Tuning-fork watch is one of the first electronic watches. It was produced in series before the arrival of the quartz watch.

It was invented by the engineer Max Hetzel of theSwiss Federal Institute of Technology in Zurich (ETHZ). It was developed in the 1950s and the first one was sold in 1960. Its principle works with a resonator which is a tuning fork and which vibrates at 300 Hz and pushes at each vibration with the help of a lever a wheel equipped with 300 teeth having a diameter of 3,54 millimeters and carrying out one turn in one second.

The difficulty in this project was to develop this wheel and place 300 teeth on a length of 11.12 millimeters corresponding to the circumference of this mobile. In other words, the pitch from one tooth to another was 37 microns, the diameter of a hair being about 60 microns. The Swiss watchmaking industry not having first believed in this project its inventor had to go to the United States where an American brand believed in this project and concretized it. The tuning-fork is still today the logo of this brand which is Bulova. A few years later Max Hetzel returned to Switzerland where he developed a second model of his tuning fork movement for the Swiss watch industry.

These watches have the particularity of having a drone sound which is accentuated when the watch is placed on a wooden piece of furniture. The power reserve of the battery is about three months. This is probably why it was replaced by another electronic watch, the quartz watch, whose battery lasted much longer, about two years.