Many thanks for all your replies and advice. DC seems t be the way then, with some series resistance on the filament supply. I'll start in that direction and get something working on the bench. - Richard
On Friday, 16 June 2023 at 20:32:01 UTC+1 Moses wrote: > 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/20b78aec-a35e-4d5f-a677-921eaa14ca0fn%40googlegroups.com.
