This Bulova Accutron , model 2182, was
first made in 1968. It uses an tuning-fork for timekeeping.
Tuning-fork mechanism works on the principle
of using transistorized electronics to switch on and off the
small electromagnets which keep the tuning fork arms vibrating
at a frequency determined by their length, mass and elasticity.
The frequency for the Accutron is 360 oscillations
The vibration of the tuning fork is transformed
into circular motion using an extremely fine-toothed ratchet
wheel and 2 tiny ratchet pawls. One pawl moved by the tuning
fork, pushes the wheel round in 1 direction. Another pawl
is fixed to the watch plate and preventing the wheel from
Making this wheel is not an easy job, even
nowadays, it is less than 1/500 mm thick and has 300 teeth,
each tooth is just 1/100 mm high.