Hi Paul; Unfortunately the schematic image I posted disappeared. Here's a link to the same Image. NixieB56_Array_1.jpg <http://www.redrok.com/NixieB56_Array_1.jpg> a 56 transistor array controlled with 8 lines. and the simpler NixieB12_Array_1.jpg <http://www.redrok.com/NixieB12_Array_1.jpg> a 12 transistor array controlled with 4 lines.
These transistor arrays operate as constant current sinks. I've extensively tested the B12 using both IN-2 and IN-12B Nixies with a power supply up to 350V and a sink current of 1.5mA. They work beautifully. Of course, the draw back is only 1 transistor at a time can be activated and the micro pins must be reconfigured between 2 digital outputs, one Hi one Low. and the rest as inputs. But micros are fast and do it nicely. I think I can do this with an MCP23008 I2C bus expander. Will try that later. The question about 6/1 muxing stems from the "only 1 active transistor" thing so 6 sequential digits need about 6 times the current or about 9mA in my case. The decodesystems reference talks about high mux ratios, 6/1 doesn't seem to hi. Thanks for those references! You might ask why I'm doing this? I'm a hard core experimenter and like to push ideas to the limit to understand them. On Monday, April 2, 2018 at 6:38:33 AM UTC-5, Paul Andrews wrote: > > 1. People like to run 'anti-poisoning' routines - cycling rapidly through > all digits at full brightness. Other techniques include writing blanking > routines that turn off the display when there is no one around to look at > it. I remain to be convinced that anti-poising routines work. > 2. Later tubes were developed specifically with multiplexing in mind - > they will produce a good display with temporary higher currents. Some of > this has to do with stopping the glow spreading to the support structure, > some with the persistence of the glow between pulses and maybe some with > the resilience of the cathodes to the higher current. For example I have > seen adverts for tubes like the B5750 that explicitly mention how many > digits can be multiplexed. > > I don't thing you will need 6xI for this, but something less. > > Which tubes are you thinking of using? > > I will try to dig up some links to specific information. > > -- 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/ff584690-c20b-48ff-9420-ab0a83a1ff47%40googlegroups.com. For more options, visit https://groups.google.com/d/optout.
