Effectively learning electronics as a hobbyist? (warning: longwinded!) - Page 1
Forum section: electronics / beginners

author: Aldobrandi
author_rank: Regular Contributor
timestamp: April 14, 2012, 09:01:20 am
content: Learning electronics on your own can be fantastic on so many levels: you are free to go at your own pace, you get to craft your own curriculum, skipping whatever bores you to death, focusing on the stuff you enjoy (such as blowing caps and blinking LEDs...). But in the past couple of weeks I have found it extremely frustrating for these very reasons: without the guidance of a teacher or a strict program, I have found it very difficult to successfully balance theory and practice, to know how deep I need to go into the mathematical analysis and understanding of circuits (one thing I am inclined to do because this is how I first learned electricity and physics in high school and college), without neglecting the practical understanding of how to design elegant and functional circuits that perform just what you want with a minimum of parts in an optimized and cost-effective fashion. To put things simply, I find myself taking refuge in theory (which I am not even able to understand very well anymore, having dropped the formal study of mathematics many years ago) and being scared of learning by getting my hands, and breadboard, dirty. Sorry, I’m now a writer and you will find these longwinded introductions to be a painful staple of my posts...Here comes the question: I’m not planning to become an engineer, but I don’t want to just “toy” with electronics either, how do you suggest I organize my hobbyist’s “education” in order to understand what I’m doing and actually doing stuff even if sometimes the theory is wayyyyyyy above my head?Here are a couple of books I’ve been using with a quick assessment of how helpful/unhelpful they’ve been for me:Make: Electronics (Learning by Discovery): it was fantastic the first week or so but there isn’t enough theory for my taste and I feel like I don’t really understand what I’m doing.To complement Make book I bought the obligatory “Art of electronics” by Horowitz & Hill. It’s an incredible reference and while I haven’t actually tried any of these yet I absolutely love the exhaustive lists of “circuit ideas” and their counterpart “bad circuits”. My problem with it is similar to the previous book: although there definitely is a lot more theory than in the Make book, I feel it’s going way to fast and not giving me enough of what I need: I need more than a few pages on diodes, and I am extremely rusty on my DC and AC theory.To try to compensate the lack of details in both books I decided to get a college electronics text book: Electronics Fundamentals: Circuits, Devices, and Applications (5th edition) by Floyd. Here I am faced with the opposite problem: great for theory and math, not so great for getting your hands dirty.TLDR:I know I’ll never find the “perfect book”, the real problem is that I simply suck at learning on my own: with these 3 books (not counting the nauseating amount of blog posts, videos and tutorials I’ve watched/read) I definitely feel overwhelmed with all the information at my disposal and as a result I am not learning really well despite all what’s available. HELP !

author: Rerouter
author_rank: Super Contributor
timestamp: April 14, 2012, 09:37:44 am
content: although the flashing light programs seem mundane and stupid, they appear popular as they are a starting point, to get people into the firmware side of things, hardware meshing with software and seeing some kind of reaction to what they did,my personal reccomendation would be to look at something interesting and useful and build on it, make the design yours,practical experimentation means you get hit with things you wouldnt expect from plain theory, pickles glow on one side when exposed to mains, filters can self oscillate , logic gates have propagation delays and high voltage has corona losses, little things that the math wont make you aware of,if you must chase a book, then perhaps look into books produced by newnes, a decent amount of there books cover all the information to get into one of the respective feilds,

author: Aldobrandi
author_rank: Regular Contributor
timestamp: April 14, 2012, 09:58:04 am
content: Thanks rerouter for your reply. I think you are right, I need to build something, build on it, and not move to something else until I really understand how it's working. I'm actually currently trying to design some kind of heat alarm that'll alert me when I leave my bathroom quartz heater on for too long (or better yet, that'll turn it off automatically after a certain amount of time). So I'm in the process of learning about thermistors, comparators, and Schmitt Triggers, but I'm having a hard time understanding really how each part of the circuit works, partly because I'm super shaky on my basic DC/AC principles. The details of this project belong to another thread and maybe the best thing I can do is starting to post about my difficulties and ask for help from you guysAnyways, thanks again !

author: T4P
author_rank: Super Contributor
timestamp: April 14, 2012, 10:21:54 am
content: I learnt a shitload from :http://www.allaboutcircuits.com/Have you ?

author: Mint.
author_rank: Frequent Contributor
timestamp: April 14, 2012, 10:30:26 am
content: Quote from: Dave.S on April 14, 2012, 10:21:54 amI have learnt and still learning (reading) a load from Tab Electronics Guide to Understanding Electricity and Electronics - G. Randy Slone.It is an excellent book with a good amount of theory, basic mathematics nothing too hard, loads of circuit examples and it does not make many assumptions about you before you start the book and this makes it a bit easier!

author: quantumfall
author_rank: Regular Contributor
timestamp: April 14, 2012, 10:37:45 am
content: As a hobbyist you need to understand the circuit elements, for example a capacitor, you put a voltage across a capacitor, it looks like a dead short at first high current, low voltage , as it charges up the voltage increases and the current decreases, you picture it like this as it fills with electrons it takes more voltage to force them in. the voltage on the capacitor opposes the current as it charges. So voltage lags the current , current leads, you now have an understanding of what a capacitor will do no complicated maths needed. Apply AC and it can look like a conductor if the frequency is high enough.Do the same with a simple resistor divider , add a transistor, picture it as a variable resistor (Transfer resistor), you get the idea . Learn its a current controlled device unless its a FET ! OK You are starting to get the feel of it now....You now have an understanding basic but still true and relevant.Do the same with everything else I used a book of basic electronics formulars to do exact calculations along with ohms law. I have built many projects with a bit of experimentation and basic thorts as to power dissipation, voltage levels, component tolerance etc.As for circuit design and elegance, well I'm not a natural at it, I personally find I'm happy to learn from the past.There is so much thats been done with electronics that just to be able to get the understanding of what is being done by Dave and the guys here is reward enough for me, its a valid way of learning and enjoying, not knocking your head against the wall.OK you want to be a masterif you have the aptitude and perseverance you will learn what you need over time, years certainly.Making things the practical side is a nice skill to learn as well.You can do a lot with just basic algebra and a reading of circuit diagrams, brake it down into functional blocks PSU inputs, outputs, analog comparators, digital circuits etc.It takes time and you will get better, thats TIME.Do it slow, read as much as you can from Hobby magazines they have practical, theory and simple projects to start with in a good balance.One project I made years ago was a Zenon strobe, I did not understand how to work out the power dissipated in the zenon lamp, its the power stored in the capacitor 1/2 CV squared with no internet and only basic books available it took research I will never forget that formula now.The equipment you can get now and the resources you can find on-line are fantastic now, you can feel swamped with choice. I'm just getting back to electronics as a hobby myself.Its very rewarding when you build a more complicated project and all your soldering is good and it works.Learn the theory of a diode its the fundamentals of semiconductors in electronics, digital transistor circuits are just just analog circuits run at the extremes on or offThere is no perfect book, but you can lean a lot from just the basics, build stuff, fault find, experiment with basic circuit ideas from books put t.hem together as functional blocks.Do not get caught in the University level maths analysis mode, its not good for the hobbyists comprehension of the subject IMHO at least at first.

author: FreeThinker
author_rank: Frequent Contributor
timestamp: April 14, 2012, 10:41:00 am
content: Years ago I would of recommended getting one of the monthly mags, now even the best of them are at best poor, Elektor probably one of the better ones. ETI's format and the 'How it works' section of each project was a real winner for me. Web sites are ok but lack the 'Tactile memory' of a magazine. Still, if you of of the internet age, you will get more from web sites than I do and in reality you are limited in choice. In the Beginners section is a sticky with a list of books etc which you may find of interest.

author: amyk
author_rank: Super Contributor
timestamp: April 14, 2012, 10:59:17 am
content: Quote from: Dave.S on April 14, 2012, 10:21:54 amI can recommend this site too, it's quite detailed and informative

author: djsb
author_rank: Super Contributor
timestamp: April 14, 2012, 11:01:36 am
content: I love music but I'm not a musician. So I build stuff that reproduces music, active crossovers for my hi-fi, transmission line speakers and hopefully (when I get around to it) an FM tuner. I also find that if I have a practical problem that needs to be solved and it can be done with electronics that helps. I always follow my enthusiasm. With this approach I have long periods ofdoing not much and short bursts of activity when something catches my interest. I agree with the life-long learning approach but thats only because it suits MY learning style.For instance I'm having problems with the carburretor on my motorcycle. This got me thinking about fitting a fuel injection system (min or micro squirt). So I occasionally do a bit of reading up on that. I have to create an application for my job, so I have to read up on that.Just a sample of how it works for me. You have to find out what your learning style is and work with it.David.

author: Ed.Kloonk
author_rank: Super Contributor
timestamp: April 14, 2012, 11:22:40 am
content: May I suggest something? I don't know if it's applicable or even still available, but 20 years ago I did a Basic Electronics course via correspondence through ICS. It was good in the sense that I had to submit multiple choice tests back to them and only then could the course proceed whilst I could balance my -ahem- real job and hectic social life at the time. Would recommend it- if it is still available.However, since the advent of the internet, all the information is available to you for free if you'd be prepared to aggregate it yourself and I'd argue that, with sites such as eevblog/forum and the great people who frequent it, you can discover the many ways to skin the cat so to speak.Perhaps you could break down into little parts the first few key things about electronics that elude you. Formulate a specific question and ask away. Participate in discussions and you'll find just by rubbing shoulders with some of the smart cookies here, you can alleviate the frustration of feeling stuck.I've said it before, I wish I had Dave's vblog two decades ago because I stalled and went on and found another line of work and a lot of my understanding of my abandoned hobby is quite dated.

author: FreeThinker
author_rank: Frequent Contributor
timestamp: April 14, 2012, 11:27:24 am
content: @DJSP if you are making a home brew fuel injection system for your motorcycle please be very careful as the engine is a very noisy environment (as in electrical, not deep throaty roar) a system runaway will result in at best a sudden engine shut down and at worst sudden and uncontrollable acceleration. Should be an interesting project all the same, good luck.

author: Aldobrandi
author_rank: Regular Contributor
timestamp: April 14, 2012, 11:29:56 am
content: Thanks everyone for the awesome replies, I think I have the tendency to give up when I hit a wall but just reading all your encouraging recommendations got me all excited about learning again. I wish I had time right now to reply to you individually, maybe tonight, after I'm done with my taxes !!

author: quantumfall
author_rank: Regular Contributor
timestamp: April 14, 2012, 11:34:27 am
content: Quote from: FreeThinker on April 14, 2012, 10:41:00 amOk I do not buy them now, I was thinking of them several years ago in my comment.

author: Bored@Work
author_rank: Super Contributor
timestamp: April 14, 2012, 11:57:26 am
content: Quote from: Aldobrandi on April 14, 2012, 09:01:20 amPatience, perseverance and stop buying books.You know the definition of a hobby? A way to waste time and money to have some fun. If you aren't having fun then what about another hobby? Or another area of the hobby? One of the most strange kinds of barely an "electronics" hobby I ever encountered were people looking for, mapping and identifying cell phone towers. Not my cup of tee, but they apparently had fun driving around, taking photos, determining GPS coordinates and using hacked cell phones to identify the channels used by the towers. I am not suggesting you should do this, but look for something that is fun.If you really want to go the theoretical route then it will become hard, with not much fun, and you need patience and perseverance. Unless, of course, if your are really talented and math and physics gives you a kick. The first step would be to brush up your math. But, engineering is an applied science. Meaning, a sensible engineer hardly goes down to raw physics when building a circuit. Instead sufficiently working models, approximations and rules of thumbs are applied. Hobbyist electronics uses some of the same models, approximations and rules of thumb, but to generalize, some are even much more simplified. Down to simple templates of the kind "if you copy this it will work".The sad truth is, you will likely never know how things really, I mean really, really work. Mankind does not have a full understanding of what, for example, things like electric or magnetic fields really are or what electricity is. We have sufficiently working models of varying complexity, depending on the job to be done.For hobby electronics it is perfectly ok to work with oversimplified models. You could start with simple and shallow stuff and just have some fun if you get it to work or barely to work. And look at some theory while going along. Or start mapping cell phone towers :-)

author: HackedFridgeMagnet
author_rank: Super Contributor
timestamp: April 14, 2012, 11:59:46 am
content: I think you also have to make yourself do some theory, not just practical, because you need to learn this stuff in roughly the right order, just do a bit and gradually build on it. I think you need to start with ohms law, circuit analysis, transients and steady state before you do transistors and other semiconductors, otherwise they just wont make sense.As an aside,I clearly remember when for the first time, I understood fully how a computer worked.From Silicon to Device to logic to chip to code, it was my personal EE Epiphany.It didn't take me too long after that to realise how much I didn't understand about them.

author: djsb
author_rank: Super Contributor
timestamp: April 14, 2012, 12:20:55 pm
content: Quote from: FreeThinker on April 14, 2012, 11:27:24 amThanks for expressing your concern Freethinker. The point I was trying to make is that I THOUGHT about using a fuel injection system (microsquirt-an already designed/built system,just needs all the gubbins around it) but then dismissed it after doing some research. In doing the research I picked up some knowledge without even trying very hard.Unfortunately I don't have a garage and a spare engine to experiment with, so I'm not about to blow myself up

author: Bored@Work
author_rank: Super Contributor
timestamp: April 14, 2012, 12:21:42 pm
content: Quote from: amyk on April 14, 2012, 10:59:17 amI usually strongly advice against this site/book. The reason ishttp://www.allaboutcircuits.com/vol_1/chpt_1/7.htmlQuoteBzzzt, Game over on Player One. You lost.This is such a fundamental mistake that it IMHO devalues much of the book. The author, billing himself as a teacher ..., can come up with as much anecdotal "evidence" that electron flow notation is good, but the fact is, it is plain stupid. He, and the "authorities" he cites, didn't understand what a model is, and that one purpose of everyone using the common, established model for current is proper communication with others.

author: djsb
author_rank: Super Contributor
timestamp: April 14, 2012, 12:27:44 pm
content: Try explaining electron flow to first year design students with no experience. I just use the water analogy as it at least gives them an idea of how current/charge flows in a circuit. Works well for explaining how to connect up a MOSFET as well.David.P.S It is of course CHARGE that flows and not current, but this makes no difference.

author: FreeThinker
author_rank: Frequent Contributor
timestamp: April 14, 2012, 01:03:52 pm
content: Quote from: djsb on April 14, 2012, 12:20:55 pmDepending on the make/model I'm fairly sure you can retrofit an injection system but not sure as to cost effectiveness and you most certainly would need a workshop of some sort, but a new carb will certainly be cheaper Lol. Drive safe.

author: ejeffrey
author_rank: Super Contributor
timestamp: April 14, 2012, 02:02:29 pm
content: Quote from: BoredAtWork on April 14, 2012, 12:21:42 pmWow, that is terrible. That is probably the worst thing I have ever seen in the introduction to a textbook. It is like "warning: this book is wrong, and will confuse you for the rest of your life"For any newbies out there who aren't convinced or have sympathy for the "electron flow model:":If you find conventional flow confusing or backwards, your thinking is wrong, you should try to fix it. In particular, you shouldn't think about electrons. They are unimportant and unnecessary distrations to electronics.If you do ever get into semiconductor physics you will have to consider carrier motion. At that point you will discover that both positive and negative carriers exist, and that you can't ignore either. Until you get there, you can do 99% of all electronics, including using (but not constructing) semiconductor devices without paying any attention to the existence of electrons.

author: quantumfall
author_rank: Regular Contributor
timestamp: April 14, 2012, 03:19:09 pm
content: Quote from: ejeffrey on April 14, 2012, 02:02:29 pmI think it depends how you are started out being taught, I find the idea of something flowing from the positive side wrong, an electronics course I did based on an American company "Control Data Institute" a subsidiary of the famous Control Data Computer manufacturer in the 1980's used electron flow and "Hole flow" in semiconductor teaching, which makes me feel strange thinking of imaginary holes flowing from the positive, it just seems its electrons that flow.I draw Voltage at the top of a circuit diagram and ground at the bottom, I see voltage drops between the two points but electrons flowing up.when electrons flow in a conductor one enters one end and pushes one out the other is how I see it. It does not flash down the circuit at the speed of light but the influence moves fast not the physical electron. like moving a rod or bar you move one end and the other moves almost instantly, the atoms only move as fast as the rod moves but the influence on the end of the bar is very fast.

author: djsb
author_rank: Super Contributor
timestamp: April 14, 2012, 03:41:30 pm
content: If you come from a background of trying to understand thermionic valves (tubes) then it's useful to imagine electrons being emitted from a heated cathode and being attracted to a positive anode. However current still flows in the opposite direction from anode to cathode (something still used in diode terminology). It really does not add to practical understanding otherwise (unless your a semiconductor Physicist).David.

author: quantumfall
author_rank: Regular Contributor
timestamp: April 14, 2012, 03:46:51 pm
content: Quote from: djsb on April 14, 2012, 03:41:30 pmI disagree its electrons that constitute a flow of current, they flow from negative to positive

author: Unknown
author_rank: Unknown
timestamp: April 14, 2012, 04:27:08 pm
content: You're missing the point that ejeffrey already made: current flow is an abstraction of the flow of charge carriers. The type of charge carriers doesn't matter for the abstraction. Handling abstractions is critical to engineering, otherwise we would all be applying quantum theory to simple systems consisting of a few atoms. It doesn't matter for the abstraction which direction you choose, and going against the convention for no good reason is dumb.How would you determine current flow through salt water or the pickle Rerouter suggested? Does the current flow reverse when charge is transfered from electrons to cations?

author: FreeThinker
author_rank: Frequent Contributor
timestamp: April 14, 2012, 04:30:16 pm
content: Hmmm! Just wonder what the OP thinks of this electron flow rubbish. C'mon guys give him a break. Conventional current flow from + to - is the norm and there is no good reason to contradict this even if it is wrong.

author: T4P
author_rank: Super Contributor
timestamp: April 14, 2012, 05:02:08 pm
content: Quote from: quantumfall on April 14, 2012, 10:37:45 amWRONGWRONGWRONGWRONG !http://amasci.com/amateur/transis.html

author: FreeThinker
author_rank: Frequent Contributor
timestamp: April 14, 2012, 05:22:13 pm
content: Quote from: Dave.S on April 14, 2012, 05:02:08 pmYes but does it MATTER? So long as a beginner gets the FEEL of how it works a 70% understanding is more than enough. As his/her experience grows they will come to realise this themselves and adjust accordingly. Bogging them down in unnecessary details kills enthusiasm.

author: djsb
author_rank: Super Contributor
timestamp: April 14, 2012, 05:24:37 pm
content: Quote from: Dave.S on April 14, 2012, 05:02:08 pmThanks Dave.s for the link. It's changed my way of looking at charge flow (I nearly said current flow). The explanation is useful.Thanks.David.P.S I still believe that water is still a useful everyday analogy. I will replace the word current with charge when explaining to students.

author: quantumfall
author_rank: Regular Contributor
timestamp: April 14, 2012, 06:10:28 pm
content: Quote from: Dave.S on April 14, 2012, 05:02:08 pmOne wrong will do thank you. The main point I make is that a transistor is use as a resistor with control you get the hang of circuits like that. I was taught that its a base current to collector current ratio that how you use a bipolar transistor. A current amplifier device. I think the link is correct in that the depletion region is made smaller but its the injection of electrons a current that makes it smaller not just a voltage. Perhaps its you thats got it wrong ? and the link is wrong just maybe ? but I'm not a semiconductor physicist I'm putting it as I was shown on a professional course, as a current controlled device.

author: quantumfall
author_rank: Regular Contributor
timestamp: April 14, 2012, 06:26:03 pm
content: Quote from: djsb on April 14, 2012, 05:24:37 pmWater is a great analogy you do not have a flow of bubbles, sorry I could not resist that djsb a cheap shot.A charge is intrinsic to electrons and protons maybe other exotic particles, but to me a current is a flow of Electricity, named like electron I think there is a clue their, Just because a current was described to flow from positive to negative as "Conventional" I do not see the reasoning behind that. Of course its just as valid to use electricity like that if it works as said its an abstraction electrons or lack off electrons it matters not to them.I'm not trying to be smart, I really think the electron flow is a better analogy. Enough please. I did post with the wrong name now fixed I think with an edit.

author: quantumfall
author_rank: Regular Contributor
timestamp: April 14, 2012, 06:37:39 pm
content: Sorry Aldobrandi its been dragged of topic, still its not all bad to have strange ideas slung at youAs a hobby electronics is very interesting and can be very enjoyable. As a job / profession its riddled with politics, FUD, vested interests and legal traps like all else and more.

author: Aldobrandi
author_rank: Regular Contributor
timestamp: April 16, 2012, 05:29:55 pm
content: Please do not apologize, I've been pretty silent but I'm very grateful for everybody's insight on charge flow, as it is one of the many points which confuses me (along with grounding). Part of my problem, as was pointed somewhere in this discussion, is that I have to choose what it is that I want as a hobby : in my case, it is practical electronics, in which case I'm going to have to go along with lumped abstractions and many other simplifications in order to enjoy designing stuff (and not apply Maxwell equations every time I'm designing a small circuit). Thanks again for all your answers.

author: quantumfall
author_rank: Regular Contributor
timestamp: April 16, 2012, 10:25:47 pm
content: Quote from: Aldobrandi on April 16, 2012, 05:29:55 pmOf course you need to understand electronics to enjoy it at any level, myself I appreciate the physics way of it fundamentally, and use simple abstractions as well of course, thats good enough to be allowed to work on some stuff. I like the water analogy as a basic , its not perfect it has no electrostatic field that fits easy ( Air filled bladders inside metal tanks work like capacitors possibly). You can get a lot done by using simple comparisons, a transistor works as a circuit element like a variable resistor, which it is if you ignore its capacitance, inductance and the internal physics. You will find it's all analogy even the highest maths is that IMHO

author: vk6zgo
author_rank: Super Contributor
timestamp: April 17, 2012, 01:26:27 am
content: Going back to the original part of the thread,I would suggest that you have a look at The RSGB Manual & ARRL Handbook.These are meant for Amateur Radio Operators,but have a wealth of technical information in them.As a "Ham",it looks as if I am pushing the hobby upon people,but your National Amateur Radio Society may be a good resource.I am not sure if they publish a "Handbook" of a similar type,but they could be worth checking on.Here is the website:http://www.ref-union.org/

author: vk6zgo
author_rank: Super Contributor
timestamp: April 17, 2012, 01:47:40 am
content: Quote from: ejeffrey on April 14, 2012, 02:02:29 pmSpoken like a true Engineer!"Conventional" current flow is a historic accident!The decision was made to say "Current flows from positive to negative" because it was a convenient concept.Professional Engineers have always been taught Conventional Current Flow,& that is the way they think about it.Many other people were trained using Electron Flow.In a Vacuum tube,there is no other form of charge carrier present,so if Electron flow isn't how things work,they would not function.Positive charge carriers in Semiconductors,or "holes" are really just a spot where an Electron is missing,but they act in every way like a carrier,so you can design things assuming they are.In normal conductors Electron flow is a logical way of visualising current flow.In most cases,it doesn't really matter,but if you are going to be a hobbyist,be aware that most of the more useful books you will use assume Electron Flow.

author: amspire
author_rank: Super Contributor
timestamp: April 17, 2012, 02:30:21 am
content: Quote from: vk6zgo on April 17, 2012, 01:47:40 amNot really sure the point you are trying to make.Even if you have a nice little diagram showing electrons going from negative to positive, current always flows from positive to negative. There is just no such thing as a SI unit for Electron Flow Current, and if you did make up such a thing, you are going to get very confused.Even if you are working with valves, you think in terms of electrons, but the current still flows from the anode to the cathode.In many ways, I have always though it a lucky thing when the electron was defined as a negative charge rather then a positive charge, as current is just not meant to be a measurement of the flow of electrons. It a measure is the flow of charged particles and it is best not to confuse it with the specific case of electron flow.The notion of current flowing from positive to negative is more then a convenience, current does flow from positive to negative, and to try and say anything else is simply confusing.No book on electronics will have current flowing in any other direction then from positive to negative. They will have diagrams showing the directions electrons are moving or drifting, but that is different. No equation for Ohm's Law will ever say V = -I x R.Richard.

author: jpc6204
author_rank: Contributor
timestamp: April 17, 2012, 02:40:00 am
content: Quote from: Dave.S on April 14, 2012, 05:02:08 pmI've never seen this link before - thanks for sharing. As a PhD in semiconductor physics I can confidently say this is the best (non mathematical) description of a BJT I've ever read.Jeff...

author: m12lrpv
author_rank: Regular Contributor
timestamp: April 17, 2012, 06:09:19 am
content: Hi Aldobrandi,As a new hobbyist myself I found that the greatest learning motivator is to pursue a specific project that takes your interest.Years (decades) ago as a kid I tried to play with electronics but never "got it". It just didn't gel in my head because I just couldn't see the point of it. It made no sense. I didn't understandwhyI needed to know how things work.But recently I was introduced to the arduino's and as a programmer it was a fun tool that I wanted to play with.But that fun tool finally gave me a reason to use and understand electronics.It provided me with ideas for projects that I wanted to build and the micro overcomes limitations in electronics knowledge by allowing me to let the microcontroller do the things that could otherwise be done with regular electronics but which is beyond my current electronics understanding.Having ideas for micro controller projects led me into other things and I've spent more time learning general electronics than I ever thought I would. Playing with metal detector circuits, LC meter circuits, oscillator circuits, audio switches.And then there's the IC's that are out there.I had the opportunity to purchase a stack of IC's on the cheap from Indonesia while on a work trip so I googled around and came up with a list of IC's to get. Comparators, op amps, shift registers and 4000 cmos chips. Then it was a matter of finding projects to use them in or simply to build circuits to test that they actually worked.This led me to appreciate the wonderful world of application notes ( and a few IC's that I still cannot figure out good uses for)Moving on from those simple IC's to the more complex ones like clock ic's (and soon digital pots) which need to be interfaced with led me into learning I2C and SPI communication.So that's my tale.I'm learning because I found something within the electronics world that ignites a specific interest and has me dreaming up projects. Pursuing those projects has the effect of giving the electronics purpose in my mind and made it something that I am self motivated to learn.Hopefully you can get something from all of that to apply to your situation.

author: Bored@Work
author_rank: Super Contributor
timestamp: April 17, 2012, 07:15:00 am
content: Quote from: vk6zgo on April 17, 2012, 01:47:40 amI start to repeat myself. No, it is not about Engineers or not.It is about communication.Almost 100% of those taught electronics beyond the very basic levels these days are taught conventional flow. Almost 100% of books, datasheets, literature, use conventional flow. The notation is so perversive, no one mentions any more that they use conventional flow. It doesn't matter if it is a historical accident, everyone knows it is, and still it is a model that works and is accepted.Teaching people the "real" flow in a non-trivial electronics course is depriving them of easy access to current and historic literature and complicates their life just so the teacher can vent a personal spleen.QuoteNo one claims otherwise. And still the current flow isby definitionin the opposite direction. Current in electronics is an abstraction, a model, a simplification, whatever you call it, it is derived from the physics, but doesn't claim to exactly represent the physics. And even physicists these days use conventional flow most of the time, unless they need to wade knee deep through nuclear particles and that stuff.

author: vk6zgo
author_rank: Super Contributor
timestamp: April 17, 2012, 07:45:47 am
content: Quote from: BoredAtWork on April 17, 2012, 07:15:00 amSo all these people are more stupid than First Year Technical Trainees,& can't quite understand that Electron flow is how it really works,& for historical reasons Conventional Current Flow is used in most calculations,& such things as "Right hand rules",etc.People in basic Electrical Courses saw this relationship & quite easily worked with it.It usually took a Lecturer about 3 minutes to explain it to the satisfaction of everybody in the class.Pretending that Electron Flow does not exist is more likely to cause confusion than to acknowledge it & also point out that Conventional Current Flow is in much more common use.You in fact,"vented your spleen" in a complete over reaction to the original posting re the particular link.You could have just pointed out,in a pleasant way,that Conventional Current Flow was the standard,but then again,I forgot,you don't do pleasant!

author: vk6zgo
author_rank: Super Contributor
timestamp: April 17, 2012, 08:05:47 am
content: Quote from: amspire on April 17, 2012, 02:30:21 amIt seems, that as Bored At Work says, Conventional Current Flow has become so all pervasive,that people have forgotten the existence of Electron flow.Many Technical publications over tens of years used Electron Flow as an alternative to Conventional Current flow.The OP is quite likely to come across some of these books.

author: quantumfall
author_rank: Regular Contributor
timestamp: April 17, 2012, 09:16:46 am
content: Conventional current flow it seems a fudge. The standard measure of current is the ampere an SI unit, which is one coulomb per second (an SI derived unit ) or 6.241 × 1018electronsper second. what more do you need as proof than that. "Current" is not an SI Unit. If you say you use Amperes you are talking about electrons no question about it.jpc6204 "As a PhD in semiconductor physics I can confidently say this is the best (non mathematical) description of a BJT I've ever read."I would like to ask , Is it a voltage controlled device , will it work, switch on without current flow (like a FET gate, lets forget the initial charge on the gate here thats needed.) in its base terminal ?Is it a current controlled device (As I was taught) a voltage controlled device or are both of these the wrong to look at it ?

author: saturation
author_rank: Super Contributor
timestamp: April 17, 2012, 11:38:40 am
content: Learning electronics requires a properly laid out curriculum, just like learning to read you need to know the letters before the words, before sentences.R,L,C, RLC networks, diodes, transistors, FETS for example, in that order. Most textbooks are laid out that way, but few, have the detail to make full working circuits. I think other posters have mentioned the sequence.If you jump around, you'll have the equivalent of a phrase book. If you mix and match phrase books and practical theory, you'll have the Rosetta Stone. It won't make you fluent, but you can get by. But to have real control over it, you have to understand all the working parameters of each component from a practical point of view, i.e. at least the lumped element model.

author: KD0CAC John
author_rank: Frequent Contributor
timestamp: April 17, 2012, 03:34:16 pm
content: How to learn electronics , for beginners .Start with opposing the masses .I've been doing it for 58 yrs. , thanks , now I can say I told them soI'm waiting for that link so sink in , bookmarked , thanks again .JohnKD0CAC73

author: pickle9000
author_rank: Super Contributor
timestamp: April 17, 2012, 04:56:59 pm
content: Wow nice topic, I started with a 100 in 1 kit from Radio Shack (over 40 years ago). You can still buy versions of the kit. From there I went to the Forrest M Mimms books.Do you get enough from that kind of material? No, but it's hands on and is a great primer. I still pull out the kit and use it on the bench with the nieces and nephews.The reality is that electronics is a very large field, you can't know it all. You need to reeducate regularly for most projects. I get to learn new things all the time, it's the best. I do get paid for my work but I love it as much now as when I was 10. It does take time to be proficient but remember you need to blow a few things up to get better. Nothing like the smell of burning semiconductors.Put a basic bench to together, meter, scope, signal gen and so on. It's makes things much easier. If you get it wrong, no problem, just start over.Good luck to you....mike

author: jpc6204
author_rank: Contributor
timestamp: April 18, 2012, 03:57:06 am
content: jpc6204 "As a PhD in semiconductor physics I can confidently say this is the best (non mathematical) description of a BJT I've ever read."I would like to ask , Is it a voltage controlled device , will it work, switch on without current flow (like a FET gate, lets forget the initial charge on the gate here thats needed.) in its base terminal ?Is it a current controlled device (As I was taught) a voltage controlled device or are both of these the wrong to look at it ?At a device physics level it is a voltage-controlled device. BJTs deal with PN junctions and FETs deal with metal oxide semiconductor (MOS) interfaces - both have charged carriers (electrons and holes) and charge is moved by potential gradients (voltage). For MOS structures you have an insulator in the way so no current flows (excluding oxide tunneling current) when a potential is applied to the gate. In a PN junction (think base-emitter junction in a BJT) there is no insulator, just a depletion layer. The depletion layer reacts to an applied potential (voltage). Once a potential (voltage) overcomes the junction, current will flow. So yes, you will have current flowing at the base when a BJT is on, however you must have an applied voltage for any of this to occur.Consider a solar cell. Photons from the sun are directly converted to free carriers (electrons and holes) in the depletion region of a PN junction. These free carriers move within the depletion region (ie. current). This generation and movement of free charge carriers does not affect the depletion layer, nor does it "turn on" the solar cell. Solar cells are not on-off devices. If the generation of free charge carriers and its subsequent movement (ie. current) turned a solar cell off or on we would have a problem.Hope this helps.Jeff...

author: Aldobrandi
author_rank: Regular Contributor
timestamp: April 18, 2012, 05:01:19 pm
content: Thanks a lot jpc6204 for this post, it clarified a lot of things for me (I wasn't particularly fond of the rather agressive style of the author of that article (albeit an informative and eye opening one!) onhttp://amasci.com/amateur/transis.html). For some reason, I can't feel like I have a good understanding of how to use a device in a practical fashion if I don't have at least a basic theoretical understanding of it on paper: I always need at some point to come back to the physics. But I am still incredibly new to all this, so maybe in a decade or so of working on circuits, I will have a much more symbiotic relationship with theoryThanks again for the incredibly enlightening discussion. And please keep the stories of how you came to electronics (either as a hobby or as a profession) coming, I find them all very very inspiring.

author: jpc6204
author_rank: Contributor
timestamp: April 19, 2012, 04:42:43 am
content: Aldobrandi - I find myself in similar shoes. I have a very good theoretical understanding of what is going on in each chip, I just lack practical experience putting everything together in a circuit. I just graduated a year ago and realized that I need to learn more. I bought some electronics and Arduino books to help round me out. I still have a long way to go. Don't worry about what you know or don't know, just make sure it's fun. The beauty of this forum is there is a a great group of people who will have answers for questions that we have (no matter how silly they are). 15 years ago learning electronics would have been very different.Best of luck with all your electronic adventures!Jeff...

author: quantumfall
author_rank: Regular Contributor
timestamp: April 19, 2012, 06:20:40 am
content: Quote from: jpc6204 on April 18, 2012, 03:57:06 amFor MOS structures you have an insulator in the way so no current flows (excluding oxide tunneling current) when a potential is applied to the gate. In a PN junction (think base-emitter junction in a BJT) there is no insulator, just a depletion layer. The depletion layer reacts to an applied potential (voltage). Once a potential (voltage) overcomes the junction, current will flow. So yes, you will have current flowing at the base when a BJT is on, however you must have an applied voltage for any of this to occur.Hope this helps.Jeff...Obviously for a current to flow their has to be a voltage I can see that, but once the junction voltage is overcome the BJT is then controlled by the current into the base.Their has to be a voltage I can see that about 0.8V to make the base conduct, but after that the control mechanism is a current correct ? as I was taught. It is misleading to call it a voltage controlled device in the WRONG WRONG WRONG WRONG reply I so kindly received. Collector current is in a ratio to base currentnotvoltage across the base, correct ? Even a FET will have a small current to charge the gate at first, its capacitance I suppose, but minute so its not counted normally.

author: MrPlacid
author_rank: Frequent Contributor
timestamp: April 19, 2012, 08:00:05 am
content: Op, this is longwinded too.I remember back then when I first got into electronics and scrounged youtube for videos. That was where I saw dave who just got started blogging.As I study electronics, I always keep in mind of my journey through programming, and how I suddenly understood it one day. I was hoping a similar thing would happen. I saw alot of parallels between the programming and electronic worlds. However, I must admit that learning electronics took much longer. The reasons are in the next few paragraphs.One is that visualization of the components such as inductor, capacitor, conductor, etc.. The visualization also must make sense with their formulas. If it breaks the formulas, it's back to square one of finding a better visualization for that component or accept magic. When the books tell us to visualize capacitor as a water tower, the question is why? They often don't go into the details other than tell us to do so.Two is the electronic lingo. Back then I was lost over mere things like coulomb, volt, amp, cathode and anode (this is opposite to the chemistry's ones), current direction, input impedance, output impedance, high, low, RMS, etc... . Books and engineering gurus used them like normal talk. I remember seeing the book use something like "high input impedance" then I check back if they even explain that. This put us hobbyists in a "I think it means this, but I am not 100% absolutely sure" state.Third is to actively learn. This is where it gets expensive in both time and money. When you see them talk about a circuit, build a simplify version of it and test it. Reading about it is the same as watching the cooking channel all day long and walking away still not knowing how to cook.Anyways, it's not the best way to study electronics, but below (pic) is how I study electronics as a hobbyist. As I read or watch the gurus' videos, I come up with study materials. Then I enter my materials into my personal study site. (site address is undisclosed, but there are many good free study sites) This has help me greatly. Us hobbyists don't do electronics everyday nor even weekly, so something to refresh the memory is good.

author: Aldobrandi
author_rank: Regular Contributor
timestamp: April 19, 2012, 09:09:35 am
content: Quote from: jpc6204 on April 19, 2012, 04:42:43 amI think this must but some sort of PhD effect. Being a student in a PhD. program myself (in a vastly unrelated field...) I always feel tied to the theoretical aspect of things and often feel like I don't speak the same language as people in my field who focus on more practical thingsSometimes I wonder if a PhD is really preparing me well for the "real world" job market haha! But I guess, as the Simpsons pointed out a while ago, PhD students are not bad people, they just made awful life decisions!

author: Unknown
author_rank: Unknown
timestamp: April 19, 2012, 05:34:00 pm
content: Quote from: quantumfall on April 19, 2012, 06:20:40 amThis is a simple approximation that works OK for using it as a simple switch, but you get in trouble if you take this model too far. What is the ratio between ICand IBcalled? Ever looked of a graph of this parameter in adatasheetversus collector current, frequency or temperature? Ever observed how well it's specified in a datasheet? The spec. for the 2N3904 is between 100 and 300 for IC=100 mA at T=25°C. That's a very lousy accuracy for almost any circuit. Note the absence of IBfrom transistor models like the Ebers-Moll model. You can't understand circuits like current mirrors if you consider transistors current-controlled devices.

author: robrenz
author_rank: Super Contributor
timestamp: April 19, 2012, 06:09:36 pm
content: I will admit his stylehttp://amasci.com/amateur/transis.htmlis kind of in your face but It certainly rang true with the way my brain works. Having immensely more experience in Hydraulics than electronics myself, his charge and fluid analogies really hit home with me. I have seen and used many in the past but his presentation took my conceptual understanding to a new level (2 instead of 1 on a scale of 100). I am not specifically talking about just his transistor description but lots of others on the site that are electronic related. The whole charge thing related to conductors, semiconductors, and insulators is great. I plan to read some more of his stuff because it just hits home with the way I am wired.

author: quantumfall
author_rank: Regular Contributor
timestamp: April 19, 2012, 07:54:22 pm
content: Quote from: alm on April 19, 2012, 05:34:00 pmThanks for your reply, I looked at the data sheet and OK we are talking about the relationship of base to collector current beta a gain of between 100 and 300 typically I see it varies a lot. I looked at the Ebers-Moll model and to be frank its over my head mathematically, if it was explained slow and carefully I might get it, but for now I do not understand it.I was thinking and looking at the common emitter circuit and when you bias the circuit half way along a load line in the active use region " Collector current is proportional to base current" (Not a simple transistor but a circuit I know).I admit I'm a rusty amateur hobbyist who did a few basic electronics courses 30 years ago, when we studied basic circuits, Load line diagrams etc which I have not used since.It always was in my head that a BJT was a current operated device , I'm going to have to sort this out I'm not doubting your knowledge, I just can't see the voltage control bit at the moment, I believe you are correct I have no reason to doubt you. I have always taken that to be a trait of a FET alone.

author: jpc6204
author_rank: Contributor
timestamp: April 20, 2012, 04:05:21 pm
content: Quote from: Aldobrandi on April 19, 2012, 09:09:35 amHahaa. There are certainly days I think that.