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Frequency Deviations In Continental Europe Are Causing Electric Clocks To Run Behind By 5 Minutes (entsoe.eu)
elgatozorbas shares a short note from the European Network of Transmission System Operators for Electricity (ENTSO-E): Apparently the Continental European Power System has been off since mid-January, causing some clocks to run behind by 5 minutes. How common are these mains-frequency synchronized clocks anyway, and why are they built that way? "The power deviations have led to a slight drop in the electric frequency," reports ENTSO-E. "This in turn has also affected those electric clocks that are steered by the frequency of the power system and not by a quartz crystal... All actions are taken by the transmission system operators (TSOs) of Continental Europe and by ENTSO-E to resolve the situation."
I had a digital alarm clock given to me when I was 5 years old (1978). I had it until I was ~24. It kept absolutely perfect time from 1978 until 1992, when I went off to college. Iowa State University has its own power grid and power plant. The two years I lived in the dorms on-campus, my alarm clock gained 5 minutes PER WEEK. (Yes, PER WEEK.) I got in the habit of setting it back five minutes every Sunday. I wore out the minute-advance button in those two years, fixed it a couple of times with a soldering iron. 1994 I moved off-campus and got an apartment, and boom, clock worked perfectly again, only set it twice a year for daylight savings. I asked around the engineering department and several people said, yea, ISU's power plant doesn't sync to the city's grid. I've taken apart a lot of things in my life. I've seen tons and tons of clocks' innards. Many of the mechanical ones have synchronous motors, and gearing ratios that completely and totally depend on the power grid being exactly 60Hz. It's been like that for much of the 20th century (one of the clocks I took apart was from the 1950's).