Ah -- I also see the "1", "4" and "7" characters take advantage of that column, for better formed/placed digits. Very cool.
On Monday, June 10, 2019 at 12:55:47 PM UTC-5, Terry S wrote: > > The far right column is part of the matrix as you would expect. It's the > column adjacent that seems unusual. I guess if the decoding is there for > it, you could illuminate a + sign with that column. > > On Monday, June 10, 2019 at 12:38:49 PM UTC-5, gregebert wrote: >> >> I cant figure out why there is a duplicate column of LEDs on the far >> right side. >> >> The IC is probably a custom BCD-to-segment driver specifically for >> discrete LEDs. There is only 1 resistor on the board, so the driver IC >> probably does the current-limiting. >> I'm fairly certain the IC is not MOS/CMOS, so it's probably still OK (not >> damaged by ESD), and it should not be too difficult to reverse-engineer the >> connector pinout. >> >> If the LEDs are wired in-series, you can estimate the required >> power-supply voltage by measuring the forward voltage of 1 LED (roughly 2V >> @ 10mA). >> >> If they are parallel, I would assume 5V operation. The 120 ohm resistor >> would give 23mA thru an LED that has a 2.2V drop and a 5V supply. See how >> many LEDs are connected to it. >> >> Nice find, and I hope you win the auction. >> > -- 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/376765b2-43f8-4822-9f7a-970e28b6cbfd%40googlegroups.com. For more options, visit https://groups.google.com/d/optout.
