"Roy J. Tellason" wrote to "Greg Mayman" (19 Dec 02  04:06:08)
 --- on the topic of "DIGITAL CLOCKS"

 RJT> Greg Mayman wrote in a message to Roy J. Tellason:
 GM> Yup, 7490 counters. And some stages had feedback to reset the clock
 GM> on 0110 so it would divide by 6 for tens of minutes/seconds.

 RJT> Or use a 7492 instead,  /2 and /6!

 GM> And 7447 decoder/drivers.

 RJT> Yep.

Oh, just remembered there was a cmos ic a 4566 called an "industrial
timebase" which consisted of 2 BCD dividers. One was a divide by 10 and
the other a divide by 5 or 6. Connected to sample the powerline it could
divide by 50 or 60 for driving clocks 1 pulse per second or by 5 or 6
for 10 pulses per second in finer increments. Similarly it could divide
by 12 or 15 if one really wanted it.

 Mike
 ****

... 'Keep the smoke inside.' -- 1st Rule of Electronics.
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