Learning by Doing
Before We Begin: Learning by Doing
In a subject as broad and complex as electronics, experience is very important. There is no substitute for building and working with circuits. Much of what I have learned comes from figuring out why the circuits I have built don’t work. There is no magic in electronics. Everything about a circuit makes sense once you have the knowledge required and know how to apply that knowledge. Everything in electronics derives from a surprisingly simply set of basic principles. That said, applying these principles can be challenging due to the complexity that arises in large circuits.
Complexity appears for two reasons. The first has to do with the sheer number of interconnected components. Every component can be understood easily in isolation, but their interaction with other components leads to behaviors that can take some time to understand. The second reason for the complexity inherent in large circuits has nothing to do with electrical theory and everything to do with how information is being processed in the circuit. A circuit is more than the sum of its parts. When viewed at a high level, the input to the circuit is being manipulated in some way to produce an output. Understanding all of the low level component interactions is not sufficient to understand what the circuit is doing. You must understand, as a whole, what those interactions accomplish.
To be able to manage this complexity, you must be very comfortable with the fundamentals. Trying to work out what the components in the circuit are doing at the same time you are working out how the information in it is being processed, is an overwhelming task.
Building circuits, and testing them, is an essential part of learning how things work. There really is no substitute for doing this. There is a close second, however. It is simulating the circuit. Modern circuit simulation programs are very good and yield results that are most often identical to, or very close to, the results you get when you build the circuit. There are a number of available options, both as paid and free apps. LTspice Quick Start provides an introduction to using LTspice, a freeware SPICE simulator available from Linear Technology. LTspice is available for both the Mac and Windows and works very well. This appendix also briefly discusses some of the other available options.
If you are exploring new concepts, or are having difficulty grasping what is going on, simulating the circuit is a good option. That said, there is really no substitute for spending some hands-on time when it comes to understanding what is happening. Take the time to build circuits and explore how they work.
If you are at a loss for where to start, build a kit. Once it is working, spend some time with it making measurements while taking the time to understand the principles involved. Start small and build more complex circuits as your knowledge increases. When you are first starting out, the educational kits frequently marketed under names such as “150 in 1 Electronics Science Fair Projects” are as good a place to start as any. Searching the internet for “electronics project kit” or “electronic project lab” should yield a variety of kits to choose from. You need to get your hands dirty. The cost of many of these introductory electronics kits are quite reasonable. The additional equipment you need, such as a DMM (digital multimeter) can be found for a very reasonable cost. A beginner’s DMM can be purchased for less than $30 US.
This book takes a distinctly different approach than most that cover the same material. Traditional textbooks that introduce electronics rely on the use of practice problems to cement concepts in the student’s mind. This works well, but does not fit with the approach taken here. Using this book, in conjunction with a traditional textbook, is recommended if you believe you would benefit from solving practice problems.