HN Explorer

Ask HN: What are some good resources to learn how electricity works?

472 points by farleykr ↗ HN
I've tried several times to understand the vocabulary and concepts of electricity - basic things like volts, amps, resistance - but I'm not having much success with self-led study. Can anyone recommend any good videos, books, courses, etc.? Thank you.

183 comments

[ 2.3 ms ] story [ 229 ms ] thread
yesenadam
I got a lot from the articles on amasci.com by Bill Beaty. He's done a lot of experimenting, reading, and thinking about this stuff and how to explain it. And is a gifted communicator.

Articles on Electricity http://amasci.com/ele-edu.html

Great essays on understanding electricity, current, voltage, capacitors, transistors, batteries, static electricity etc etc, and popular misconceptions.

boruto
Thanks thanks thanks, I read the article about why three prongs long ago. Every now and then I want to say the same article to someone else but did not remember where I read it.

There is also one about different types of plugs in Europe and UK which I cannot find

jussij
There's a ton of content on YouTube that covers this topic.

For example I did a search for ohm's law class 11 and that search finds pages of introductory videos on that topic.

steve_adams_86
I personally learned a lot from sparkfun's tutorials. The format is pretty digestible, there are some good videos, and it links out to a few other good resources as well.

https://learn.sparkfun.com/tutorials/where-do-i-start/all

bonzini
Sparkfun and Adafruit schematics are a great source for learning, too. I designed an I/O shield (with optoisolated inputs and relay outputs) with their open source hardware as the main learning material, and I was delighted that it passed the review of an experienced EE!
asd4
I second this. Hobby focused content might seem amateur but it has some advantages in my mind.

Context: My biggest gripe with traditional education is lack of context for why a principle is important or useful. Not a problem when you are focused on a project.

Practicality: The practical aspects of theory are usually limited to core principles and help you see through the fog of all the details.

Narrative: Bringing many topics together in a project narrative give a linear path through the related principles which is less overwhelming.

https://hackaday.com articles, in my experience, have been a good jumping off point and often have solid links for better understanding.

A weakness of this approach is that it ignores the mathematical techniques to solving some of the problems. I doubt you will learn how to analyze circuits with differential equations or phasor analysis on a hobby site. That said, I rarely use these tools outside of an academic setting.

I'm sure someone will recommend The Art of Electronics. Its a great resource once you have the basics under your belt, but hard to use as a learning tool without prior knowledge. It touches on a lot of details by presenting a circuit and summarizing key points about its operation.

Once you have a handle on the basics I highly recommend playing with some circuits in a simulator. LTSpice is free and very high quality. There are other online options too.

You can experiment on hardware relatively safely if you stay away from high voltages and currents (avoid mains power and car batteries, always use circuit protection such as fuses). You will be frustrated if you have no test equipment though, a multimeter is a must-have.

pjc50
Hmm. What level do you want to start from, and do you want to start from a practical/experimentalist viewpoint or go straight to the mathematical models?

How comfortable are you with "lies for children" oversimplifications of things that are extremely complicated but mostly irrelevant except in edge cases? (This phrase sounds perjorative but isn't, most of the time you don't need the complicated version and it actively impairs understanding what's going on. But it can be the only way to properly answer some questions like "what is electricity?")

I've occasionally considered writing my own, based on answering questions at electronics stackexchange, e.g. https://electronics.stackexchange.com/questions/245610/is-vo... / https://electronics.stackexchange.com/questions/272694/how-d... ; probably I would target explaining how the electron is a big source of "lies to children", and mostly an irrelevant distraction for beginner/intermediate work.

If you want a large book, The Art Of Electronics is the undisputed classic.

henrikeh
I just want to weigh in and say that fantastic as _The Art of Electronics_ is, it is _not_ geared for learning about electricity and electric circuits. The first 13-ish pages (3rd edition) deals with electricity and then quickly moves on to signals, electronics and everything else needed to _develop_ electronic systems.
joeberon
I think you're wrong, mainly because learning how to develop electronic systems is, in my opinion (and also in the opinion of the authors of that book), the best way to learn how electricity actually works.
henrikeh
There is no reason to be so absolute about it. I'm not saying it is a bad book or that you should read "Field and Wave Electromagnetics" before you ever dare touch a multimeter.

As an example of my reasoning. AoE and the Arduino starter kit cost roughly the same in my country. They are of course not comparable, but I'd would definitely recommend the latter to someone completely new to electronics, exactly because the latter gives the tools for experimenting.

OnACoffeeBreak
I agree with you. I have a degree in electrical engineering and use that book to quickly remind myself how something that I haven't used in a long time works and get an overview of practical do's and don'ts. If I had tried learning the basics of electrical circuits from it, I think I'd become discouraged very quickly.
jeffreyrogers
It was pretty much my introduction to circuits, and had it not been used in a class with a significant lab component I would have also been discouraged. Great reference, but not good for teaching yourself unless you're very comfortable being confused or have had prior exposure to the material.
0culus
While AoE (and the newly released X-Chapters!) is an excellent handbook to keep around, I would agree with the other commenters that it is not a particularly friendly textbook for a beginner.
[deleted]
(comment deleted)
Kim_Bruning
The Minecraft mod Electrical Age is surprisingly useful to (literally play around and) get a feel for things. It was originally designed to teach electrical engineers once upon a time. Currently it's been a bit gamified -sure-, but the core MNA solver is still there.

Still somewhat surprising to me, this kind of simulation actually does help. It turns out that you actually do pick up a lot of intuitive feel that can serve well in an industrial context. I guess no matter how much theory you study on, it's still really insightful to just blow up some circuits. ;-)

Note that Electrical age currently works with older versions of minecraft (1.7) , though a rewrite is in the works.

https://electrical-age.net/

samstave
Problem: there is a difference of velocity of understanding between guided experimentation vs study vs mentorship...

(Many fail and are put off to learning the subject whenthere is no person they personally know to guide them through speed bumps)

p_l
That's where Electrical Age comes in, at least when it comes to power systems, generation etc.

All the stuff you're learning is in a way directly useful, whereas try to get a steam turbine IRL for learning at home...

phasetransition
I originally learned electricity from Isaac Asimov's understanding physics, volume 2 when I was 13(?). I don't remember the details, but it clearly worked and helped me in all future education.

If you want to try and learn some basics, and then try apply them, both AoE (mentioned already by pjc50) and "Practical Electronics for Inventors" are good choices.

The latter is much more affordable than AoE.

dannypgh
I would suggest things that use the hydraulics analogy, like this: https://ece.uwaterloo.ca/~dwharder/Analogy/
sunstone
I would probably recommend this. Thinking of electricity as analogous to water flow under gravity can get you a long way. I do recommend studying the mathematics of imaginary numbers (not hard, just takes a bit of time) since this is used for AC circuits and this is the tool that makes that stuff make sense.

When you get to active (transistors, diodes etc) devices don't spend much time trying to figure out the physics of these things just use the equations and keep it simple. Just as when you're cooking eggs in the morning it doesn't help much to understand prospecting, mining and metallurgy to use the frying pan.

elric
I enjoyed "There are No Electrons: Electronics for Earthlings" by Kenn Amdahl. It's a light hearted take in the form of a silly story, but it explains things surprisingly well.

Guess I should add that it covers the basics of electricity and the basics of electronics.

granitepail
The Art of Electronics is perhaps the best textbook (in any subject) that I have read. I’d highly recommend it. It’s exceedingly pragmatic and will discuss a mix of physical underpinnings as well as applications.
blueatlas
Try "Code: The Hidden Language of Computer Hardware and Software." It provides a very simple introduction to electricity. Beyond that, it's just a great introductory book on computing.

https://www.amazon.com/Code-Language-Computer-Hardware-Softw...

coldpie
I absolutely love this book, but I'd say it's more an intro to computing (like you said) than electricity. Electricity is in there, but IIRC it doesn't go much further than the "water analogy" style of thinking about electricity.
mymythisisthis
Army manual on electricity https://archive.org/stream/FM55-506-1/#page/n1/mode/2up
take_a_breath
= Geared a little more towards mechanical engineering, but Jeremy Fielding on YouTube has helped me understand some of the concepts with examples rather than textbooks. https://m.youtube.com/channel/UC_SLthyNX_ivd-dmsFgmJVg

= For straight up electric concepts, I’d look at the Georgia Institute of Technology stuff on Coursera. “Introduction to Engineering Mechanics” and “Linear Circuits 1” were helpful.

aphextron
Walter Lewin's electromagnetism course from MIT [0]. These lectures completely transformed my understanding of physics. He mixes practical demonstration with a rigorous mathematical underpinning in a way that doesn't over simplify things.

[0] https://m.youtube.com/playlist?list=PLyQSN7X0ro2314mKyUiOILa...

kenny87
+1 for Walter Lewin's explanations. I also can't say enough about the clarity of explanations and examples in Feynman's Lectures [1] and the HyperPhysics [2] tutorials.

[1] https://www.feynmanlectures.caltech.edu/II_toc.html

[2] http://hyperphysics.phy-astr.gsu.edu/hbase/hframe.html

acqq
I would add also the whole Feynman's Vol I

https://www.feynmanlectures.caltech.edu/I_toc.html

I believe one can't appreciate the whole subject enough without knowing that the electromagnetic forces are how the atoms "work", also producing "chemistry" and everything we see.

To paraphrase Feynman, the electromagnetic forces also keep you from falling down through the floor.

For the start:

"If, in some cataclysm, all of scientific knowledge were to be destroyed, and only one sentence passed on to the next generations of creatures, what statement would contain the most information in the fewest words? I believe it is the atomic hypothesis (or the atomic fact, or whatever you wish to call it) that all things are made of atoms—little particles that move around in perpetual motion, attracting each other when they are a little distance apart, but repelling upon being squeezed into one another. In that one sentence, you will see, there is an enormous amount of information about the world, if just a little imagination and thinking are applied."

ar0b
I had an electronics learning lab from radio shack and loved the hands on aspects. https://www.amazon.com/RadioShack-28-280-Electronics-Learnin...

You can still find them on ebay, or similar kits if you look around.

stx
I had these as a kid but in reality at the time I think I was too young to understand the details of what was going on. Many of the components I would accidentally attach a large battery to and let the magic smoke out. I do miss Radio Shack though.
gallamine
Hyperphysics presents a organized tree-like view of concepts, terminology and examples. It's easy to click around and start building up a mental model of how things relate: http://hyperphysics.phy-astr.gsu.edu/hbase/hframe.html
swiley
I love that site! They’ve got a lot of neat stuff on holograms too.
kiliantics
This page was a staple of mine during my physics degree, and also during my PhD when I was teaching these concepts
soheilpro
Try ElectroBOOM channel on YouTube: https://www.youtube.com/user/msadaghd
teh_klev
I'm genuinely amazed he's not been found burned to a crisp in his workspace. The same goes for Photonic Induction, how he's not burned down his street, let alone his house is a miracle:

https://www.youtube.com/user/Photonvids/videos

gburdell3
That's how you know he actually knows what he's doing: he knows precisely how to shock himself for comedic effect without causing any damage.
yreg
This, most of the dangerous mistakes are just gags.

IIRC Mehdi admitted on reddit that the one time he really screwed up and was genuinely scared was when the Jacob's Ladder fell on him[0].

[0] - https://youtu.be/lT3vGaOLWqE?t=467