How do analog clocks/watches tick at exactly a second?
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Watches that tick once a second are usually powered by electronic movements. Mechanical escapements in a watch are far too tiny to get a pulse a second out of.
The electronic circuit has a quartz crystal (hence the early term, “quartz watch.”) The crystal is cut to vibrate at exactly 32,768 times a second when stimulated by a tiny electric voltage. Crystals are fairly accurate over a reasonable range of temperature, so they keep the time quite well.
The oscillations then go through a series of frequency divider circuits that successively divide them by powers of two (32768 – 16384 – 8192 – 4096 – 1024 – 512 – 256 – 16 – 8 – 4 – 2 -1.)
Once the output circuit is providing one pulse per second, the signal is amplified and used to rotate a tiny permanent magnet using a coil of wire (electromagnet). The magnet is geared to the watch hands and voila! You get a nice analog display with the second hand ticking once a second.
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