I ended up just using three separate 470K voltage halfers per tube pair, it works pretty well and only leaks about .5mA per tube pair. Now there are only three or four specific instances where ghosting will occur at all (at full brightness). I bet lower brightness would decrease this problem further. It's still annoying that it happens at all though.
On Feb 11, 12:49 pm, threeneurons <threeneur...@yahoo.com> wrote: > You can move the anode mid pulls to the collector side of the MPSA92 > anode drivers. That way it should not dim the tubes. > > Yes, the mid-pull resistors draw extra current. Maybe another entry in > the 'disadvantage' column of multiplexed vs direct drive. > > BTW, this scheme works on leakage problems thru two actions: (1) The > mid-pulls drag the nixie to an area where it won't ionize, so even if > you have a leaky transistor, it won't get past the tube. And (2) Those > resistors also add a extra current path, where the leaked current can > flow. Say you have 100uA of leakage current. That dropped across a > 220K resistor is only 22V. Not enough to ionize a tube, and that's if > all of it goes thru the resistor. If any tries to start leaking thru > the tube, the drop is even less. That last part is just a mental > exercise, since the current won't go thru a tube under ionizing > potential. > > > > > > > > > which burns 3.4 extra mA. ... > > > Pull-mids on the anode have some effect, but I have to > > use resistances low enough that they also seriously dim the tube. -- You received this message because you are subscribed to the Google Groups "neonixie-l" group. To post to this group, send an email to neonixie-l@googlegroups.com. To unsubscribe from this group, send email to neonixie-l+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/neonixie-l?hl=en-GB.
