Introduction

For some time now, I've been designing and building circuits as a hobby. They're documented to varying degrees, in a variety of forms (photos, napkin schematics, forum posts), and with varying quality. I've started this blog primarily as a way to organize that information. Not uncommonly, I find myself writing an explanation of a circuit I've built, and wished it was simpler to just give a URL to one of the previous explanations I wrote. I'll still document in varying degrees of detail, but hopefully it will mostly be in one place. I'll be posting some about some older projects, and also about new ones as they come along.

I work with both analog and digital circuits, but I'll basically only post about the analog ones here. The design of digital circuits just isn't as interesting -- anything complicated is handled by a specialty chip or a microprocessor. There's nothing wrong with that, and it's very useful, but I don't find it as interesting -- and there are a lot more people posting about it on the internet already. Analog design, on the other hand, is more complex and subtle, just as important to the hobbyist, and there's less about it on the Web already.

By far the most interesting circuits combine the two domains. They do so in myriad ways, driven by the wide ranging sets of requirements on different sorts of circuits. These days, it is rare to see a circuit that operates purely in the analog domain. Microprocessors are so cheap, and can do so much, that there really isn't much point. But the environment they operate in is decidedly and unavoidably analog, and ignoring that aspect of the circuit leads to more errors, and subtler ones, than many hobbyists realize.