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Comment by expertentipp | Hacker News Reader

Does it have a digital clock? Adjusting the bloody clocks on every appliance twice a year is such fun.

I kinda wish mine had a clock (though I agree it's a pain having to adjust for DST). The power company has a lower rate after 9pm so I'd love to be able to set the dishwasher start time. Instead mine had a start delay, which technically works but is just more klunky.

Mine is integrated... Meaning behind fake door...

So no visible clock... But also no visible indicator of how long it will go on... I might prefer the incorrect time to that...

Only in places that twiddle with the clocks twice a year.

Plus powercuts, plus them drifting.

If you have a clock that shuts off when the power is cut, you don't need to worry about drifting:

Most of those are synchronized to the grid, and the grid keeps time really, really well. They actually synchronize the grid to atomic clocks etc for that purpose.

I have clocks in various mains powered devices that will drift noticeably over a couple of months. Some survive small brownouts, some don't, I have one which will last for a decent length cut.

I'd wager all of them get timing from an internal oscilator driven by a low-voltage DC supply and have no mains frequency or voltage anywhere near them.

I guess, if they survive any power cut at all, they are probably not taking their time cues from the main's frequency. I agree with your wager that they probably run on low-voltage DC and perhaps have a capacitor somewhere to bridge short outages.

Where do you live that you have frequent enough brown outs to notice these things?

I have a time switch. It looks entirely mechanical, but I suspect it gets its time signal from the mains: it doesn't seem to drift at all. If there's ever a power outage (which happens from time to time when our breaker trips, not because the real mains is down) it just stops advancing the time, but doesn't reset, because it's all mechanical.

> Most of those

Where do you live, and how old are your oldest electronics?

I am saying the ones that immediately go out when the power is cut.

Anything that uses DC would likely have at least some capacitors in them.

The grid? As in power lines? How in the world would that even work? I've seen a clock that could reset its own time using radio signals. I don't think radio counts as the grid however.

Some clocks use the mains frequency as the input reference. They aren't talking about the time of day being synchronized, just time intervals. I wonder how common that is among modern appliances.

Interesting, I had never heard of this. Thanks. I found this and got some clarity.

https://hackaday.com/2018/03/29/ask-hackaday-is-your-clock-t...

That is nuts and I’ll not buy an appliance with a clock for that reason.

i think messing with time is what's nuts and looking forward to the day US follows other countries in getting rid of that largely pointless busywork

I agree.

The US doesn’t mess with time in some states, including where we live (Arizona).

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