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For most of us, nothing is fun if you have to break a sweat thinking about every little step. Putting some effort into a big problem and solving it can be a thrill, but you also need to make visible progress.
For me, learning electronics was one of those tasks that seemed too big to tackle. There was so much ‘magic’ involved – so much physics – that I would never be able to keep it all straight in my head. It seemed like every little circuit would have to be designed while using two notebooks full of rules and formulae.
Then I realized, there has to be a better way. There are too many hobbyists and engineers out there designing circuits for it to be as hard as my physics textbook made it seem. And it is simple, once you’ve learned some rules of thumb.
When I was working as a programmer, a professional circuit designer said to me, “You program using a computer and compiler, I program with solder.” It’s true. If you can program some simple software on a computer, then you can certainly design circuits. The rules are different, but the way you think about things is the same.
I hope you’re reading this page because you would like to learn how to design some circuits. I’d like to try and help as best I can. I am a self-taught circuit designer, and I learned nearly everything I know about circuits from a few books.
This, I think, is good news for anyone who wants to get into circuits. It means it doesn’t take four years of college and a EE degree to learn. It probably only takes a few weeks if you’re highly motivated, or a little longer if you’re just in it for the ride. Either way, it’s a skill that can be acquired without any special mental powers.
Some pitfalls to avoid in learning basic circuits:
- Don’t get bogged down in the physics. If you want to learn physics, then do so, but basic circuit design isn’t about how much charge an electron has or cosmic rays.
- Don’t get bogged down in formulae. There are a few formulas you’ll need to remember, but probably less then 10, and they’re all short/easy ones.
- Build projects you think are fun. Try and choose some things to build that are interesting as well as challenging. Avoid little toy things built for kids (unless that’s what you like).
- Avoid kits for the purpose of learning. Kits are great for building neat stuff (like nixie clocks!), but you won’t really learn how to design your own circuits unless you create something from scratch. All you’ll learn from a kit is how to build what’s in the kit.
- Don’t be intimidated by the parts catalogs. DigiKey, Mouser, Newark, and others have HUGE catalogs. They’re great for looking through, but can be confusing when all you want is a 1 Ohm resistor and they have 1000 different types. My best advice is to figure out the minimum requirements you need (say, a 1 Ohm resistor that can sink 0.1 Watt of power) and then buy the cheapest one in the catalog that has these properties. Just ignore the other choices. Then, just keep using that type of part for projects until your needs change, or your knowledge grows.
- Don’t start with surface mount. Use through-hole to learn. Later you can use surface mount components.
Below are some products I recommend for learning. Start with the books, then move on to building things using the catalogs, software and other tools.
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"Basic Electricity"
This is a book written for the Navy to teach incoming technicians. It’s origins date back to its first edition in 1952. Fortunately, basic electricity hasn’t changed since 1952, so the book is still very relevant.
This book is for the complete beginner. It has many illustrations and takes you right from the beginning without assuming any knowledge. It’s always easier to skip stuff you know, than to not have stuff you need.
This is the place to start if you need to learn about voltage, current, resistance, inductance, capacitance, motors and the like. If you don’t plan on building anything with motors, you can just skim the last sections of the book. If motors are you’re thing, then this is a great introduction.
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"The Art of Electronics"
In the world of electronics, this book may be my Best-Book-Ever winner. This is the book that took me from knowing some simple physics and very basic electronics terms, to that “ah-ha!” moment where I “got it.”
This book reviews the basics, but then jumps into transistors and logic and more advanced design ideas in a big way. With lots of example circuits and explanations, this book is all about PRACTICAL electronics. Ok, there are a few short detours into the underlying physics here and there, but feel free to skim those for now. I think this book touches the physics just enough so you know when the simple rules of thumb may not apply, but doesn’t waste your time by dwelling on these exceptions for too long.
After reading this book, I designed my first nixie clock.
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Mouser
Digikey
Newark |
Parts Distributors
Go online and order a catalog from DigiKey.com and Mouser.com. It’s free, and the catalogs are good sources for ideas.
I personally prefer Mouser, because they have no minimum order, and have very helpful call-center support. Mouser doesn’t tell you the shipping charges at the time you order (they wait until everything is packaged and then charge you when it’s all boxed up). However, I’ve never had them charge me shipping that seemed at all unreasonable.
DigiKey is probably the most well known parts distributor, but they do have a $5 fee for small orders.
Don’t be overwhelmed by the catalogs you get in the mail. They look like phone books. The catalogs are for browsing; use the online search at the websites to find the parts you need.
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Tools
For prototyping, get a breadboard and some jumper wire. These are available from Mouser.com. Breadboards are boards with many holes in them where you can easily insert and remove parts and wires for rapid circuit building. You can buy pre-cut jumper wire made for these breadboards, which is a real time-saver.
To build durable circuits, you’ll need a soldering iron, some solder, and of course parts. If you can afford it, get yourself a nice iron with temperature control. I have a Weller WES51.
You’ll need some solder as well; purchase the regular 63/37 kind (63% tin, 37% lead). A 0.031 inch diameter is good to start. If you wish, you can experiment with lead-free solder types later, after you’ve acquired good soldering skills with the leaded kind.
A digital multi-meter is also must. This device will measure voltage, current and resistance (and sometimes other things). DO NOT purchase a $10 multi-meter from a big box store or Harbor Freight. These cheap meters are all over the place, and I’ve observed about a 50% failure rate. The problem is, sometimes they seem to be working, but they don’t give a correct reading. If it costs less than $40 or $50, then there’s a reason.
You’ll need other tools (snippers, pliers, screw drivers, etc.), but you probably have many of these already, and will figure these out without much difficulty as you go along. Many or all of the tools you’ll need can be purchased at your local Radio Shack, or Mouser.com, or Amazon.com (please use the links to the left to support this site).
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Printed Circuit Boards
When you get an idea for a more advanced circuit, or you want to build something to last, a printed circuit board (PCB) is a must. Many hobbyists will try to make these themselves, but unfortunately there is no really good home-brew method. Yes, you will find several methods you can use (milling, blue paper, laser printers, etc.), but they all have their weaknesses. I’ve tried many, but unfortunately can’t recommend any of them.
If you have the money, I recommend E-TekNet for PCB manufacture. The reason is they are very cheap. Sometimes they deliver a little late, but they are friendly/helpful on the phone, and the quality has always been good. There are many PCB manufacturers out there, so feel free to shop around.
Another good PCB service is Advanced Circuits. They have a $500 new customer special which should make your first round or two of prototypes free. They also have a very nice pre-order error checking service (it's part of the free quote) which may be useful for your first attempts at making a PCB.
To design the PCBs and make the files, I recommend Eagle, from CadSoft. There is a free version suitable for hobbyist use (full function, except that the size of the PCB is limited to 3 inches by 4 inches, plenty for a 4-tube nixie clock!). Learning how to design PCBs takes a while, but there is documentation on the Eagle website. It’s quite a thrill to send out your first set of CAD files from Eagle, and get real printed circuit boards in the mail a few days later!
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Hopefully the above information is enough to get you on your way. Start with the books, and move on from there. I hope you pick up circuits as a hobby or even a career – it’s great fun!
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