Concise Electronics for Geeks (2010) | Hacker News Reader

Concise Electronics for Geeks (2010)

lcamtuf.coredump.cx

481 pointsnbmh49 comments

Shameless but possibly relevant plug... Here's my introduction to electronics series of tutorial videos: http://afrotechmods.com/tutorials/category/tutorials/beginne...

It's about an hour's worth of material and it is very concise.

Also here in Youtube playlist format: http://www.youtube.com/watch?v=8gvJzrjwjds&list=PLzqS33DOPhJ...

Just wanted to say I love your videos. Do you have any plans to continue uploading new content?

Thank you. I will surely upload more stuff in future but it won't be on any sort of regular schedule.

I'm another big fan. Watched your videos some years ago and it started me on a fairly intense electronics hobby. Your videos on op-amps and radio are simply brilliant. Thank you!!

Nice to see you here, I've been a long-time subscriber to your channel!

Another great channel for electronics basics is TheGreatScott: https://www.youtube.com/channel/UC6mIxFTvXkWQVEHPsEdflzQ

Of interest this is the guy that developed American Fuzzy Lop[1], and the Guerrilla guide to CNC machining[2] (which is similarly well written).

[1] http://lcamtuf.coredump.cx/afl/

[2] http://lcamtuf.coredump.cx/gcnc/

Thank you for pointing to these, I was going to pass on the electronics.

But wait, there's more! I also make tables [1] and doomsday predictions [2].

[1] http://lcamtuf.coredump.cx/table/

[2] http://lcamtuf.coredump.cx/prep/

Hey, I really enjoy your hardware work! Ever since finding your website over 5 years ago, I've been checking in regularly for new projects and updates. The highlight for me is probably your precision resin casting projects.

Yeah there is a conspiracy theory that you are the bourbaki of computer security.

Difficult to see how you can really be just one human.

> Yeah there is a conspiracy theory that you are the bourbaki of computer security.

Nicolas Borubaki wrote in a very abstract and badly readable style. So: no.

Bourbaki was a pseudonym for a collective, which is what GP was referring to.

One thing that took me a long time to `get` was the concept of voltage is a bit miss-leading if you look up the definition even in the video of (http://afrotechmods.com/tutorials/2016/10/03/basic-electrici...).

Everyone wants to talk about the penitential energy and what-not. Though that is mostly pointless unless you grasp the first fundamental concept of voltage. Voltage is just simply the effort exerted by electromagnetic field on neighboring electrons.

As soon as you grasp that all definition of voltage relate to the real world of doing `work` eg... heating, moving then the concept of voltage of amps is a lot easier to understand.

I was taught to think of voltage as a level or “elevation” of sorts. Ie the difference between two charges in relation to one another.

I was taught the same, though I never liked the concept of elevation, water, ect... It easier for me to quantify it when it relates to the real world such as newton force or doing work. The other reason I never really liked the concept of elevation it means nothing if you dont have gravity that is constantly acting on a object.

The other reason I never really liked the concept of elevation it means nothing if you dont have gravity that is constantly acting on a object

It's an analogy. That's how analogies work. I was hoping for some substantive reasons the analogy doesn't hold.

I think there is a caveat here:

force on electrons is "EMF", https://en.wikipedia.org/wiki/Electromotive_force

This scan be measure in volts, or joules.

"potential difference" seems to be the relative difference between the "EMF" of two conductors, which is analogous to pressure-difference and is the relevant factor wrt current, power, etc.

Cheers Chris, cleared up the issue I had with potential difference didn't see it that way.

> Voltage is just simply the effort exerted by electromagnetic field on neighboring electrons.

That sounds like you are talking about the _electric field_, which is a vector field. Charged particles feel a force in the direction that the electric field is pointing. This is analogous to the gravitational force field (a vector field pointing towards the ground) and how objects with mass feel a force in this direction.

The electric field has a _potential_ [0] (called the _electric potential_), which is a scalar field. This is analogous to gravitational potential, which coincides with height.

_Voltage_ is the difference between the electric potentials of two points, for example the two leads of a resistor (or other circuit element).

[0] https://en.wikipedia.org/wiki/Scalar_potential

This is awesome and great as a short-form resource. For years, my long-form (non-concise?) go-to book has been "The Art of Electronics" [0] by Paul Horowitz (and others depending on the edition). It has everything you need in a single reference book!

[0] http://amzn.to/2iZfjbG

So true. The associated Lab Manual is even more fun if you want the hands-on experience. It's top notch.

Just skimmed but looks pretty comprehensive.

Another great reference is the Art of Electronics.

Tons a practical advice for selecting components and building circuits that is still relatively relevant even today.

I can second that. I've been using that book since the 90s and it has served me well.

Previous discussion:

https://news.ycombinator.com/item?id=9653898

I've been learning about basic circuit design recently and realized that I don't have any clue how things relate to the underlying electrodynamics. Does anyone have some good textbook recommendations that derive things like Ohm's law and concepts of capacitance, etc, from first principles?

I try to get into this at least a little bit in https://www.circuitlab.com/textbook/

Ohm's law was not derived. It probably shouldn't be called a law either. Capacitance, etc. can be found in Introduction to Electrodynamics by Griffiths, which is a standard E&M college text.

Hyperphysics does a decent job of providing some insight: http://hyperphysics.phy-astr.gsu.edu/hbase/electric/pplate.h...

The "first principles" part of E&M has some tricky math which can be mitigated by a well chosen problem domain. If you really want to dive into it, I hope you love (or learn to love) multi-variate calculus, linear algebra, and switching coordinate systems (cartesian, polar, spherical) multiple times to solve a problem.

Those are two very different things (Ohm's Law and Capacitance).

Capacitance is basically the relation between electric field and charge, whereas inductance is the relation between magnetic fields and currents. Those follow from fundamental equations, if you want a calculus intensive derivation from the "first principles" of Maxwell's Laws. Someone on this thread mentioned Griffiths, which is a good text, it's what I used in E&M undergrad. Wangsness has a good E&M text too I liked.

Ohm's Law is a macroscopic statistical mechanical Law that happens in bulk.

It can be derived from even some of the simplest electron models (eg the very simplistic Druude Model). Where it can be shown that the current density through a chunk of material is proportional to the applied electric field. https://en.m.wikipedia.org/wiki/Drude_model

But it breaks down in smaller systems, where statistical averages don't hold (for example ballistic conductance in a nanowire). Or other systems when quantum mechanical effects will dominate (eg bandgap non-linearities of a PN Junction or Quantum Well, or how the bandgap of a semiconductor causes an increase of resistance at lower temperatures as opposed to decrease of resistance for metals).

I used to have a nice presentation of the latter on my old uni website called A Quick and Dirty Preview to Solid State Physics, but alas they disabled my old account after nearly a decade past graduatiOn. (Had to make the webpage for a class early in grad school, and it was linked by many other solid state physics classes interestingly).

Its still available via the way-back machine: https://web.archive.org/web/20150219055858/http://www.pha.jh...

You rock!!

I've only met one electrical engineer who ever knew about anything below the typical EE abstraction. Everyone still gets the job done without having a clue. It helps if you're doing RF design or very high frequency stuff and that's about it.

This youtuber has some good videos with animations of visual analogies for analog electronics: https://www.youtube.com/watch?v=m4jzgqZu-4s

20,000 word document titled "Concise electronics for geeks". Excellent choice of title!

Also, this looks like a really awesome primer!

Relative to the kinds of things geeks read, I think the title is valid.

Another very good source of information is the US Navy Electricity and Electronics Training Series (NEETS). https://maritime.org/doc/neets Also towards the end of the parent directory check the "Electronics Technician" volumes and other interesting stuff on welding, repairing etc.

Great review as an embedded SW guy to nourish my EE background. Nicely peppered with practical tricks and techniques that are useful in the field. I enjoyed seeing the low-pass and high-pass filtered wave signatures along with the explanation of what the problem might be (long/close connections and broken traces, respectively).

Nice, this looks really cool!

Although...it is going onto a 'read this soon' list, and I'm probably not alone in that. With these sorts of concise primer articles, have you considered providing a .pdf or .tex of the page?

> "providing a .pdf or .tex of the page"

I'm not the author, but in the case of .pdf, couldn't you just use a 'Print to PDF' solution? On Windows I've used PrimoPDF before, don't know what OS you use but guessing all the major platforms have something similar.

Yeah, good point, I guess there are already tons of existing solutions for that which wouldn't eat up the author's bandwidth; the modern web really has spoiled us with so many 1-click conveniences, huh?

Poor man's LaTeX in Firefox: about:reader?url=http://lcamtuf.coredump.cx/electronics/

:-)

Both Chrome and Firefox provide built-in print to PDF feature on Linux and Windows (possibly other OSes too, but I'm not sure). Just click Print and select "save as PDF" or "print to file". Chrome even allows removing the URLs and other metadata from headers and footers.

I like to convert this kind of things to en epub to read later in an ebook, I use https://dotepub.com/?lang=en

From the article: "...consequently, several capacitors in series resemble one capacitor with a larger plate surface area."

s/series/parallel/ ??

Should be parallel given C for a parallel plate capacitor is proportional to its crossectional area.

A really good article.

too much wall of text and few images

This is why this article is good.

Not when the subject is about graphs of electric components.

Reply on news.ycombinator.com