How do I learn about electronic design??

[bearman68]

Hi all.
I'm based in South East Wales. I'm interested in learning a bit more about circuit board design. I have a family and a full time job, so a traditional BSc is well out of the question, and in any case, this is probably a bit too deep into it for what I'm looking for.
I'm not (really) after a qualification though if I end up with one, that's fine to, I just some basic knowledge and understanding.

Any ideas??

[anonymous-user]

There are worse places to start than here:

http://www.eevblog.com/


Also, this is fairly comprehensive:

The_art_of_electronics_book


Depending what sort of electronics you want to design, then a quick route to a decent level of understanding is to buy lots of electronic things, take them apart, and work out why they are like they are!

[bearman68]

Thanks for that.

The reason I think I need to know things, is that I've taken them apart, and haven't got a clue what I'm looking at....

[anonymous-user]

Well, the good news is that electronics is very simple at a basic level.

Simply being able to understand V = IR opens up pretty much all electronics design, and basic theories for things like impedance or inductance will cover pretty much everything else.


Also worth getting a cheap "breadboard" of ebay, and having a play with some basic circuits (lots of examples on you tube etc these days)

[Nigel Worc's]

bearman68 said:

Thanks for that.

The reason I think I need to know things, is that I've taken them apart, and haven't got a clue what I'm looking at....

I like you quest for knowledge, good for you.

Why do people take things apart then wonder how they work ?

I think you'd be better off looking at basic electronic stuff before you venture onto design.

I started in the 1970's (old git that I am ), and I started with a GCE O level at school.

[Who me ?]

Try local college for evening classes in basic electronics. You first need to understand the basics of units ( in discrete circuits ,that's resistance in OHMs and the multiples, capacitance in fractions of Farads , and inductance in fractions of henries) and ( as said ) Ohms Law . Then there's symbols and how semiconductors work. Then there's what you want to design - is it discrete component circuits / IC circuits or digital ?
Forget about getting boards and breaking them down. Look at the type of circuit you are interested in ,and find how it works. For that you will need to know Ohms law and the maths of a circuit. Have a look in local libraries for books on electronic circuits and how they work . As said- get a breadboard and make a circuit. Then get cheap digital meter ( these days some at low £ are as good at this stage as dearer ones), do some calculations, and confirm the results by measuring. Good luck - only problem is more you learn ,the more you find you don't know. One other source of education might be a radio amateurs club, where they are always only too keen to impart information .

[bearman68]

To be fair, I'm not to bad at the maths side of things, and use V=IR etc in day to day work. I'm a mechanical engineering grad from the 80's, and always worked in mech eng. It dawned on me that I knew nothing (John Snow) when someone suggested using a different shunt resistor to modify the current trip on a semi conductor. It was one of those - 'bugger, I don't know anything' moments that seem to be very common in my word.

Thanks for the kindly comments - I've just ordered 'electronics for dummies' so I'm going to have a plough through that before some of the more complex books suggested.

I love PH for this - doesn't matter what you ask, someone will have constructive advice (normally followed by 2 pages of rubbish and abuse )

Cheers all

[carinaman]

It sounds like you'd just need a little explanation on that scenario. You know Ohm's Law so altering the Resistor will alter the current flowing.

Altering a resistor will alter the voltage dropped across it (potential) so that will alter the voltage on the terminal on the semiconductor and that may cause it to start conducting or not.

edX do free online courses but the last time I looked they started around the same times as US academic terms or semesters. They had a first year degree Electronics module.

As the example you mentioned was about conducting thresholds for semiconductors I was thinking transistors. There's stuff online about transistors and diodes:

https://www.youtube.com/results?search_query=how+s...

[Nigel Worc's]

bearman68 said:

To be fair, I'm not to bad at the maths side of things, and use V=IR etc in day to day work. I'm a mechanical engineering grad from the 80's, and always worked in mech eng. It dawned on me that I knew nothing (John Snow) when someone suggested using a different shunt resistor to modify the current trip on a semi conductor. It was one of those - 'bugger, I don't know anything' moments that seem to be very common in my word.

Thanks for the kindly comments - I've just ordered 'electronics for dummies' so I'm going to have a plough through that before some of the more complex books suggested.

I love PH for this - doesn't matter what you ask, someone will have constructive advice (normally followed by 2 pages of rubbish and abuse )

Cheers all

Once you've had your fill of reading, and think you understand enough to make you happy, just download an "app" onto your smart phone, like the rest of us :-).

[Zad]

The on-line courses are highly variable. I did the first run through of MIT's 6.002x as a refresher, and my thought was "Jeez, students pay $30,000 a year for this quality?". 90% of the learning is from reading the lecturer's own book. Maybe it is just the American approach to things, but I think if I hadn't have known some of the stuff already, then I'd have been stuffed.

See for yourself anyway, this is the complete series of lectures on YouTube:

http://ocw.mit.edu/courses/electrical-engineering-...

https://www.youtube.com/results?search_query=6.002...

Like any field of engineering, electronics is vast. Obviously, to become a competent electronics design engineer takes just as long as it took you in mech eng. You can learn a certain amount which will get you a long way though, and having a good background in maths will help a lot.

Most courses start with circuit theory / network analysis, breaking down DC circuits into voltage/current sources and resistances, and connecting them before analysing them in terms of a mesh or nodes. Wikipedia is especially confusing on this matter, the article tries to cram way too much into a small space. Note that for 99.9% of electronics work, you don't need to go anywhere near Maxwell's laws and physics, but it is worth sticking with circuit theory as the foundation for the whole subject. To eager new students and people trying to sell a sexy subject, it is dull and rather abstract. But to an engineer it is the basis of a good solid set of mental tools.

You might want to look into local amateur radio classes, they provide a good structured approach but with obvious real world applications along the way. They also provide contact with real people that you can ask questions.

If you sign up to the EEVBlog forum, you will get the impression that you need to immediately rush out and buy a Fluke multimeter, fancy oscilloscope and huge tool kit. I suspect 90% of the people on there who do that simply end up with a decorative if rather expensive shelf. Cheap component kits and a budget LCD multimeter are all you need in the first instance.

What sort of PCB design do you want to do? Each CAD software has its own way of doing things, and you can get software like KiCAD or Eagle (limited free capability) for nothing. If you want to play around with circuit simulators, download a copy of LTSpice (again, free) and use YouTube tutorial videos.

[ATG]

I'd learn by playing. Get a breadboard, a cheap and cheerful analogue multimeter, a multi pack of resistors and electrolytic capacitors, some LEDs, a few bipolar transistors 2N2222, a few diodes, a couple of 741 op amps and a 555 timer chip. That'll probably set you back about £30. And a couple of those little 9V batteries that no one uses anyone. Butcher some old earphones to use as a speaker and microphone. You now have a junior electronics kit that will let you explore a huge, huge amount. When I was a kid I got hold of a copy of a book by some lunatic called some like Forrest Mims III. It introduces all the basics using cartoon diagrams that evolve into circuit diagrams, and it covers the basic relationships like Ohm's law, charge versus voltage for a capacitor, characteristic frequency of RC circuits. It contains one howler of an error, but I reckon a book like that plus the kit I've outlined would be enough to give someone with a bit of interest a basic grounding in electronics in a few days.

[Simpo Two]

ATG said:

a few diodes, a couple of 741 op amps and a 555 timer chip.

It's good to see that some thngs haven't changed since I took Practical Electronics in the '70s!

Most of the projects I made didn't work, but I just liked making things and had no idea about what was going on inside. Much prefer levers and wheels to electrons!

Did anyone here make the Sinclair Cambridge calculator? I still have my home-made version somewhere.

[Zad]

Stuff not working is the best thing that can happen! That way you have to really understand what it is doing in order to be able to fix it!

741s were superseded in commercial applications long ago by lower current higher gain MOSFET based op-amps, but they are still really good building blocks, and the 555 is still going strong in new designs.

[anonymous-user]

These days, you can also get a good understanding of circuits using a suitable circuit simulation software program.

For example, you can download LTspice for free, and just start playing with it, there are plenty of examples and tutorials on line (it's a bit clunky to get up and running but the basics are simple enough).

[Simpo Two]

Zad said:

Stuff not working is the best thing that can happen! That way you have to really understand what it is doing in order to be able to fix it!

Sadly I had no way to understand or diagnose. I knew roughly what each component did but not why.

The only thing I made that worked properly first time was a battery back-up for my (dynamo-powered) bicycle lights (which otherwise faded to black as you stopped). It had a zener diode in it, which IIRC only passes current once it gets above a certain voltage.

The calculator worked after someone fixed it for me. The amplifier worked after someone fixed it for me. The Christmas tree light random flasher managed one pattern of flashing; that had a triac that combined two oscillators I think. The rpm counter for model aeroplanes never worked because I couldn't find the opto-electronic jobbie (ZTX something). I practiced miniaturisation by building a ZN414-based FM radio into a tiny balsawood box, but I don't think it ever made a noise. But it was fun to build, as they all were!

Edited by Simpo Two on Wednesday 17th June 22:42

[bucksmanuk]

Mechanical engineer myself
I like to build stuff like this
https://www.kitronik.co.uk/project-kits.html
http://store.qkits.com/

[Simpo Two]

Simpo Two said:

I practiced miniaturisation by building a ZN414-based FM radio into a tiny balsawood box, but I don't think it ever made a noise.

Much like this! http://www.mds975.co.uk/Content/trfradios.html