Something I'm getting ready to build with scrap parts. When my motion sensor (shown in this circuit as a push button) detects movement it will sound the alarm (shown as a lamp).
In this simple setup, you push the NO button near the center to turn on the lamp. When you release the NO button the relay keeps the lamp powered on until you push the NC button next to the power source.
Thanks Ulric1994 for commenting on my previous flawed model. This one works the way I want it to. I added ampermeters simply to route wires cleanly and prevent them from showing crisscrossed.
