4 ms·

If anyone's thinking of making a clock that assumes the average frequency is 50Hz: Don't do that. There is no commitment to having the average frequency be 50Hz

by tormeh 9y ago

If anyone's thinking of making a clock that assumes the average frequency is 50Hz: Don't do that. There is no commitment to having the average frequency be 50Hz. There is a commitment to keeping frequency close to 50Hz, but no one in the energy industry is thinking about the average. So don't build things on top of that.

duffmancd 9y ago
It depends where you are. I know for example that the Australian standards require an accumulated time error of less than +/-5 sec on the mainland (+/-15s in Tasmania). Looking at other comments, it seems that we're a little weird down under and most places don't track the drift.
emiliobumachar 9y ago
Additionally, it will be a region-locked clock by its very nature. We use 60Hz here in Brazil.
- rowyourboat 9y ago
  When moving from the US to Europe, I had the opposite problem. I had brought along a number of devices that I powered off a transformer (230V -> 115V) here, among them an alarm clock. Which worked off the AC frequency and thus was losing 10 minutes every hour on 50Hz.
zAy0LfpBZLC8mAC 9y ago
Yes, there is, any accumulated phase error during the day is normally corrected at night.
petschge 9y ago
That is actually not true for the synchronized european power grid we are talking about here. The time that a clock that runs of the power grid is known as "Netzzeit" (grid time) and there is standards on how far that is allowed to deviate from the legal, public time. There is websites such as https://www.swissgrid.ch/swissgrid/en/home/experts/topics/frequency.html https://www.swissgrid.ch/swissgrid/en/home/experts/topics/fr... that track and display the deviation.
zaarn 9y ago
There is definitely a commitment. European Power Providers keep the average frequency at 50hz in relation to UTC time. With very very high precision.
sjclemmy 9y ago
Way back in the dim distant past I had a lovely Sony cube radio alarm clock. It had a switch on the back to determine the clock speed, either 50 or 60Hz. One day, unbeknowst to me, I, or someone else, moved the switch from 50 to 60Hz. When the alarm went off the following morning, I proceeded to get ready for lectures (This clock was my only means of telling the time, there were no phones or computers in my room) and after having showered I switched on the TV (which could only receive 3 channels at the time!) where I was met with unfamiliar programmes. This confused me for a long while until I realised the time was about 40 minutes later than the clock told me. I missed my first lecture.

by tormeh 9y ago

duffmancd 9y ago

It depends where you are. I know for example that the Australian standards require an accumulated time error of less than +/-5 sec on the mainland (+/-15s in Tasmania). Looking at other comments, it seems that we're a little weird down under and most places don't track the drift.

emiliobumachar 9y ago

Additionally, it will be a region-locked clock by its very nature. We use 60Hz here in Brazil.

rowyourboat 9y ago
When moving from the US to Europe, I had the opposite problem. I had brought along a number of devices that I powered off a transformer (230V -> 115V) here, among them an alarm clock. Which worked off the AC frequency and thus was losing 10 minutes every hour on 50Hz.

zAy0LfpBZLC8mAC 9y ago

Yes, there is, any accumulated phase error during the day is normally corrected at night.

petschge 9y ago

That is actually not true for the synchronized european power grid we are talking about here. The time that a clock that runs of the power grid is known as "Netzzeit" (grid time) and there is standards on how far that is allowed to deviate from the legal, public time. There is websites such as https://www.swissgrid.ch/swissgrid/en/home/experts/topics/frequency.html https://www.swissgrid.ch/swissgrid/en/home/experts/topics/fr... that track and display the deviation.

zaarn 9y ago

There is definitely a commitment. European Power Providers keep the average frequency at 50hz in relation to UTC time. With very very high precision.

sjclemmy 9y ago

Way back in the dim distant past I had a lovely Sony cube radio alarm clock. It had a switch on the back to determine the clock speed, either 50 or 60Hz. One day, unbeknowst to me, I, or someone else, moved the switch from 50 to 60Hz. When the alarm went off the following morning, I proceeded to get ready for lectures (This clock was my only means of telling the time, there were no phones or computers in my room) and after having showered I switched on the TV (which could only receive 3 channels at the time!) where I was met with unfamiliar programmes. This confused me for a long while until I realised the time was about 40 minutes later than the clock told me. I missed my first lecture.