I use a Heathkit ET-3300 powered breadboard for my prototyping. But setting it up has always been a chore in itself. I need to run wires from the power supplies to the power buses, which is messy (though admittedly not nearly as messy as the rest of the circuit will be) and often add voltage regulators, since the Heathkit’s power supplies of +12V, -12V and +5V are more appropriate to the 1970s than the 2010s. So I made a power distribution board that addresses these problems.
I like the Heathkit ET-3300 because it has lots of breadboard area, built-in power supplies, three independent power buses, and more nostalgia and geek cred than any other solderless breadboard. I’ve occasionally used the +12V supply, often used the +5V supply, and never used the -12V supply. But I’ve also needed +9V, and for my current microcontroller of choice, the PIC32, I need +3.3V. This meant wiring up voltage regulators.
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So the power distribution board I designed plugs into the ET-3300’s power outlets, includes a 3.3V regulator, and adds binding posts that I can plug an external power supply into, to get any voltage I want.
The board also plugs into the three power buses. A set of jumpers lets me choose, for each power bus, whether it gets +12V, -12V, +5V, +3.3V, or the external power from the binding posts.
It’s not a great technological achievement, but it makes my life a little easier.
(See also Heathkit Hack #1, An Oscilloscope from the Trash and Heathkit Hack #2, Hacking a Heathkit Clock.)
