Astron (wristwatch)
Encyclopedia
The Astron wristwatch, formally known as the Seiko Quartz-Astron 35SQ, was the world's first "quartz clock
Quartz clock
A quartz clock is a clock that uses an electronic oscillator that is regulated by a quartz crystal to keep time. This crystal oscillator creates a signal with very precise frequency, so that quartz clocks are at least an order of magnitude more accurate than good mechanical clocks...

" wristwatch, i.e., one based on a quartz
Quartz
Quartz is the second-most-abundant mineral in the Earth's continental crust, after feldspar. It is made up of a continuous framework of SiO4 silicon–oxygen tetrahedra, with each oxygen being shared between two tetrahedra, giving an overall formula SiO2. There are many different varieties of quartz,...

 crystal oscillator
Crystal oscillator
A crystal oscillator is an electronic oscillator circuit that uses the mechanical resonance of a vibrating crystal of piezoelectric material to create an electrical signal with a very precise frequency...

. It is now registered on the List of IEEE Milestones as a key advance in electrical engineering
Electrical engineering
Electrical engineering is a field of engineering that generally deals with the study and application of electricity, electronics and electromagnetism. The field first became an identifiable occupation in the late nineteenth century after commercialization of the electric telegraph and electrical...

.

The Astron was unveiled in Tokyo
Tokyo
, ; officially , is one of the 47 prefectures of Japan. Tokyo is the capital of Japan, the center of the Greater Tokyo Area, and the largest metropolitan area of Japan. It is the seat of the Japanese government and the Imperial Palace, and the home of the Japanese Imperial Family...

 on December 25, 1969, after ten years of research and development at Suwa Seikosha
Seikosha
was a branch of the Japanese company Seiko that produces clocks, watches, shutters, computer printers and other devices. It was the root of the manufacturing companies of the Seiko Group.*1881 — Kintarō Hattori opens the watch and jewelry shop "K...

 (currently named Seiko Epson
Seiko Epson
, commonly known as Epson, is a Japanese technology company and one of the world's largest manufacturers of computer printers, information and imaging related equipment...

), a manufacturing company of Seiko Group
Seiko Group
is a Japanese corporate group consisting of three core companies Seiko Holdings Corp. , Seiko Instruments Inc. and Seiko Epson Corp . They are independent companies linked together by the common thread of timepiece technology...

. Within one week 100 gold watches had been sold, at a retail price of 450,000 yen (US$1,250) each (at the time, equivalent to the price of a medium-sized Japanese automobile). Essential elements included a quartz crystal oscillator (8,192 cyles/second), a hybrid integrated circuit
Integrated circuit
An integrated circuit or monolithic integrated circuit is an electronic circuit manufactured by the patterned diffusion of trace elements into the surface of a thin substrate of semiconductor material...

, and a miniature stepping motor to turn its hands. The Astron was accurate to ±5 seconds per month, or one minute per year.
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