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Posted by on Jul 4, 2016 in Tell Me Why |

Who Invented the Quartz Clock?

Who Invented the Quartz Clock?

In 1927, Canadian-born Warren Marrison, a telecommunications engineer, was searching for reliable frequency standards at Bell Telephone Laboratories. He developed a very large, highly accurate clock based on the regular vibrations of a quartz crystal in an electrical circuit—the first quartz clock. Quartz clock operation is based on the piezoelectric property of quartz crystals. If you apply an electric field to the crystal, it changes its shape, and if you squeeze it or bend it, it generates an electric field.

When put in a suitable electronic circuit, this interaction between mechanical stress and electric field causes the crystal to vibrate, and generate a constant frequency electric signal that can be used to operate an electronic clock display. Quartz crystal clocks were better because they had no gears or escapements to disturb their regular frequency.

Even so, they still relied on a mechanical vibration whose frequency depended critically on the crystal’s size and shape. Thus, no two crystals can be precisely alike, with exactly the same frequency. Quartz crystal clocks were better because they had no gears or escapements to disturb their regular frequency. Such quartz clocks continue to dominate the market in numbers because their performance is excellent and they are inexpensive.

The piezoelectric properties of quartz were discovered by Jacques and Pierre Curie in 1880. The first quartz crystal oscillator was built by Walter G. Cady in 1921. In 1923, D. W. Dye at the National Physical Laboratory in the UK and Warren Marrison at Bell Telephone Laboratories produced sequences of precision time signals with quartz oscillators. In 1927, the first quartz clock was built by Warren Marrison and J.W. Horton at Bell Telephone Laboratories.

The next three decades saw the development of quartz clocks as precision time standards in laboratory settings; the bulky delicate counting electronics, built with vacuum tubes, limited their use elsewhere. In 1932 a quartz clock was able to measure tiny variations in the rotation rate of the Earth over periods as short as a few weeks.

In Japan in 1932, Issac Koga developed a crystal cut that gave an oscillation frequency independent of temperature variation. The National Bureau of Standards (now NIST) based the time standard of the US on quartz clocks between the 1930s and the 1960s, then it went to atomic clocks, but actually, in 2014, they used a quartz clock that was so accurate, they simply use an atomic clock to update it every 24 hours.

The wider use of quartz clock technology had to await the development of cheap semiconductor digital logic in the 1960s. The revised 14th edition of Encyclopedia Britannica stated that quartz clocks would probably never be affordable enough to be used domestically.

The world’s first prototype analog quartz wristwatches were revealed in 1967: the Beta 1 revealed by the Centre Electronique Horloger (CEH) in Neuchâtel Switzerland, and the prototype of the Astron revealed by Seiko in Japan. (Seiko had been working on quartz clocks since 1958).

In 1969, Seiko produced the world’s first commercial quartz wristwatch, the Astron, this watch was released just prior to the introduction of the Swiss Beta21, which was developed by 16 Swiss Watch manufactures and used by Rolex, Patek and famously Omega in their electroquartz models. The Beta 21 watches had an accuracy of 5 seconds per month but were swiftly overtaken by the introduction of more economical and accurate quartz watches.

The inherent accuracy and low cost of production has resulted in the proliferation of quartz clocks and watches since that time. By the 1980s, quartz technology had taken over applications such as kitchen timers, alarm clocks, bank vault time locks, and time fuzes on munitions, from earlier mechanical balance wheel movements, an upheaval known in watch making as the quartz crisis.

Quartz timepieces have dominated the wristwatch and clock market since the 1980s, Because of the high Q factor and low temperature coefficient of the quartz crystal they are more accurate than the best mechanical timepieces, and the elimination of all moving parts makes them more rugged and eliminates the need for periodic maintenance.

Commercial analog and digital wall clocks became available in 2014 that utilize a double oven quartz oscillator, accurate to 0.2 ppb. These clocks are factory synchronized with the atomic time standard and typically do not require any further time adjustments for the life of the clock.

Content for this question contributed by Robert Parker, resident of University Heights, Cuyahoga County, Ohio, USA