I’ve heard that there’s a signal riding on the 60 Hertz wave (in NA).
I’ve also heard that it comes over the air.
What’s the scoop?
Sent from my adequate mobile device using Tapatalk.
Most probably use GPS.
For decades, the standard has been to use the several signals being broadcast by NIST - WWV, WWVB, and WWVH.
But, these days GPS receivers are ubiquitous (I have one in my sports watch), and so that is taking over.
ETA: Any smart clocks that are connected to the Internet can use NTP, too.
supplemental question: and how do we fix the time on these magical clocks when they have the wrong time?
The NIST radio signals were quite weak in many areas for indoor clocks and the receivers in many clocks were not that great. I had a few NIST alarm clocks and their syncing was pretty sketchy. Hopefully GPS will be better.
If you can post a make/model, maybe we can find a work-around.
I know my “SkyScan” clock has a manual set feature.
I think the OP is mistaken about a time signal from AC lines. Traditionally, many analog electric clocks used the 60Hz frequency to sync the clock rate. But that’s purely relative, not absolute time.
Cell phone towers use GPS to set their clocks and that is in turn used by cell phones to set their time. Quick Googling doesn’t indicate that there’s any simple (and free) way to get the time from a nearby tower for clock setting. But since you can dial 911 on any phone, there’s gotta be some way. But a standalone clock with a cell system inside seems Rube Goldbergian.
Supposedly “most” Android phones using GPS for time are off 15 (or is it 16?) seconds due to not taking into account leap seconds. Not so sure about that.
Not exactly sure what you mean here but you may be confusing this with how plug-in electric clocks work. The have motors that rely on the fact that U.S. AC power has a cycle of 60Hz. It doesn’t carry information about what time it is–the clock just counts cycles and knows that 60 cycles is exactly one second (for the most part).
NTP provides only UTC. It has no notion of local time or daylight savings time, so you can’t make DST adjustments based on NTP.
Sorry for the hijack but I’ve been meaning to ask you, do you manually write this after all your posts? The only reason I ask is because yours are the only posts from Tapatalk users that have the word “adequate” tacked on to the end. Normally, it’s some overtly positive word (which I can’t remember now).
Sure you can.
Just have the location information in the device.
GPS is even less likely to work than NIST for indoor clocks. It has an incredibly weak signal.
Lots of consumer devices these days have WiFi, and can therefore use NTP. WiFi costs a couple of dollars to build in, and will be more reliable than the other radio schemes. Certainly networked TVs, game consoles, etc. use network time.
I can’t speak for Leaffan, but there’s usually something in the settings to edit (or remove) the the automated signature. This is how some people’s messages are tagged with “Posted from my toaster” instead of “iPhone”.
I edited the standard message which told the world what my (adequate) phone make and model was. You don’t need to know that, and I like to maintain the fact that I’m posting by phone in case I screw up royally.
That’s all.
Neither does GPS* nor WWV. Such clocks have a time zone setting and have firmware that keeps track of the date and does auto-DST adjustments. (Until they change the dates again.)
Devices that do auto-DST adjustment have been around for quite some time. Had VCRs that did auto-DST change. Turned off that feature and went back to manual when they changed the dates the last time.
- That’s the signal itself. Sufficiently advanced devices take your coordinates and figure out your TZ based on that.
Or use the SDMB Signature field.
This isn’t the clock we have at home (don’t recall make/model) but it appears to do the same thing. It somehow pulls the current time from being plugged in. I know ours doesn’t have any internet access - no mention of this one doing that either. Seems to be something related to the electrical power.
And it also of course is dependent on the AC reliably being 60Hz. When I was stationed in Japan, the AC current on-base (at least in the facilities primarily for American use) was 120v/50Hz for whatever reason (at a guess, it had something to do with us drawing commercial power from off-base and converting it to something American equipment could use).
For the most part, it worked, you just had to never rely on your oven’s clock for accurate time keeping.
If I’m reading the patent correctly, this clock doesn’t actually get any time information from any source. It has the UTC time programmed into it at the factory, and when the user configures it for his locale, it figures out everything. Kind of a cheat, if you ask me.
It’s because part of Japan uses 50Hz mains power. The other part uses 60Hz power. Most devices don’t care, but a few (e.g. clocks that are syncing to 60Hz mains power for timekeeping purposes) do.
So are you saying the time is kept like a CPU clock, when it’s powered off? What if it was kept unplugged for several years? Would it still know the time, or given a dead battery would it not work?