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.
