By Andrew Hazleton – Updated March 24, 2022
Quartz movements have become the standard for reliable timekeeping in watches, combining precision, low cost, and long battery life. Quartz crystals—commonly found in smartphones and other electronics—provide a stable reference that remains accurate across temperature and motion variations.
A quartz crystal generates a steady series of electrical pulses at a fixed frequency, typically 32,768 oscillations per second (32.768 kHz). An integrated circuit counts these pulses, converting the high‑frequency signal into a single pulse every second. This one‑second pulse drives the watch’s display, ensuring that the time increments precisely each second.
The heart of the movement is a small piece of silicon dioxide, either fabricated or naturally sourced. This crystal is cut to a specific orientation that makes it piezoelectric—meaning it vibrates when an electric field is applied. Its vibration rate is highly stable, remaining essentially unchanged despite temperature swings or mechanical stress.
When powered by a battery, the oscillator circuit couples to the quartz crystal and produces the 32.768 kHz frequency. Because the crystal’s resonant frequency is constant, the oscillator delivers a steady output regardless of voltage fluctuations or motion, providing a reliable time base for the watch.
The oscillator’s output feeds a counter that tallies 32,768 input pulses before emitting a single output pulse. A 15‑bit counter is used for this purpose, and the resulting pulse occurs exactly once per second. This division step translates the high‑frequency crystal signal into a usable one‑second tick.
Quartz watches can feature analog or digital displays. In an analog watch, a miniature stepper motor advances the second hand by 1/60 of the dial each pulse. In a digital watch, the second digits increment by one for each pulse, producing a smooth, accurate time readout.
