Digital watches use electronic movements to keep time. These movements are powered by a small battery and are highly accurate, able to keep time to within a few seconds per year.
To understand how digital watches keep time, it’s helpful to know how they differ from analog watches. Analog watches use mechanical movements, which are powered by a mainspring that drives a series of gears and hands to indicate the time on a dial. Digital watches, on the other hand, use electronic movements that use a crystal oscillator to generate an electrical signal at a precise frequency.
The crystal oscillator in a digital watch is made of a small piece of crystal, such as quartz, that vibrates at a very high frequency when an electric current is applied to it. The vibrations of the crystal create an electrical signal that is used to drive the watch’s display and other functions.
To keep time, the crystal oscillator in a digital watch generates a certain number of vibrations per second, which is used to measure the passage of time. For example, a digital watch may generate 32,768 vibrations per second, which is used to keep track of time in increments of 1/32,768 of a second. This high level of accuracy allows digital watches to keep time to within a few seconds per year.
Digital watches can also be synchronized with a time signal, such as the time signal transmitted by atomic clocks or GPS satellites. This allows the watch to automatically set the time to the most accurate time available, which can further improve its accuracy.
In conclusion, digital watches use electronic movements and crystal oscillators to keep time. These movements are highly accurate and can be synchronized with a time signal to further improve their accuracy.