The watch is one of the most popular personal jewelry items on the market and dates back to the 14th century with the first wind up watches that one carried in a pocket. Today the same components used to make wind-up watches remains pretty much the same as those from the beginning. The basic parts of a wind-up watch are a spring to provide power, an oscillating mass for the timebase, two hands, a numbered dial, and gears regulate the ticking rate to the hands on the dial.



Bulova began seeking new technology for watches in the 1960s and replaced the oscillating balance wheel with a transistor oscillator replacing the wind-up spring with a battery. This new technology used a tuning fork, but the search was on for an even more accurate method of keeping time. Integrated circuits were being developed now and becoming less expensive and the LED technology was being introduced as well but the problem watchmakers faced was to find a new timing element and creating a circuit that would be able to run on a battery small enough to place in a watch.

The new element decided upon was of course the quartz crystal. They had been used for years in radio transmitters, receivers and early computers. The reason quartz is so accurate is that it is unaffected by most solvents and maintains its crystalline properties even when subjected to intense heat. The electronic charge of a crystal comes from compressing it.

Most modern quartz watches now use tuning-fork-shaped crystal. Often, these crystals are made from thin sheets of quartz plated like an integrated circuit and engraved chemically to shape. The major difference between good and indifferent time keeping is the initial frequency accuracy and the precision of the angle of cut of the quartz sheet with respect to the crystalline axis. The amount of contamination that is allowed to get through the encapsulation to the crystal surface inside the watch can also affect the accuracy.

The electronics inside a watch amplify the internal noise at the frequency of the crystal which creates oscillation and makes the crystal ring. In digital watches this is converted into pulses for the digital circuits. In the quartz watches most of us wear today that have a face with hands, one second pulses drive a small electric motor connected to gears which move the hands. This is what gives the movement we see in most quartz watches with the exception of the Rolex and its perpetual movement innovation, but that is the subject of another article.