3 ms·
These kind of clocks are used in many European Rail networks - the basic idea being that they get their time information by radio (usually DCF77 in central Euro
by DocTomoe 5y ago
These kind of clocks are used in many European Rail networks - the basic idea being that they get their time information by radio (usually DCF77 in central Europe), which beeps each second, but sends extra information bits such as date, hour and minute in the 59th second... which also is why when they have lost electricity, it takes up to one minute to reset to the actual time.
- Johnythree 5y agoMany office buildings had a network of slave clocks which were driven by one master clock. In normal operation each clock is stepped forward by a DC pulse each minute, but in the last minute any slow clocks are driven by multiple rapid reverse polarity pulses, which align the hands to the 12:00 o'clock position. This means that the hands of most clocks smoothly step forward, but any incorrect clocks will catch up by suddenly racing to the 12:00 o'clock position once each hour.