Hello Jonathan, I may eventually end up using a fixed voltage regulator but the reason I have an LM317 in this schematic is that I already have these and necessary resistors so it was mainly just to keep cost down. And that's an excellent point about multiplexing that I hadn't really though of so I thank you for that. After this and the previous comments I think I may just use direct drive. I'm not sure why but I was originally thinking that multiplexing would be more feasible because I wasn't sure if I could get enough power out the power supply. But after I took another look at it I think the power supply will have no problem driving the necessary ~38mA. I'm still weighing the pros and cons as I figure them out.
Shep On Tuesday, March 29, 2016 at 1:04:19 PM UTC-6, Asstroman wrote: > > 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 [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/615de83e-a334-4c5a-ad57-6ef8883337f2%40googlegroups.com. For more options, visit https://groups.google.com/d/optout.
