What parts do you intend to use for the power supply? If you want to save parts, use a 7805 regulator for the 5V, you don't need R1, R2,PC2 then.
About Multiplexing, if you have a 1:6 Multiplex, then every tube is only one sixth of the time on, resulting in lower brightness. A IN-18 is specified to have 4-6mA per tube. If you want the same brightness that direct drive would have, you have to drive the IN-18 with six times the rated current! But, personally, for home usage i think most clocks are too bright at rated current, especially at night. So a lower brightness may be nice. You could replace the NPN Transistors with mosfets, they can be driven directly by 5V, no more parts needed. Am Dienstag, 29. März 2016 21:04:19 UTC+2 schrieb Asstroman: > > Hello, this is my first post here in the NeoNixie group so I hope this is > an acceptable thread topic. I'm excited to find other people interested in > this sort of thing to get some feedback if anyone has it to offer. > Attached is a preliminary schematic that I designed for my first go at a > Nixie clock. (When I say I designed I mean pieced together from the > internet and filled in some gaps). I'd greatly appreciate any feedback > anyone has on it concerning better methods or any major problems that would > prevent if from working. Eventually I'd like to add in more features like > acquiring the time via WiFi or GPS, temperature sensing and better dimming > control and such, but for now I'm keeping it relatively bare bones (I > think). I'm using an Atmega328p as the uC which will be communicating via > I2C with a MAX1771ESA+ RTC chip. Even though I know multiplexing shortens > the lifespan of the tubes I've decided to go with using MUXing because I'm > not so knowledgeable on SMPSupplies (yet) and don't quite know how to get > the necessary current out of one to use Direct Drive. My scheme is to use a > 3:8 encoder on the anode side to select which anode is on. And on the > cathode side I'm using a bin-decimal converter to select which digit is > displayed. Each digit of a tube is attached to the same digit on the other > tubes so that when the bin-decimal converter turns on the base, say for the > "1"s transistor, all the "1"s for each tube will turn on on the cathode > side, but only the correct anode will be on, thus displaying only the > correct number on the intended tube. I haven't seen another design that > does exactly this in the same way so I am not 100% confident it will work. > It seems pretty straight forward, but then again, as with all electronics > projects it probably isn't. I will include in my code some measures to > avoid cathode poisoning, however, I just learned of another issue which is > blue spots appearing somewhere on the anode mesh... I think. I still need > to do some research about this and how to avoid it but if anyone has any > knowledge about this they'd like to share I would appreciate it as I'd like > to avoid this from happening in my design. Thanks for your time and I look > forward to any and all responses. > > > Shep > > > > <https://lh3.googleusercontent.com/-RRq4J135lbY/VvrQxlYW6XI/AAAAAAAAAIc/2oLMtnUf_D8VJ-XBmZ1EXu7h3Dj5EsVsQ/s1600/PG1.png> > > > > > <https://lh3.googleusercontent.com/-X4PchxD2EL0/VvrQiT0novI/AAAAAAAAAIU/cnEds-f5Ogw4bWnU0JzZSScAFpwxayLbw/s1600/PG2.png> > > > -- 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 neonixie-l+unsubscr...@googlegroups.com. To post to this group, send an email to neonixie-l@googlegroups.com. To view this discussion on the web, visit https://groups.google.com/d/msgid/neonixie-l/ec524de2-fe85-41c6-aa58-930ac42f29a4%40googlegroups.com. For more options, visit https://groups.google.com/d/optout.
