Electronic wrist watches

Mercuric oxide batteries have been widely used as seeondary standards of voltage beeause of the higher order of voltage maintenance and ability to withstand mechanical and electrical abuses (Figure 37.1). For use as reference sources in regulated power supplies, radiation detection meters, portable potentiometers, electronic computers, voltage recorders, scientific and military equipment, hearing-aids, electronic wrist watches and cameras, and similar equipment, desirable features are as follows ... 

Time interval standards. The familiar, though expensive, electronic wrist watches are clearly time interval standards since they are read in seconds, minutes, and hours. Yet at the heart of the watch is a crystal-controlled oscillator operating at a frequency of 1 MHz so the lucky owner also possesses a personal frequency standard of quite respectable quality. Having made the point that time and frequency standards are basically identical, we recall that for many centuries our methods of determining time intervals have relied on sub-division of a basic standard the length of the day as measured on earth (see Table 18.4). In the... 

Crystalline chemical and electrochemical manganese dioxides are employed in billions of cells of Leclanche type which remain today probably the most popular and inexpensive power sources for wrist watches, cameras, flashlights, portable electronic products, etc. Worldwide annual output of power sources is estimated at 40 bln. pieces more than 70% of them are those operating with Mn02 chemistry as a cathode active material or a... 

Development from Wrist Watches, Electronic Calculators, and Word Processors Towards Flat-Screen TVs... 

---