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All About Circuits

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I am an electrical engineer. I used this site as a reference all throughout my schooling. Yes, it's incomplete, but it's a great resource nonetheless.

I'm surprised that this has never shown up on HN before. I can't think of any ECE or EE students I know who haven't used the resources from this site. Maybe there aren't as many of us here as I'd imagined.

Am I the only one who can work through electronics textbook after textbook and still can't figure out how to wire a reasonably useful circuit?

You're not alone. I've had good luck treating circuits as modules that are connected together. Analysis of complex analogue circuits escapes me, though.

I've found that with hardware design, at least at the beginner level, you can read up and cram all the theory you can get into your brain, and not really be able to build much. I think that by actually doing, and having someone show you the basics of "this is the way we do something, and this is why we do that something" is much more helpful, and opens up realms of possibility.

I remember from learning to program that there was a point where, probably because of good teaching, I "got it" and then I was able to teach myself. But I haven't yet gotten to the autodidact point in electronics. I've been looking for the book that gives me this "got it" experience!

In my EE work, I tend to use formal analogies in my thought processes, sometimes unconsciously. For example, water and electricity behave in same way [1]. You don't design the whole circuit in the water domain, but you might temporarily flip over to water to understand a particular aspect, then flip back to electrical. Typically I won't write anything down in the alternative domain, using it just enough to clarify my thinking in the electrical domain, then recording things in electrical terms. There's all sorts of other domains too: acoustics, mechanics, pneumatics, ... Pick the one you are most comfortable with in the situation.

[1] http://en.wikipedia.org/wiki/Hydraulic_analogy

In short: Learn constant coefficient 2nd order differential equations, and you can design a whole slew of mechanical, electrical, and hydraulic contraptions.

A real application of this: before computers, mechanical systems control engineers would write the equations of their mechanical systems, write their controllers, and then implement their controllers around the electrical circuit that duplicated the behavior of their mechanical system. Sort of an analog computer way of simulating a system.

Or as in my experience as an EE, learn how to use Laplace transforms, find a table for the 2nd order differential equations, use Laplace transforms, forget how to solve differential equations.

Wire or design? Studying signal analysis, and accompanying programs, can help with the design part. The wiring part comes with practice. Once it becomes really complicated or size is an issue, it is usually simulated and machine made.

I meant design.

If you haven't studied signal analysis, I would recommend it. As a BME it was especially important to convert sensor analog signals to a desired digital signal for processing. It opens up a huge area that allows creation of black boxes that get the desired job done. It may be a little much if just for a hobby, but it is a great super power.

Have you ever tried prototyping with an arduino?

I started out from zero, and have slowly been able to get to the point where I can build small robots. Its been challenging, but enjoyable. Electronics is unlike software, where you can code and code libraires without an end product (the library itself). Electronics require you to have some kind of end goal (a trinket!).

Try it out. Its cheap, accessible, and fun.

Of course not, that's why electronics courses generally have labs. Same deal with CS theory and application.

Even then, there were definitely people who would do very well on the theory, but struggle with the labs. And vice versa.

I noticed my tweenager son playing with redstone circuits on minecraft. I asked him to make a JK flipflop. To my surprise he not only knew what it was, but had made a few flipflops.

So check out Minecraft. It's good to get immediate feedback and make 'actual' machines.

Amusingly, minecraft is the second link on google when you search for T flipflop.

It really depends on what you are making. Blinking LED's require little theory, and voltage dividers never really need to be precise.

But, when making a multi-pole active filter, the whole "grab a few resistors and test it until it works" is a colossal waste of time- you need the graphs, equations, and so forth (or at least a computer program that will take care of that).

You also need to build it still as at least 50% of the time, there are problems with the ideal world simulations.

This is normal. Most of the textbooks are crap and teach you nothing but theory. Most EE's spend a lot of time in front of a computer these days doing nothing practical.

Grab a copy of "The Art Of Electronics Student Manual" which will give you lots of "ahh I see" moments.

The best book to get if you want to build things is: The Art of Electronics, by Paul Horowitz and Winfield Hill http://en.wikipedia.org/wiki/The_Art_of_Electronics

My EE professor told us if we wanted to make things, we should get this book. While the current edition is quite old (1989) it is still a great reference. There is also a lab book that goes with it.

Nope.

I graduated with a BSEE over two decades ago (gulp!). A few months after graduation, I was asked to analyze a simple filter circuit to make some changes. I had absolutely no idea what I was doing and it pissed me off to no end that after 4 years of hard-as-hell classes I couldn't do it.

Then I happened to look at the paper from a different angle and it just hit me -- the filter was nothing more than a 2-port network. I knew everything about analyzing 2-port networks!

I sympathize, but I can assure you that it will get better with practice.

http://www.play-hookey.com/ is a similar site that has been helpful to me over the years. It has interactive examples as well.

I remember this from a few years ago; hopefully it's more complete now than it was then. I stuck with Sedra and Smith.

Edit: looks like there are still a lot of missing and incomplete sections in the semiconductor volume.

Sedra/Smith was a classic - I remember I picked mine up used from the campus bookstore, and it'd been cycled through the course so many times it was almost perfectly annotated and highlighted for the way one particular prof taught the material.

Of all the textbooks I used in my schooling, Sedra & Smith is on the short list of ones I remember explicitly - along with Silberschatz & Galvin on operating systems (with the ridiculous dinosaurs on the cover), Oppenheim and Willsky's Signals and Systems, EOPL, and Stewart's Calculus.

Did you go to a Canadian engineering school? These are the exact texts that I used for my CE courses

I also had the Silberschatz (such a weird cover!) and Oppenheim books. I think Sedra and Smith is pretty widely accepted as the canonical introductory electronics book.

Most frustrating book I had to deal with: Random Variables and Stochastic Processes by Papoulis and Pillai. I understand it's also very popular, but I found it really hard to follow.

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