Power grid change may disrupt clocks

http://old.news.yahoo.com/s/ap/20110624/ap_on_hi_te/us_sci_power_clocks

by mentat • 15 years ago

5 2 15 years ago

old.news.yahoo.com

ChuckMcM• 15 years ago

I don't think they appreciate just how screwy this can make things. A lot of embedded controllers use zero crossing detectors in their power supplies to provide the time signal.

Its been such a good thing for so long that I am not sure people really internalize the assumption they are making. I see this when I put things (like embedded controllers) on 'pure sine' UPSs (this is where the AC power charges the battery and the load always runs off the inverter). Since they do not accurately track 60 hz things like my NetApp filer lose and gain time sporadically (only kept sane by some NTP work which is poorly supported in the StoreVault series but that is another rant).

ithkuil• 15 years ago

"anything that flashes "12:00" when it loses power "

Not true. That anything could as well be a battery-less quartz driven clock that doesn't rely on grid frequency but needs power.

Power grid change may disrupt clocks

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