if you want to sync to mains.. this is what "mains" looks like

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phil99 Guru Joined: 11/02/2018 Location: Australia Posts: 2857	Posted: 09:14pm 03 Dec 2024         Quote   It averages 50Hz so a mains derived clock will maintain time within a few seconds indefinitely. Yes, the old synchronous motor clocks never needed adjusting, other than after a outage. The small brief fluctuations in frequency that Poida's mains plot shows are due to phase shifts along transmission lines rather than actual changes in grid frequency. The endlessly changing pattern of load current and PF combined with the distributed reactance of the transmission lines produces the rapid phase shifts. If the phase is changing a a rate of 3.6°/second it will appear as a frequency shift of 0.01Hz, relative to the generating end.