> I'm trying to make a new board for medium size nixie tubes like the IN-8 and > smiliar ones.
I just did that for a divergence meter. > Since the PCB cant be very big in size i'm thinking about multiplexing the > tubes. > > But not the standart-multiplexing with an 7414 IC. I'v used the HV5122/5222 > 32-bit HV shift registers in my last projects (direct drive) and i like to > use just one of these in this project. > > That would result in two position multiplexing because the IC can handle only > 3 tubes at a time. > > To load the HV5122 it takes 5us. > And i would leave the digits on for 15us for example. > This would result in 20us cycles at a 50/50 duty rate. > > Has anybody experience with multiplexing? > > Is 20us too long, just right, too short? > I would like to see no flicker, if possible I'd say 20µs is WAY too short. Due to stray capacitance and anode switching time, you're likely to get severe ghosting. What you usually need to do is turn one on, then off, have some dead time, then turn the other one on, then off, then more dead time. 100Hz (10,000µs) is fast enough to avoid visible flicker, but you can go faster if you want to. Note that the faster you go, the higher anode voltage you need so the tubes will ionize quickly enough. - John -- 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/47BE2184-5DC9-4941-8E03-AD3BC623523C%40mac.com. For more options, visit https://groups.google.com/d/optout.
