Electromechanical oscillator

An electric clock is a clock that is powered by electricity, as opposed to a mechanical clock which is powered by a hanging weight or a mainspring. The term is often applied to the electrically powered mechanical clocks that were used before quartz clocks were introduced in the 1980s. The first experimental electric clocks were constructed around 1840, but they were not widely manufactured until mains electric power became available in the 1890s. In the 1930s the synchronous electric clock replaced mechanical clocks as the most widely used type of clock.

Electric clocks can operate by several different types of mechanism:

In 1814, Sir Francis Ronalds (1788-1873) of London invented the first electric clock. It was powered with dry piles, a high voltage battery with extremely long life but the disadvantage of its electrical properties varying with the weather. He trialled various means of regulating the electricity and these models proved to be reliable across a range of meteorological conditions.

In 1815, Giuseppe Zamboni (1776-1846) of Verona invented and showed another electrostatic clock run with dry pile batteries and an oscillating orb. His team produced improved clocks over many years, which were later denoted as "the most elegant and at the same time the most simple movement yet produced by the electric column". Zamboni's clock had a vertical needle supported by a pivot and was so energy efficient that it could operate on one battery for over 50 years.

In 1840, Alexander Bain (1811-1877), a Scottish clock and instrument maker was the first to invent and patent a clock powered by electric current. His original electric clock patent is dated October 10, 1840. On January 11, 1841, Alexander Bain along with John Barwise, a chronometer maker, took out another important patent describing a clock in which an electromagnetic pendulum and an electric current is employed to keep the clock going instead of springs or weights. Later patents expanded on his original ideas.

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