Science on the Web – Part Three, All About Circuits

 

If you are planning on a career in electrical or electronic work All About Circuits is dedicated to you. Go through each and every chapter (under sitemap), do not skip and do the tests. Electrical or electronic students have one thing in common, they love reading and they love reading about how things work.

 

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Technically minded people are not usually money-savvy because money is of secondary importance. Technicians never die of starvation – Confucious 551BC ~ 479BC

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Not that long ago a student at any learning centre had to go to the local library to find literature on his subjects of choice or purchase the books which are stipulated in the syllabus. Things only got better with the internet and much better with Wikipedia. Yes, academics strongly advise their students not to plagiarise neither get their information from Wiki based on the inaccuracies posted but for all intents and purposes Wiki serves a really great purpose and by knowing the fundamentals and doing further research a student would be able to sift the fact from fiction. Here’s the thing though, sometimes we are just lucky enough to find a gem of a website where the scribe is indeed an academic and indeed posts their own training to students or lecture material for free on the web.

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All About Circuits is just such a website.  I can guarantee any avid reader of literature where core material is based on electricity and magnetism, audio or circuits in general, web linking will take you to Rod Elliott, Tomi Engdahl and/or Tony Kuphaldt’s All About Circuits website.  I first came across this website quite a few years back whilst writing a program to determine the correct Power Factor Correction capacitors for an inductive load on an a.c. circuit. I studied a.c. circuits in the mid to late 70s and really never needed to use any circuit design remotely associated to power factor correction until then. Because of the sudden interest in seeing what else Mr. Kuphaldt’s website had to say I spent the better part of five hours going through the website, so brilliant it was. Yes it is open commons but who cares. It has been authored extremely well and caters for the needs of most electrical or electronic students.

 

 

What makes All About Circuits so wonderful to browse through or if you are a student, starting a brainstorming session, is the Q&A, forums and the lack of all the bells and whistles inherent to any website selling you a product. Here the product is ‘read, learn and experiment’ and it is free after all.

 

Note that this article was written in 2013.  By 2025 it had evolved massively and has a massive following. To summarise, through Grok:

 

All About Circuits (allaboutcircuits.com) is one of the most respected and longest-standing online resources for learning electrical engineering and electronics, especially for students, hobbyists, self-learners, technicians, and even working engineers who want to refresh fundamentals.

When people refer to “Tony R. Kuphaldt’s website ‘All About Circuits'”, they’re usually thinking of the site’s legendary free, open-source textbook series:

Lessons in Electric Circuits (also widely known simply as the “All About Circuits textbook”)

This is a comprehensive, multi-volume set originally written by Tony R. Kuphaldt (an instructor in industrial electronics and instrumentation) and first released in the early 2000s under a very permissive open license (Design Science License).

The textbooks have been hosted/hosted on/integrated with allaboutcircuits.com for many years, and the site has continued to maintain, format, and slightly update them over time with help from the community.

Quick overview of how most people describe it:

• The best free university-level introductory-to-intermediate electronics textbook series available online

• Extremely clear explanations — Tony has a real talent for explaining difficult concepts in a straightforward, practical way without drowning the reader in heavy math

• Classic volumes people usually refer to:

  1. DC (Direct Current fundamentals)
  2. AC (Alternating Current, phasors, complex numbers, etc.)
  3. Semiconductors (diodes, transistors, op-amps, the heart of analog electronics)
  4. Digital (logic gates → flip-flops → state machines → microcontrollers basics)
  5. Reference (lots of useful tables, formulas, conventions)
  6. Experiments (practical lab-style worksheets)

• Very widely recommended on forums, Reddit, YouTube, university courses, trade schools, and among self-taught electronics enthusiasts

• Still considered one of the gold standards for learning the foundations of electricity & electronics in 2026 — even though the site itself has evolved into a much larger professional engineering community with articles, news, forums, podcasts, webinars, etc.

 

Previous: Science on the Web – Australia and Rod Elliott – Science on the Web – Tomi Engdahl