A learner's rant

[jeroen74]

On the other hand, AoE is old, second edition is from 1989. Transmission lines where not that important or often encountered as they are now I guess.

And the question is how much do you want to pack into one book, it's already quite voluminous. For almost each subject in AoE you could write a complete book on itself and most likely are available too.

For high speed digital I believe 'High-Speed-Digital - A handbook of black magic' is universally regarded as the definite book on the subject. Start reading at page 229

[ptricks]

For the beginner to electronics I always recommend anything by Forest Mims, I started my interest in electronics back in 1984 with his 555 timer book , then collected all the others that radio shack sold.

http://www.amazon.com/Getting-Started-Electronics-Forrest-Mims/dp/0945053282/ref=la_B003UGHJVE_1_1?s=books&ie=UTF8&qid=1355402604&sr=1-1

[JuiceKing]

I've been teaching myself about electronics over the last few years from various books, websites, experimenting and conversations with smarter people than I. With every source of knowledge (besides experimenting), I have the same complaint, and it's reached the point lately of driving me fucking berserk (and I've realised it's why I've abandoned so many attempts to learn in the past), so I'd like to humbly request right here and right now that nobody producing educational content ever again uses the following words together:

"Let's assume that..."

No. Let's NOT assume anything. Tell me why it's the case. Whether it's choosing a collector current, or a filter cap value, pull up/down resistor values, input/output impedances, fuse sizes, whatever, please tell me WHY we're using that value/voltage/current/etc. Don't shortcut, teach it properly or don't bother.

I understand that at a certain point you collect a certain amount of knowledge and can fill in the blanks for yourself. I'm reaching that point myself now in lots of situations. But it has been hell to get there. It seems like every damn book or tutorial I ever find on a subject starts on some unexplained assumption and leaves me scouring 20 other books or sites for an explanation of why we started with that assumption. I have so many dog eared half finished books laying around because the information is completely useless to me until I find out why they chose certain starting points in a circuit. The info is fine to copy their design, but tells you absolutely stuff all about designing your own circuits for your own requirements.

I hope this rant makes sense. It's hard to explain exactly what I mean. Argh. My brain is fried right now. I just got halfway through reading another whopping explanation on a topic only to find another value chosen to explain equations with no explanation of why out of every possible value available you'd choose that one. Is it related to impedance? Power dissipation? Stability? Frequency response? NFI.

Now... off to go figure that out from another 50 sources before I can continue 


P.S. This is why I'd love to see Dave tackle some super basic beginner concepts at some point, he makes things so much easier to understand. Maybe it's because we both speak Strayan, I dunno

I have had the same frustration.

All I can say is to do experiments which focus on very simple circuits that explore DC and AC interactions with passive components so that you are utterly comfortable with Ohm's Law, as well as impedance and resonance concepts. Then add in the active stuff. For me, there was an "aha" when I understood that certain passive components (or combinations of them) were doing multiple jobs depending on the frequency of the signal. Here's an example that was very helpful for me:



- Ken

[M0BSW]

Now "Let's Assume" all these replies are right,we can  then assume,you have the answer you need
and "Let's assume" you'll still have to keep reading the books , it's better than watching the evening TV 

[free_electron]

it's better than watching the evening TV 

and that, my friend, is NOT an assumption but pure fact.

[mark5009]

Hmmm. 

"Let's assume" is a simplification.  It represents an ideal situation where all the nasty bits that a working designer has to deal with.  But then, being a smart guy, I suspect that you know that.

So, you're getting frustrated when reality is different from the model?  Or are after something else?  I don't get it. 

Let's say that you have a buffer circuit that uses a generic NPN transistor. You see that the transistor says "BC109, BC549, 2N2222 etc.", do you want to know which one to choose?  Is that the kind of thing?  Or do you need someone to explain that it really doesn't matter and that any NPN GP transistor will work and why that is the case?  Or do we assume that you know the basics about transistors and just want to know how to construct buffers, and what the trade-offs might be between transistor buffers, JFET buffers or op amp buffers?  Then, do you want to know how a TL072 works, and on, and on...  Or do you just want to create a buffer?

Whichever way you want to go, you are going to hit model simplification.  Get over it.

[As an aside, a couple of astro-physics friend say that, when it comes down to it, there are only three interesting numbers in astronomy: 0, 1 and infinity.  To a first-order approximation  :-) ]

[SgtRock]

Dear Dave:

--You said "I actually have on my to-do list a video just about pull-up resistors. Because someone asked that once on here (you?), and I was curious to see how long a video I could make on the details of choosing one of the most mundane component values in electronics.

--To which I say, bring it on, I am your huckleberry. This is an area which is a subset of the Venn Diagram of my ignorance.

--You could even throw in pull downs as well, if it does not seem long enough.

"He was born ignorant, and has been losing ground ever since."
Fred Allen 1894 - 1956

Best Regards
Clear Ether

[urbanwriter]

Broadly speaking... I certainly sympathize with the OP; my frustration dates back to junior high school when some cad said 'well, we'll use an imaginary number...'

I think is difficult is for someone who has mastered a skill to recognize, in a very positive sense, how much they know. And when you are at that level of skill perhaps one of the defining notions is that you can start with 'we'll assume...,' while the beginner is mystified, perhaps, that the 'assumed value' works at all.

Ah, to hell with it. This could be a 3,000 word essay; I'm not writing it, you're not reading it. Be curious, have fun, allow for a couple mistakes.

Oh, Dave, on the 'French question.' That is how 'other' languages are taught. If you speak Chinese, and you wish to learn English as ESL, you would be taught so much about verbs and nouns and adjectives and nominatives and past-perfect. The list goes on. But you'll also be taught that you can't start a sentence with 'but,' but you can. In Montreal a local guy, Quebecois, said that if I wanted to learn French, get a local girlfriend. I guess your options are limited to French classes. ; )

Oh, please, I beseech thee, do pull-up resistors. And, as Sgt Rock has intimated, throw in the pull-downs as well.

[Bored@Work]

The boring whining of a generation that doesn't want to put any own work in and requires to be spoon feed.

[EEVblog]

Oh, Dave, on the 'French question.' That is how 'other' languages are taught.

Then I posit they are doing it wrong. Just like starting electronics with quantum physics, it's a stupid way to do it and kills your enthusiasm.
In this case the object of the (short) course was to give you the ability to hold a basic short conversation in French, not get a degree in the language 
Kinda like being able to wire up and program an Arduino to give you the ability to control some hardware - they should have only taught the high level French stuff, not the low level.

Dave.

[Razor512]

For me when it comes to learning through tutorials, I am not looking for unrelated basics, (eg the basics of learning to use a car is not how to build an engine)

The problem that many tutorials have is that they assume you know everything in the world except what they are trying to teach you. It is difficult to describe it for electronics, while less related, i feel a good example of bad tutorials are math books.
Many math textbooks will give you the major steps to solving a problem, but they will not tell you the steps in between the major steps. And one of the basic properties of math and numbers is that there an unlimited number of ways to get any number, If I don't understand how it got from one step to the next then I don't understand the problem, even if I do some calculation that gets me the same result, it may not be the proper way to solve the problem

With a proper tutorial (in my opinion), if there is a step where it is not completely intuitive and leading (eg a GUI install has a next button so a tutorial explaining an install does not need those in-between steps), then it must be explained why you chose what you chose or did what you did  to reach the next step.

Nothing is to be left to multiple interpretations, which is important when it comes to error free learning. I am currently doing student teaching at an elementary school and the most common problem I see are students who have completed a lesson (most commonly math) where they do not fully understand how to get to each step, and perform what ever in-between steps that they feel should be done, and get a number at the end. While it is not too bad it the error is discovered and quickly corrected, but what commonly happens is they get 20 problems for homework and perform the same mistake multiple times and thus conditioning them self into solving the problem the wrong way and if you correct them, they may follow it once and revert back into doing it the wrong way the moment they slightly forget something. This then requires an extended amount of time to get them to unlearn what they have learned before, then relearn how to solve a problem with (this time with all of the in-between steps that were missing before).

Sorry for the long winded post in advance.

(the great thing with sites like youtube is that is is easier for people to share info and tutorials so you are more likely to find someone who will post a how-to, with all of the important details)

[HackedFridgeMagnet]

Not all French language classes just start on grammar.
I went to one where the teacher couldn't speak English very well, and from the first lesson, for Everything we said, we had to at least try to say it in French first.
It was very hard but it was really a mindset thing that needed to be conquered, and it was better than learning the exact grammar.
It think this was a much better way of learning.

And for further inspiration I just needed to turn to my right to where Miss Australia was sitting!
je m'appelle Jon, comment vous appelez-vous
Needless to say, I tried my best to learn French, but couldn't get those throaty rrrs that sound like you've been smoking too much.

[David Aurora]

The boring whining of a generation that doesn't want to put any own work in and requires to be spoon feed.

The boring whining of a generation that insists that in their day they had to walk 50 miles over frozen ground to blah blah blah blah blah...

Get over it, Gramps. Technology is one of those things that you can't turn into a "In my day" story, for the simple reason that half the stuff we're trying to learn now simply didn't freakin exist a generation ago. It's one thing to start in the old technology and add a little more knowledge with each advance in technology. It's kind of different to start in the twenty-teens and catch up on the whole lot.

[TerraHertz]

Books in them days, the 70's and 80's described principles and examples in simple to understand ways, ...
...  get the 'old' books from the 50's and 60's, even valve based, and the detail and explanations is beyond belief.

A lot of the foundations and basics what you may want to learn is no longer available in today’s publications or on the internet, as you've discovered it's all assumed you know it all.  It has gone with those that knew and have since died.

I second that! If you can find a local 2nd-hand bookshop that stocks old science/electronics texts, treasure it!
My first real introduction to electronics was a 1964 edition of the Radio Amateur's Handbook, that a neighbor gave me when I was about 9. The introductory section is brilliant. Still have it, see pic.
Plenty of old textbooks on all kinds of topics are available 2nd hand for purchase online very cheaply. For instance see http://www.abebooks.com/servlet/SearchResults?sts=t&tn=radio+amateur%27s+handbook+1964

ps , get the old books, i have books from librarys that were put out of circulation and had their hard covers ripped from them do dissuade people from taking them from the bins, old, damaged but worth their weight in knowledge that is now disappearing.

ADMIN EDIT: Link to Crackpot website removed

Edit to add: It's also fun to find wonderful old books. For instance from the discussions here of Jim William's classic App Notes, I realized my data book library has nothing from Linear Technologies after 1989. So I found a set on ebay: Linear Applications Handbook Vol I, II & III, Linear Technologies, 1990, 93 & 97. Really looking forward to those arriving.

[urbanwriter]

Dave, I didn't say I agreed with the way language is taught, when the teaching is a commodity, I just noted that 'that's the way it is' in far more cases than nought.

I wanted to order food with at least some respect for my hosts in French, in Foo Chow, in Malay, in Spanish so I learned fairly promptly in each case. And, just as with electronics fora, some participants were more helpful than others.

[JuiceKing]

Posted without further comment.

 
Now back to our regularly scheduled program.

[TerraHertz]

Those Linear Technology application books arrived. They are really excellent. Even more fun than the old Nat-Semi application databooks. See pic. If you ever spot these in 2nd hand sales, grab them they are worth their weight in gold.

JuiceKing, yeah, if there was a smiley for 'warning, extreme fringe' I'd have added it.
But one has to wonder at the mentality of people who destroy books 'because they are old' or whatever other reason they may claim. I've seen it myself - a whole library at a Montessori school my kids were attending. The principle decided all the books should be disposed of, and new ones bought. He was in the process of loading them up to take to the tip when I found out. Most looked fine to me. I was able to take them to the Salvos myself instead. But he really wanted to landfill them. Hundreds of books, donated to the school by parents over many years. I forget his name, but it was compatible with that article.

Edit: Oh, and another sad example of book destruction. In Sydney near Central Station there's an 'excess print run' (remaindered) book seller called Basement Books. Very low prices, on essentially new books. They used to have an excellent section for technical, networking and computer science books. A lot of which I think came from nearby University Coop bookstores. Then suddenly that section was virtually eliminated. No more cheap high quality tech books. I asked why, and was told that the publishers now require technical bookstores like the Coop to return all unsold stock for destruction. So that's a profit margin motive - the few people happy to buy such books cheaply a year or so after they were current, are cutting into bookseller profits to an unbearable extent, apparently. Better to destroy all excess copies. But this reasoning doesn't extend to _other_ types of books.