I carry around my project composition book with me just about everywhere I go, because you never know when a smokin' cool idea is going to hit. Setting up the plasma for a cut is alway a pain in the ass, and remanent cuts should just be easier. So it was probably natural that this idea would come up as we were making some killer fire pits.
I'd like to point out that while this is kinda cool, you could actually put together a pocket sized device with a Trinket, BLE HID, a little Li-Po battery, two little buttons and one of those tiny joystick switches.....
.....just sayin'.
I'm also going to go over the original board that was in the case. It's super simple and a good exercise in RF.