I was inspired by the BNC Adapter Lamp, a beautiful creation made from bench parts that is vaguely reminiscent of steampunk styling.

Simple, yet incredibly novel and artistic. It inspired me to try something similar, except perhaps a little more steampunk and using some of my other hobby, vacuum tube gear. I know voltage regulator tubes glow depending on their gas content and voltage rating, and came across this Voltage Regulator Night Light which uses an incredibly simple circuit to light an 0A3 (VR75) voltage regulator from a line source.

My current plan is to combine these two projects. I envision a project box a bit larger than the Night Light one, with the regulator tube mounted in the center and three BNC connectors coming up out of it spaced 120° around the tube. I could possibly use a circular container for this, as well. Attached to each of those, run NE-2A neon lamps inside of similar diffuser rods.

After studying the datasheets for these devices, I’ve come up with this schematic:

Each lamp draws 0.7mA of current at 105-125V; a 150K current limiting resistor to ensure there is no damage. The regulator tube can provide 5-40mA of current, so a we’ll need a minimum of 9 lamps to be on the safe side or the tube could stop conducting or become damaged, either way not the desired outcome.

Next steps: order parts and see what happens. I have one project on my bench right now, but after that, I think this is the next one.