Nearly everything that is plugged in has a digital clock these days. In my kitchen alone, there are 3. One on the stove, one on the microwave and one on my desktop oven. My thermostat has a digital clock too. Lets also not forget the various devices in the entertainment center and the digital clock in my car.
There is one thing that most of these clocks have in common. They show the wrong time. Most of them are fast, the thermostat clock is slow. The ancient electric range, that clock, keeps perfect time.
So my question is this:
Why is it so fucking hard to make digital clocks with any semblance of accuracy? I would accept +/- 1 minute per year to be fine. I reset these clocks twice a year for the time changes. But no, my microwave gains 1 minute every 2 weeks.
I just want to understand why in this day and age, we can’t have digital clocks that keep somewhat accurate time. Can anyone explain this to me?
Is the answer something to do with time dilation?
The short answer comes down to the manufacturer’s using super cheap components in digital devices. “Real time clock” ICs cost a bit more, so instead they throw a cheap quartz crystal in there that is not quite 60 Hertz, resulting in time loss/gain.
Your ancient range is probably basing it’s clock on the AC 60 Hz power line, which is a pretty solid frequency signal.
I know next to nothing about clocks, but…
I assume the fact that it’s digital doesn’t have anything to do with it. It’s just a different display interface. At the end of the day, it depends on what the innards look like: the time-keeping crystal or whatever is in the insides determines how much deviation it will have over time. Cheap parts mean poor time-keeping. I don’t know how much those parts cost, but I could see a larger more expensive range being more willing to absorb the cost of good components than a cheap commodity-market microwave.
Edit: Wot they said. And it’s possible that the range could be built better, or it might be entirely coincidental that it happened to be built with parts that happened to have a low error.
Most clocks don’t have an external reference to compare against, so their accuracy is entirely based on the quality of their parts. Quartz crystals can be pretty accurate, but there’s still going to be some margin of error, especially if they’re going for cheaper parts or build quality. You can get better accuracy, but it costs more.
Ill pay the extra nickel or even dollar for accurate clocks.
I think the historical answer is that the timing crystal for digital circuitry doesn’t have to be very accurate to generate usable time pulses for ordinary digital logic signals. Given a more or less accurate crystal already specced for the device, it would be cheaper and easier for manufacturers to just use a component they had to have anyway for some other purpose to calculate time, instead of paying the extra dollar or whatever it costs plus the board space needed for a dedicated higher quality crystal. This may still be true of cheap electronics.
The answer is to not use the clocks. Thankfully my microwave’s clock does not even display anything if it isn’t set. Same with my rice cooker. Unfortunately, my oven will verbally complain (expensive Kitchenaid). My TV will verbally complain everytime it turns on.
I’ve been fortunate with these things I guess. I’ve got more digital clocks than I can count right now, and every single one of them has been extremely accurate, from the clocks in my computers, to wall clocks, to alarm clocks, car clock, TV, VCR, DVD, microwave, even a cheap little disposable clock I use at work. Granted, 80% of them are 10 years old or older, but even the newer ones have been good.
It is just very annoying the manufacturers will not cough up the extra few cents to get a better crystal or timing mechanism. I mean they are going to the extra expense to put in a digital clock, they might as well make it somewhat accurate.
“Digital” clocks should be ones with fingers, and/or toes. But they aren’t even the ones with hands. Did you ever think about that?
If they had hands, they’d just gnaw on them while obsessing about accuracy.
Then drill holes in their faces.