[time-nuts] Digital Clock kit - no Integrated circuits!
David Forbes
dforbes at dakotacom.net
Sat Jan 9 15:50:31 UTC 2010
At 7:30 AM -0800 1/9/10, Lux, Jim (337C) wrote:
>
>I can't help wondering if you go do better than the 4 bit
>counter:4-10 decoder:10-7 decoder. Yeah, simple diode matrices in
>an AOI configuration are easy, but surely a bit of work (as in
>digging up archaic designs) could find a "lower part count"
>approach. Time to use that Karnaugh map.
If they had used proper Nixies instead of those awful 7 segment LED
displays, then they could have used the same circuit in the 5245 and
gotten the job done with 8 transistors and 8 neon lamps and some CdS
photoresistors per decade.
My twin brother built a clock out of some old Beckman hollow-state counters...
http://www.selectric.org/tubeclock/index.html
--
--David Forbes, Tucson, AZ
http://www.cathodecorner.com/
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