<html><head></head><body><div class="gmail_quote">On October 17, 2015 6:09:21 PM CDT, Tim Lavoie <tim@fractaldragon.net> wrote:<blockquote class="gmail_quote" style="margin: 0pt 0pt 0pt 0.8ex; border-left: 1px solid rgb(204, 204, 204); padding-left: 1ex;">
<pre class="k9mail">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.<br /><br /><blockquote class="gmail_quote" style="margin: 0pt 0pt 1ex 0.8ex; border-left: 1px solid #729fcf; padding-left: 1ex;"> On Oct 17, 2015, at 14:36, Trevor Cordes <trevor@tecnopolis.ca> wrote:<br /> <br /> Off-topic, but cool:<br /> <br /> <a href="http://www.transistorclock.com/?imm_mid=0da80b&cmp=em-prog-na-na-newsltr_20151017">http://www.transistorclock.com/?imm_mid=0da80b&cmp=em-prog-na-na-newsltr_20151017</a><br /> <br /> A guy selling kits to make a all-parts-exposed digital wall clock that <br /> uses *no ICs* and *no crystals*. You build it yourself, 1250 parts to <br /> solder onto a custom board. Too pricey for me, otherwise I'd love to put <br /> one together.<br /> <br /> ICYW, I dug around the FAQ and he is cheating a bit: he's using the 60Hz <br /> of the AC as a timer source.<br /> <br /> Hmm, since it plus into AC, does that mean touching some parts of the <br /> exposed circuits might give you a nice zap?<br /><hr /><br /> Roundtable mailing list<br /> Roundtable@muug.mb.ca<br /> <a href="http://www.muug.mb.ca/mailman/listinfo/roundtable">http://www.muug.mb.ca/mailman/listinfo/roundtable</a><br /> <br /></blockquote><br /><hr /><br />Roundtable mailing list<br />Roundtable@muug.mb.ca<br /><a href="http://www.muug.mb.ca/mailman/listinfo/roundtable">http://www.muug.mb.ca/mailman/listinfo/roundtable</a><br /></pre></blockquote></div><br clear="all">When the A/C grid is heavily loaded the generators slow below 60Hz.<br>
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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.<br>
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Most cheap digital clocks haven't had the oscillator regulated so their time creeps off.<br>
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NTP fan, Daryl<br>
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Daryl F</body></html>