It's always peaceful to stop drilling metal and pounding rivets once in awhile, and settle down to the workbench with a soldering iron and a little wire. It is - quiet! Yesterday I was working on this little annunciator light panel for the Dream Tundra we're building. Despite having a whizz-bang EFIS that alerts me to all sorts of things, I like having a simple set of warning and reminder lights that really get my attention, right near the glare shield.
You can get these little 12 volt LED lights for less than a buck on the web, and with just a little metal art work, you can build a bezel to mount them in a strip. Solder some leads on the back, cover with a little heat shrink, and then wire away. This five light panel has an oil pressure light (wired directly to a switch on the engine), two warning lights for the two alternators, one light to come on when the Fuel Boost Pump switch is on, and one more to tell me that the landing Lights are on.
Although you can build all sorts of fancy microprocessor-controlled warning systems, this one is just purely switches grounds, and voltage. The voltage regulators for the alternators output a low voltage signal that drives their lights, and the other three are dirt simple. There’s no dimming capability – but this is just a day VFR airplane, so it's not really important.
This kind of tinkering is part of the fun of homebuilding for me – creating the panel I want with simple components and a little of my time. I’d be surprised if I have more than six dollars (and a couple of hours) wrapped up in this one. Money well spent for a little quiet time at the workbench.