Building a clock from salvaged Vacuum Fluorescent Displays

When was disassembling an old calculator (as you do) I found these cool VFD tubes: Normally, a whole display is built into a single flat package, which doesn't look particularly interesting. These ones have the individual digits inside a standard vacuum-tube housing, which gives them a cool nixie-esque look. Because vacuum tubes are rather archaic components, they deserve some introduction. The simplest tube has two electrodes: A filament and anode plate. Similar to an old-school lightbulb, the filament is a tungsten wire that heats up when a current passes through it. On a microscopic scale, heat is vibration of atoms — which knocks some (negatively charged) electrons out of the wire and into the surrounding space. If the plate has a positive voltage, it attracts some free electrons which allows a current to flow. If the plate is negative, the electrons are repelled and the tube doesn't conduct. This diode configuration is useful for power supplies, but most tubes added a wire mesh…