For anode-side, I use a PMOS device (see attached picture). The current is set to (PRDV-Vgs)/R7. You can get Vgs(on) from the datasheet, usually it's around 4V for higher-voltage PMOS devices. The PDRV signal generated from a potentiometer and a small 12V DC-DC converter; adjust it to obtain proper current..
The zener diode protects the gate-source from unexpected spikes. The 10meg resistor is for bleeding any ESD; the value isn't critical but I use the highest value SMT resistor I can get at low-cost. I'm being overly paranoid about voltage spikes and ESD because if the PMOS device is damaged it could fail later in time and damage the nixie. The resistor R8 is intended to act like a fuse, though R7 would likely burn out first. It will take about 20mA to do that, which is a lot more than the nixie tube is rated for, but at least it wont allow basically unlimited current. -- You received this message because you are subscribed to the Google Groups "neonixie-l" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send an email to [email protected]. To view this discussion on the web, visit https://groups.google.com/d/msgid/neonixie-l/703d945a-4096-4654-bd01-8fc62ae09b91%40googlegroups.com. For more options, visit https://groups.google.com/d/optout.
