On October 17, 2015 6:09:21 PM CDT, Tim Lavoie tim@fractaldragon.net wrote:
The AC frequency as a clock source will also be a problem of the utility happens to mess with that timing. Forget why the do, but it happens.
On Oct 17, 2015, at 14:36, Trevor Cordes trevor@tecnopolis.ca
wrote:
Off-topic, but cool:
http://www.transistorclock.com/?imm_mid=0da80b&cmp=em-prog-na-na-newsltr...
A guy selling kits to make a all-parts-exposed digital wall clock
that
uses *no ICs* and *no crystals*. You build it yourself, 1250 parts
to
solder onto a custom board. Too pricey for me, otherwise I'd love to
put
one together.
ICYW, I dug around the FAQ and he is cheating a bit: he's using the
60Hz
of the AC as a timer source.
Hmm, since it plus into AC, does that mean touching some parts of the
exposed circuits might give you a nice zap? _______________________________________________ Roundtable mailing list Roundtable@muug.mb.ca http://www.muug.mb.ca/mailman/listinfo/roundtable
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When the A/C grid is heavily loaded the generators slow below 60Hz.
The make up for it in later by generating higher than 60Hz. That's why the old A/C clocks with synchronous motors never need correction over long periods of time.
Most cheap digital clocks haven't had the oscillator regulated so their time creeps off.
NTP fan, Daryl