How did people make blinky lights before transistors, LEDs and the venerable 555 timer? T'was the Night Before Christmas - Only Passive Parts If you would venture outside during a sociable hour, you should see a very bright yellow lamp in the sky - the sun - yeah, that one - amazing isn't it? The sun is a huge nuclear powered neon lamp - not the kind of thing you can make in your radio shack, but if you go and dig deep into the scary nether regions of your junk box, you may find a couple of NE2 neon bulbs. (Put on some gloves, you may have to dig so deep you may cut a finger - I did... yeow...) New bulbs only cost a few pence, so if you are scared of spiders, or other unspeakable things lurking in the bottom of your junk box, next time you order toys from Digikey or Mouser, include a handful of them. Neons can make any new project look retro-cool with a mystical yellow glow. A neon bulb starts to glow at about 90 Volt and stops glowing at about 60 Volt.