Quartz clock

A quartz clock

A quartz clock is a clock that uses an electronic oscillator that is regulated by a quartz crystal to keep time. This crystal oscillator creates a signal with very precise frequency, so that quartz clocks are at least an order of magnitude more accurate than good mechanical clocks. Generally, some form of digital logic counts the cycles of this signal and provides a numeric time display, usually in units of hours, minutes, and seconds. Since the 1970s, they have become the most widely used timekeeping technology.

Quartz Clock Media

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  Circuit board of an e block from a chronograph-wristwatch. Quartz oscillator crystal on right.

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  Disassembled analog quartz clockwork; quartz crystal oscillator (top left), Lavet-type stepping motor (left) with a black rotor sprocket and connected white and transparent gears (right). These gears control the movement of the second, minute and hour hands.

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  Basic quartz wristwatch movement. Bottom right: quartz crystal oscillator, left: button cell watch battery, top right: oscillator counter, digital frequency divider and driver for the stepping motor (under black epoxy), top left: the coil of the stepper motor that powers the watch hands.

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  Each flip-flop decreases the frequency by a factor of 2

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  Picture of a quartz crystal resonator, used as the timekeeping component in quartz watches and clocks, with the case removed. It is formed in the shape of a tuning fork. Most such quartz clock crystals vibrate at a frequency of 32768 Hz.

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  A quartz clock hung on a wall, 2005