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  2. Clock - Wikipedia

    en.wikipedia.org/wiki/Clock

    The electric clock was patented in 1840, and electronic clocks were introduced in the 20th century, becoming widespread with the development of small battery-powered semiconductor devices. The timekeeping element in every modern clock is a harmonic oscillator, a physical object that vibrates or oscillates at a particular frequency. [2]

  3. Lemon battery - Wikipedia

    en.wikipedia.org/wiki/Lemon_battery

    Note that incandescent light bulbs from flashlights are not used because the lemon battery is not designed to produce enough electric current to light them. Such a battery typically produces 0.001 A (1 mA) of current at a potential difference of 0.7 V; these values are multiplied together to determine the overall power of 0.0007 W (0.7 mW).

  4. Electric clock - Wikipedia

    en.wikipedia.org/wiki/Electric_clock

    These keep time by counting the oscillations of a calibrated tuning fork with a specific frequency. These were only made in battery-powered form. Battery-powered clocks have been made using the schemes above with the obvious exception of a synchronous movement. All battery-powered clocks have been largely replaced by the lower cost quartz movement.

  5. Telechron - Wikipedia

    en.wikipedia.org/wiki/Telechron

    The electric clock market grew rapidly in the 1930s, and Telechron's patented power interruption indicator gave his clocks an advantage over competing synchronous clocks, but by the 1950s battery-operated clocks that weren't dependent on the power grid took market share, and in the 1960s the quartz clock replaced synchronous clocks.

  6. Quartz clock - Wikipedia

    en.wikipedia.org/wiki/Quartz_clock

    In most clocks, the resonator is in a small cylindrical or flat package, about 4 to 6 mm (0.16 to 0.24 in) long. [6] The 32 768 Hz resonator has become so common due to a compromise between the large physical size of low-frequency crystals for watches and the larger current drain of high-frequency crystals, which reduces the life of the watch ...

  7. History of timekeeping devices - Wikipedia

    en.wikipedia.org/wiki/History_of_timekeeping_devices

    The 12th-century Jayrun Water Clock at the Umayyad Mosque in Damascus was constructed by Muhammad al-Sa'ati, and was later described by his son Ridwan ibn al-Sa'ati in his On the Construction of Clocks and their Use (1203). [45] A sophisticated water-powered astronomical clock was described by Al-Jazari in his treatise on machines, written in ...