15 Oct
2007
15 Oct
'07
8:53 p.m.
> > The only 8-pin TTL chips I (just) rememebr
the 7456 ands 7457 (I
think)
> > which were /50 and /60 counters (desigend to
get 1Hz clocks from
Europe=
> And speaking of 50 and 60 Hz, I have this digital clock here that I
got=20
> *real* cheap, because it has a problem. it
gains a LOT of time every
ho=
> ur. =20
> Something like 10 minutes, maybe? I'm convinced that it's jumpered
(or=20
something) for
50 Hz line power. :-)
If it was, it would add 72 minutes instead of 60 ever hour, I think. So
it would gain 12 minutes per hour. Sounds just like your problem.
Most LSI digital clock chips could be jumpered for 50Hz or 60Hz input.
SOme earely ones seem to have been 60Hz only (I've not seen one that's
50Hz only, but that may be because most of the books I've read on this
originiated in the States).
-tony