When shopping for the VFD, LegionLabs also brought me back some Nixies! Nixies require a high voltage supply... ok, given certain other experiments on this blog, a medium voltage supply - usually said to be 200V or so. In my laziness, I tried the simplest possible supply - rectifying the 110V wall voltage and smoothing it with a capacitor. Works a peach.
This ends up at 155V or so (110V x 0.707). Not that a voltage doubler is hard in the end, i just had a bridge rectifier right there. I'm using a 47K resistor in this picture - although in other tests a 36K seemed to give a slightly better brightness. The tube uses around a millamp.
In an example of total overkill, i simulated the circuit using CircuitLab. It was a really just a way to try out Circuitlab on something easy, and in the end, i'm a fan.