Learning  - Page 1
Forum section: electronics / beginners

author: Deathwish
author_rank: Unknown
timestamp: June 12, 2015, 04:24:17 pm
content: Ok this may be just my opinion and worthless but I like what I think, my brain is defective and does strange things like see humor in a post on the forum so I post a jokey reply to it. Often it is unwanted or people think jeesus what has it got to do with the subject post, much like what I have just said, I know what I meant and why I said it though.I feel that many beginners are swamped by the math in electronics, likewise those who have already attained the level of expert then look upon those who have not grasped the basics as needing to find another field of work or hobby, as they will clearly never "get it". I think myself that if someone is not getting it then it is more a case of the teacher being a bad one or expecting too much of the pupil and having or giving no consideration or empathy with their pupils confusion.Many of you will become disenchanted with things if your first few designs do not work, or if you simply sit reading a book / watching a video and feel more confused than ever before. Don't give up, walk away for a bit and then find another teacher or book or video that WILL explain it to you so you can understand it. Capacitors are my nemesis, and for years I had problems working out on a schematic which transistor was a NPN or PNP untll one day someone said to me that the arrow in a design pointed at the N material, that made it clear to me which was which in a schematic. Basically if the arrow points at the base it is a PNP. Little things like that make it easier to understand.If you have problems with all the math like I do and think you can never grasp it all, then just go blow a few things up, I know a couple of people who, if they had started in college would never be where they are now, but they went and did the hands on approach first, learnt a few basic things and then when they worked out how x worked went and did the theory which was then much clearer to them than had they been sat in a room with some person throwing theory at them till their brain fried and they learnt nothing and gave up.Never give up, never say I can not learn this, or that it is too complicated, not everyone is an Einstein or has the same level of intellectual capability as those above them until they get there. Those above you sometimes forget they were you or in your shoes at one time, they need to be patient and try another approach if you are not getting what they are saying. No one understands a baby going goo goo when asking you something but they grow up to be able to communicate in your language eventually ( I love that analogy ).

author: Deathwish
author_rank: Unknown
timestamp: June 12, 2015, 04:40:20 pm
content: One of the greatest feelings I ever had was when I was stood in Maplins in Reading Berkshire, I saw a young lad of about 12 looking at a catalogue and the rows of bits on the shelves, he looked confused and worried, I asked him if he was alright, and he said that he didn't know what to buy as he couldn't find a capacitor he wanted for his project because they did not have it on the shelf, now me, I hate the things, but I knew that he needed to go higher in value to the next one in voltage to get what he wanted, and so I told him, he smiled a smile that meant more to me than much in the world and finally looked happy,got what he wanted and went home, I often wonder how much stress or worry that lad went through trying to work it out or if he was going to fail, how much time he spent looking for an answer or how much it made his heart sink he could not get the bit he needed, it was so easy for me to help him rather than ignore him or laugh because he had no idea. WE teach the next generation whatever our level of experience, if we dont then we fail ourselves. It is easier to make someone smile and succeed than watch them fail and hurt.

author: Hex173t
author_rank: Contributor
timestamp: June 12, 2015, 04:53:40 pm
content: ^^Like^^Very good of you to help that kid out.

author: lapm
author_rank: Frequent Contributor
timestamp: June 12, 2015, 06:09:16 pm
content: reminds me time when i worked in component store.. Lots of cases like that kid... Lots of comments, you know you could do ....

author: Chuki
author_rank: Newbie
timestamp: January 01, 2019, 09:27:15 pm
content: Sometimes things become clear with time when you force to study something in another discipline and then found a parallel that helps you to understand that old construction.I remember that is University at electricity courses all we were doing calculating equivalent circuits more and more complex day after day and starting from some point that lost any sense and understanding. So I got virtual "pass" mark and forget about that. What was my surprise when reading "Art of Electronics" I found advice to consider 3 main parallel resistors configurations r-2r-10xR. I felt like I was treated by teachers... cause nobody ever tried to teach us that. We lived in the world or 43 Ohm connected to 121 and 477 Ohms some weird 13.5 times... and the idea was only a final digit. If it is off - you are out.I asked a guy on work what is the resistance of 5 and 10 Ohm in parallel. He told me 5 and stared at me like "are you kidding me?!". When I explained why I was surprised he told me that always applied that rule why repairing his musician stuff and it worked.Just was reading an article about transformer K factor (https://canadatransformers.com/k-factor/) and found a nice image of main sine and its harmonics.Decided to "find that image in google" option to see if bigger resolution exists to save it for explanatory cases.But was surprised how Google thought about this sine

author: rstofer
author_rank: Super Contributor
timestamp: January 01, 2019, 10:57:49 pm
content: PNP points IN - it rhymes, sort of...There is a lot of electronics that can be done with basic concepts and all of those concepts can be picked up along the way. There is another thread playing out that goes into this in much more depth but the results will be the same: You absolutely need Ohm's Law and you will probably need Kirchhoff's Laws and that's about it.Copy and Paste is another way to get moving in electronics. Go find a project that matches what you want to do (or comes close) and copy it. Make some guesses as to how it works and try to verify it with measurements. A simple DMM is probably the only tool necessary.It just isn't that hard to have great experiences with electronics. Start building stuff!

author: Johncanfield
author_rank: Regular Contributor
timestamp: January 01, 2019, 11:09:54 pm
content: My electronics instructor in high school told us PNP is peeing in the cup. The same guy taught taught us Bad Bovs Ravish Our Young Girls But Veronica Give Willingly for the resistor color code. He was a retired navy electronics tech. What a character.

author: rstofer
author_rank: Super Contributor
timestamp: January 02, 2019, 12:16:54 am
content: Quote from: Chuki on January 01, 2019, 09:27:15 pmAnd that's the problem with EE school. Hours and hours of calculations and no intuition taught. Today we can use solvers like MATLAB and Octave but probably not on the tests and that's a shame. You still have to write out the proper equations but you don't need to grind through the arithmetic. They should go with a "run what you brung" approach to solving the arithmetic. We certainly don't do calculations by hand in industry, there's too much at stake.I would seriously hate to try to analyze Figure 1.11 in Art of Electronics. There's an awful lot of nodes or meshes. It would be fairly easy to do with MATLAB.What I want to see: A shared printer in the classroom so everybody can shovel their MATLAB exam results to the instructor and all of the students using laptops or tablets (with keyboards).Or at least allow graphing calculators with the Computer Algebra System (CAS) enabled. The clever student will have figured out how to solve matrices.It's the concepts that are important.

author: vk6zgo
author_rank: Super Contributor
timestamp: January 02, 2019, 12:33:05 am
content: Quote from: Chuki on January 01, 2019, 09:27:15 pmHe told you what??5 ohms in parallel with 10 ohms are exactly the same as three 10 ohm resistors in parallel, & that isn't 5 ohms!QuoteWere you surprised that he was talking nonsense, or did you think that was the correct answer, & were surprised that you weren't the only person with this misconception?Quote

author: spec
author_rank: Frequent Contributor
timestamp: January 02, 2019, 10:27:01 am
content: It is very important, in any field, to get to the core principles and leave the esoteric stuff for formal courses or for specific applications that may crop up when you need to delve in a bit deeper. That way you will not be drowned in a sea of detail, which 'experts' can try to impress you with. Some of the older books on electronics were particularly bad at this and the smothering effects of verbosity. Once in a while, I have a look at the textbooks that I used in the early days, and they make me cringe.The other thing is that the field of electronics is so vast that you cannot possibly know it all, but it is important to learn how to learn. That way, when an area crops up that you know nothing about, you have the technique to acquire the necessary knowledge- the internet itself, and the publications on the internet are an absolute godsend in these situations (but you need to able to filter nonsense too). In addition to the internet there are plenty of true experts around who are normally only too pleased to help out (there are some on EEV). This also applies to math at all levels.If you work in electronics, very often you will not have any idea what a new project is all about, so you have to acquire the knowledge. One experience I had was a new job, Helicopter Radiometer. I knew what a helicopter was but didn't have a clue what a radiometer was.To illustrate how not to teach electronics, my introduction to transistors was a drawing of a grounded base configuration, complete with junctions, re, rb, rc, cb, cbe, etc, etc. This was surrounded by a blackboard full of h parameters. And, to cap it all, the instructors kicked off with a long dissertation on leakage currents and the fatal consequences of thermal run-away. Non of this made any sense to the class and was as turgid as ditch water.But what we should have been taught, initially, is that an NPN transistor has three leads: collector base and emitter and shown a grounded emitter configuration, which is the most common and easy to understand. The initial model then would be that you shove some current into the base/emitter circuit and HFE (current gain) times that current flows from the collector to the emitter. It just so happens that under these condition the emitter base voltage is 600mV. And that is it. Later we found out that the lecturer was actually a mathematician who had recently been diverted to introducing transistors. But don't miss read this- most of our lecturers were fist rate, both at teaching and in their electronics knowledge.If you get these fundamental models of electronic components fixed in your mind you can go a very long long way in electronics and the whole thing becomes much more interesting and productive. As rstofer says in reply #7, all you need then is Ohms law (simply simple), Kirchhoff's two laws (dead simple), basic arithmetic (simple) and elementary algebra (not terribly difficult with practice) and you have a firm foundation for a life in electronics, if you want to be, a Design Engineer, Development Engineer, Microwave Engineer, EMC Engineer, Lab Technician, Test Engineer, Field Service Engineer, Hobbyist ... Naturally, you would need formal qualification as well for most of these positions.In parallel with the fundamental learning phase, it is a good idea to specialize in one area that interests you. For many it is power supplies, audio power amplifiers, ham radio, microprocessors, you name it. You would be amazed how much general and detailed electronics knowledge you pick up by this- just talk to a radio ham, about matching, standing waves, Q etc.The big danger with all this is boredom, but nobody says you have to study all the time. You can still experiment, blow things up and do what you want, but in the background follow a structured learning progression. With this approach I would say that a person with a good logical brain could have a working understanding of the foundations of practical electronics within a year without too much effort, six months if you are reasonably dedicated.I have said this many times before: I wish to hell that the internet, all the fantastic cheap electronic components, excellent books and videos, were around in my initial years. The other revolution is the low cost, but excellent, test equipment available to you. You can actually get a half-decent digital multimeter in the UK for around £12UK. A DMM wasn't even invented in my day, and a decent analog multimeter cost the earth. And as for an oscilloscope- forget it.In addition to all that there are computers and applications: ECAD, Simulators, Illustrators, Word Processors, Spread Sheets, Databases, the list goes on and on.So here endeth the sermon, but just remember that the one most important and overriding thing that is required is you- you must have an ice-cold logical mind, be accurate, terse, consistent, inquisitive and, above all, make mistakes and learn from them.