4 ms·
Grid frequency actually is hyper accurate in a lot of places. i.e. in the Western US the grid is regulated such that a clock running off it will never deviate m
by opencl 7y ago
Grid frequency actually is hyper accurate in a lot of places. i.e. in the Western US the grid is regulated such that a clock running off it will never deviate more than 2 seconds from the atomic clock derived National Bureau of Standards time [1].
Compare to a typical quartz oscillator which will gain or lose around 15 seconds per month.
[1] https://www.naesb.org//pdf2/weq_bklet_011505_tec_mc.pdf https://www.naesb.org//pdf2/weq_bklet_011505_tec_mc.pdf
- avn2109 7y agoThis comment should be higher up in the thread.
- mrguyorama 7y agoThis is being pedantic but I guess I was saying it's not hyper accurate in terms of time keeping, even though it's pretty accurate in practical terms. Also, I guess that means my devices with clocks that drift more than two seconds, ie several full minutes, are actually using crystal oscillators? I guess it makes sense for a microwave which needs second level granularity, but that seems odd to me.
- HeyLaughingBoy 7y agoYes. The crystal in your microwave's CPU clock circuit will drift, and so will the time-of-day derived from it until you set the time again, if there is no external reference. The benefit of using the incoming 50/60Hz AC signal as a timebase is that the power station is responsible for controlling the long term frequency to avoid drift so it can be used as a very reliable reference.