I have been reading Jason Harper's article on driving nixies with discrete transistors. I understand the portion of using a MPSA42 to control the cathode side of a nixie; however, I dont understand why you couldn't use the same approach to control the tube anode. Most of the designs seem to use a MPSA42 and MPSA92.
I came across a discussion board entry which explained that: "Remember for a transistor to turn ON there needs to be a current flow from base to emitter. This can only occur (for an NPN) if the emitter voltage is less than the base voltage, by the forward voltage drop of silicon. That voltage being ~0.7V at room temperature. An 'emitter- follower' circuit has current gain, but no voltage gain. " I'm not grasping the concept of why the MPSA42 method works on the cathode side but not the anode side. Any further insight/explanation would be appreciated. -- 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]. For more options, visit this group at http://groups.google.com/group/neonixie-l?hl=en-GB.
