Breadboards are meant to be used with unipolar power supplies, and after quite a few close calls plugging in things wrong, I decided to standardize my setup and build myself a little power module.
Maybe it will inspire you, so I’ll give it its own thread, plus let’s hear how others are powering their setup.
It’s two standards cheapo breadboards fastened together with adhesive in the back.
For the rails, I used POSCA acrylic paint markers, this stuff isn’t cheap but lasts long and sticks to everything. Those are the kind of breadboards where the two lateral halves of the power rail don’t connect, so there’s a little wire to connect them (you won’t see it well on the photo).
For the color scheme, I picked red, yellow, and blue, because it’s the least ambiguous to me: does black mean negative or ground? Depends who you ask. Yellow seems more accepted to mean ground rather than negative.
For the layout, I matched the one I use for my custom prototype boards:
I cut this protoboard in half using a Dremel and a heavy-duty cutoff wheel. Don’t attempt without a respirator!
I fastened both halves using pin headers.
The pin headers that connect to the rails should be placed on the breadboard and soldered while on the breadboard, to ensure perfect alignment.
I expect it to incur a fair amount of mechanical stress over its service life, so I added a generous helping of hot glue everywhere. It’s not really necessary.
There’s a 10µF capacitor on each rail, since it pretty much comes standard on every single build.
There’s reverse polarity protection diodes, since I always use them, this way I won’t have nasty surprises with the voltage drop they cause.
I didn’t add a switch as I prefer to cut off the entire supply, and it could be a bit mechanically unstable to add it to the board.
You really don’t need a schematic, but hey, why not:
Nitpicking, but I don’t think I’ve ever seen yellow used as ground, neither have I seen black to mean anything but ground in a bipolar situation. I, for one, use yellow for +5v.
I’m also a black = ground person, after having heard @fredrik’s acerbic views on the subject, and blue for -12 V. I’m not married to a convention for 5 V, but I guess I’ve used yellow.
As for rail order, I’ve been known to use MI’s Breadboard Friends, so I use their convention:
The colors are very much a culture-dependent and an application-dependent thing anyway. As far as I’m concerned, in a DIY build, the correct color is the one where you’ll never plug in things wrong.
I’ve been looking at power supplies lately and they all seem to use the red=positive, black=negative, green=ground color schema. I’m a black=ground, green=negative person myself, but luckily you can swap/replace binding posts. That said, yeah, whatever your brain says when you look at the color, go with that, otherwise you end up having to re-train yourself and that just leads to frustration and burned out ICs.
I think I ended up using blue for 5v and yellow for 3v3 when I replaced the posts on my ATX PSU adapter board.
In the US, DC wiring (for solar power, batteries, etc.) has red for +V, white for grounded neutral, black for -V, and green, bare, or yellow stripe on green for protective ground. And of course in other countries it’s different — brown for +V, etc.
But that’s only relevant if that’s what you learned for wiring solar panels and you don’t want to try to retrain your brain for building synths.
