Another reason for not using an op-amp, as a comparator, in this app, is speed. Op-amps are slew-rate limited by design. Some are faster than others, but most have added limiting circuitry. In this app, you're going to be piping a serial data stream, as fast as possible. Using common op-amps (LM324, TL084), you're not going to be able to stream faster than 10Kbpss. Maybe only 5Kbpss with the LM324.
For simplicity, I think the 4000 CMOS level shifters are the best option. Another option, is just using common emitter transistor stages. The pull-up, will be a simple resistor, so that will limit, your maximum speed. It should be good for a 100kbpss, or so, with 2.2K pull-ups, on the collectors. You can use the same value for the base current limiters. The logic phase will also, be inverted, but that can be compensated for, in software. On Tuesday, April 21, 2015 at 7:15:03 AM UTC-7, Mitch wrote: > > This is my first attempt and before I go further, I would really > appreciate critique and comments. This will never be a commercial product, > just a platform for me to keep the mind working as I retire from > application software development after many years. I mostly have the > software running on an Arduinix multiplexed, but I want to directly drive > the nixies for this project. > > This is for the Z573M, of which I have many, and the Arduino Micro. If it > works out, I'll modify the design to use the IN-18. > > I intend to add RGB lighting, neon or LED colons, GPS, RTC, and whatever > else I can think of. > > I started with Eagle, but because of board size limitations, I switched to > Diptrace. > > Thanks in advance. > -- 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/68a66342-2458-41c3-bc71-a9e090dcf7fb%40googlegroups.com. For more options, visit https://groups.google.com/d/optout.
