How Do Tuning Forks Work in Watches?

Background

• In 1960, Bulova Watch Company introduced the Accutron, the first mass-produced tuning fork watch, according to the Accutron Watch Page.

Replacing Conventional Parts

• A tuning fork replaces the mechanical watch's conventional balance wheel by functioning as the balance, with a battery serving as the spring.

Servo System

• The battery and tuning fork act as a servo system with the battery providing a sustained electrical circuit and the tuning fork, which features a tiny magnet and surrounded by a coil, providing resonance to amplify the circuit.

Transistor

• The battery's power is carried through a transistor, then through the coil and a secondary coil attached to the transistor's plate.

Fluctuating Feedback

• The coils provide a fluctuating electrical current, which attract and reverse the tuning fork magnets and causes a vibration to generate an electrical current, according to Electric Watches.

More Efficient

• Watch tuning forks hum, or vibrate, up to 720 times a second compared to a balance wheel, which vibrates 2 1/2 times a second, and keep better time than mechanical watches.