Richard, Same here! I started to experiment with the IV-21 tube and how to drive it recently. I have some drivers on the way. I don't have much experience with VFDs at the moment.. but I did light one up on the bench recently.
I used the datasheet recommended filament voltage/current on the IV-21 of about 2.7v at 35ma, and I lit up all the segments/girds manually without a driver IC. With everything on, I was able to perceive a difference in the brightness but I had to be looking for it, it was not obvious. Now in operation as a clock, as opposed to a static display with all segments on, I would expect it to be less noticeable. The IV-21 is one of those 8 digit small calculator type tubes, the filament is about 40cm long or so. I believe the IV-22 single digit tube would have a shorter filament, and hence less of an effect? Maybe. Keep us updated on your progress. Regards, -Moses On Thursday, June 15, 2023 at 10:45:02 PM UTC-7 Richard Scales wrote: > Greetings all, > > I am starting to look at VFD displays and am reading all I can about them. > > I am trying to get a better understanding of the pros and cons of using a > AC filament drive rather than an DC one. > > I am aware that on larger displays (like those monster ones from Russia) > it is necessary in order to create a more even glow across segments. I > wonder however how important this is for smaller segments like those in > IV-22 for example. > > Making the filament drive AC adds a small degree of complexity but if the > difference is visible and beneficial then I'd like to go that way. > > My project would be direct drive, no multiplexing required. > > Any advice would be greatly appreciated. > > - Richard > > > -- 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 view this discussion on the web, visit https://groups.google.com/d/msgid/neonixie-l/4e3c4f47-eb29-4303-ab92-4159b1aef512n%40googlegroups.com.
