An electric watch is one that uses an electric battery to charge an electromagnet, which provides mechanical power to a balance wheel. Electric movements were produced from 1957 through the mid 1970s by companies like Hamilton, LIP, ETA, Seiko, and Timex.
Early Electric Watches
LIP in France and Elgin in the United States independently began developing battery electric watches in the late 1940s. Since both were developing similar technology and were challenging Swiss watchmakers, they joined forced, announcing in 1951 that they would soon deliver the first electric watch. Development took most of the decade, and Hamilton was able to deliver the first such watch in 1957. The Hamilton Ventura, famous for its unique case shape and association with American singer Elvis, used a moving coil mounted on the balance wheel. Hamilton later worked with Ricoh in Japan to create inexpensive electric watch movements.
The LIP/Elgin design, delivered in 1958, used a fixed coil on the plate instead, but required two batteries. It also added a diode to prevent sparking and wear of the contacts. LIP created the first electric dive watch in 1967, the LIP Nautic-Ski.
ETA subsidiary Landeron created the first Swiss electric movement in 1961. Timex acquired West German Laco in 1962 to access their high-quality electric movements, though they sold the company to ETA in 1965. Timex later created their own simple and durable electric movement, which would continue in production for a decade.
Léon Hatot of France invented a system that used induction in a coil to trigger a transistor to energize the electromagnetic coil. This eliminated the problematic contacts of earlier designs, improving reliability. This was licensed by many makers in later years, and the "ATO" mark seen on their movements is a reference to Hatot. ESA's Dynotron was the first production transistorized electric watch movement in 1967, and these were widely used by Swiss watch manufacturers. Derby was another manufacturer within Ebauches SA that made electric movements, and theirs took the Swissonic name, which was also applied to tuning fork ("Mosaba") and quartz movements in the 1970s.