On 03/10/2018 11:00 PM, Levi Pearson wrote:
> After a bit more digging, I've found that there have been cheap
> integrated digital clocks with mains-frequency references for a very
> long time. I've even got one kicking around here from an old digital
> alarm clock/radio. There's one big chunky IC that is basically an
> AM/FM radio on a chip, and another one that's basically a
> mains-referenced digital clock with 7-segment display drivers. I'd be
> very surprised if there weren't a couple of similar LSI clock ICs
> during the 80s/90s that wer customized for appliance clock purposes
> rather than alarm clocks.
That's really interesting!
> So, I have no idea what's in modern high-tech ovens and microwaves,
> but I'll bet there are still a lot of old control mechanisms still in
> use on cheaper cost-optimized units and even newer ones may have
> mains-referenced real-time clocks.
I suspect mains-referenced digital clocks are more common than I
thought, even in new appliances. I haven't noticed my oven or microwave
losing significant time over a couple of years, which a cheap quartz
solution would, so maybe they are mains referenced. Makes sense,
especially since apparently people really noticed the lag in Europe.
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