Electric watch

An electric watch is one that uses an electric current to power a conventional wheel train and balance. This is differentiated from an electronic watch which uses a circuit and electronic timer (typically a quartz crystal) to keep the time.

Electric watch prototypes were produced throughout the 1940s, but it was 1952 when the concept gained serious traction. A French inventor presented a practical electric wristwatch prototype to the French Academy of Sciences and LIP and Elgin partnered to bring the concept to production. Called "The Watch of the Future" at the time, it was produced in both Besançon and Illinois. Initial sales were set to start in 1953 but the model ultimately was not available to customers until 1957. An unrelated electric watch was soon introduced by Hamilton in the United States as well, and the Hamilton Ventura of 1961 became the most famous electric watch of this period.

Ebauches SA debuted a fully-functional electric watch movement, Cal. L-4750, at the Basel Fair in 1961. Their goal was to develop an electric movement that was no more expensive than an automatic lever watch, had comparable timekeeping performance, had a separate battery or accumulator for recharging, and was as simple as possible to manufacture and service. Ebauches SA used an electro-magnetic balance which drove a conventional wheel train. The circuit was made and broken by two contact springs. Although first demonstrated in 1960 with an accumulator, the production watch used a conventional battery that was said to last 12-15 months. The movement also had a hacking seconds lever that disconnected the battery when the watch was not in use, preserving the battery during shipment and storage.