The Accutron ( right ) , an electromechanical watch developed by Max Hetzel and manufactured by Bulova beginning in 1960 , used a 360 hertz steel tuning fork as its timekeeper , powered by electromagnets attached to a battery-powered transistor oscillator circuit .
The Accutron , an electromechanical watch developed by Max Hetzel and manufactured by Bulova beginning in 1960 , used a 360-hertz steel tuning fork powered by a battery as its timekeeping element .