Search Results for: Radio broadcast receivers without an external power source
chain. the study of timekeeping is known as horology . watches progressed in the th century from spring-powered clocks, which appeared as early as the th century. during most of its history the watch was a mechanical device, driven by clockwork , powered by winding a mainspring , and keeping time with an
most electronic quartz watches, on the other hand, include time-related features such as timers , chronographs and alarm functions. furthermore, some modern smartwatches even incorporate calculators , gps [ ] and bluetooth technology or have heart-rate monitoring capabilities, and some of them use radio...
https://en.wikipedia.org/wiki/Wristwatch