40-pad protoboard

October 7, 2010 12:26:01 AM CDT

Here's another of my prototyping ideas: the 40-pad protoboard.

I've noticed that when I build haystack circuits over a protoboard, I don't use much of the board itself. That prompted me to take a serious look at the areas I was using.

Turns out most of my base plane use falls into three categories: power distribution, 'programming' components (the ones that tell a chip how to behave), and subcircuits that only consist of a few components.

I already have some new ideas about how to handle power distribution (coming soon), and the other two use patterns demonstrate modular design in action. Most circuits break down into a collection of smaller pieces with well-defined jobs, and it makes sense to put the components of those smaller pieces all in one place. Otherwise you end up with the hardware equivalent of spaghetti code.

Looking at the problem that way, I realized that I don't want one large, general purpose breadboard for my haystack assemblies, I want a bunch of small ones. Thus evolved the design shown to the right.

This layout is just big enough to hold a traditional single transistor amplifier. The left field is big enough for the input network -- voltage divider for bias, decoupling cap at the input, resistor to the base of the transistor if necessary -- and the right field is big enough for a transistor with collector and emitter resistors.

Obviously you can do other things as well, but the transistor amp is a good example of a half dozen components arranged in a useful and interesting way.