[time-nuts] Digital Clock kit - no Integrated circuits!

[David Forbes]

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/