Comment by TheOtherHobbes | Hacker News Reader

Comment by TheOtherHobbes | Hacker News Reader

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They're not really two separate things because of the way they're taught. They're separate things because they're actually separate.

A fully qualified EE understands circuits at a deep mathematical level.

Analog circuit design is basically a variant of the same theory used to model masses/springs and various other equivalent systems. (Of which there are many.) It's based on diff eqs with various simplifications (specifically the s-plane transformation for simplified analysis and its z-plane equivalent for DSP.)

There are maybe a couple of hundred or so standard circuit configurations to learn with their associated models and properties. The rest can be worked out. But it's essentially undergrad calculus and numerical analysis applied to an unexpectedly large collection of standard configurations which were invented/characterised by researchers with PhDs, often quite some time ago.

There are also specialisms - digital, RF/uWave, component design, data compression and encoding - which have their own lore.

Electronics is cookbook-level circuit design using a small selection of the standard models described with simple pre-calculus algebraic descriptions. It's hugely simplified and watered down. You can get a long way with it, but it's more like LEGO in that you can clip circuits together with only a very superficial idea of how they work.

Anyone who says they can make electronic engineering simple is lying. It's a subset of applied physics, so it's not simple at all.

Cookbook level electronics can be as simple as you want, but doesn't provide a deep understanding of circuit design, or issues like noise, distortion, and RF/shielding problems, data encoding systems, and so on. If you want those you'll need the full course, and that's a lot of work.

Chop wood, carry water. Using cookbook circuits is kind of like that zen story. You come full circle.

There's little enough honestly new in electronics that almost anything you do will look cookbook to an outsider. Designing actual products is exacting and deep, though. An example to look at is the writeup nwavguy did on his O2 headphone amp. He makes it look easy. The core amp is not an app note design or reference design but if he'd chosen the equivalent parts from TI it just about could have been. It's very straightforward. There is nothing exotic in it. The parts are cheap. The layout is even pretty mundane for high end audio. And yet it measures to be just about flawless, it has a nice no-pop turn-on circuit, etc. and there are plenty of headphone amps you can buy that do not. Without specific experience and expertise in audio design most fully qualified EEs would pathetically struggle to make something that nice.

It's one of the best electronic designs for hobbyists I've ever seen. All of you should build one if you think you might want something like that.

The only flaw I've found in mine is that the hysteresis on the low battery cutoff is not sufficient for some batteries (as they age and the internal resistance goes up) and it can "motorboat" before the battery cuts out. A really good low battery cutoff circuit is also surprisingly challenging.

“The novice says to the master, ‘What does one do before enlightenment?’ ‘Chop wood. Carry water,’ replies the master. The novice asks, ‘What, then, does one do after enlightenment?’ ‘Chop wood. Carry water.'”

When I was young I loved magazines like Popular Electronics.

After getting my EE, I looked back at those magazines in my collection I immediately thought "That's so wrong!" or "That omits so/too much" or "I can't believe I thought this was electronics" or "Baby project! How lame!".

:-)

So it's very much about what can be absorbed and tailoring to the audience. You can't start with the math load that an EE student gets with a broad, general audience.

You see the opposite of this with academic papers - either the level of assumed audience is stratospheric OR it's clearly wording to keep the riff-raff out of the field. Mostly the former but sometimes the latter. You often also see this in STEM textbooks - the audience isn't even freshmen oriented!

One of my mentors said "read all the hobby magazines, you never know what you might learn, sometimes they pick up new technology faster than industry". So did Bob Pease in one of his columns. But yeah, there's a lot of groaners in them.

> You can't start with the math load that an EE student gets with a broad, general audience.

Yeah, it's Wittgenstein's 'ladder', from the Tractatus:

> My propositions are elucidatory in this way: he who understands me finally recognizes them as nonsensical, when he has climbed out on them, over them. (He must - so to speak - throw away the ladder, after he has climbed up on it.)

>A fully qualified EE understands circuits at a deep mathematical level.

this is so funny. i have a buddy who's finishing up his phd in ee that works on SDR and who lead a team that won the darpa spectrum challenge a few years ago. he has no idea (absolutely no idea) how odes model LRC systems. i'm closer to CS than EE so he was explaining SDR to me and at some point i said "oh like the ode representation <something something>" and he had no clue what i was talking about. sure he took the class where that was covered but he completely ignored it (probably barely passed).

just one data point.

Of course you can find PhDs that don’t master fundamentals properly, but that remains rare. PhD quals are supposed to root that out. It’s also true that in day to day electronic engineering, any sufficiently complicated circuit would be solved with SPICE or an equivalent. For a PhD student in electronic engineering to not know that SPICE essentially solves ODEs still seems very surprising.

Actually I found that almost no one mastered fundamentals properly when I was an EE undergrad, at least with respect semiconductor physics (and an antenna theory). The "holes and electrons" stuff fundamentally violates conservation of charge because at first the "holes" are stationary but later, with the Hall Effect, suddenly they're moving, that's a bit of sleight of hand that no one cottoned on to. Not the profs, not the legions of grad students. It really does go to show how much of education is cargo cult learning. It turns out that in fact both the 'holes' and the 'electrons' of semiconductor theory are statistical virtual particles and not the fundamental particles that they are purported to be. (Somewhere in my past comments is the similar bit about antennas if anyone is interested)

Great explanation of the differences! I would argue though that even for noise, distortion, and RF/shielding problems you can get quite far with "cookbook" level knowledge (though I'll grant that it's quite likely to get let astray by leaky abstractions with these, like the many answers to "how/whether you should connect the shield of a USB plug/socket to PCB and/or chassis ground").

This cookbook analogy is pretty true for all fields.

There are tons of software engineers who have never taken a higher math course, the "cookbook" and the intuition is enough to get the job done efficiently enough.

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