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Atomic Clock DST

While my car doesn't do it automatically, going to/from DST is easy because the setting system is based on a up/down scanner where the hour is set independently from the minutes. Takes me less than 20 seconds.
 
Mediafrog+ said:
I’ve wondered if those “atomic clocks” that use the 60 kHz WWVB signal would also work in Europe with MSF in the UK, or in the Far East with JJY in Japan. Both those time reference stations are on 60 kHz, but I don’t know offhand if the data format is compatible with WWVB.
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This NIST document includes a schematic for a multi-standard atomic clock, including a 40 kHz crystal is for JJY, 60 kHz crystal is for JJY, MSF, and WWVB, and 77.5 kHz crystal for DCF77:
 
There are watches that can receive multiple longwave time signals, like Casio GShocks that cover 6 systems. They'll chose the best one based on what city you program.
 
Never owned an atomic clock, but have manually synced clocks to WWV on shortwave before. Even then, clocks tend to have a mind of their own, and run a couple minutes fast or slow after several months of setting them.
 
I have four clocks in my kitchen. One's a battery-operated wall clock from Ikea. The other three are electric and built into appliances (the microwave oven, the real oven and the coffeemaker). Last weekend I fired off a phone app that simulates a studio clock, using the phone's GPS to have an exact reference time, and used that to set all the clocks in the house to the same daylight saving time (as close as I could get it). When I got done they were all synchronized. Today , five days later, the kitchen clocks (except the battery Ikea one), were all wrong, all fast, all by the same number of seconds. The problem isn't me (or you, @inter1097), it's the power company. They're supposed to supply a consistent 60.0 cycle (hertz) electrical feed. They don't always do that precisely. If they feed you 59.9 hz, your clocks are going to drift slow by a few seconds a day. Conversely, if you're getting 60.1 hz, they'll drift fast. On most devices that difference won't matter, or be so small as to be insignificant. But with clocks it is cumulative. Most people won't make that connection, but I got frustrated enough with the time creep to do controlled experiments, and that is the only logical conclusion. Unless you think that multiple clocks from different manufacturers are all defective in the exact same way, and that "exact same way" is itself not consistent. More likely is your power company is not regulating its line frequency adequately and needs to correct something, but good luck finding someone there to complain to who will understand what you're trying to describe.
 
Santa fe said:
Some years ago the federal government relaxed certain standards that utilities have to meet and one of those had something to do with line frequency. That's why electric clocks drift more than they used to.
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That's really interesting, I didn't know that. Thanks. Helps to explain why what didn't used to happen now does.
 
Further research shows the standard to be +or- .01 hz from 60 hz but in some circumstances can be as great as +or- .05 hz, but did not say what those circumstances are.
Like Chicago sang, "Does anybody really know what time it is?"
 
Yabadabado1 said:
You would think that after decades of this time change crap that car makers would have a clock/car radio that would do this automatically.
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In those cases, they probably don't include automatic DST adjustment functionality on account of cars being, well, mobile. Imagine all the drivers who routinely cross time zone borders, who travel in and out of areas that don't honor DST at all, or who travel internationally between countries whose DST periods start and end on different dates. It's much simpler just letting drivers set their car clocks to "home base" time, and having those clocks maintain that time statically, with drivers mentally adjusting whatever they see based on their ever-changing locations.
Santa fe said:
Some years ago the federal government relaxed certain standards that utilities have to meet and one of those had something to do with line frequency. That's why electric clocks drift more than they used to.
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A truly first world move. Clearly nobody wanted those millions of clocks throughout the country affected by this to accurately tell time.

I wonder: have AC electronics device manufacturers compensated for this by switching from line frequency sampling to crystal oscillators like those found in DC powered clocks and watches?
 
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yeoldeschool said:
I wonder: have AC electronics device manufacturers compensated for this by switching from line frequency sampling to crystal oscillators like those found in DC powered clocks and watches?
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There probably are some high-end (read: expensive) clocks that have more sophistication. Most of us don't buy them -- most of us don't buy any clock unless an old one drops dead one day -- and when we need to buy a new one, we get the $20 version at Ikea or Walmart or Target, or pick one up on Amazon.

The clocks I referred to were built into appliances. Except for ones like that built into my expensive wall oven, they're integrated into coffeemakers and microwaves, and they're an insignificant add-on, so the manufacturers aren't likely to re-engineer them to fix a power company-created problem.
 
Seiki makes some clocks that get the time sync from GNSS satellites rather than WWVB.

www.seiko-clock.co.jp

GP501W | スペースリンク | セイコーウオッチ株式会社

セイコーウオッチ株式会社 クロック製品サイトのスペースリンク GP501Wについてご紹介します。
www.seiko-clock.co.jp www.seiko-clock.co.jp

www.seiko-clock.co.jp

GP502W | スペースリンク | セイコーウオッチ株式会社

セイコーウオッチ株式会社 クロック製品サイトのスペースリンク GP502Wについてご紹介します。
www.seiko-clock.co.jp www.seiko-clock.co.jp
 
kevtronics said:
Texas' ERCOT gives a real-time readout of their power line frequency. Currently it's 60.012 Hz:
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I'm reminded of the famous 1965 WABC blackout aircheck, whose low frequency region, spectrally graphed by Sox, reveals a real-time visual track precisely documenting the slow collapse of the northeastern power grid's AC frequency. (Image source.) A couple years ago, @Weiserguy gave some great technical information in this thread about how the sagging grid frequency affected WABC's turntables and cart machines.

The aircheck must have been recorded in a distant town fed by a different, unaffected power grid segment, because the Sox graph also shows the presence of a perfectly flat 60 Hz waveform (along with some apparent equally stable sum/difference products). But beneath that inducted 60 Hz waveform, because one of WABC's studio components wasn't perfectly isolated from its own local AC, you can faintly see the northeast's grid frequency fluttering wildly as it gradually dropped from 58 Hz at the aircheck's outset into a sudden nosedive to 48 Hz by the end. That appears to be what triggered the mass cascade of generating stations tripping off, judging by the slight recovery of all the spinning generators' speeds immediately after the nosedive (note the fast recovery from 48 to 51 Hz). But by then, of course, so many generating stations would have left the grid, the rest would've tripped off as well from the sheer load stress of trying to carry the entire grid by themselves.
 
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Those in the studio must have been terrified when everything went out. I'm sure back then the had a generator, but still it had to be very scary for the millions affected. And wasn't there a comedy movie about that with Doris Day? And didn't the birthrate jump nine months later? At least we can't blame that one on First Energy!
 
Santa fe said:
Those in the studio must have been terrified when everything went out.
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If you were in a station in a market with normally very stable AC power, it must have been alarming.
Santa fe said:
I'm sure back then the had a generator, but still it had to be very scary for the millions affected.
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Again, only in areas where power outages are not common.
Santa fe said:
And wasn't there a comedy movie about that with Doris Day? And didn't the birthrate jump nine months later? At least we can't blame that one on First Energy!
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But to many in areas more subject to power outages or in other countries where power outages are common, it is just annoying, not frightening.

In Puerto Rico in the 70's and 90's, we counted annual occasions when studios and transmitters went on the generator... it averaged between 30 and 35 per year over the decades. Some outages were short, others more than a day long.

At my home in the Palm Springs metro, I have had a genny for just over 10 years. It has been activated 5 times in 10 yearers, and in three of those it was for scheduled power company scheduled maintenance and lasted under an hour. The 4th was a lightening strike and the 5th was a drunk driver attacking a power pole..
 
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Santa fe said:
Those in the studio must have been terrified when everything went out. I'm sure back then the had a generator, but still it had to be very scary for the millions affected. And wasn't there a comedy movie about that with Doris Day? And didn't the birthrate jump nine months later? At least we can't blame that one on First Energy!
Click to expand...
Sorry, you spelled the company name wrong. It's Worst Energy.
 


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