes concerning the analysis and design of low-pass, high-pass and band-pass filters.

Impedance Matching This shows the derivation of a variety of ways to match one impedance to another using two reactive elements.  It is a little cryptic but if you know what you are doing it makes perfect sense.

Notes on Transistors and Diodes  These are an extensive set of notes I developed for teaching an engineering course concerning diodes and transistors including details on analysis and design rarely found elsewhere.  You could spend hours on the information in this link.

Notes on Operational Amplifiers  These are an extensive set of notes I developed for teaching an engineering course concerning operational amplifiers and applications.  You could spend hours on the information in this link.

Feedback Effects on Amplifier Response This is an introductory note for students seeking to understand how negative feedback reduces amplifier gain and widens frequency response.  The companion spreadsheet for this note is feedback_amplifier_response.xls .

General Electronics Notes  This link has a couple of useful information for electronic engineers at around the middle of the page.

68hc11.asm This ASCII file is a learning aid to the instruction set of the Motorola 68HC11 processor. I developed this file for use when I taught EE337. The file shows all permutations of each instruction along with a pseudo-C equivalent of the instruction. The instructions are also logically grouped. I recommend that anybody working with a new processor develop an equivalent file. This file can be assembled by the assembler to see the hex codes for each instruction. There are a few minor errors that I intend to fix someday.

The Science of Design This is a paper that I wrote and presented some years ago about the design process based on my many years of experience designing electronic circuits. I have adapted it for posting on the Internet.

An Introduction to Design Reviews This is a paper that I wrote to assist students preparing for a design review.

Impedance Measurement  This is a short note about how to measure complex impedance with a simple setup and some calculations.   An excellent off-site article about the use of decoupling capacitors.  See the spreadsheet below to plot the examples given.

capacitor_z.xls This is a spreadsheet to calculate and plot the net impedance of up to three capacitors in parallel.  Each capacitor model includes ESR and series inductance.  Very interesting impedance effects can be seen with arbitrary capacitors.  Different size capacitors have to be combined with care in bypass and similar circuits.

Managed Alias Sampling  This brief note discusses a clever method to eliminate power line alias for low frequency sampled data systems where the sample frequency is low compared to that of the power line.

rf_enclosure_design.pdf  This is a brief note that describes the fundamentals of designing an enclosure that is opaque to RF energy.

bjt_analyzer.xls Spreadsheet for analyzing bipolar transistor amplifiers.

jfet_analysis.xls Spreadsheet for analyzing field-effect transistor amplifiers.

op_amp_calculator.xls Spreadsheet for doing basic operational amplifier calculations.

Introduction to H-bridges  This is a note for students needing to build an H-bridge.

frs.xls Spreadsheet for calculating frequency response of up to 7th order system. Version 1.3 corrects an error in earlier versions.
lpf_design.xls Spreadsheet for designing Butterworth and Chebyshev low-pass filters of up to 16th order

salen_key_design.xls Spreadsheet for designing components for Sallen-Key low-pass filter section.

a2dsim.xls Spreadsheet for doing experiments with analog to digital and digital to analog converters.

ee431lab8.pdf Some experiments to try using a2dsim.xls.

Distortion Analyzer  This is a short article on how to build a simple harmonic distortion analyzer using the notch technique with simple components.  It is intended for people who have a need to measure distortion down to below 1 percent at 1,000 Hz but can not afford a more advanced instrument.

A Method for Locating Short Circuits  This is a short article that describes how to locate a short between two nets on a printed circuit board.  This is often very hard to do but becomes easy with the right technique.

debounce.c Version 1.00 - Robust algorithm for de-bouncing mechanical contacts or noisy bit streams in software. There is an article about this algorithm and universal code at Debounce Algorithm Using Integration

nfilter.c Version 1.00 - Algorithm for smoothing noisy data for display. Smooth and fast at the same time!
nlfilter_demo.xls  Version 1.00 -- This is a demonstration of nlfilter.c and illustrates operation via a graph.  User can change settings to study the effects.

ctrlbang.c Version 1.00 - Bang-bang controller algorithm. A revised version is coming soon.

Servo Tuning This is a draft of a piece I am working on concern tuning of P, PD, PI, and PID controllers.  The ctrlpid.c file below implements the features discussed.  An Excel spreadsheet simulation, thermal_control_simulator.xls, will be posted in the near future.
ctrlpid.c Version 2.3 - PID control algorithm with integrator management. This new version has practically a textbook on applied PID control in the comments.  This is the stuff you do not get in the classroom -- only from the school of hard knocks.

wp_clip.c  This is a short routine for clipping wild points out of a data stream derived from analog systems.  The comments are a brief text on the subject.  This is a link to some great technical articles on electronic circuits written by Ramon Vargas who teaches at a university in Peru.  Many of the pdf articles near the bottom of the link are in English so do not let the Spanish you will initially see scare you away.  Even those articles that are in Spanish are highly mathematical and since math is the universal language you can easily tell what is going on.  Definitely check these out.  The information in these articles is of the sort that is hard to find but highly useful.   This is the personal web site of Ramon Vargas and has more very informative articles about electronics.  I highly recommend these two web sites!

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