Great explanation. Thanks! So then I could actually just use a zener in place of that resistor/diode network, right?
On Saturday, September 8, 2012 3:25:41 AM UTC-4, Frank Bemelman wrote: > > Hi Ron, > > Multiplexing was also often seen with LED displays (7 segment) and that > worked > very well because the segments are diodes. No currents that flow in > unexpected > ways. > > Nixieclocks of the last decade also often use multiplexing. The ‘segments’ > don’t behave > like diodes at all. Many unexpected current paths exist, depending on > which anodes are > on, which cathodes are off. Be aware that identical digits of different > tubes are connected > in series, because the cathodes of these identical digits are all wired > together. Disconnecting > a cathode junction sets all these cathodes floating. There is always 1 > active anode. From > that active anode it is not difficult to find two digits in series, which > leads you to another > (turned off) anode, but that tube has at least one digit connected to > ground. That is not a very > good climate to ensure digits will turn off rapidly. This is the situation > if single transistors > are used as switching element. A 74141 has clamping zeners, and solves > this problem by > preventing the cathodes going too high. > > You could also lower the HV. Below 135 volt you will have no ghosting. > > If you add the voltage divider + diode, the cathodes (of your little > neons) are > not allowed to go higher than half HV. They are still in series between > anode > drivers, but not enough voltage left over to get ghosting issues. > > Frank > > > > > -- You received this message because you are subscribed to the Google Groups "neonixie-l" group. To post to this group, send an email to [email protected]. To unsubscribe from this group, send email to [email protected]. To view this discussion on the web, visit https://groups.google.com/d/msg/neonixie-l/-/4nHVg5dMvCEJ. For more options, visit https://groups.google.com/groups/opt_out.
