Seeing tiny electronics

[MaxHeadRoom]

BTW - What are the good forums for DIY electronics projects?

Steve

They are plentifull out there, e.g. http://www.allaboutcircuits.com/
If you want to experiment you could start with the 555, there are 100's of circuits out there for this popular IC.
When you are ready to get into micro processors, there is the PicMicro site that not only has free development s/w but the programmers and debuggers are all over for around $30.00.
These are amazingly powerful and are only a couple of $$.
I recommend starting with the 16F628A and there is a tuition site by Nigel Goodwin. http://www.winpicprog.co.uk/pic_tutorial.htm
Max.

[Weston Bye]

BTW - What are the good forums for DIY electronics projects?

Steve

(Shameless Self Promotion Warning)

Not a forum, but I present various articles and projects combining electronics and machining in every issue of Digital Machinist.

I explain the how and why of the electronic circuits.

[Mcgyver]

I've got my Electronics for Dummies book, a bunch of circuit boards I pulled out of an old rear projection TV and I'm diving in for my electronics education.

Is this meant tongue in cheek? To be blunt, I can't imagine a more frustrating way to come at it (u said reverse engineering earlier iirc). Complex boards, likely multilayer, tiny SMT components, embedded microprocessors with software you'll never get to see. Ugh. I've found/finding electronics a challenge to learn on my own, that is without an instructor to interact with. Sitting there staring at a simple schematic trying to understand what is going on is tough enough for the beginner; debugging a simple circuit is a challenge. No schematic= a nightmare.

First you understand what all the stuff is/does as its hooked up to one another (that in itself is a challenge, where i am after years), then you try to debug a circuit WITH A SCHEMATIC IN HAND...non of which would come close to reverse engineering a (potentially) multi layer, SMT, (likely) microcontroller circuit. Short of doing it as a job, not sure many would be able to or want to.

My advice is get a bread board & components. Get a multimeter and a scope. Read your book. Find a SIMPLE circuit you want to build; try to understand the schematic, build it, see whats going on with the scope and meter and gradually you start to see whats going on.

[Pete F]

I'm in the middle of this book and find it to be an excellent source of information, if you are looking to learn.

-Pete

[Seastar]

Tiny SMD components

I just use a headband magnifier and if that isn't strong enough I use a pocket magnifier.
However to answer the OP's question I forwarded it to my Chief Engineer at
www.ritron.com
Here is his answer:
quote
Bill,
I didn't know, so I had our Manufacturing Engineer weigh in. His response:

"An old stereoscope would work ... best bet would be anything over 7x and more comfortably 10-15x would be ideal. Our scopes here go from 7x to 45x, with anything above 25x being extreme. Keep in mind that resistors are only marked down to 0603 and i have yet to see a chip capacitor 0805 or less marked and very few are marked even as large as 1210. Most tantalums are marked however."

Sam
unquote

Hope this helps--
Bill

[Evan]

Precise values of electrolytic capacitors are rarely important in digital electronics. The same goes for bypass capacitors. One can judge fairly closely just on the size and where it is in the circuit. I also have a meter with a capacitance measuring function which I sometimes use. The part must be out of circuit though. It isn't difficult to assemble a collection of SMD caps which may then be measured to produce a reference collection.

SMD sub-microfarad caps in analog circuits are a different story, especially in picofarad values. Then values do matter and are much harder to measure accurately. However, a simple 555 test circuit can be built to make a pretty good guess at the capacitance of small value caps based on oscillation frequency. The 555 is well suited to that as it is not affected by operating voltage variation and can be battery powered.

[Seastar]

SMD parts

Evan is correct.

At Ritron we design and build two way radios, voice and data.
In those types of circuits the value of capacitors is critical as is the composition.
We have very sophisticated test equipment to measure all sort of SMD parameters.
It would be difficult to reverse engineer one of our current RF circuit boards.
It has been done.
Back when the components were thru-hole it was much easier and we were copied more often.
Bill

[SteveF]

Hmm, so it seems like my plan to learn about electronics from studying an existing circuit board isn't going to work out.

Oh well, at least I've learned some things I didn't know two days ago.

"Circuitbuilding DIY for Dummies" here I come!

Steve

[Mcgyver]

There is a great depth of electronics knowledge here that has helped me many times....so you're in a good place. imo its a challenging enough subject without starting with overly complex stuff. keep it simple.

Another suggestion is some hobbyist electronics mags. While a text gives the rules and functions, the magazine articles come at it along the lines of "so whats happening in this circuit is...."

[J Tiers]

The very best way to start is by getting some more "hobbyist" text that will give you a good intuitive "feel" for what the various kinds of parts do, and why the different varieties of each type may be chosen in a particular case.

After that, looking at schematics can give you a 'real world" jump-start on seeing how (and maybe why) they go together.

A good stock of 'through-hole" parts of various kinds, along with one of those "breadboarding sockets", if you can find one, is very good for practical circuit design and construction.

I do not think you can ever have a good understanding until you have designed a number of things and have seen why/how/if they work, or do not work.

Without a good intuitive understanding of the parts, you will struggle. Start there.

There are some practical 'electrionics for people who want to get a working circuit without being an engineer" type books around.... I suspect several folks can point you at them.

[Paul Alciatore]

I have worked with constantly shrinking electronic components for over 50 years. I started with tubes, the big ones, not the 7 and 9 pin miniatures and have progressed to the present day IC with hundreds of thousands of components on a single chip which can be smaller than my finger nail.

I have had a 10X Hastings Triplet magnifier in my right pants pocket every day for the past 45 years except for short lapses when a replacement was on order. It has served me very well for over 95% of all viewing I needed to do.

http://www.edmundoptics.com/products...productid=1730

The Hastings Triplet is a three element, symmetric (you can use it in either direction with equal results) magnifying lens with excellent correction of most of the optical defects that a simple lens will exhibit. So it provides a high quality image of what you are viewing. And the 10X version provides a good compromise between magnification and field of view/distance to the object. There really is no compromise in the quality of these magnifiers for any practical usage. I have found many "microscopic" defects in circuit boards with this lens.

Somewhere about 30 years ago I added a 20X version of the same Hastings Triplet to my left pocket. This closed the 5% gap in my viewing needs down to about 1%. For anything more critical than that, I have two microscopes: one 10-30X zoom and one conventional microscope that goes to 500X with the present set of lenses that I have. I have never actually needed that 500X scope for any electronic needs but I have used the zoom scope for several things that the pocket lenses just would not do. One such task was viewing heads on video recorders while they were installed. The 20X would have been just fine except I could not get my head in position inside the recorders to use it so the longer zoom scope came in very handy.

I have never felt that anything more powerful or more expensive was really needed. Stereo microscopes are nice but I have never felt that the price was even remotely justified for this kind of work.

[Ernie]

I’ve gotten a lot of info from these sites. The first 4 have a lot of circuits you can build. The fifth one has a lot of info on stepper motors. The last one gives you access to 6 volumes of electronics books which you can download and save as pdf files. Keep in mind they are works in progress and some are not quite complete yet. Check back every few months or so. They also have links to other web sites, enough to keep you busy for a very long time.

http://www.electronics-tutorials.com/index.htm

http://www.bowdenshobbycircuits.info/

http://www.discovercircuits.com/list.htm

http://www.rfcafe.com/references/electrical.htm

http://www.divms.uiowa.edu/~jones/step/

http://openbookproject.net/electricCircuits/

Ernie

[lwalker]

Oh, if the real goal is to learn electronics I'd suggest you assemble a few cheap kits and then branch out into building things on your own. I'm one of those people who learn best by building stuff, and that's been working pretty well for me [except for a 4-year diversion into engineering school :-) ].

Make something simple to start, like an LED light chaser, or a motor controller. I have never used them, but I've heard that the Velleman kits are well regarded.