The Analog-Style LED Clock uses the 50 or 60Hz from the electric utility as a time base to keep accurate time without the use of a crystal oscillator. The clock automatically detects whether it is connected to 50 or 60Hz and adjusts accordingly. A question I’m often asked is “How accurate is the electric utility frequency?” The short answer is that it is surprisingly accurate.
Continue reading Using the electric utility frequency for timekeeping — How accurate is it?