3 ms·
This is quite interesting; I've been reading up on PLL and chip design lately, as well as VCOs, TCXOs, etc. And now I'm wondering how accurate someone could ma
by geerlingguy 3y ago
This is quite interesting; I've been reading up on PLL and chip design lately, as well as VCOs, TCXOs, etc.
And now I'm wondering how accurate someone could make a reference signal from a physical pendulum like this—or what strange quirks you could introduce into a system using such a 'weighty' clock source!
- tvb 3y agoMany pendulum clocks are capable of well under 1 ppm accuracy, which is better than many quartz oscillators. Here is a tour of clock precision by orders of magnitude: http://leapsecond.com/ten/ http://leapsecond.com/ten/ Here is a world record setting pendulum clock from a few years ago: http://leapsecond.com/pend/clockb/ http://leapsecond.com/pend/clockb/ Precision pendulum clocks are a very deep rabbit hole.
- zokier 3y agoSee also https://en.wikipedia.org/wiki/Shortt%E2%80%93Synchronome_clock https://en.wikipedia.org/wiki/Shortt%E2%80%93Synchronome_clo... > The Shortt was the first clock to be a more accurate timekeeper than the Earth itself; it was used in 1926 to detect tiny seasonal changes in the Earth's rotation rate. Shortt clocks achieved accuracy of around a second per year If my math is right, thats about 30ppb