Brother and I survived 6hrs of holiday workshops at Scitech with 7-14yr-olds after developing a blinky-light bracelet kit.
Luckily the kids were all very focused and switched-on. Many of them knew a thing or two about circuits, but that didn’t stop them tangling their conductive threads terribly.
We designed (and extensively tweaked – see images below) a twin oscillator board to demonstrate beat frequencies. We ran out of time for the explanation, but the pulsing was pretty.
Instructions and diagrams to come soon!
Special thanks: Scitech, Perth Artifactory, Sparkfun, Toysdownunder, Altronics, Element14