Le 16/09/2018 à 10:54, Stephen a écrit :
> On 16/09/2018 02:16, Cousin Ricky wrote:
>>> I was surprised to learn that clocks still use the wall 60Hz for a
>>> clock. Every clock ran 8 minutes a day fast. Even my coffee pot. I
>>> figured it's a computer, it has a crystal.
>>
>> What???  That's quite an ASSumption on the part of the clock maker!  I
>> can't imagine any such clocks would be any more than useless around here.
> 
> Not an assumption at all. Until the 1980s a lot of electric clocks used
> an AC synchronous motor. The early ones did not self start. You had to
> spin the motor manually. I have one that uses a lever and ratchet to
> start it. Others could be made to run backwards. They were accurate to
> one ac cycle a day if your grid was half decent.
> My pc clock is 1·9 seconds behind according to https://time.is
> 
> 

Earlier this year, in continental Europe, we add a small scandal about
two countries playing bad with the grid: all the microwaves' clock were
getting late, to the point of getting in the TV news of 13h and 20h !

The cumulated delta was about 20 minutes in April, IIRC, the assholes
having pushed a 49,5Hz instead of 50Hz, in order to not provide the
other with a better current, while pocketing the money...

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