Hamilton Electric were the pioneers of the first electric watch unlike the Quartz and the Bulova Accutron this was the first movement to use a battery as a source to oscillate the balance wheel. Hamilton released two models of the Electric: the first released was the Hamilton 500 on January 3, 1957, which was produced into 1959. This model had problems with the contact wires misaligning and the watch returned to Hamilton for alignment. The Hamilton 505 was an improvement on the 500 and was more reliable: the contact wires were removed and a non-adjustable contact on the balance assembly delivered the power to the balance wheel.
A movement of a watch is the mechanism that measures the passage of time and displays the current time (and possibly other information including date, month and day). Movements may be entirely mechanical, entirely electronic (potentially with no moving parts), or they might be a blend of both. Most watches intended mainly for timekeeping today have electronic movements, with mechanical hands on the watch face indicating the time.
The commercial introduction of the quartz watch in 1969 in the form of the Omega Beta 21 and the Seiko Astron was a revolutionary improvement in watch technology. In place of a balance wheel which oscillated at perhaps 5 or 6 beats per second, they used a quartz crystal resonator which vibrated at 8,192 Hz, driven by a battery-powered oscillator circuit. Since the 1980s, more quartz watches than mechanical ones have been marketed.