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

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

#51

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...

+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

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

#52

Earlier quoted context omitted.

> Then I realized that a 5V supply will always be 5V in normal operation and ohms law means the current varies. This is a great observation. I've often thought that teaching Ohms law as I=V/R would lead to less confusion. Similarly, in intro physics why is mass acceleration introduced as f=ma? Wouldn't a=f/m have a clearer meaning?

Division is hard!

It becomes infinitely more clear and simple to understand when you stop thinking in terms of "A equals F divided by M" and think of it as "A equals the ratio of F to M".

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

#53

I recommend having a look at "Practical Electronics for Inventors" by Paul Scherz and Simon Monk. The book offers a very good introduction about the basics of electricity with many helpful illustrations, written in a down-to-earth style. In case you are interested in electronics, you will find that the book covers many intermediate/advanced topics such as operational amplifiers with lots of practical examples.

I came here to recommend the same book. It's not an easy book though to read from cover to cover though. I found it useful to try to understand a completed circuit design (say for a solar controller or something else I was interested in) and when I ran into something I didn't understand I'd then open up that book and read areas that were relevant.

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

#54
There is a basic circuits course upcoming in HackadayU, which is targeted at newbies and is pay-as-you-wish. https://hackaday.com/2020/06/17/schools-in-session-with-hack...

Just another resource that may help! You'll have no shortage of perspectives and approaches from the links here.

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

#57
post #33

Before you try to understand electricity try to understand work and energy. Know the definition for a watt and what that means mechanically for example. For really basic things: maxewels equations, ohms law, and the idea that in a closed system potential and kinetic energy are constant. Just grab a university level physics book. V=IR (ohms law) gives you most of what you need for DC circuits. Remember that power is v…

I would stay away from Maxwell's equations unless doing something to which they're truly relevant (designing an antenna or something I guess, maybe building a rail gun if you're into that). Maybe I'm blinded by the years I spent as a computational electrodynamics researcher but the model is a little heavyweight for your standard hobby project.

That said I really like your suggestion of starting with basic mechanics and thermodynamics. "Resistors get hot, motors do work, and capaciductors are like springs" goes a long way to tie everything else together

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

#59
post #7

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 active…

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.

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.

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

#60

I recommend having a look at "Practical Electronics for Inventors" by Paul Scherz and Simon Monk. The book offers a very good introduction about the basics of electricity with many helpful illustrations, written in a down-to-earth style. In case you are interested in electronics, you will find that the book covers many intermediate/advanced topics such as operational amplifiers with lots of practical examples.

I came here to recommend the same book. It's not an easy book though to read from cover to cover though. I found it useful to try to understand a completed circuit design (say for a solar controller or something else I was interested in) and when I ran into something I didn't understand I'd then open up that book and read areas that were relevant.

Yes, I had the same experience and I use it in the same way. It's a great book to have on your bookshelf as it covers a lot of topics and the chapters are, iirc, fairly self-contained; but I never read it from cover to cover.
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